Download Fish communities across a spectrum of habitats in the western

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Marine pollution wikipedia , lookup

Marine geology of the Cape Peninsula and False Bay wikipedia , lookup

Red Sea wikipedia , lookup

The Marine Mammal Center wikipedia , lookup

Sea in culture wikipedia , lookup

Sea wikipedia , lookup

Demersal fish wikipedia , lookup

Marine biology wikipedia , lookup

Climate change in the Arctic wikipedia , lookup

Marine habitats wikipedia , lookup

Arctic Ocean wikipedia , lookup

Beaufort Sea wikipedia , lookup

Transcript
Progress in Oceanography 136 (2015) 115–132
Contents lists available at ScienceDirect
Progress in Oceanography
journal homepage: www.elsevier.com/locate/pocean
Fish communities across a spectrum of habitats in the western Beaufort
Sea and Chukchi Sea
E. Logerwell a,⇑, M. Busby a, C. Carothers b, S. Cotton b, J. Duffy-Anderson a, E. Farley c, P. Goddard a,
R. Heintz c, B. Holladay b, J. Horne a,d, S. Johnson c, B. Lauth a, L. Moulton e, D. Neff c, B. Norcross b,
S. Parker-Stetter d,f, J. Seigle g, T. Sformo h
a
NOAA/NMFS, Alaska Fisheries Science Center, 7600 Sand Point Way, N.E., Seattle, WA 98115, United States
School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N. Koyukuk Dr., Fairbanks, AK 99775, United States
NOAA/NMFS, Alaska Fisheries Science Center, Auke Bay Laboratory, Ted Stevens Marine Research Institute, 17109 Pt. Lena Loop Rd., Juneau, AK 99801, United States
d
School of Aquatic and Fisheries Science, University of Washington, Box 355020, Seattle, WA 98105, United States
e
MJM Research, LLC, 1012 Shoreland Drive, Lopez Islands, WA 98261, United States
f
NOAA/NMFS, Northwest Fisheries Science Center, 2725 Montlake Blvd., Seattle, WA 98112, United States
g
ABR, Inc. – Environmental Research & Services, P.O. Box 240268, Anchorage, AK 99524, United States
h
North Slope Borough Department of Wildlife Management, P.O. Box 69, Barrow, AK 99723, United States
b
c
a r t i c l e
i n f o
Article history:
Available online 12 May 2015
a b s t r a c t
The increased scientific interest in the Arctic due to climate change and potential oil and gas development
has resulted in numerous surveys of Arctic marine fish communities since the mid-2000s. Surveys have
been conducted in nearly all Arctic marine fish habitats: from lagoons, beaches and across the continental
shelf and slope. This provides an opportunity only recently available to study Arctic fish communities
across a spectrum of habitats. We examined fish survey data from lagoon, beach, nearshore benthic, shelf
pelagic and shelf benthic habitats in the western Beaufort Sea and Chukchi Sea. Specifically, we compare
and contrast relative fish abundance and length (a proxy for age) among habitats and seas. We also examined ichthyoplankton presence/absence and abundance of dominant taxa in the shelf habitat. Our synthesis revealed more similarities than differences between the two seas. For example, our results show that
the nearshore habitat is utilized by forage fish across age classes, and is also a nursery area for other species. Our results also indicated that some species may be expanding their range to the north, for example,
Chinook Salmon. In addition, we documented the presence of commercially important taxa such as
Walleye Pollock and flatfishes (Pleuronectidae). Our synthesis of information on relative abundance
and age allowed us to propose detailed conceptual models for the life history distribution of key gadids
in Arctic food webs: Arctic and Saffron Cod. Finally, we identify research gaps, such as the need for surveys of the surface waters of the Beaufort Sea, surveys of the lagoons of the Chukchi Sea, and winter season surveys in all areas. We recommend field studies on fish life history that sample multiple age classes
in multiple habitats throughout the year to confirm, resolve and interpret the patterns in fish habitat use
that we observed.
Published by Elsevier Ltd.
1. Introduction
There are 242 currently known species of benthic and pelagic
fishes in Arctic marine waters, distributed among 45 families
(Mecklenburg et al., 2010). Fish such as Arctic Cod (Boreogadus
saida), salmon and forage fishes (e.g., Capelin Mallotus villosus) play
a key role in the Arctic, as they do in many systems, as prey to seabirds, marine mammals and humans (Bradstreet et al., 1986;
Whitehouse et al., 2014). They are also potentially important consumers of secondary production in the Arctic in both benthic and
pelagic zones (Frost and Lowry, 1981, 1983; Jarvela and
Thorsteinson, 1999). A synthesis of current fish community
⇑ Corresponding author.
E-mail addresses: [email protected] (E. Logerwell), [email protected] (M. Busby), [email protected] (C. Carothers), [email protected] (S.
Cotton), [email protected] (J. Duffy-Anderson), [email protected] (E. Farley), [email protected] (P. Goddard), [email protected] (R. Heintz),
[email protected] (B. Holladay), [email protected] (J. Horne), [email protected] (S. Johnson), [email protected] (B. Lauth), [email protected] (L.
Moulton), [email protected] (D. Neff), [email protected] (B. Norcross), [email protected] (S. Parker-Stetter), [email protected] (J. Seigle), todd.
[email protected] (T. Sformo).
http://dx.doi.org/10.1016/j.pocean.2015.05.013
0079-6611/Published by Elsevier Ltd.
116
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
composition and habitat use supports the goals of SOAR by providing a baseline against which to measure future change. In addition,
it provides insight into how climate change might impact Arctic
fish communities and the predators that depend on them via
changes to their habitat.
Surveys have been conducted in nearly all Arctic marine fish
habitats during the past decade: from coastal lagoons out to the
continental slope. The shallow lagoons inshore of barrier islands
of the Beaufort Sea are characterized in the ice-free season by
brackish and relatively warm water. This water is formed during
spring when floodwaters from North Slope rivers flow to sea and
mix with marine waters (Craig, 1984). The nearshore zone is a
transition between estuarine waters originating from lagoons and
marine waters offshore. The extent of the band of estuarine water
in the nearshore depends on the amount of freshwater input, nearshore currents and prevailing winds. By the end of winter the shallow waters of lagoons and the nearshore are frozen solid. Lagoon
habitat is less prevalent in the Chukchi Sea and less well-studied,
but presumably the lagoons and nearshore habitats in the
Chukchi have similar characteristics as those observed in the
Beaufort. Beaches in the Beaufort and Chukchi Seas are rarely steep
and rocky, but instead are typically sand, gravel, mud or some
combination of these (https://alaskafisheries.noaa.gov/shorezone/).
The shallow (50 m) and wide Chukchi Sea shelf extends
800 km northward from Bering Strait to the shelfbreak. Water
flows north through Bering Strait, bringing heat, nutrients, carbon
and organisms that strongly influence the characteristics of the
Chukchi Sea ecosystem (Weingartner, 2008). The Alaskan
Beaufort Sea shelf is narrower than the Chukchi Sea shelf
(80 km wide) and relatively flat; bottom depths increase gradually from the coast to the 80 m isobath and then drop off rapidly
along the shelfbreak and slope. Oceanographic characteristics of
the Beaufort Sea are influenced by water flowing eastward from
the Chukchi Sea, from the westward flowing southern limb of the
Beaufort Gyre and discharge from the Mackenzie River
(Weingartner, 2008).
Increased scientific interest in the Arctic due to climate change,
potential oil and gas development and the International Polar Year
(IPY 2007–2009) has resulted in the surveys of Arctic fish communities synthesized here. There was a period of large-scale Arctic
surveys in the early 1970s to the early 1990s when there was a
concerted effort to study areas of potential oil and gas development, the Outer Continental Shelf Environmental Assessment
Program (OCSEAP, 1990). There has been a gap in large-scale
Arctic research since the OCSEAP era until the 2000s. Our surveys
from 2007 to the present provide an opportunity only recently
available to study Arctic fish communities across a spectrum of
habitats. This project was a collaboration among researchers at a
number of agencies, local and federal, and universities providing
data in a cooperative fashion from their individual surveys. We
compare the fish community composition in lagoon, beach, nearshore benthic, shelf pelagic and shelf benthic habitats. We also
use information on age-class of fish along with ichthyoplankton
data to compare and contrast how different taxa use these habitats
throughout their life history. Finally, we explore similarities and
differences in community composition and habitat use of
Beaufort and Chukchi Sea fishes. Our synthesis provides a baseline
for climate change impacts in the future and suggests directions for
future research.
2. Methods
The temporal scope of our synthesis is the ice-free spring to fall
season and the years 2007–2012. These years represent our best
available data coverage across habitats. In addition, 2007 marks
the first recent historical low in summer sea ice (NCAR, 2007)
and can be considered the start of the ‘‘new normal’’ in Arctic
climate and ocean conditions (Jeffries et al., 2013).
We synthesized data from fish surveys of several habitats in the
western Beaufort and Chukchi Seas: coastal lagoon, beach (waters
<5 m deep), nearshore benthic (waters <10 m deep), shelf (>20 m
deep) surface, shelf midwater (pelagic habitat below the surface
and above the bottom) and shelf benthic. We did not have data
for the central and eastern Beaufort Sea. We also examine ichthyoplankton data from shelf surveys from both seas. Table 1 summarizes the years, months and habitats for which we had survey data,
and Fig. 1 shows the locations of all stations (subsequent figures
will show which surveys sampled at which stations). Data were
collected from as early as June to as late as October. There were
no data from the shelf surface of the Beaufort Sea, nor from the
lagoon and shelf midwater of the Chukchi Sea. Fish caught were
often identified to species, but not always, so catch by family is
reported in some cases. Catch-per-unit effort (CPUE), a measure
of fish density, was used to represent relative fish abundance for
each habitat. In addition individual length data were summarized
for each species or taxonomic group (average and min–max).
Virtually no fish age data were available from the surveys, so fish
age ranges were based on age-length relationships from other
areas (predominantly Alaska region). Finally, three diversity
indices were calculated for each habitat in each Sea: Richness (S),
Simpson’s Index (D) and Shannon Index (H) (Begon et al., 1990).
Because of the different levels of taxonomic resolution in the datasets, diversity indices were calculated at the level of Family. Maps
of survey stations were created in ESRI ArcMap 10.0, using Albers
projection and the North American Datum 1983.
