Download Ocean Climate Indicators Status Report: 2015

Ocean Climate Indicators Status Report: 2015
Report to collaborators at
Cordell Bank and Greater Farallones National Marine Sanctuaries
June 2016
Meredith Elliott and Jaime Jahncke
Ocean Climate Indicators Status Report: 2015
June 2016
Point Blue Conservation Science
Meredith Elliott and Jaime Jahncke
Acknowledgements
We would like to thank our partners at Cordell Bank National Marine Sanctuary (Dan Howard
and Danielle Lipski), Greater Farallones National Marine Sanctuary (Maria Brown and Jan
Roletto), and Bill Douros with the West Coast Region, Office of National Marine
Sanctuaries. We also acknowledge U.S. Fish and Wildlife Service and the Farallon National
Wildlife Refuge (Anne Morkill and Gerry McChesney) for partnering with Point Blue to monitor
wildlife on the Farallon Islands, California Department of Public Health (Gregg Langlois) for
contributing phytoplankton data, the Institute of Ocean Sciences (Moira Galbraith) for helping
process zooplankton samples collected during ACCESS cruises, and Ben Saenz for helping
process the acoustics data. The Romberg Tiburon Center for Environmental Studies (with Ryan
Hartnett, under the guidance of Frances Wilkerson) provided nutrient analyses, and the U.C.
Davis Bodega Marine Laboratory (with Catherine Davis, under the direction of Tessa Hill)
conduct ocean acidification monitoring; we are grateful to these academic institutions and staff
for these new avenues of research. Thanks to the crew of the NOAA research vessel Fulmar.
Funders of the ACCESS Partnership include Elinor Patterson Baker Trust Fund, Bently
Foundation, Bonnell Cove Foundation, Boring Family Foundation, California Sea Grant,
California Dept. of Fish and Wildlife, Cordell Marine Sanctuary Foundation, DJ&T Foundation,
Farallones Sanctuary Association, Faucett Catalyst Foundation, Firedoll Foundation, Hellman
Family Foundation, McCaw Family Foundation, Giles W. & Elise G. Mead Foundation, Moore
Family Foundation, National Fish and Wildlife Foundation, Oikonos Ecosystem Knowledge,
Pacific Life Foundation, Resources Legacy Fund Foundation, Restoration Center (NOAA), Richard
Grand Foundation, Office of National Marine Sanctuaries, Thelma Doelger Trust, the Volgenau
Foundation, and Point Blue Anonymous Donors. Results in this report would not be possible
without Point Blue staff, interns and volunteers. The Southeast Farallon sea surface
temperature and sea surface salinity data are provided by the Shore Stations Program with
funding provided by the California Parks and Recreation, Department of Boating and
Waterways, award # CA DPR-C1370020; these data are collected by research personnel with
Point Blue Conservation Science.
Suggested Citation, and website link
Elliott, M. L. and J. Jahncke. 2016. Ocean Climate Indicators Status Report: 2015. Unpublished
Report. Point Blue Conservation Science, Petaluma, California.
http://accessoceans.org/uploads/Ocean_Climate_Indicators_Report_2015.pdf
For further information contact the director of the California Current Group at
[email protected] or Point Blue Conservation Science, 3820 Cypress Drive #11,
Petaluma, CA, 94954.
Point Blue Conservation Science – Point Blue’s 140 staff and seasonal scientists
conserve birds, other wildlife and their ecosystems through scientific research and
outreach.
At the core of our work is ecosystem science, studying birds and other
indicators of nature’s health. Visit Point Blue on the web www.pointblue.org.
Executive Summary
Physical ocean climate indicators illustrated anomalously warm water conditions for 2015.
Different sources of sea surface temperature were unanimously high for the year, showing a
brief period (April-May) of cold surface waters. Sea surface salinity values were normal,
nutrient concentrations were low, and sea surface heights were anomalously high the entire
year, suggesting downwelling conditions and resulting in lower than average productivity.
Alongshore winds were relatively weak in the early months of the year. Upwelling indices were
mixed depending on the source, showing relatively normal upwelling (on a regional scale) and
downwelling (on a local scale). Spring transition date was average. All basin-wide climate
indices also showed warm water conditions. The Southern Oscillation Index (SOI) showed
neutral to warm conditions in the early months (January-April) followed by warm waters for the
rest of the year. The Pacific Decadal Oscillation (PDO) index indicated anomalously warm water
conditions for the North Pacific Ocean, while the North Pacific Gyre Oscillation showed warm,
less productive waters through the year.
We show new results on aragonite saturation and hypoxia for years 2010-15. Aragonite
saturation state was low (i.e. indicating acidic, corrosive conditions for calcifying organisms) for
most depths and years, and low oxygen waters were noted in deeper waters (below 120 m) for
most years.
Biological ocean climate indicators echo results from the physical indicators. Starting at the
base of the marine food web, phytoplankton abundance (as indicated by chlorophyll a
concentrations) showed non-consecutive peaks in the first half of the year, followed by low
phytoplankton densities for the latter half of the year. While we do not have 2015
phytoplankton community results for 2015 yet, 2014 samples (another warm-water year)
consisted mostly of diatoms; this result is confounding, as this normally indicates productive
ocean conditions.
Zooplankton community composition results are not yet available for 2013-15; we show results
from 2004-2012. Results from 2011 reflect productive ocean conditions on most zooplankton
taxa, with increased abundances of most groups compared to warm, poor productivity years
(e.g. 2004-06), particularly for euphausiids and copepods. However, preliminary results from
2012 show a decline in the abundances of common zooplankton groups. Intra-annual results
generally show increasing zooplankton abundance in spring, peak abundance in June, and a
decline in fall. Analyses of zooplankton samples show two main clusters of abundance levels:
the first three years (2004-06, warm water years), and the next six years (2007-12, cold water
years).