2.1. Beaufort Sea
We synthesized data from fish surveys conducted in five different habitats in the western Beaufort Sea: lagoon, beach, nearshore
benthic, shelf midwater and shelf benthic. Data were collected
from June through September (depending on the survey).
The lagoon habitat of the Beaufort Sea was sampled with two
net types, fyke nets and gill nets. The purpose of these on-going
surveys is to investigate the subsistence fishery in Elson Lagoon,
an important resource for the community of Barrow (Bacon et al.,
2009). Fyke nets were maintained by scientists from the North
Slope Borough Department of Wildlife Management to estimate
species present, size and age distribution and health status of fish.
In addition, daily gill net surveys of subsistence fishermen are
conducted
(http://www.north-slope.org/departments/wildlifemanagement/studies-and-research-projects/fish/fish-surveys). The
fyke net had a minimum mesh size of 6.4 mm and was deployed
at several locations within the Elson Lagoon system
(Figs. 2 and 3). The net was fixed in place and left open to fish for
24 h and sampled each day (with the exception of weekends or
before storms) between the months of June and August. Data from
2009–2012 were used for this analysis (Moulton and Seigle, 2012).
Catch-per-unit-effort (CPUE) was calculated as No. fish/effort hours,
where No. fish was the total number of fish caught in a year and
effort hours was the total number of hours the net was open in a
year. Total effort hours from 2009–2012 was 2304. The lagoon gill
net data were from the 2011 subsistence gill net fishery from the
months of June–September. The purpose of the gill net study was
to gather information on salmon use, abundance and distribution
in the Arctic (Cotton, 2012). Gill nets were deployed by fishermen
at several locations spanning the west to east range of the fyke
net locations (Fig. 3). The mesh size of the gill nets used in the fishery ranged from 64 to 203 mm. Catches were from daily net observations and fisher’s logbook data of recorded catches. Daily CPUE
Sept
Sept
Aug–Sept
Aug–Sept
Aug–Sept
Sept
Aug–Sept
July
July–Oct
Shelf benthic
Shelf surface
Nearshore benthic
Beach
Lagoon
Aug–Sept
Aug–Sept
Aug–Sept
Chukchi Sea
Sept
Aug
Aug
Aug
2007
2008
2009
2010
2011
2012
July–Sept
July–Sept
July–Sept
July–Sept
Nearshore benthic
Beach
Shelf surface
Aug
Shelf midwater
Aug
Shelf benthic
Aug
Ichthyo-plankton
Beaufort Sea
Lagoon
Year
Table 1
Years, months and habitats for which fish and ichthyoplankton survey data were available for the synthesis, for the Beaufort and Chukchi Seas.
Aug–Sept
Aug–Sept
Aug–Sept
Shelf midwater
Aug–Sept
Ichthyo-plankton
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
117
was calculated by dividing No. fish by effort, which was the number
of hours the net was fished standardized to a common net length
(60 feet). The total number of hours all nets were fished in 2011
was 20,072. The average of daily CPUE was then calculated.
The beach and nearshore benthic habitat was sampled as part of
a study to update information on fishes of coastal waters of the
Alaskan Arctic (Johnson et al., 2010). Fish were captured with a
beach seine and bottom trawl on the seaward side of Cooper
Island (Figs. 2 and 3). The beach seine stations were in water
<5 m deep and were <20 m from shore. The net was a 37 m long
variable mesh beach seine with 3.2 mm square mesh in the bunt
and was set as a ‘‘round haul’’ (National Marine Fisheries Service
(NMFS), 2010). Offshore of each beach seine station, fish were captured with a bottom trawl at two depths: 5 m (about 1.0 km offshore) and 8 m (about 2.5 km offshore). The trawl mouth was
2.6 m wide and 1.2 m deep, the trawl total length was 5.2 m, and
the codend was made of 3.2 mm stretch mesh. The trawl was
towed from a skiff at about 2.5 knots. Three stations were sampled
with beach seines in August 2007 and September 2009. One haul
was made at each station. CPUE was No. fish per haul and mean
CPUE was calculated for each sampling period (n = 3 hauls).
Three stations, each with two depths, were sampled with the bottom trawl in August 2007 and 2009 and September 2009. CPUE
was No. fish per haul and mean CPUE was calculated for each sampling period (n = 6 hauls).
The shelf midwater and benthic habitats were sampled as part
of an August 2008 survey of the Beaufort Sea, the goal of which was
to provide baseline information on areas of potential oil and gas
development (Logerwell et al., 2010; Rand and Logerwell, 2010;
Parker-Stetter et al., 2011). The midwater was sampled with a
Marinovich trawl net as part of an acoustic survey (Parker-Stetter
et al., 2011), so the net was deployed to identify constituents of
the backscatter across the study area (Fig. 2). Net depth ranged
from 15 m to 320 m (maximum depth was 10 m off bottom). The
fishing dimensions of the Marinovich net were 3–4 m vertical
and 6 m horizontal and the mesh of the codend liner was 12 mm.
Vessel speed was maintained at 2–4 knots while towing the net.
Net position and headrope height were monitored in real-time
during the deployment. CPUE was calculated as No. fish per minute
(haul duration) and averaged over all hauls (n = 28 hauls). The shelf
benthic habitat was sampled with an 83-112 Eastern otter trawl
deployed on a depth-stratified grid of stations. Positions were
modified from a regular grid by the presence of ice and untrawlable bottom (Fig. 2). The net had a 25.3 m headrope, a 34.1 m footrope and had a 38 mm mesh liner throughout the body and
codend. The net was towed at a vessel speed around 3 knots. Net
height and width were measured and monitored in real time with
acoustic net mensuration equipment and trawl foot rope contact
with the seafloor was monitored using a bottom contact sensor.
These data were used to estimate area swept by the net. CPUE
was calculated as No. fish per area swept and averaged over all
hauls (n = 11 hauls).
An ichthyoplankton survey was also part of the August 2008
study (Logerwell et al., 2010). A MARMAP 60 cm bongo net fitted
with 0.505 mm mesh nets was deployed at oceanographic sampling stations across the range of depths (Fig. 2). The net was
towed double-oblique from the surface down to a depth 10 m off
bottom and back to the surface. Ichthyoplankton density was calculated as No./10 m2 and then averaged over all stations (n = 28
stations).
2.2. Chukchi Sea
We synthesized data from fish surveys conducted in five different habitats in the Chukchi Sea: beach, nearshore benthic, shelf
118
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Fig. 1. Stations sampled by fish and ichthyoplankton surveys of the Beaufort and Chukchi Seas, 2007–2012 (total number of stations = 467). Dashed line indicates
longitudinal boundary between Beaufort and Chukchi Seas.
Fig. 2. Beaufort Sea study area. Stations sampled in the lagoon (fyke net), beach (seine), nearshore benthic (bottom trawl), shelf benthic (bottom trawl), and shelf midwater
(trawl). Stations sampled by ichthyoplankton survey are also shown.
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
119
Fig. 3. Detail of lagoon and nearshore study areas of the Beaufort Sea. Stations sampled by the fyke net, beach seine and nearshore bottom trawl are shown. Gill nets were set
near the most northern fyke net and spanning the shore westward towards the other fuke net locations shown in Elson Lagoon (indicated by shaded area).
surface, shelf midwater and shelf benthic. Data were collected from
July through September (depending on the survey).
The beach and nearshore benthic habitats were sampled as part
of the Coastal Assessments research program of NOAA Alaska
Fisheries Science Center Auke Bay Laboratory (http://www.afsc.
noaa.gov/ABL/Habitat/ablhab_coastal.htm). Fish were captured
with a beach seine and bottom trawl on the coast near Barrow
(Figs. 4 and 5). The gear and deployment methods were the same
as those used to survey the Beaufort beach and nearshore habitats
(Thedinga et al., 2013). The beach seine stations were in water
<5 m deep. Offshore of each beach seine station, fish were captured
with a bottom trawl at two depths: 5 m and 8 m. Six stations were
sampled with beach seines in August 2007–2009 and September
2009. One haul was made at each station. CPUE was No. fish per
haul and mean CPUE was calculated for each sampling period
(n = 6 hauls). Six stations, each with two depths, were sampled
with the bottom trawl in August 2007–2009 and September
2009. CPUE was No. fish per haul and mean CPUE was calculated
for each sampling period (n = 12 hauls).
The shelf surface waters were sampled as part of the Bering
Sea-Aleutian Salmon International Survey (BASIS; http://www.
npafc.org/science_basis.html)
and
the
Arctic
Ecosystem
Integrated Survey (EIS; https://web.sfos.uaf.edu/wordpress/arcticeis/). BASIS was a coordinated program of cooperative research
on Pacific salmon in the Bering Sea designed to investigate the
response of salmon to climate change. The survey typically
extended from the Alaska Peninsula to just north of St. Lawrence
Island, but in 2007 it included the Bering Strait and northeastern
Chukchi Sea. Arctic EIS was a multi-disciplinary study of the
oceanography, lower trophic levels, crab and fish communities of
the northeastern Bering Sea and eastern Chukchi Sea. Station
spacing was 36–55 km. 25 stations were sampled in September
2007 and 81 were sampled in August-September 2012 (Fig. 4).
Pelagic fish were captured with a Cantrawl 300 midwater trawl
with a mean horizontal spread of 54 m, mesh size of 12 mm, rigged
to sample the top 12 m of the water column. CPUE was No.
fish/km2 and mean CPUE was calculated for each survey.
The shelf benthic habitat was sampled with a large bottom
trawl as part of the Arctic EIS. Sampling design was based on a
55.6 km (30 nmi) square grid pattern with the trawl stations
located at the approximate center of each grid cell, resulting in a
total of 71 sampling locations (Fig. 4). The survey was conducted
during August-September 2012. The bottom trawl was an 83-112
Eastern otter trawl, the same net used to sample the Beaufort shelf
benthic habitat. The codend of the net had a liner of 3.2 cm mesh.
CPUE was calculated as No. fish/area swept (ha; derived from net
mensuration data) and averaged over all hauls.
The shelf benthic habitat was also sampled with a smaller net,
the 3 m plumb-staff beam trawl (Gunderson and Ellis, 1986).
This gear was deployed at stations throughout the Chukchi Sea
over the course of seven multi-disciplinary surveys (Fig. 6).