We examined copepods, pteropods, and euphausiids in more detail, as these are important
low- to mid-trophic level species in the ecosystem. Copepod species composition results to date
indicate large increases in the abundance of boreal copepods (i.e., species from northern
latitudes which are generally considered better prey based on their larger size and greater lipid
content) during cold, productive ocean conditions. Copepod species common to mid-latitudes
also became more abundant in cold water years, although not as dramatically. Equatorial
copepods (i.e., copepods from southern latitudes which are smaller and have less lipid content)
increased in abundance in the September cruises some years. However, declines in all
copepods are evident in preliminary results for 2012. Within year results for the copepod
groups generally showed peak abundances of boreal copepods in June, while the other
copepod groups showed highest abundances in the fall. Pteropod abundance has remained
relatively low throughout our time series, with significant increases in 2011-12. Euphausiid
biomass (as measured by acoustics) appears to peak in late summer (July) in most years. Adult
euphausiids, which are larger and higher in lipid content than their younger counterparts,
dominate the zooplankton samples during cold water years; however, warm water conditions
shows a decline in the percentage of adult stages. Additionally, adult euphausiids are larger in
cold water years (e.g. 2007-13) and smaller in warm water years (e.g. 2014-15).
The top-level predators in our region are represented by three resident breeding seabirds and
two migrant whales. Cassin’s auklet, a zooplanktivorous seabird, was observed foraging close to
SEFI in 2015; the average egg laying date was slightly later for this species, and it experienced
average productivity. An omnivorous seabird species, the common murre, foraged across the
shelf and in nearshore waters in 2015, started breeding a little late, experienced near-average
breeding success, and consumed rockfish and anchovy/sardine. Brandt’s cormorants are
piscivorous and were observed in low numbers near SEFI and in nearshore waters in 2015. This
species had a slightly later start to breeding, experienced near-average productivity (contrary to
recent years of low breeding success), and consumed mostly rockfish and sculpin species in
2015.
For marine mammals in 2015, humpback whales were observed in higher numbers in the June
and July cruises; they were spotted between SEFI and Cordell Bank in June, then north of
Cordell Bank in July. Blue whales were observed near SEFI in June 2015, then near the shelf
break north of Cordell Bank in July. September counts for these two species were lower yet
consistent with recent annual trends. Despite the record high densities of blue whales in the
region, euphausiid densities were very low.
Introduction
The Applied California Current Ecosystem Studies (ACCESS) is a partnership between a nonprofit science organization, Point Blue, and a Federal agency, NOAA, to inform management in
support of marine wildlife conservation in central California, including Cordell Bank National
Marine Sanctuary (CBNMS), Greater Farallones National Marine Sanctuary (GFNMS), and the
northern portion of Monterey Bay National Marine Sanctuary (MBNMS; Figure 1). We conduct
coordinated private and government research at an ecosystem scale to support management of
a healthy marine ecosystem in the region. This includes integrated, collaborative, and multidisciplinary research to monitor distribution, abundance and demography of marine wildlife in
the context of underlying physical oceanographic processes.
Data collected by ACCESS is used to inform effective management and conservation of
resources in national marine sanctuaries. Some of the main potential issues we aim to address
include 1) Wildlife Conservation (improve conservation of marine wildlife and their food webs),
2) Ocean Zoning (guide human uses to provide protection of the marine ecosystem), 3) Climate
Change (document effects on the ecosystem and inform climate-smart conservation), 4) Ocean
Acidification (document changes in water properties and assess biological responses), and 5)
Ecosystem Indicators (use long-term data to inform ecosystem-based management
approaches).
ACCESS is a long-term monitoring project with proven applicability to urgent management
concerns and at the same time has been adaptable to emerging issues and changes in
jurisdictions. In June 2015, NOAA expanded the boundaries of CBNMS and GFNMS, which
more than doubled the size of both sanctuaries by extending boundaries north to Manchester
Beach in Sonoma County (for GFNMS) and west to include important subsea features such as
the deep depths of the continental slope (for CBNMS). In 2014, four survey lines were added to
the proposed expansion area, now part of the sanctuaries, to collect baseline information in the
northern areas, and these lines continued as part of the ACCESS sampling grid in 2015.
The purpose of this report is to inform managers and policy-makers about wildlife responses to
changes in ocean conditions and to make this information available to other researchers and
the public. We present data collected during the ACCESS at-sea surveys which have been
conducted 3-4 times a year since 2004. These data include phytoplankton composition,
zooplankton composition, euphausiid abundance from hydroacoustics, and at-sea observations
of seabirds and marine mammals. We have also compiled a variety of datasets to look at longterm trends; these include climate and upwelling indices, sea surface temperature and salinity
measured from the Farallon Islands, buoy data (winds, sea surface temperature), satellite data
(sea surface temperature and height, and phytoplankton abundance), and seabird data
(productivity and timing of breeding) on Southeast Farallon Island. While some datasets have
been updated through this year, not all 2015 data are available. We have shown here what we
could obtain at the time we released this report, up to and including the 2015 field season for
some metrics.
This reporting effort builds off the report Ocean Climate Indicators: A Monitoring Inventory and
Plan for Tracking Climate Change in the North-central California Coast and Ocean Region
(Duncan et al 2013) (http://farallones.noaa.gov/manage/climate/pdf/GFNMS-IndicatorsMonitoring-Plan-FINAL.pdf), which was used to help prioritize indicators for monitoring and to
include in this report. Other indicators (e.g., basin-scale climate indices, sizes of euphausiids,
at-sea distributions of seabirds and marine mammals) that were readily available and provide a
more comprehensive picture of regional ocean conditions were also included. The information
we collect is available upon request and will be available to collaborators as part of the
California Avian Data Center (http://data.prbo.org/cadc). The report is available at
accessoceans.org and sanctuarysimon.org.
Figure 1. Applied California Current Ecosystem Studies (ACCESS) study area.
Sea surface temperature
Overview
Sea surface temperature (SST) is an indicator of the productivity of the ecosystem, as cold,
nutrient rich water is brought to the surface during upwelling in early spring, which influences
productivity. The surface waters eventually warm up during relaxation events that follow
upwelling, typically in late summer or early fall. We used buoy and Southeast Farallon Island
data for local observations, and satellite data (covering a 4 km2 area) were used for a more
regional perspective on SST. Each of these datasets shows an intra-annual pattern in SST: a
decline during upwelling (March-May), then increasing SSTs through September (which is the
peak SST for the year), followed by another decline.
Buoy data
SSTs in 2015 were anomalously warm (i.e. large positive red bars) for most of the years
(Figure 2). SSTs were close to average values in the early months of 2004. In 2005 and 2006,
anomalously warm SSTs were observed in the winter and spring months. In contrast, low SSTs
(i.e. negative blue bars) were noted in most months of years 2007-13; short periods of
average or warm waters (e.g. late months of 2008, early months of 2010) suggest local
downwelling/relaxation events. The recent warm water event began in mid-2014 and
remained high through 2015.
Southeast Farallon Island data
SST data collected near Southeast Farallon Island (SEFI) shows warm (i.e., positive red bars)
temperatures observed throughout most of 2015 (Figure 3). Short upwelling events defined
by cold waters (i.e. negative blue bars) were observed in 2004, but most values were closer
to the long-term averages. Warm SSTs were observed throughout 2005-06 and 2014-15.
Conversely, cold SSTs were observed throughout the early months of 2007-09, late 2010, and
2012-13. Cold temperatures appeared late (April and May) in 2010. SSTs in 2011 were normal
to warm for most of the year.
Satellite data
Satellite results shows warm (i.e., positive red bars) SSTs during most of 2014-15 (Figure 4).
Temperatures in 2004 through mid-2005 were consistently warm; this differs from the buoy
and SEFI data, as these other data show periods of cold (i.e., negative blue bars), upwelled
water at the surface. Similar to buoy and SEFI results, 2006 had warmer SSTs in the first half
of 2006, and cold SSTs in the first half of years 2007-09. Warm waters in the early months
and cold waters in the later months of 2010 are also consistent with other SST results. SSTs in
2011 were average, while 2012 and 2013 showed mostly cooler SSTs.
Data source: http://www.ndbc.noaa.gov/station_history.php?station=46013, with
additional data from: http://www.ndbc.noaa.gov/station_history.php?station=46026,
http://www.ndbc.noaa.gov/station_history.php?station=46012,
http://bml.ucdavis.edu/boon/cordell_bank_buoy.html
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Figure 2. Monthly anomalies of SSTs, Bodega buoy, 2004–15.
Black lines represent ±99% confidence intervals around the long-term monthly means.
Data source: http://shorestation.ucsd.edu/active/index_active.html#farallonstation
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Figure 3. Monthly anomalies of SSTs, SEFI, 2004-15.
Black lines represent ±99% confidence intervals around the long-term monthly means.
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Data source: http://oceancolor.gsfc.nasa.gov/
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Figure 4. Monthly anomalies of SSTs, MODIS Aqua satellite, 2004-November 2015.
Black lines represent ±99% confidence intervals around the long-term monthly means.
Sea surface salinity, ocean acidification, and hypoxia
Overview
Sea surface salinity values are also used as indicators of upwelling, as high sea surface
salinities can be a sign of nutrient inputs from deeper waters.
Two climate change-related phenomena have become issues of concern for our coastal
oceans: ocean acidification and hypoxia. Rising concentrations of atmospheric carbon dioxide
(CO2) have led to an increase in the amount of CO2 dissolved in the world’s oceans, which has
decreased ocean pH (acidifying the water) and also led to decreased concentrations of
carbonate and bicarbonate ions, important building blocks for calcium carbonate shells.
Ocean acidification is typically monitored through investigating changes in the aragonite
saturation state, which is the measure of the soluble form of calcium carbonate and used by
many marine calcifying organisms, and is reported on an Omega scale (Ω). An aragonite
saturation state of 1 or above is favorable to shell building for calcifying organisms; less than
one is considered not favorable for shell building. Building on work developed for other
regions of the west coast (Juranek et al., 2009; Alin et al., 2012), Catherine Davis and Tessa Hill
(UC Davis, Bodega Marine Lab) worked with ACCESS to mathematically derive aragonite
saturation state for the local region using easily-measured properties of the water:
temperature, salinity, and dissolved oxygen. The working relationship is still preliminary with
further sampling and verification of this regional saturation state relationship needed and
planned on future ACCESS cruises.
Hypoxia is defined as an incidence of low oxygen waters, particularly < 2 mg/L of dissolved
oxygen. These low oxygen conditions are of concern for marine species, especially in benthic
habitats where organisms may be less mobile or unable to move to areas with sufficient
oxygen. Commercially-important fisheries (e.g. Dungeness crab) are at risk from finding dead
crabs in their pots (as seen off Bodega Bay and Half Moon Bay in 2015; J. Jahncke, pers.
comm.) and losing millions of dollars from hypoxia events. There is a need for broad scale
oxygen monitoring in northern California. With dissolved oxygen data collected during CTD
casts during ACCESS cruises since 2010, we hope to contribute to the understanding of when
and where these hypoxic events occur.
Southeast Farallon Island data
Sea surface salinity data from SEFI in the first half of 2015 showed high but not anomalous
salinity values (i.e. the positive blue bars); the second half of 2015 had low salinity values (i.e.
the negative red bars; Figure 5). Low salinity values (i.e. the negative red bars) were evident
in 2004-06, indicating weak upwelling conditions. Anomalously high salinity values were
observed in early months of 2007-09 and 2012. Salinity values in 2010-11 were average,
indicating a lack of strong upwelling events in the early months of these years. Conversely,
2012-14 had high salinity values in the early months, suggesting upwelling during this time.
Aragonite saturation state
Calculated aragonite saturation state from variables measured from CTD casts west of Cordell
Bank during September cruises showed low aragonite saturation (< 1.0 Ω) throughout the
water column (Figure 6). Only surface waters (~40 m and above) in 2012, 2013, and 2015
displayed aragonite saturation levels above 1. .
Dissolved oxygen
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Data source: http://shorestation.ucsd.edu/active/index_active.html#farallonstation
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Dissolved oxygen concentrations measured west of Cordell Bank during September cruises
showed hypoxic conditions (< 2 mg/L, shown in red) at depth (Figure 7). We do not have data
at depth in 2015; however, near-hypoxic conditions were noted at ~140 m and deeper in
2012-14. In 2010, hypoxic conditions were observed in shallower locations (~120 m below
the surface).
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Figure 5. Monthly anomalies of sea surface salinity, SEFI, 2004 – October 2015.
Black lines represent ±99% confidence intervals around the long-term monthly means.