Table 2 provides a summary of the years, months, vessel/cruise
name and acronym, and number of stations sampled for each survey. Stations were selected by two methods, coincident with other
disciplines (2009-RUSALCA and two CSESP surveys), or opportunistic samples when time was made available by the host cruise, usually at night or along a set cruise track (BASIS, COMIDA, 2007
Oshoro Maru and 2008 Oshoro Maru). During all surveys, a 3 m
plumb staff beam trawl with a 4 mm mesh codend liner and an
effective mouth opening of 2.26 width and 1.2 m height was used
to collect benthic fishes. The net was towed at 1–1.5 knots on the
bottom for 2–5 minutes, typically, and distance was calculated
120
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Fig. 4. Chukchi Sea study area. Stations sampling the nearshore (nearshore bottom trawl and beach seine), shelf benthic (bottom trawl), and shelf surface (trawl) are shown.
Fig. 5. Detail of the nearshore study area of the Chukchi Sea. Stations sampled by beach seine and nearshore bottom trawl are shown.
121
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Fig. 6. Chukchi Sea study area. Stations sampled by plumb staff beam trawl on several surveys are shown.
Table 2
Summary of shelf beam trawl surveys.
Table 3
Summary of ichthyoplankton surveys.
Year
Month(s)
Vessel/Cruise name
No.
stations
Year
Month(s)
Vessel/
Gear
Cruise name
2007
September
27
2007
2008
2009
August
July
August
2007
2009
2010
2011
September
September
August–September
August–September
BASIS
RUSALCA
CHAOZ
CHAOZ
2009
2009
September–October
July–August
2009
September
Bering Sea-Aleutian Salmon
International Survey (BASIS)a
Oshoro Marub
Oshoro Marub
August Chukchi Sea
Environmental Studies Program
(CSESP)c
September CSESPc
Chukchi Sea Offshore Monitoring
in Drilling Area (COMIDA)d
Russian-American Long-term
Census of the Arctic (RUSALCA)e
9
15
25
26
30
21
a
http://www.npafc.org/science_basis.html.
Norcross et al. (2013a,b).
c
Day et al. (2013) and Norcross et al. (2013b).
d
http://www.comidacab.org/Default.aspx, Holladay et al. unpublished data.
e
http://www.arctic.noaa.gov/aro/russian-american, Holladay et al. unpublished
data.
b
between positions of the vessel when towing cable was fully
deployed and haul back began. CPUE was No. fish/1000 m2 and
mean CPUE was calculated for each survey.
Fish catch composition for each habitat type was calculated as %
CPUE by number averaged over all surveys for that net type/habitat
with the exception of the surface trawl surveys. Catch composition
for the surface trawl surveys of 2007 and 2012 was very different,
so data for each year are presented separately. Even though the
beam trawl surveys conducted in 2007, 2008 and 2009 only had
No. stations
60-cm bongo
47
60-cm bongo
31
2
1-m epibenthic sled 56
1-m2 epibenthic sled 84
partial spatial and temporal overlap, the catch compositions
among surveys were not dissimilar. The top ten taxa in terms of
relative CPUE were similar among all beam trawl surveys, thus
the CPUEs from all surveys were averaged and catch composition
was calculated.
Ichthyoplankton data were collected during four cruises in the
Chukchi Sea (Table 3 and Fig. 7). Ichthyoplankton was sampled
during the 2007 BASIS and 2009 RUSALCA cruises described above
using a standard MARMAP 60 cm bongo net (Posgay and Marak,
1980) fitted with 0.505 mm mesh nets. The net was towed
double-obliquely from the surface down to a depth 10 m off bottom and back to the surface. Ichthyoplankton was collected during
the BOEM Chukchi Acoustics, Oceanography, and Zooplankton
(CHAOZ) surveys in 2010 and 2011 with a 1 m2 epibenthic sled
trawl (Tabery et al., 1977) fitted with 0.333 mm mesh nets. In
2010, a single net was fitted on the sled and fished obliquely from
the bottom to surface. In 2011, two nets were used with the first
net being fished for approximately 5 minutes with the sled in contact with the bottom and the second fished obliquely from the bottom to surface. Presence/absence of all taxa was tabulated and
density (No./10 m2) was calculated for the most abundant taxa.
The mean density across surveys was then calculated, with one
122
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Fig. 7. Chukchi Sea study area. Stations sampled by ichthyoplankton nets on several surveys are shown.
exception. Because there was virtually no spatial overlap between
the 2009 and the 2007, 2010 and 2011 surveys, the data from the
2009 survey were treated separately.
3. Results and discussion
3.1. Beaufort Sea
Salmonids (Salmonidae) made up a large portion of the catch in
the lagoon, in both the fyke net and gill net surveys (Table 4). The
gill net catches were particularly dominated by salmonids, but
these data were from subsistence fishers and were thus biased
because salmonids such as Broad Whitefish (Coregonus nasus)
and Least Cisco (Coregonus sardinella) were target species. Least
Cisco, Chum Salmon (Oncorhynchus keta) and Pink Salmon
(Oncorhynchus gorbuscha) dominated the catches. Least Cisco,
Chum Salmon and Pink Salmon are Arctic residents so this result
is expected. However, a few Sockeye Salmon (Oncorhynchus nerka)
and one Chinook Salmon (Oncorhynchus tshawytscha) also were
caught. Sockeye Salmon are known to spawn in the Mackenzie
River, so the potential for capturing adult Sockeye returning to
their natal river is high, however Chinook Salmon have rarely been
found in the Arctic, so this result is highly unusual (Stephenson,
2006; Irvine et al., 2009). The size range of the salmonids (426–
775 mm) indicates that these fishes were immature and maturing
(Table 5; Farley et al., 2009; Moss et al., 2009; E. Farley, unpubl.).
Forage fishes (Smelts (Osmeridae), Pacific Herring (Clupea pallasii) and Pacific Sand Lance (Ammodytes hexapterus)) seemed to
have a greater tendency to use habitats close to shore (Table 4).
The lagoon, beach and nearshore benthic habitats were characterized by a greater number of forage fish species than the shelf
midwater and benthic. Capelin were found in all habitats and dominated the beach seine catch.
Arctic Cod dominated the nearshore bottom trawl, shelf midwater trawl and shelf bottom trawl catch (Table 4). The size range of
Arctic Cod in all habitats was similar and fairly broad (26–230 mm;
Table 5), and likely spans several age classes from age-0 to age-3
and greater (Norcross et al., 2015). In the three habitats outside
the lagoon, Arctic Cod were largest in the shelf benthic, although
smaller (age-0) fish were present on the shelf benthic along with
the large fish. Arctic Cod eggs, larvae and juveniles were found in
the shelf ichthyoplankton (Table 6). Furthermore, catch density
of Arctic Cod larvae was greatest of all ichthyoplankton taxa
(Table 7). This suggests that Arctic Cod use the Beaufort Sea shelf
for spawning and larval development, development of age-0 fish
occurs throughout the nearshore and shelf and fish move/stay offshore as they age.
Saffron Cod (Eleginus gracilis) was present in the lagoon, beach
and nearshore habitats (Table 4). Saffron Cod were also present
in the shelf benthic habitat but at low relative CPUE (0.005%).
Saffron Cod were largest in length in the lagoon (74–394 mm;
Table 5). Results from the ichthyoplankton survey on the shelf
showed that Saffron Cod were the second most abundant taxa in
the catch (Table 7). Length range of Saffron Cod in the nearshore
and beach (22–78 mm) indicates these fish were juveniles
(Table 5 (Norcross et al., 2015)). These patterns in larval, juvenile
and adult distribution suggest that Saffron Cod spawn on the shelf
and move into nearshore and the lagoon as they age. This hypothesis could be addressed by seasonal sampling of multiple life stages
of Saffron Cod, including sampling the surface waters (our surface
trawl data from the Chukchi Sea have shown relatively high densities of Saffron Cod). In addition, ichthyoplankton sampling in the
lagoon would reveal whether they also spawn in that habitat.
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
123
Table 4
Catch composition in the Beaufort Sea, % CPUE. Mesh size of the net is shown at the top, along with the months and years that sampling took place. Sample sizes are reported as
hours fished for the fyke and gill net data, and as number of stations across all years for the other data. Catch composition is % CPUE by number averaged over all surveys for that
net type/habitat. Cells are coded such that darkest cells represent species/families with the greatest% CPUE for that net type/habitat. Richness (S), Simpson’s Index (D) and
Shannon Index (H) for each habitat are shown at the bottom.
a
b
a
b
Number of hours the net was fished standardized to a common net length (60 feet).
Most of the sculpin in the shelf midwater trawl catch were unidentified.
Three species that are commercially important outside the
Arctic, Walleye Pollock (Gadus chalcogrammus), Pacific Cod (Gadus
macrocephalus) and Greenland Halibut (Reinhardtius hippoglossoides), were only present in shelf demersal habitat (Table 4).
Walleye Pollock ranged in size 80–320 mm (Table 5). These fish
were 1–3 years old, and smaller at age than Bering Sea Pollock
(Rand and Logerwell, 2010) and thus not likely to be large enough
to be of commercial value. Pacific Cod were 240–330 mm (Table 5),
likely age 1–3 (Matta and Kimura, 2012). Greenland Halibut specimens have been found across the Beaufort Sea previous to this
work (Chiperzak et al., 1995). Greenland Halibut reported here
were 130–400 mm (Table 5), age 1–6 (Matta and Kimura, 2012)
younger and smaller than those that recruit to the fishery in the
Bering Sea (Barbeaux et al., 2013). None of these three species were
present in the shelf ichthyoplankton (Table 6), indicating that they
are likely not yet spawning at Arctic latitudes, but were transported from the Bering Sea after being spawned there.
The lagoon habitat appears to play a role in the life history of
salmonids, forage fishes, and Saffron Cod. Furthermore, there were
two species that appeared to use the lagoon habitat to an extent
124
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Table 5
Fish length in mm (mean and range) in the Beaufort Sea. Mesh size of the net is shown at the top, along with the months and years that sampling took place and the number of
fish measured (all species combined). ‘‘ND’’ stands for ‘‘no data’’. The cells are coded the same as Table 1, and thus indicate relative % CPUE.
a
a
a
a
Sample size = 1.
Table 6
Presence/absence of taxa in the ichthyoplankton, in the Beaufort Sea August 2008 (n = 28 stations).