Depth (m)
Aragonite saturation state
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Figure 6. Aragonite saturation state measured to 200 m below the surface on
September ACCESS cruises, line 2, station W, 2010-15.
Depth (m)
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Figure 7. Dissolved oxygen concentrations measured to 200 m below the surface on
September ACCESS cruises, line 2, station W, 2010 and 2012-15.
Winds, upwelling and sea level height
Overview
Upwelling is a wind-driven process where coastal winds blowing parallel to the coast result in
an offshore movement of surface water drawing deep, cold, nutrient-rich waters to the
surface nearshore. The strength and periodicity of upwelling can have a significant effect on
the marine ecosystem; periods of strong upwelling are normally alternated by relaxation
events that allow for the spring bloom to occur. Historically, alongshore winds and upwelling
values increase during the early months (both reaching a maximum in June), then decline
through the remainder of the year. In addition to wind and upwelling indices, sea surface
height is an indicator of upwelling conditions. When sea surface height is low, this is an
indication that winds have pushed surface waters offshore and upwelling is occurring.
Winds
Strong winds (i.e. negative blue bars), measured locally at the NOAA buoy 46013, were
evident in early (January-April) and late (September-December) months of 2015, while the
middle of the year (May-August) showed relaxed conditions (i.e. positive red bars; Figure 8).
There was moderate alongshore wind activity in 2004, followed by a lack of alongshore winds
in 2005-06. Strong, upwelling-producing winds are clearly visible in the early months of 200709. Alongshore winds in 2010 appeared to weaken, with some strong wind activity in MayJune and November. Winds continued to be moderate to weak throughout most of 2011-12,
with periods of stronger winds observed in the early and later months of these years.
Stronger alongshore winds were observed in 2013, with a relaxation event during the
summer months. Alongshore winds in 2014 were weak, with strong winds observed in Jan
and May.
Upwelling
NOAA Pacific Fisheries Environmental Lab regional upwelling indices show moderate
upwelling conditions (i.e. positive blue bars) throughout 2015, with downwelling (i.e.
negative red bars) only evident in July-August (Figure 9). Intermittent upwelling and
downwelling (i.e. negative red bars) events were noticed in the early months of some years
(e.g. 2004, 2011), while upwelling was weak and delayed in 2005-06 and 2010. Strong
upwelling conditions were found in the early months of 2007-09, followed by relaxation
events. Strong upwelling was noted in most of 2012 and 2013, while upwelling weakened in
2014. In contrast, measurements from a local buoy in 2015 indicate mostly downwelling
conditions through Aug, followed by upwelling conditions for the remainder of the year
(Figure 10). This buoy may be capturing localized conditions not observed in the monthly
indices.
Satellite data
Sea surface height measured from satellites throughout 2015 was higher (i.e., positive red
bars), suggesting downwelling conditions during this period (Figure 11). Higher than average
heights were observed in 2004-06, indicating downwelling or relaxation conditions. From
early 2007 through the first half of 2009, sea surface height declined (i.e., negative blue
bars), suggesting upwelling in the region. Downwelling conditions returned in mid-2009, then
switched to upwelling in mid-2010, which persisted through February 2011. Weak relaxation
conditions returned in May-September 2011, then weak upwelling conditions dominated the
remainder of the year and into 2012. Weak upwelling was followed by weak downwelling in
both 2012 and 2013. Sea surface heights have been anomalously high since late 2013.
Data source: http://www.ndbc.noaa.gov/station_history.php?station=46013
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Figure 8. Monthly anomalies of alongshore winds, 2004–15.
Black lines represent ±99% confidence intervals around long-term monthly means. Red
bars indicate weak winds, and blue bars indicate strong winds.
Data source: http://www.pfeg.noaa.gov/products/PFEL/modeled/indices/upwelling/NA/upwell_menu_NA.html
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Figure 9. Monthly anomalies of regional upwelling indices, 2004 –15.
Black lines represent ±99% confidence intervals around long-term monthly means. Red
bars indicate downwelling, and blue bars indicate upwelling.
Data source: http://www.ndbc.noaa.gov/station_history.php?station=46013
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Figure 10. Monthly anomalies of local upwelling indices as calculated from the Bodega
buoy data, 2004–15.
Black lines represent ±99% confidence intervals around long-term monthly means. Red
bars indicate downwelling, and blue bars indicate upwelling.
Data source: http://www.aviso.oceanobs.com/en/data/products/index.html
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Figure 11. Monthly anomalies of sea surface heights, Aviso satellite, 2004– November
2015.
Black lines represent ±99% confidence intervals around the long-term monthly means.
Spring transition
Overview
The timing of upwelling can have significant effects on the marine ecosystem. The beginning
of the upwelling season is known as the spring transition date, and earlier spring transition
dates are linked to greater productivity in our regional marine ecosystem. The average spring
transition date is March 29, the earliest date was February 18 (in 2007, a cold water year),
and the latest date was May 11 (in 1983, an El Niño year).
Spring transition
The spring transition date based on daily upwelling values in 2015 was March 28, which is the
average transition date in the time series (Figure 12). Most of the recent years (e.g. 2006-09,
2012-13) showed earlier transition dates (i.e. negative bars) and some years (e.g. 2010) had a
late spring transition (i.e. positive bars). Spring transition dates calculated from Bodega Bay
buoy data since 1981 show similar results as dates calculated from upwelling indices for most
years, including an average date for 2015 (Figure 13). Late transition dates tend to be
associated with El Niño events (e.g. 1983) and early dates with La Niña years (e.g. 2007).
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Figure 12. Anomalies of spring transition dates based on daily upwelling indices, 19722015.
Black lines represent ±99% confidence intervals around 44-year mean. Negative bars
indicate early transition dates, and positive bars indicate late transition dates.
Figure 13. Anomalies of spring transition dates based on Bodega Bay buoy data, 19812015.
Black lines represent ±99% confidence intervals around 35-year mean. Negative bars
indicate early transition dates, and positive bars indicate late transition dates.