Family
Common name
Scientific name
AMMODYTIDEA
Pacific Sand Lance
Ammodytes hexapterus
GADIDAE
Unidentified cod
Arctic Cod
Saffron Cod
Boreogadus saida
Eleginus gracilis
COTTIDAE
Arctic Staghorn Sculpin
Shorthorn Sculpin
Gymnocanthus tricuspis
Myoxocephalus scorpius
X
X
STICHAEIDAE
Unidentified pricklebacks
Slender Eelblenny
Daubed Shanny
Lumpenus fabricii
Leptoclinus maculatus
X
X
X
LIPARIDAE
Kelp Snailfish
Unidentified snailfish
PLEURONECTIDAE
Unidentified flounder
Longhead Dab
Bering Flounder
Eggs
Larvae
Juveniles
X
X
Liparis tunicatus
X
X
X
X
X
X
X
X
Limanda proboscidea
Hippoglossoides robustus
not usual for their taxa, a sculpin and a flatfish (Table 4). Fourhorn
Sculpin (Myoxocephalus quadricornis) was one of the dominant species in the lagoon and was not present in shelf midwater and
X
X
X
benthic habitats. In contrast, the other sculpin species were found
only outside the lagoon from the beach to the shelf. Arctic Flounder
(Pleuronectes glacialis) were only caught in the lagoon. Other
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Table 7
Mean density (No./10 m2) of most abundant taxa in the ichthyoplankton, in the
Beaufort Sea August 2008 (n = 28 stations). Most of the catch was larval fish, with a
few juvenile Arctic and Saffron Cod.
Common name
Scientifica name
Mean density (No./10 m2)
Arctic Cod
Saffron Cod
Bering Flounder
Longhead Dab
Boreogadus saida
Eleginus gracilis
Hippoglossoides robustus
Limanda proboscidea
4.7
0.7
0.3
0.4
flatfishes were only present outside the lagoon from the nearshore
to shelf. Another indication that the lagoon habitat may be unique
is that taxonomic diversity (D and H) in the fyke net catch was the
highest of the habitats examined (Table 4). Perhaps some fish taxa
prefer the shallow, warmer and brackish waters of lagoon habitats
compared to other habitats offshore (Craig et al., 1982). For example, it has been noted that the abundances of most anadromous
species in nearshore and lagoon waters of the Beaufort Sea are correlated with warm temperatures and low salinities (Craig, 1984).
There may also be a benefit from greater availability of
terrestrial-based nutrients (Dunton et al., 2006) and abundant food
resources, predominantly epibenthic mysids and amphipods (Craig
and Haldorson, 1981; Griffiths and Dillinger, 1981; Craig, 1984). In
addition, anadromous fishes may use lagoons as migration corridors during spring and fall migration (Craig, 1984). Alternatively,
there may be conditions in the lagoon that exclude other fishes,
such as high seasonal variability in temperature and salinity. For
example, in North Salt Lagoon, surface salinity in late June is 0–4
and rises to 27–29 over the course of the summer (T. Sformo,
unpubl.) and lagoon temperatures can fluctuate between 0 and
14 °C (Craig et al., 1982).
Our data on fish distribution and size across habitats, combined
with ichthyoplankton data generates ideas about the spawning and
ontogenetic movements of several taxa. As discussed above, Arctic
Cod appears to use all habitats for most life history functions, with
the largest fish staying/moving offshore to the shelf benthic habitat. Whereas Saffron Cod appear to spawn on the shelf and move
into nearshore and the lagoon as they age. Pricklebacks and eelblennies (Stichaeidae) were larger away from the beach (Table 5)
and were present as larvae over the shelf (Table 6), suggesting that
spawning occurs on the shelf, larvae are transported inshore, and
fish move offshore as they age. Snailfish (Liparidae) larvae were
present on the shelf (Table 6), suggesting they spawn there. In contrast, eelpouts (Zoarcidae) and poachers (Agonidae), were not
found in the ichthyoplankton on the shelf (Table 6), suggesting
they spawn elsewhere or at an early season. Several species that
were dominant or restricted to the lagoon and/or beach habitats
were not found in the shelf ichthyoplankton: Fourhorn Sculpin,
Arctic Flounder, sticklebacks (Gasterosteidae), and Capelin
(Tables 4 and 6). We hypothesize that they spawn in the lagoon
and beach habitats where the adult stages were found. In contrast,
Pacific Sand Lance, which was found only in the beach habitat as
adults (Table 4) was present in the shelf ichthyoplankton
(Table 6). Pacific Sand Lance spawn in subtidal or intertidal sand
substrates (Robards et al., 1999) and our data suggest that the larvae (and perhaps the eggs) are then transported offshore. Seasonal
surveys of multiple life stages of fish in all habitats would address
the hypotheses and unknowns about the life history of these taxa
discussed here.
Smaller, presumably younger, fish were found in the beach and
nearshore benthic habitats, consistent with the hypothesis that
these are nursery areas. For example age-0 Arctic Cod (Gallaway
and Norcross, 2011), Saffron Cod (Norcross et al., 2015), Slender
Eelblenny (Lumpenus fabricii; Norcross et al., 2015), Capelin
(Doyle et al., 2002), and sculpin (Cottidae; Gallaway and
125
Norcross, 2011), were present in these habitats closer to shore
(Table 5). However, age-0 fish were also present further offshore
along with older fish. For example, Arctic Cod up to age 3+ were
caught in the shelf midwater and shelf benthic habitats along with
age-0 fish. Thus the beach and nearshore habitats do not appear to
be the only habitats used as nursery areas; although older fish may
prefer offshore habitats.
3.2. Chukchi Sea
Salmonids (Salmonidae) were found almost exclusively in the
surface waters of the shelf, with the exception of a relatively low
catch of Arctic Cisco (Coregonus autumnalis) and Pink Salmon in
the beach habitat (Table 8). This is not surprising, given that the
surface trawl survey was designed to assess the distribution of
juvenile salmonids. Pink and Chum Salmon were the dominant
species in 2007 and Chum were in 2009. Chinook, Coho and
Sockeye Salmon were caught at relatively low % CPUE. As discussed
above for the Beaufort Sea results, it is unusual to catch Chinook
Salmon in the Arctic (Stephenson, 2006; Irvine et al., 2009).
Salmonids ranged from 170 to 331 mm (Table 9) and were thus
age-0 (Chinook) to juveniles or maturing (Farley et al., 2009;
Moss et al., 2009). The relatively high CPUE of juvenile Pink and
Chum Salmon during 2007 (Table 8) provided some evidence that
increased warming in the Arctic, evidenced by the 2007 sea ice
minimum (Woodgate et al., 2010), may be beneficial for future salmonid productivity in the region. For instance, adult Pink Salmon
were captured in anomalously high numbers within subsistence
nets off Barrow, Alaska during 2008 (E. Farley, unpubl.). Perhaps
not surprisingly, Pink Salmon catch made up 22% of total CPUE in
the lagoon gill net survey in the Beaufort Sea (this study).
Juvenile Pink Salmon return to their natal spawning streams after
one year in the ocean, suggesting that the high CPUE of juvenile
Pink Salmon during 2007 was linked to increased catches the following year. Similarly, anomalously high numbers of adult Chum
Salmon were captured off Barrow in subsistence nets during
2009 and 2010 (E. Farley, unpubl.), following the typical 2–3 year
marine life history for these fish. The summer sea temperatures
in the Chukchi Sea were very warm during 2007 (Woodgate
et al., 2010), potentially contributing to the success of juvenile
Pink and Chum Salmon during that year. Thus future warming in
the Arctic, particularly during summer months, may contribute
to better early marine growth for juvenile salmonids and increased
returns to spawning habitat (Andrews et al., 2009; Moss et al.,
2009).
Forage fishes (Smelts (Osmeridae), Pacific Herring and Pacific
Sand Lance) were found in all habitats, although Pacific Sand
Lance was the only forage species caught in the beam trawl
(Table 8). The greatest relative densities of forage fishes were
found in the beach and shelf surface habitats, in particular
Capelin. Capelin were caught in a somewhat similar range of
lengths in all habitats, although the smallest fish (29 mm) were
found in the beach habitat and the largest (180 mm) in the shelf
surface waters (Table 9). This range of lengths likely corresponds
to post flexion larvae (Doyle et al., 2002) to age 3+ (Brown,
2002). The length of Rainbow Smelt (Osmerus dentex) increased
from the nearshore to the shelf from a minimum size of 72 mm
to a maximum of 300 mm (Table 9). Pacific Herring were caught
in a similar range of lengths in the shelf surface and benthic habitats. The largest range of Herring sizes occurred in the shelf surface
habitat (in 2012), 78–313 mm (Table 9), likely ages <1 to 9+
(Lassuy, 1989). Capelin and Pacific Sand Lance spawn on or near
the beach (Brown, 2002; Robards et al., 1999), thus the catches
of larval and age-0 forage fishes suggests that after spawning, juvenile fishes spend some amount of time in the nearshore before
moving offshore into deeper waters. Large spawning events of
126
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Table 8
Catch composition (% CPUE) from each net type/habitat in the Chukchi Sea. Mesh size of the net and survey months are shown at the top. Sample size is the number of stations
sampled summed over all years. Cells are coded such that darkest cells represent species/families with the greatest% CPUE for that net type/habitat. Richness (S), Simpson’s Index
(D) and Shannon Index (H) for each habitat are shown at the bottom.
Capelin on beaches near Barrow have been reported (S. Johnson,
unpubl.), whereas spawning areas of Pacific Sand Lance and other
forage fishes in the Arctic are largely unknown.
Arctic Cod were present in all habitats. They made up relatively
large portions of the catch in the nearshore and shelf benthic habitats (Table 8). The minimum size of Arctic Cod was somewhat similar across habitats, 30–40 mm (Table 9), age-0 (Gallaway and
Norcross, 2011). However, the maximum length of Arctic Cod
increased from the beach to the benthic shelf from 66 mm to
260 mm (age-0/1 to age-3+ (Gallaway and Norcross, 2011)).
Arctic Cod larvae were one of the top four most abundant taxa in
the ichthyoplankton catch (Table 11), suggesting that they use
the shelf habitat for larval development and possibly spawning.
The pattern in fish lengths and ichthyoplankton catch suggests that
Arctic Cod use nearshore and shelf habitats for multiple life history
functions, with the older Cod staying/moving offshore to the shelf
benthic habitat.
Saffron Cod were likewise found in all habitats, making up a
large portion of the catch in the shelf surface habitat (Table 8).
Saffron Cod had a similar size distribution as Arctic Cod across
127
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Table 9
Fish length in mm (mean and range) in the Chukchi Sea. Mesh size of the net is shown at the top, along with the months and years that sampling took place and the number of fish
measured (all species combined). ‘‘ND’’ stands for ‘‘no data’’. The cells are coded the same as Table 8, and thus indicate relative % CPUE.
a
a
If no min–max shown, only one fish was measured.
habitats. The smallest fish were 26–40 mm (Table 9), age-0
(Norcross et al., 2015). The maximum lengths increased from
50 mm in the beach habitat to 360 mm on the shelf, likely spanning at least 3 age classes (Table 9). This suggests that their use
of different habitats through development is similar to that of
Arctic Cod.
Pacific Cod and Walleye Pollock, important commercial cod
(Gadidae) species in the Bering Sea, were found in the nearshore
and shelf benthic habitats, at low relative CPUE (0.5% or less;
Table 8). Walleye Pollock were also found in the shelf surface habitat at low % CPUE (Table 8). Walleye Pollock ranged in size from 58
to 160 mm (Table 9). These fish were likely mostly age-1 to age-2
(Brown et al., 2001; Hinckley, 1984) and thus were not commercially valuable (Walleye Pollock recruit to the Bering Sea fishery
at age-3 or-4 (Ianelli et al., 2013)). Although no adult Walleye
Pollock were caught, their eggs, larvae and juveniles were found
in the shelf ichthyoplankton survey (Table 10). These could have
been transported into the Chukchi Sea from the Bering Sea, or
could have been spawned and reared in the north.
Documentation of mature adult Walleye Pollock in the Chukchi is
needed to confirm spawning activity for this species in the
Arctic. In addition, determining the developmental stage of eggs
caught in the Arctic could help reveal whether eggs may have been
transported from the south or were spawned locally. Pacific Cod,
another important commercial cod in the Bering Sea, ranged in size
from 100 to 254 mm (Table 9), likely age 1–2 (Matta and Kimura,
2012). Pacific Cod larvae were not found in the ichthyoplankton
(Table 10) so we hypothesize that these fish were spawned in
the Bering Sea and transported north.
Flatfishes (Pleuronectidae) were found in all habitats. The greatest number of flatfish species and the greatest relative CPUE
occurred in the shelf benthic habitat (Table 8). Bering Flounder
(Hippoglossoides robustus) and Yellowfin Sole (Limanda aspera)
dominated the shelf benthic flatfish catch, although the % CPUE
was not very large (around 5%). Species that are commercially
important in the Bering Sea, Yellowfin Sole, Greenland Halibut
and Alaska Plaice (Pleuronectes quadrituberculatus), ranged in average size from 45 to 191 mm (Table 9). This corresponds to ages 0–2
128
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Table 10
Presence/absence of taxa in the ichthyoplankton, in the Chukchi Sea September 2007–2011 (n = 218 stations, all years).
Family
Common name
Scientific name
2007, 2010, 2011
OSMERIDAE
Capelin
Unidentified smelts
Mallotus villosus
AMMODYTIDAE
Pacific Sand Lance
Ammodytes hexapterus
GADIDAE
Arctic Cod
Walleye Pollock
Unidentified cod
Boreogadus saida
Gadus chalcogrammus
COTTIDAE
Butterfly Sculpin
Arctic Staghorn Sculpin
Spatulate Sculpin
Shorthorn Sculpin
Hamecon
Unidentified Myoxocephalus
Hemilepidotus papilio
Gymnocanthus tricuspis
Icelus spatula
Myoxocephalus scorpius
Artediellus scaber
STICHAEIDAE
Slender Eelblenny
Daubed Shanny
Blackline Prickleback
Fourline Snakeblenny
Stout Eelblenny
Arctic Shanny
Unidentified Lumpenus
Lumpenus fabricii
Leptoclinus maculatus
Acantholumpenus mackayi
Eumesogrammus praecisus
Anisarchus medius
Stichaeus punctatus
LIPARIDAE
Unidentified Liparis
Variegated Snailfish
Kelp Snailfish
Liparis gibbus
Liparis tunicatus
X
X
X
AGONIDAE
Arctic Alligatorfish
Gray Starsnout
Alligatorfish
Aspidophoroides olrikii
Bathyagonus alascanus
Aspidophoroides monopterygius
X
X
X
PLEURONECTIDAE
Bering Flounder
Unidentified Limanda
Yellowfin Sole
Longhead Dab
Sakhalin Sole
Alaska Plaice
Hippoglossoides robustus
Limanda aspera
Limanda proboscidea
Limanda sakhalinensis
Pleuronectes quadrituberculatus
X
X
X
X
Whitespotted Greenling
Masked Greenling
Hexagrammos stelleri
Hexagrammos octogrammus
X
X
Eggs
HEXAGRAMMIDAE
Scientific name
Arctic Cod
Bering Flounder
Yellowfin Sole
Longhead Dab
Boreogadus saida
Hippoglossoides robustus
Limanda aspera
Limanda proboscidea
Juveniles
Eggs
X
X
Larvae
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Table 11
Mean density (No./10 m2) of most abundant taxa in the ichthyoplankton, in the
Chukchi Sea September 2007–2011 (n = 218 stations, all years).
Common name
Larvae
2009
Mean density (No./10 m2)
2007, 2010, 2011
2009
0.02
2.5
80.2
0.8
1.3
0.2
for Greenland Halibut and ages 0–6 for Yellowfin Sole (Matta and
Kimura, 2012), younger and smaller than those that recruit to
the fishery in the Bering Sea (Barbeaux et al., 2013; Wilderbuer
et al., 2013). Alaska Plaice was not found in the shelf ichthyoplankton (Table 10), suggesting they are not spawning in the Arctic.
Greenland Halibut were similarly not found in the ichthyoplankton
(Table 10), but Greenland Halibut larvae grow to large sizes in the
plankton (80 mm in the Bering Sea, Duffy-Anderson, unpubl.) and
may be too large to be sampled effectively by the zooplankton nets
used in these surveys. In fact, Greenland Halibut ranging in size
from 63 to 80 mm were caught in the shelf surface trawl
(Table 9) so it appears that this species may spawn in the Arctic.
Yellowfin Sole was one of the top four species in the ichthyoplankton, dominating the catch by two orders of magnitude in some surveys (Table 11). Although Greenland Halibut and Yellowfin Sole
larvae were found in the Chukchi, the fish caught in the bottom
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
trawls were sub-adults. Age data and collection of spawning
females would clarify whether, when and where these species
are spawning in the Chukchi Sea.
We examined the shelf surface trawl data for each year (2007
and 2012) separately because of striking between-year differences
in catch composition. In 2007 Saffron Cod dominated the catch
whereas in 2012 Capelin were dominant (Table 8). 2007 was an
anomalous year due to warm water advected to the Chukchi
(Woodgate et al., 2010), coincident with the first new record ice
minima (NCAR, 2007). Cooler summer water temperatures prevailed in the Chukchi Sea during years after 2007 (Proshutinsky
et al., 2011; Timmermans et al., 2012). Capelin are thought to prefer cooler water temperatures (Anderson and Piatt, 1999), so this
difference between 2007 and 2012 ocean conditions may explain
the difference in species composition in the surface waters.
We examined data from two different gear types deployed in
the same habitat, the benthic shelf, and not surprisingly the catch
composition was different. The shelf plumb staff beam trawl catch
was dominated by sculpins (Arctic Staghorn (Gymnocanthus tricuspis) and Shorthorn (Myoxocephalus scorpius)) and by Slender
Eelblenny. In contrast, the catch of the larger mesh shelf 83-112
Eastern otter bottom trawl was dominated by Arctic Cod
(Table 8). Arctic Cod were present in the beam trawl catch, but
at lower relative density. Similarly, Saffron Cod were caught in
both nets, but at a lower relative density in the beam trawl.
Differences in net size and speed of deployment likely contributed
to this pattern. A paired trawl experiment in the Chukchi Sea during the 2012 Arctic EIS survey allowed for a comparison of the
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
catch of the beam trawl and the 83-112 trawl data (Britt et al.,
2013). Although the two trawls caught a similar number of fish
taxa per haul, a station-by-station comparison showed that the
catch composition was very different: 33% of the fish species
caught were gear-specific. The beam trawl was more effective at
catching juvenile fishes, whereas the 83-112 trawl was more efficient at capturing larger and more mobile organisms. Britt et al.
(2013) conclude that the two trawls are complementary sampling
tools and used together provide a more inclusive catalog of species
composition than either gear used alone.
Our data on fish distribution and size across habitats in the
Chukchi Sea, combined with ichthyoplankton data generate
hypotheses regarding life history and habitat use of several taxa.
As discussed above, it appears that Arctic and Saffron Cod use multiple habitats for multiple life history functions, with the older fish
staying/moving offshore. A similar pattern was observed for other
taxa. Sculpins (Cottidae) were present in all habitats, with greatest
% CPUE in the shelf surface and benthic habitats (Table 8). The largest fish were in the shelf benthic, likely age-4 or higher (Table 9).
Although fish were smaller and likely younger towards shore
(age-0 to age-3), smaller, presumably age-0 sculpins were found
offshore with the larger sculpins (Gallaway and Norcross, 2011).
Pricklebacks (Stichaeidae) were likewise present in all habitats,
with greatest relative CPUE in the nearshore benthic and shelf benthic habitats (Table 8). Fish increased in size from the beach out to
the offshore shelf habitat being as large as 205 mm in the shelf surface habitat and as large as 390 mm in the shelf benthic habitat
(Table 9), likely greater than age-3 (Gallaway and Norcross,
2011). Similar to the cods (Gadidae) and sculpins, age-0 pricklebacks (30–50 mm) were also caught in the shelf benthic habitat
along with the older, larger fish (Table 9). Snailfishes (Liparidae)
and poachers (Agonidae) were found in all habitats but at relatively
low% CPUE (2% or less; Table 8). Eelpouts (Zoarcidae) were found in
all habitats, except the beach, at 4% CPUE or less (Table 8).