Climate Indices
Overview
Several climate indices have been developed to understand climate effects on the basin-level
scale. The Southern Oscillation Index (SOI) is based on differences in mean sea level pressure
anomalies between Tahiti and Darwin, Australia. Negative SOI values indicate warm ocean
conditions related to El Niño, and cold water conditions are shown in positive SOI values. The
Pacific Decadal Oscillation (PDO) shows changes in surface waters in the North Pacific (from
20°N to the pole) at inter-decadal scales. Positive PDO values correspond to warmer ocean
waters in the eastern Pacific, and negative PDO values correspond to cold waters. The North
Pacific Gyre Oscillation (NPGO) measures changes in circulation of the North Pacific gyre, and
is highly correlated with nutrients and overall productivity. Similar to the SOI, negative NPGO
values reflect warm water and poor productivity, while cold water and high productivity
correspond to positive NPGO values.
Southern Oscillation Index (SOI)
SOI values in 2015 showed warm water conditions (i.e. negative red bars) throughout most of
the year (Figure 14). Warm waters were observed from 2004 through the first half of 2007.
Cold water conditions (i.e., positive blue bars) were observed from mid-2007 through early
2009, at which point the SOI changed to negative values again. The SOI remained mostly
negative throughout the later months of 2009 and early 2010, switching to positive values in
March 2010. SOI values in 2011 showed cold water conditions, while values in 2012 were
average to warm. Normal to cool conditions dominated 2013, then switched to warmer
conditions in 2014.
Pacific Decadal Oscillation (PDO)
PDO results for 2015 showed warm water conditions (i.e. positive red bars) for the year
(Figure 15). Warm water conditions dominated the early years of this time series (roughly
2004-07), while cold water conditions (i.e. negative blue bars) were more prominent from
late 2007 through the end of 2009. A brief period of warm water conditions returned in late
2009 and early 2010, then giving way to cold conditions from mid-2010 through 2013. Warm
waters dominated from 2014 to present.
North Pacific Gyre Oscillation (NPGO)
NPGO values for 2015 indicate warm water, poor productivity conditions (i.e. negative red
bars; Figure 16). Warm water, poor productivity conditions were evident throughout 2005
and 2006. Normal values were observed for most of 2009, while cold, productive conditions
6
4
2
0
-2
-4
-6
-8
Data source: http://www.cgd.ucar.edu/cas/catalog/climind/SOI.signal.ascii
Jan
Jun
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May
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Mar
Aug
Jan
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Nov
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Jul
Dec
May
Oct
Mar
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Jan
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Sep
SOI values
(i.e. positive blue bars) were evident in all other years. Similar to the PDO, results for 2013
indicated a warming trend, which has continued to the present.
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
3
2
1
0
-1
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Data source: http://jisao.washington.edu/pdo/
Jan
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Mar
Aug
Jan
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Nov
Apr
Sep
Feb
Jul
Dec
May
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Mar
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May
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Aug
PDO values
Figure 14. Southern Oscillation Index (SOI) values, 2004 –15.
Black lines represent ±99% confidence intervals around the long-term monthly means.
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
3
2
1
0
-1
-2
-3
Data source: http://eros.eas.gatech.edu/npgo/
Jan
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Aug
Jan
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NPGO values
Figure 15. Pacific Decadal Oscillation (PDO) values, 2004–15.
Black lines represent ±99% confidence intervals around the long-term monthly means.
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
Figure 16. North Pacific Gyre Oscillation (NPGO) values, 2004-15. Black lines represent
±99% confidence intervals around the long-term monthly means.
Nutrients
Overview
With the input of nutrients like nitrate, phosphate, and silicon to the surface layers of the ocean
during upwelling, phytoplankton have light from the sun and the necessary components to grow
and reproduce. Phytoplankton need nitrate and phosphate for photosynthesis, while diatoms
use silicon to build their cell walls. Nutrient concentrations can be used to track conditions
conducive to primary production and the productivity of the regional marine ecosystem.
At-sea water sample data
30
NO3+NO2
20
Si
10
0
-10
-20
2005
2006
2007
2008
2009
2010
Sep
Jun
Jul
Sep
May
Jul
Sep
May
Jul
May
Jul
May
Jun
Apr
Jun
Oct
Jun
Oct
Jun
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
Apr
Average [PO4] (µM)
Average [NO3+NO2] and
[Si] (µM)
Surface concentrations of nitrogen-based (NO3+NO2), silicon-based (Si), and phosphate-based
(PO4) nutrients in 2015 were low, continuing the decline that began in mid-2014 (Figure 17).
Other warm-water events (e.g. 2005-06, mid-2009) also showed reduced nutrient
concentrations, while higher concentrations were observed in cold-water conditions (e.g. 200708, early 2009).
2011 2012 2013 2014 2015
Figure 17. Average surface concentrations of and NO3+NO2, Si, and PO4 ACCESS cruises, 200515.
Chlorophyll a and phytoplankton composition
Overview
Concentrations of chlorophyll a can provide information on the amount of phytoplankton in
surface waters. The timing of peak phytoplankton abundance could also have effects on how
productive a marine ecosystem will be. Satellite data provide us with phytoplankton abundance
estimates; long-term monthly means in abundance show increasing phytoplankton abundance in
March-May, a slight decline through September, then a peak in October. Phytoplankton
collected within and adjacent to the Sanctuaries was analyzed by the California Department of
Health to evaluate Harmful Algal Bloom (HAB) species, which also helps us understand the
phytoplankton community composition. Composition of the phytoplankton community can
provide insight into how productive an ecosystem might be. For instance, an increase in the
abundance of dinoflagellates (a small organism) could signify poor ocean conditions, whereas a
greater abundance of diatoms (a larger organism) could indicate more productive ocean waters.
Satellite data
Phytoplankton blooms (i.e. positive anomalies) were observed in most months through Jun 2015
(Figure 18). There is some evidence of peak chlorophyll in the spring and fall months of 2004-06,
but evidence for sustained phytoplankton blooms is lacking in 2007-15. From the oceanographic
results, we might have anticipated seeing anomalously high chlorophyll a concentrations in
2007-09, when upwelling conditions were good. However, blooms are known to occur after the
seasonal thermocline is established, so the peak chlorophyll concentrations in later months (fall
and winter) of 2005 and 2006 could be explained by the delayed upwelling in those years. Strong
upwelling and a lack of relaxation could explain the average to low phytoplankton abundance in
2007-10. Blooms appeared more frequently in 2011 but were relatively small and sporadic,
whereas blooms were relatively non-existent in 2012. Evidence of more substantial
phytoplankton blooms were evident in the early months of 2013-15.