Snailfishes, eelpouts and poachers all increased in size from the
beach through the nearshore and to the offshore surface and bottom habitats (Table 9). Similar to the species discussed above,
smaller and presumably younger fishes were also present in the
offshore habitats along with the bigger, older fishes.
Smaller, presumably younger, fishes were found in the beach
and nearshore benthic habitats, suggesting these are nursery areas.
For example age-0 Arctic Cod (Gallaway and Norcross, 2011),
Saffron Cod (Gallaway and Norcross, 2011), Slender Eelblenny
(Gallaway and Norcross, 2011), Capelin (Doyle et al., 2002) and
sculpins (Gallaway and Norcross, 2011) were present in these habitats closer to shore. However, age-0 fishes were also present further offshore along with older fishes, age 3 and higher.
3.3. Overall patterns
The sampling effort differed among the two seas, particularly on
the shelf, with fewer surveys occurring during fewer years in the
Beaufort Sea compared to the Chukchi Sea. This could lead to bias
in fish community composition or distribution due to different
sample sizes and/or different oceanographic conditions among
years. Nonetheless, there were numerous similarities between
the patterns observed in the two seas.
Salmon (Oncorhynchus sp.) were most prevalent in the lagoon
habitat in the Beaufort Sea and the shelf surface habitat in the
Chukchi Sea. However, no shelf surface surveys have been conducted in the Beaufort, so it is as yet unknown if salmon use the
surface waters as they do in the Chukchi. Conversely, no surveys
of Chukchi lagoons have been conducted, so it is unknown if salmon use lagoons as they do in the Beaufort. Lagoon habitat is less
prevalent in the Chukchi than the Beaufort, so it is possible that the
salmon found in the Chukchi Sea are restricted to the shelf during
129
their marine phase. Surveys of the surface waters of the Beaufort
and the lagoons of the Chukchi are needed to resolve this apparent
difference in habitat use of salmon. Pink and Chum Salmon were
common salmon species in both Seas, not surprisingly, given that
they are Arctic residents. Chinook Salmon were also caught, albeit
at relatively low abundance, in both Seas. Chinook Salmon are
rarely seen in the Arctic leading to speculation that their range
may be expanding due to climate change (Moss et al., 2009), but
more evidence is needed to confirm this hypothesis (Stephenson,
2006).
Forage fishes (Pacific Sand Lance, Pacific Herring, Capelin,
Rainbow Smelt) in both Seas seem to prefer habitats relatively
close to shore such as the lagoon, beach and nearshore. As discussed above (in the Beaufort Sea section), lagoon habitat may be
preferred due to the relatively warm and low salinity waters, abundant food resources and proximity to natal streams for anadromous fishes. The brackish water characteristic of lagoons can
extend out to the beach and nearshore depths (<10 m), is distinct
from adjacent marine waters and provides important feeding habitat for anadromous and marine fishes in summer (Craig, 1984).
During winter this estuarine band is absent and most anadromous
fishes return to North Slope rivers and marine fishes move offshore
as nearshore waters freeze. The nearshore of the Chukchi Sea coast
is similarly warm and low salinity during summer due to solar
heating and freshwater inputs (R. Heinz, unpubl.). Capelin and
Pacific Sand Lance use beach and intertidal habitats for spawning
in summer (Robards et al., 1999). Mass spawning of Capelin has
been observed on beaches near Barrow in previous studies
(George et al., 2009). Forage fishes also occurred in the surface
waters of the Chukchi Sea shelf with some species, such as
Capelin, dominating the catch. A surface trawl survey in the
Beaufort Sea is needed to determine whether this distribution is
unique to the Chukchi Sea or typical of Arctic forage fishes.
Arctic Cod dominated the benthic habitats of the nearshore and
shelf in both Seas. Arctic Cod were also relatively abundant in the
shelf midwater of the Beaufort Sea. Although we present no survey
data from the Chukchi midwater habitat, preliminary results from
the 2012 and 2013 acoustic-trawl surveys of the Arctic Ecosystem
Integrate Survey (EIS) show that the one of the primary acoustic
targets observed in the midwater of the Chukchi Sea were age-0
Arctic Cod (https://web.sfos.uaf.edu/wordpress/arcticeis/).
We hypothesize that the life history distribution of Arctic Cod is
similar for the Beaufort and Chukchi Seas: spawning and larval
development takes place on the shelf, development of age-0 fish
occurs throughout the nearshore and shelf and fish move/stay offshore as they age. The life history distribution of Arctic Cod in the
Chukchi and Beaufort Seas has not been documented in detail. It is
known that they spawn under sea ice during winter, between
November and March (Rass, 1968; Craig et al., 1982). The eggs
are buoyant and remain at the surface through hatching (Graham
and Hop, 1995). Larvae remain at the surface for several months
after hatching, until September when they settle to the bottom
(Baranenkova et al., 1966; Sekerak, 1982). Age-0 fish are known
to be planktonic and found in bays, fjords and offshore. Juveniles
and adults are understood to be found either dispersed throughout
the water column of concentrated in schools at the ice edge, along
shorelines in summer and in deep offshore waters (Bradstreet
et al., 1986). Our synthesis of Arctic Cod distribution based on
the limited large scale survey data available provides a more current and more detailed state of understanding of how Arctic Cod
may use different habitats throughout their life history. Field studies focusing on Arctic Cod life history that would sample multiple
age classes in multiple habitats throughout the year are needed to
confirm and refine our ideas.
We suggest that the distribution and habitat use of Saffron Cod
was different between the two Seas. In the Beaufort, the data are
130
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
consistent with fish spawning on the shelf and moving into the
nearshore and lagoon as they age. In the Chukchi it appears that,
similar to Arctic Cod, they use nearshore and shelf habitats for
multiple life history functions with older fish staying or moving
offshore. As discussed above, no surveys have been conducted in
Chukchi lagoons, so the use of lagoons by Saffron Cod in this area
cannot be ruled out. However, given the relative paucity of lagoon
habitat in the Chukchi, it is possible that this habitat use behavior
is unique to the Beaufort Sea. The little published information on
Saffron Cod life history indicates that they spawn in winter,
December–February, in relatively cold and shallow waters close
to shore. The eggs are demersal and non-adhesive. Larvae and juveniles have been caught in surveys of Norton Sound, Bering Strait
and eastern Bering Sea (Dunn and Matarese, 1987); and recently
as an ‘‘invader’’ of nearshore habitats of Prince William Sound,
Alaska (Johnson et al., 2009). As suggested above, for Arctic Cod,
our synthesis provides the most current and detailed conceptual
models for the life history distribution of Saffron Cod and further
surveys of multiple life history stages of Saffron Cod across seasons
are needed.
Species of cod and flatfish that are commercially important
elsewhere were found in both Seas: Walleye Pollock, Pacific Cod,
and Greenland Halibut. Yellowfin Sole were also found in the
Chukchi Sea. None of these species were found in the ichthyoplankton in the Beaufort Sea suggesting they are not yet spawning
that far north. In contrast, Walleye Pollock and Greenland Halibut
larvae were present in the Chukchi Sea, as were high abundances of
Yellowfin Sole larvae. Larvae were present; however, adult fish of
these species were not. Continued monitoring of multiple life
stages of Walleye Pollock and flatfishes in the Arctic, including
spawning adults, if present, will determine whether the ranges of
these valuable species are shifting north with climate change.
However, the current perspective is that bottom water temperatures in the Arctic are too cold to support spawning Walleye
Pollock and that the sub-adult fish that are caught at high latitudes
were advected by currents from spawning locations in the Bering
Sea (Hollowed et al., 2013). In contrast, Greenland Halibut are
found in Arctic latitudes in the Atlantic and it is thought that there
is potential for the spawning range of Greenland Halibut to extend
into the Pacific Arctic given appropriate temperature and feeding
conditions (Hollowed et al., 2013). Similarly, there is a potential
for the range of Yellowfin Sole to extend into the Arctic given its
presence at high latitudes and eclectic diet (Hollowed et al.,
2013). Regardless of whether any of these species are spawning
in the Arctic at this time, none of the fish caught in our surveys
were large enough to be commercially valuable.
Patterns in taxonomic diversity across habitats differed between
the Beaufort and Chukchi Seas. The dominance of Capelin in the
beach and shelf surface habitats of the Chukchi Sea resulted in the
lowest taxonomic diversity (D and H indices) compared to other
Chukchi habitats. This is in contrast to the Beaufort Sea where the
nearshore benthic, shelf midwater and shelf benthic habitats had
low diversity scores due to the dominance of Arctic Cod. The
Chukchi Sea shelf beam trawl catch data had the highest indices of
taxonomic diversity, due to the distribution of catch among gadid,
sculpins, pricklebacks, eelpouts, and flatfish. No one species made
up more the 30% of the total CPUE in the shelf beam trawl catch.
The highest taxonomic diversity in the Beaufort Sea was observed
in the lagoon, due to the distribution of catch among salmonids,
smelts, sticklebacks, cod, sculpins and flatfishes.
Nearshore habitats have been shown to be nursery areas in
Northeast Pacific marine systems, such as Southeast Alaska
(Johnson et al., 2005), Bering Sea-Aleutian Islands (Thedinga
et al., 2008), Prince William Sound, Alaska (Norcross et al., 2001)
and the Gulf of Alaska (Norcross et al., 1995; Brown, 2002).
Species groups using the nearshore in these systems for juvenile
development include cod, forage fishes and salmonids. For many
taxa in our datasets age-0 fishes were found nearshore and older
fishes were further offshore consistent with the idea that the nearshore provides nursery habitat. However, this does not appear to
be a straightforward ontogenetic offshore migration because at
least some age-0 fishes were present offshore with the older fishes.
Again, field studies of multiple ages classes in multiple habitats
throughout the year would help resolve and interpret these patterns. Arctic nursery habitat may not be typical, compared to other
temperate and tropical areas (Beck et al., 2001). In temperate and
tropical areas, nursery habitat often includes physical structure
such as eel grass beds or kelp patches. Much of the nearshore areas
of the Arctic are overlaid with shorefast ice for most of the year. Ice
keels, extending as deep as 20–30 m, can cause significant bottom
scouring as the ice deforms in mid-winter and moves out in summer. Consequently, there are few physical features or vegetation to
provide juvenile fish with cover in the nearshore. Instead of physical cover, oceanographic conditions (i.e. temperature and salinity)
in nearshore waters during the Arctic summer may provide age-0
fish with a predator refuge that simultaneously traps prey and
offers temperatures that optimize growing conditions (Jarvela
and Thorsteinson, 1999).