California Department of Health data
Phytoplankton composition results for 2015 are not yet available; however, 2014 was largely
dominated by diatoms, similar to 2012-13 (Figure 19). Other years (e.g. 2006, 2007, 2009 and
2011) showed an increase in dinoflagellates from spring/summer to fall/winter, while other
years (e.g. 2010 and 2012-13) showed low dinoflagellate abundance throughout the year.
Dinoflagellates are most associated with warm, less turbulent waters later in the year (when
diatoms sink and become scarce in surface waters) and are responsible for harmful algal blooms
(e.g. red tides) common in the fall months. Contrary to most years, dinoflagellates were
relatively more abundant than diatoms in the spring/summer of 2008. The greater importance of
diatoms (i.e., the species most associated with cold, turbulent ocean waters) throughout the 10year time series could indicate improved upwelling conditions through time.
Data source: http://oceancolor.gsfc.nasa.gov/
Jan
Jun
Nov
Apr
Sep
Feb
Jul
Dec
May
Oct
Mar
Aug
Jan
Jun
Nov
Apr
Sep
Feb
Jul
Dec
May
Oct
Mar
Aug
Jan
Jun
Nov
Apr
Sep
Monthly anomalies
4
3
2
1
0
-1
-2
-3
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2006
2007
2008
2009
2010
2011
2012
2013
Aug-Feb
Mar-Jul
Aug-Feb
Mar-Jul
Aug-Feb
Mar-Jul
Aug-Feb
Mar-Jul
Aug-Feb
Mar-Jul
Aug-Feb
Mar-Jul
Aug-Feb
Mar-Jul
Aug-Feb
Mar-Jul
Aug-Feb
Aug-Feb
2005
Mar-Jul
diatoms
dinoflagellates
16
14
12
10
8
6
4
2
0
Mar-Jul
Average percent composition
Figure 18. Monthly anomalies of chlorophyll a, MODIS Aqua satellite, 2004 – November
2015. Black lines represent ±99% confidence intervals around the long-term monthly
means.
2014
Figure 19. Average relative composition of diatoms and dinoflagellates in offshore
samples, 2005-14.
Zooplankton composition
Overview
Information on the abundance and species composition of zooplankton are also indicators of
the productivity of an ecosystem. For example, an overabundance of gelatinous species can
signify poor productivity, and a highly productive ecosystem may have high abundances of
euphausiids which are important prey for fish, seabirds, and marine mammals.
Overall relative composition
While 2013-15 data are not yet available, we can see variability in zooplankton abundance
and composition in years 2004-12 (Figure 20). Anecdotal observations of zooplankton
samples taken during 2014 and early 2015 ACCESS cruises appeared to be dominated by
gelatinous zooplankton; small amounts of small euphasiids reappeared in summer 2015 and
larger amounts of larger euphausiids were present in fall 2015. From Sep 2004 through Oct
2006, the overall average abundance of zooplankton is greatly reduced and never reaches
over 30 individuals per cubic meter of water sampled. The trend changed in 2007, when
overall zooplankton abundance increased dramatically, and this overall increase in
zooplankton abundance is sustained for most surveys in 2007 and 2008. This is mainly
attributed to increases in euphausiid and copepod abundance. The first half of 2009 shows
high zooplankton abundance (especially euphausiids and copepods), followed by a return to
low zooplankton densities. Results from 2010 show increasing zooplankton abundances
through the year, with a significant increase (particularly for copepods) in Sep. Zooplankton
increased in abundance considerably in 2011, particularly euphausiids. However, preliminary
results for 2012 reveal a drastic decline in zooplankton. While we do not have samples from
each month of the year, our results show increasing zooplankton abundance in spring, a peak
in Jun, and a decline in fall; however, not all years show this pattern (e.g. 2010, 2011).
Overall community analysis
We looked for similarities between different years based on the zooplankton species
composition data by performing a non-metric multi-dimensional scaling analysis for samples
collected in the spring and summer months (Apr-Jul; Figure 21). In general, there appear to
be two main groups that cluster together: years 2004-06, and years 2007-12. A scattering of
samples in the upper left corner are largely from samples collected in July 2009, and June and
July 2010. Conditions in mid-2009 changed from cold waters to warm waters, which revealed
a change in the zooplankton community (Fontana et al., in review), and this could be one
reason for the departure of these samples from the others in the 2007-12 group.
AMPHIPODS
COPEPODS
DECAPODS
EUPHAUSIIDS
MYSIDS
PISCES
Other
500
400
300
200
100
2004
2005
2006
2007
2008
2009
2010
2011
Sep
Jun
Jul
Sep
Jun
Sep
Jun
Sep
May
Sep
May
Jul
May
Jul
May
Feb
0
Sep
Average abundance (# / m3)
600
2012
Figure 20. Zooplankton composition in the upper 50 m of the water column determined from
hoop net samples, 2004- September 2012.
NOTE: Euphausiid abundances include all life stages except eggs. Data are not complete for 2012.
Figure 21. Non-metric multi-dimensional scaling analysis of zooplankton results, April-July
samples, 2004-12.
NOTE: Data are not complete for 2012.
Copepods
Overview
Copepods are mid-trophic level organisms, and they are the most abundant and diverse
zooplankton taxon, constituting the largest source of protein in the marine environment.
Copepod communities change in response to changing oceanographic conditions, and the
presence and absence of key species can indicate these changes. Copepods that are common to
northern latitudes (called boreal species) become more abundant in colder, productive ocean
waters. Transition zone species are common species to this region, yet they can become more
abundant in colder waters and less abundant in poor ocean conditions. Equatorial species (i.e.,
species from tropical or subtropical regions) can be found during warm water intrusions (e.g., El
Niño events) from southern latitudes.
Relative composition
While we do not yet have data for all years, the results we do have indicate changes in the
copepod species composition, the most notable in the boreal species (Figure 22). These species
were largely absent for the first three years of data (2004-06), and abundance increased
significantly in 2007-08; boreal species declined again in the latter half of 2009, but a dramatic
increase was observed in 2010 and 2011. Preliminary results for 2012 illustrate another sharp
reduction in boreal species. While we do not have samples from each month of the year, our
results for boreal copepods generally show increasing abundances in spring, peak abundance in
Jun, and declining densities in fall, but this varies with ocean conditions (e.g. 2009, 2010).