The relative abundance estimates of small fishes near shore
could have been influenced by differences in gear type. The nets
fished on the beach and in the nearshore benthic habitat had smaller mesh than the shelf surface trawl and shelf bottom trawl. The
beach and nearshore nets were also smaller in overall dimensions.
There is a possibility that bigger fish were able to avoid the smaller
mesh inshore nets, because they were towed at slower speeds than
the larger shelf bottom trawl. Another concern might be that the
larger mesh offshore nets were not capable of catching small fish.
However small fishes of many taxa were caught in the nets fished
offshore, so this bias does not appear to be a problem at the resolution of the analyses discussed above.
All the surveys that contributed to the synthesis of fish distribution and habitat use across habitats were conducted in spring-fall,
ice-free seasons. This highlights the need for surveys of fishes in
their overwinter habitats, which would need to be conducted
under the ice and in polynyas such as those near Wrangell and
St. Lawrence Islands.
4. Summary
In summary, our synthesis of fish survey data across a spectrum
of habitats in the Beaufort and Chukchi Seas revealed more similarities than differences. Some highlights are that Chinook Salmon
may be moving into the Arctic; and that the nearshore is a habitat
for forage fish across age classes and also a nursery area for other
species. In addition, we document the presence of commercially
important Walleye Pollock and flatfishes and although they are
not likely spawning in the Arctic now, the flatfishes have potential
to expand their range into the Arctic. Finally, we provide the most
current and detailed conceptual models for the life history distribution of key gadids in Arctic food webs: Arctic and Saffron Cod.
We also identify research gaps, such as the need for surveys of
the surface waters of the Beaufort Sea, surveys of the lagoons of
the Chukchi Sea, and winter season surveys in all areas. We recommend field studies on fish life history that sample multiple age
classes in multiple habitats throughout the year to confirm, resolve
and interpret the patterns in fish habitat use that we observed.
Acknowledgements
The authors thank 3 anonymous reviewers for their constructive comments. This study is part of the Synthesis of Arctic
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Research (SOAR) and was funded in part by the U.S. Department of
the Interior, Bureau of Ocean Energy Management, Environmental
Studies Program through Interagency Agreement No. M11PG00034
with the U.S. Department of Commerce, National Oceanic and
Atmospheric Administration (NOAA), Office of Oceanic and
Atmospheric Research (OAR), Pacific Marine Environmental
Laboratory (PMEL). This research is contribution EcoFOCI-0835 to
NOAA’s Ecosystems and Fisheries-Oceanography Coordinated
Investigations.
References
Anderson, P.J., Piatt, J.F., 1999. Community reorganization in the Gulf of Alaska
following ocean climate regime shift. Marine Ecology Progress Series 189, 117–
123.
Andrews, A.G., Farley, E.V., Moss, J.H., Murphy, J.M., Husoe, E.F., 2009. Energy
density and length of juvenile pink salmon Oncorhynchus gorbuscha in the
eastern Bering Sea from 2004 to 2007: a period of relatively warm and cool sea
surface temperatures. North Pacific Anadromous Fish Commission Bulletin No.
5, 183–189.
Bacon, J.J., Hepa, T.R., Pederson, M., Olemaun, T.P., George, J.C., Corrigan, B.G., 2009.
Estimates of subsistence harvest for village on the North Slope of Alaska, 1994–
2003. Barrow, Alaska.
Baranenkova, A.S., Ponomarenko, V.P., Khokhlina, N.S., 1966. Distribution, size and
growth of larvae and fry of Boreogadus saida (Lepechin) in the Barents Sea.
Voprosy Iktiologii 6, 498–518.
Barbeaux, S.J., Ianelli, J., Nichols, D., Hoff, J., 2013. Stock Assessment of Greenland
Turbot (Reinhardtius hippoglossoides) in the Bering Sea and Aleutian Islands. In:
Stock Assessment and Evaluation Report for the Groundfish Resources of the
Bering Sea/Aleutian Islands Regions. North Pacific Fisheries Management
Council, P.O. Box 103136, Anchorage, Alaska, 99510.
Beck, M.W., Heck Jr., K.L., Able, K.W., Childers, D.L., Eggleston, D.B., Gillanders, B.M.,
Halpern, B., Hays, C.G., Hoshino, K., Minello, T.J., Orth, R.J., Sheridan, P.F.,
Weinstein, M.P., 2001. The Identification, conservation, and management of
estuarine and marine nurseries for fish and invertebrates. BioScience 51, 633–
641.
Begon, M., Harper, J.L., Townsend, C.R., 1990. Ecology: Individuals, Populations and
Communities, second ed. Blackwell Scientific Publications, Boston, MA.
Bradstreet, M.S.W., Finley, K.J., Sekerak, A.D., Griffiths, W.B., Evans, C.R., Fabijan, F.F.,
Stallard, H.E., 1986. Aspects of the biology of Arctic Cod (Boreogadus saida) in
arctic marine food chains. Canadian Technical Report of Fisheries and Aquatic
Sciences 1491.
Britt, L.L., Lauth, R.R., Norcross, B.L., 2013. Distribution of Fish, Crab and Lower
Trophic Communities in the Paired Catch Comparisons from Two Standard
Bottom Trawls Used in Arctic Surveys. Draft Report to Department of the
Interior Bureau of Ocean Energy Management.
Brown, E.D., 2002. Life history, distribution, and size structure of Pacific Capelin in
Prince William Sound and the northern Gulf of Alaska. ICES Journal of Marine
Science 59, 983–996.
Brown, A.L., Busby, M.S., Mier, K.L., 2001. Walleye Pollock Theragra chalcogramma
during transformation from the larval to juvenile stage: otolith and osteological
development. Marine Biology 139, 845–851. http://dx.doi.org/10.1007/
s002270100641.
Chiperzak, D.B., Saurette, F., Raddi, P., 1995. First Record of Greenland Halibut
(Reinhardtius hippoglossoides) in the Beaufort Sea (Arctic Ocean). Arctic 48, 368–
371.
Cotton, S.S.D., 2012. Subsistence Salmon Fishing in Beaufort Sea Communities. MSc
Thesis. University of Alaska Fairbanks.
Craig, P.C., 1984. Fish use of coastal waters of the Alaska Beaufort Sea: a review.
Transactions of the American Fisheries Society 113, 265–282.
Craig, P.C., Haldorson, L., 1981. Beaufort Sea barrier island-lagoon ecological process
studies: final report, Simpson Lagoon. In: Environmental Assessment of the
Alaskan Continental Shelf, vol. 7, Biological Studies. Bureau of Land
Management, NOAA Outer Continental Shelf Environmental Assessment
Program, Boulder, Colorado.
Craig, P.C., Griffiths, W.B., Haldorson, L., McElderry, H., 1982. Ecological studies of
Arctic Cod (Boreogadus saida) in Beaufort Sea coastal waters, Alaska. Canadian
Journal of Aquatic and Fisheries Sciences 39, 395–406.
Day, R.H., Weingartner, T.J., Hopcroft, R.R., Aerts, L.A.M., Blanchard, A.L., Gall, A.E.,
Gallaway, B.J., Hannay, D.E., Holladay, B.A., Mathis, J.T., Norcross, B.L., Questel,
J.M., Wisdom, S.S., 2013. The offshore northeastern Chukchi Sea, Alaska: a
complex high-latitude ecosystem. Continental Shelf Research 67, 147–165.
Elsevier. http://dx.doi.org/10.1016/j.csr.2013.02.002.
Doyle, M.J., Busby, M.S., Duffy-Anderson, J.T., Picquelle, S.J., Matarese, A.C., 2002.
Early life history of Capelin (Mallotus villosus) in the northwest Gulf of Alaska: a
historical perspective based on larval collections, October 1977–March 1979.
ICES Journal of Marine Science 59, 997–1005.
Dunn, J.R., Matarese, A.C., 1987. A review of early life history of Northeast Pacific
gadoid fishes. Fisheries Research 5, 163–184.
Dunton, K.H., Weingartner, T., Carmack, E.C., 2006. The nearshore western Beaufort
Sea ecosystem: circulation and importance of terrestrial carbon in arctic food
webs. Progress in Oceanography 71, 362–378.
131
Farley, E.V., Murphy, J., Moss, J., Feldman, A., Eisner, L.B., 2009. Marine ecology of
western Alaska juvenile salmon. In: Krueger, C.C., Zimmerman, C.E. (Eds.),
Pacific Salmon: Ecology and Management of Western Alaska’s
Populations. American Fisheries Society Symposium 70, Bethesda, Maryland,
pp. 307–329.
Frost, K.J., Lowry, L.F., 1981. Distribution, growth, and foods of Arctic Cod
(Boreogadus saida) in the Bering, Chukchi and Beaufort Seas. Canadian Field
Naturalist 95, 186–191.
Frost, K.J., Lowry, L.F., 1983. Demersal fishes and invertebrates trawled in the
northeastern Chukchi and western Beaufort seas 1976–1977. NOAA Technical
Report NMFS SSRF-764. U.S. Department of Commerce.
Gallaway, B.J., Norcross, B.L., 2011. A synthesis of diversity, distribution, abundance,
age, size and diet of fishes in the lease sale 193 area of the Northeastern Chukchi
Sea. Final Report Prepared for Conoco Phillips Alaska Inc, Shell Exploration &
Production Company and Statoil USA E & P Inc.
George, J.C., Moulton, L.L., Johnson, M., 2009. A Field Guide to the Common Fishes of
the North Slope of Alaska. North Slope Borough, Dep. Wildl. Manage. P.O.
Box 69, Barrow, Alaska.
Graham, M., Hop, H., 1995. Aspects of reproduction and larval biology of Arctic Cod
(Boreogadus saida). Arctic 48, 130–135.
Griffiths, W.B., Dillinger, R., 1981. Beaufort Sea barrier island-lagoon ecological
process studies: final report, Simpson Lagoon. Part 5. Invertebrates. In:
Environmental Assessment of the Alaska continental Shelf: Final Reports of
Principal Investigators. BLM/NOAA, OCSEAP, Boulder, CO. pp. 1–198.
Gunderson, D.R., Ellis, I.E., 1986. Development of a plumb staff beam trawl for
sampling demersal fauna. Fisheries Research 4, 35–41.
Hinckley, S., 1984. The reproductive biology of Walleye Pollock Theragra
chalcogramma in the Bering g Sea, with reference to spawning stock structure.
Fishery Bulletin 85, 481–498.
Holladay, B.A., Chernova, N.V., Mecklenburg, C.W., Norcross, B.L., Voronina, E.P.,
2004. Spatial and temporal variability in fish communities of the Chukchi Sea,
2004–2012 (unpublished data).
Hollowed, A.B., Planque, B., Loeng, H., 2013. Potential movement of fish and
shellfish stocks from the sub-Arctic to the Arctic Ocean. Fisheries
Oceanography. http://dx.doi.org/10.1111/fog.12027.
Ianelli, J.N., Honkalehto, T., Barbeaux, S., Kotwicki, S., Aydin, K., Williamson, N.,
2013. Assessment of the walleye pollock stock in the Eastern Bering Sea. In:
Stock Assessment and Evaluation Report for the Groundfish Resources of the
Bering Sea/Aleutian Islands Regions. North Pacific Fisheries Management
Council, P.O. Box 103136, Anchorage, Alaska, 99510.
Irvine, J.R., Macdonald, R.W., Brown, R.J., Godbout, L., Reist, J.D., Carmack, E.C., 2009.
Salmon in the Arctic and how they avoid lethal low temperatures. North Pacific
Anadromous Fish Commission Bulletin 5, 39–50.
Jarvela, L.E., Thorsteinson, L.K., 1999. The epipelagic fish community of Beaufort Sea
coastal waters, Alaska. Arctic 52, 80–94.
Jeffries, M.O., Overland, J.E., Perovich, D.K., 2013. The Arctic shifts to a new normal.
Physics Today 66 (10). http://dx.doi.org/10.1063/PT.3.2147.
Johnson, S.W., Neff, A.D., Thedinga, J.F., 2005. An Atlas on the Distribution and
Habitat of Common Fishes in Shallow Nearshore Waters of Southeastern Alaska.
NOAA Technical Memorandum NMFS-AFSC-157.
Johnson, S., Thedinga, J., Neff, A., 2009. Invasion by saffron cod Eleginus gracilis into
nearshore habitats of Prince William Sound, Alaska, USA. Marine Ecology
Progress Series 389, 203–212. http://dx.doi.org/10.3354/meps08226.
Johnson, S.W., Thedinga, J.F., Neff, A.D., Hoffman, C.A., 2010. Fish Fauna in Nearshore
Waters of a Barrier Island in the Western Beaufort Sea, Alaska. NOAA Technical
Memorandum NMFS-AFSC-2010.
Lassuy, D.R., 1989. Species Profiles: Life Histories and Environmental Requirements
of Coastal Fishes and Invertebrates (Pacific Northwest). Biological Report Fish
and Wildlife Service 82 TR EL-8.
Logerwell, E.A., Rand, K., Parker-Stetter, S., Horne, J.K., Weingartner, T., Bluhm, B.A.,
2010. Beaufort Sea Marine Fish Monitoring 2008: Pilot Survey and Test of
Hypotheses. Final Report Prepared for Minerals Management Service,
Anchorage.
Matta, M.E., Kimura, D.K., 2012. Age Determination Manual of the Alaska Fisheries
Science Center Age and Growth Program. NOAA Professional Paper NMFS 13.
Mecklenburg, C.W., Møller, P.R., Steinke, D., 2010. Biodiversity of arctic marine
fishes: taxonomy and zoogeography. Marine Biodiversity 41, 109–140. http://
dx.doi.org/10.1007/s12526-010-0070-z.
Moss, J.H., Murphy, J.M., Farley, E.V., Eisner, L.B., Andrews, A.G., 2009. Juvenile pink
and chum salmon distribution, diet, and growth in the Northern Bering and
Chukchi Seas. North Pacific Anadromous Fish Commission Bulletin N, 191–196.
Moulton, L.L., Seigle, J.C., 2012. Surveys of Fish in Elson Lagoon during 1996 and
2009–2010. Barrow, Alaska.
NCAR, 2007. Arctic ice retreating more quickly than computer models project.
Science Daily.
National Marine Fisheries Service (NMFS), 2010. Nearshore Fish Atlas of Alaska.
Metadata available from <http://alaskafisheries.noaa.gov/habitat/FishAtlas/
metadata.pdf>.
Norcross, B.L., Holladay, B.A., Mueter, F.J., 1995. Nursery area characteristics of
pleuronectids in coastal Alaska, USA. Netherlands Journal of Sea Research 34,
161–175.
Norcross, B.L., Brown, E.D., Foy, R.J., Frandsen, M., Gay, S.M., Kline, T.C., Mason, D.M.,
Patrick, E.V., Paul, a.J., Stokesbury, K.D.E., 2001. A synthesis of the life history
and ecology of juvenile Pacific Herring in Prince William Sound, Alaska.
Fisheries Oceanography 10, 42–57. http://dx.doi.org/10.1046/j.1054-6006.
2001.00040.x.
132
E. Logerwell et al. / Progress in Oceanography 136 (2015) 115–132
Norcross, B.L., Holladay, B.A., Mecklenburg, C.W., 2013a. Recent and historical
distribution and ecology of demersal fishes in the Chukchi Sea Planning Area.
Final Report OCS Study BOEM, 2012–2073.
Norcross, B.L., Raborn, S.W., Holladay, B.A., Gallaway, B.J., Crawford, S.T., Priest, J.T.,
Edenfield, L.E., Meyer, R., 2013b. Northeastern Chukchi Sea demersal fishes and
associated environmental characteristics, 2009–2010. Continental Shelf
Research 67, 77–95.
Norcross, B.L., Holladay, B.A., Walker, K.L., Edenfield, L.E., 2015. Chapter 3.1. Lengthweight-age relationships of demersal fishes on the shelf of the Alaskan Beaufort
Sea, In: Central Beaufort Sea Marine Fish Monitoring, Final Report, OCS Study,
BOEM 2015.
Outer Continental Shelf Environmental Assessment Program (OCSEAP), 1990.
Comprehensive Bibliography. Anchorage, AK.
Parker-Stetter, S.L., Horne, J.K., Weingartner, T.J., 2011. Distribution of Arctic Cod
and age-0 fish in the U.S. Beaufort Sea. Polar, doi: DOI 10.1007/s00300-0111014-1.
Posgay, J.A., Marak, R.R., 1980. The MARMAP Bongo Zooplankton samplers. Journal
of Northwest Atlantic Fishery Science 1, 91–99. http://dx.doi.org/10.2960/
J.v1.a9.
Proshutinsky, A., Timmermans, M.-L., Ashik, I., Beszczynska-Moeller, A., Carmack, E.,
Eert, J., Frolov, I., et al., 2011. Arctic Report Card: Update for 2011. Ocean.
<http://www.arctic.noaa.gov/report11/ocean.html#temperature_salinity>.
Rand, K., Logerwell, E.A., 2010. The first survey of the abundance of benthic fish and
invertebrates in the offshore marine waters of the Beaufort Sea since the late
1970s. Polar Biology 34, 475–488. http://dx.doi.org/10.1007/s00300-010-09002.
Rass, T.S., 1968. Spawning and development of Polar Cod. Rapports et ProcésVerbaux des Réunions du Conseil International pour l’Exploration de la Mer
158, 135–137.
Robards, M.D., Piatt, J.F., Rose, G.A., 1999. Maturation, fecundity, and intertidal
spawning of Pacific Sand Lance in the northern Gulf of Alaska. Journal of Fish
Biology, 1050–1068.
Sekerak, A.D., 1982. Young-of-the-year cod (Boreogadus) in Lancaster Sound and
western Baffin Bay. Arctic 35, 75–87.
Stephenson, S.A., 2006. A review of the occurrence of Pacific salmon (Oncorhynchus
spp.) in the Canadian western Arctic. Arctic 59, 37–46.
Tabery, M.A., Chambers, T.J., Gooda, T.P., Smith, B.A., 1977. A Multi-Purpose
Epibenthic Sampler for Fish Eggs, Larvae, Juveniles and Adults. Texas
Instruments Inc. Ecological Services, Buchanan, NY.
Thedinga, J.F., Johnson, S.W., Neff, A.D., Lindeberg, M.R., 2008. Fish assemblages in
shallow, nearshore habitats of the Bering Sea. Transactions of the American
Fisheries Society 137, 1157–1164. http://dx.doi.org/10.1577/T07-085.1.
Thedinga, J.F., Johnson, S.W., Neff, A.D., Hoffman, C.A., Maselko, J.M., 2013.
Nearshore fish assemblages of the northeastern Chukchi Sea, Alaska. Arctic
66, 257–268.
Timmermans, M.-L., Proshutinsky, A., Ashik, I., Beszczynska-Moeller, A., Carmack, E.,
Frolov, I., Ingvaldsen, R., et al., 2012. Arctic Report Card: Update for 2012. Ocean.
<http://www.arctic.noaa.gov/report12/ocean.html>.
Weingartner, T., 2008. Physical oceanography. In: Hopcroft, R.R., Bluhm, B.,
Gradinger, R. (Eds.), Arctic Ocean Synthesis: Analysis of Climate Change
Impacts in the Chukchi and Beaufort Seas with Strategies for Future Research.
Institute of Marine Sciences, University of Alaska, Fairbanks, AK, pp. 6–17.
Whitehouse, G.A., Aydin, K., Essington, T.E., Hunt, G.L., 2014. A trophic mass balance
model of the eastern Chukchi Sea with comparisons to other high-latitude
systems. Polar Biology 37, 911–939. http://dx.doi.org/10.1007/s00300-0141490-1.
Wilderbuer, T.K., Nichol, D.G., Ianelli, J., 2013. Assessment of the yellowfin sole stock
in the Bering Sea and Aleutian Islands. In: Stock Assessment and Evaluation
Report for the Groundfish Resources of the Bering Sea/Aleutian Islands Regions.
North Pacific Fisheries Management Council, P.O. Box 103136, Anchorage,
Alaska, 99510.
Woodgate, R.A., Weingartner, T., Lindsay, R., 2010. The 2007 Bering Strait oceanic
heat flux and anomalous Arctic sea-ice retreat. Geophysical Research Letters 37.
http://dx.doi.org/10.1029/2009GL041621.