Species common to mid-latitude areas were in relatively low abundances throughout the time
series, with peaks in abundance in the latter months (especially September) in 2007-08 and
2010-11 (Figure 23). While we do not have samples from each month of the year, our within
year results varied greatly, with peak abundances in Jun for some years (e.g. 2007, 2009) and
September/October for others (e.g. 2005, 2006, 2010, 2011). Equatorial copepods remained in
low abundances throughout the nine years, except for the increases in abundance during Sep
cruises of 2007-09, and 2011; these copepods have, so far, been declining in 2012 samples
(Figure 24).
150
100
50
2004
2005
2006
2007
2008
2009
2010
2011
Jul
Sep
May
Jul
May
Jul
May
Jun
Apr
Jun
Oct
Jun
Oct
Jun
Oct
Apr
0
Jul
Average abundance (# / m3)
200
2012
Figure 22. Average abundances of boreal copepod species, 2004–September 2012.
NOTE: Data are not complete for 2012.
200
150
100
50
2004
2005
2006
2007
2008
2009
2010
2011
Jul
Sep
May
Jul
May
Jul
May
Jun
Apr
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Oct
Jun
Oct
Jun
Oct
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0
Jul
Average abundance (# / m3)
250
2012
Figure 23. Average abundances of transition zone copepod species, 2004–September
2012. NOTE: Data are not complete for 2012.
4
3
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1
2004
2005
2006
2007
2008
2009
2010
2011
Jul
Sep
May
Jul
May
Jul
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Apr
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Oct
Jun
Oct
Jun
Apr
Oct
0
Jul
Average abundance (# / m3)
5
2012
Figure 24. Average abundances of equatorial copepod species, 2004–September 2012.
NOTE: Data are not complete for 2012.
Pteropods
Overview
Pteropods are pelagic marine gastropods and are commonly known as sea butterflies. There are
two orders of these mid-trophic level organisms: Thecosomata and Gymnosomata; the former
contains a shell while the latter does not. One species belonging in the order Thecosomata,
Limacina helicina, has been used to study the effects of ocean acidification. This species’
calcium carbonate shell is sensitive to dissolution in acidic conditions, and shell thickness can be
measured on this species to assess ocean acidification and its effects on the marine
environment. L. helicina has been classified as a key indicator species of ocean acidification for
this region (Duncan et al, 2013).
Abundance
We do not yet have results from 2013-14. However, results we have so far reveal very low
abundances of L. helicina in our region during the first two years of our study (Figure 23).
Increases were first noted in Jun 2006 (which may have coincided with the beginning of the
delayed upwelling in that year). Abundances have remained at low levels since, with dramatic
increases noted in the 2011 cruises. Preliminary results from 2012 reveal very low abundances
of pteropods in June and an increase in July and September. The significance of these results so
far are still being discussed.
5
4
3
2
1
2004
2005
2006
2007
2008
2009
2010
2011
Figure 23. Average abundance of the pteropod Limacina helicina, 2004-12.
NOTE: Data are not complete for 2012.
Sep
Jun
Jul
Sep
Jun
Sep
Jun
Sep
May
Sep
May
Jul
May
Jul
May
Feb
0
Sep
Average abundance (# / m3)
Future work is being planned to measure the shell thickness of this species from the ACCESS
samples.
2012
Euphausiids
Overview
Euphausiids (commonly known as krill) are important mid-trophic level organisms, feeding
mainly on phytoplankton and then becoming prey for many marine top predators (e.g., salmon,
seabirds, and blue and humpback whales). There are two main species found in the study
region: Euphausia pacifica and Thysanoessa spinifera, the former being more abundant than
the latter. Adult and immature stages of these species are known to be the primary prey items
of the Cassin’s auklet, a zooplanktivorous seabird species breeding on the Farallon Islands.
Abundance
Acoustic biomass results show the highest euphausiid biomass in 2015 during June, followed by
a decline for the remaining months of the year (Figure 24). Abundance of euphausiids down to
200 m below the surface were lower in the first 5 years (2004-08) with seasonal peaks in
spring/summer, followed by increased abundance in 2009-13. Euphausiid abundance appeared
to be declining in 2011-14, then increased in 2015. While we do not have samples from each
month of the year, our results indicate annual peaks in euphausiid abundance appeared to shift
from mostly June cruises (2004-08), then July cruises (2009-14), and now back to Jun (2015).
The large 2006 densities are likely due to salps and other gelatinous zooplankton that were
abundant that year, as these species can confound acoustic results.
Euphausiid age classes
Adult E. pacifica were more abundant in Tucker trawl samples (i.e., sampling down to 200 m)
during the June and September cruises of 2015, while younger life stages dominated samples in
Jul (Figure 25). Adult euphausiids were more abundant during the cold, productive conditions
of 2007-08, as well as average conditions in 2010-11, while younger stages dominated during
the warm, less productive conditions observed of 2005-06, and later months of 2009, 2012, and
2014. Despite the warm conditions in 2015, there were more adult euphausiids than might be
expected. Adults were abundant for most of 2010-13, although percentages appear to be
declining through time, with fall cruises (September) usually show higher percentages of the
younger life stages.
Adult euphausiid sizes
Adult E. pacifica caught in Tucker trawls vary in size depending on the ocean conditions of the
year (Figure 26). When we combine results from the cold water years (e.g. 2007-13), the length
frequency distribution peaks at 13 mm and 20 mm. Warm water years (e.g. 2005-06, 2014-15)
show only one peak at 13 mm. Overall, cold conditions result in larger adult euphausiids
compared to warm conditions.
80
60
40
20
2004
2005
2006 2007 2008
2009
Jul
Sep
Jun
Jul
Sep
Jun
Jul
Sep
Jun
Sep
Jun
Sep
May
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May
Jul
May
Jul
May
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Sep
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May
Average density of
euphausiids (g/m2)
100
2010 2011 2012 2013 2014 2015
Figure 24. Acoustic biomass of euphausiids down to 200 m, 2004-15.
2004 2005
2006 2007 2008
zoea
2009
2010 2011 2012 2013 2014 2015
juveniles
immatures
adults
Figure 25. Percent composition of Euphausia pacifica age classes, 2004-15.
0.4
Proportion of E. pacifica adults
Sep
Jun
Jul
Sep
May
Jul
Sep
May
Jul
May
Jul
May
Jun
Apr
Jun
Oct
Jun
Oct
Jun
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Oct
Percent of total wet weight
1.0
0.8
0.6
0.4
0.2
0.0
2005-06
2007-13
0.3
2014-15
0.2
0.1
0
length ranges (mm)
Figure 26. Length frequency distributions for adult Euphausia pacifica caught in
Tucker trawls during spring/summer (May-July), 2005-15.
Birds
Overview
Seabirds are top marine predators that feed on a variety of marine organisms. Some species
breed within our study area, while other species migrate great distances to spend their nonbreeding period in the central California Current. The abundances and distributions of marine
birds have been linked to bathymetric and hydrographic features which aggregate prey;
many seabirds live in or travel to the central California Current because of the highlyproductive waters common to the region.
Relative composition
There were a total of 56 species of seabirds identified during at-sea cruises (Table 1). When
looking at the top ten most abundant seabird species, six of these are known to breed on SEFI
or other areas within the central California Current. Sooty and pink-footed shearwaters
overwinter in the study area, while phalarope species can be found here as they make their
way from their Arctic breeding grounds to tropical waters for the non-breeding period.
The next few sections will concentrate on the information available on some of these
abundant species, particularly three species which breed on SEFI: common murre, Cassin’s
auklet, and Brandt’s cormorant.
Table 1. Seabird species and average densities per cruise, 2004-15.
Common Name
common murre
sooty shearwater
Cassin's auklet
pink-footed shearwater
western gull
Brandt's cormorant
rhinoceros auklet
red-necked phalarope
unidentified phalarope
California gull
ashy storm-petrel
northern fulmar
black-footed albatross
fork-tailed storm-petrel
pigeon guillemot
red phalarope
unidentified gull
Buller's shearwater
Heermann's gull
unidentified shearwater
black-legged kittiwake
pelagic cormorant
black storm-petrel
brown pelican
Average density
(number of animals
observed per km2 of
survey area)
17.912
10.542
8.762
1.394
1.300
1.010
0.867
0.740
0.550
0.352
0.337
0.281
0.233
0.229
0.210
0.184
0.106
0.090
0.052
0.046
0.034
0.029
0.023
0.021
tufted puffin
Sabine's gull
Pacific loon
unidentified alcid
Bonaparte's gull
0.018
0.017
0.014
0.012
0.012
unidentified dark shearwater
Scripps's murrelet
short-tailed shearwater
pomarine jaeger
Arctic tern
surf scoter
unidentified auklet
double-crested cormorant
flesh-footed shearwater
glaucous-winged gull
0.011
0.010
0.010
0.008
0.007
0.005
0.005
0.003
0.003
0.003
Common Name
ancient murrelet
unidentified storm-petrel
common loon
elegant tern
South Polar skua
Laysan albatross
parasitic jaeger
Thayer's gull
unidentified loon
mottled petrel
red-throated loon
Wilson's storm-petrel
black scoter
herring gull
Average density
(number of animals
observed per km2 of
survey area)
0.003
0.002
0.002
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
Cassin’s auklet
Brief species account
The Cassin’s auklet is a small burrowing seabird that breeds on the Farallon Islands. This is a
zooplanktivorous species, with the majority of their diet consisting of euphausiids.
Abundance
In 2015, the highest number of Cassin’s auklets (376 auklets) was observed in July (Figure 27).
The highest number of Cassin’s auklets in the time series was found in May 2004 (2683
auklets). After this, less than half this peak number was observed in any cruise. In general,
counts were higher during the breeding season (March-August). The lowest number of
auklets was found in 2006, the year with delayed and weak upwelling conditions. Numbers
rebounded to some degree in 2009-14. Intra-annual results track the euphausiid acoustic
results, with peak numbers occurring during Jun for most years through 2008, then peak
auklet counts shifted to July for the remaining years.
2500
2000
1500
1000
500
0
May
Sep
Feb
May
Jul
May
Jul
May
Sep
May
Sep
Jun
Sep
Jun
Sep
Jul
Jun
Sep
Jul
Jun
Sep
Jul
Total number observed
3000
2004
2005
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Figure 27. Abundances of Cassin’s auklets observed during each cruise, 2004-15.
Distribution
Cassin’s auklets were observed between SEFI and Cordell Bank in Jun 2015 (Figure 28).
Cassin’s auklets are raising chicks during the months of May and Jun, which is why they were
found close to SEFI in some years (e.g., 2012). While not shown here, poor upwelling years
(e.g. 2005-06) were characterized by smaller auklet flocks, and they ventured farther north
and inland. Improved ocean conditions returned in 2007, and auklets were observed over
Cordell Bank, along the shelf break and closer to SEFI, but not in the large flocks noted in
2004.
2013
2012
2014
2015
Figure 28. Cassin’s auklet distributions during May or June 2012-15.
NOTE: July 2014 is shown here, as the June survey only covered a small area.
Cassin’s auklet
Timing of breeding
The Cassin’s auklet median egg lay date for 2015 was a few days later than the 44-year
average on SEFI (Figure 29). Anomalously late lay dates correspond to El Niño events (e.g.,
1982, 1992, 1998), when ocean conditions were poor. Since 2004, lay dates for Cassin’s
auklets have been average or earlier than the long-term average, with only 2005 (i.e., a poor
ocean condition year) being noticeably later. There is a slight trend towards later lay dates
through the time series, but this is not significant.
Breeding success
Breeding success for the Cassin’s auklet on SEFI was slightly higher than average in 2015,
plotting above the 45-year mean but within the 80% confidence interval (Figure 30). The
anomalously low productivity years have occurred during El Niño years (e.g., 1983, 1992) and
generally correlate with years of later egg laying (Figure 29); years 2005 and 2006 are
exceptions, as these were not El Niño years and lay dates were near the average, but they
were the worse productivity years on record. Surprisingly, the warm water conditions in
2014-15 did not translate to reduced productivity for this species. Conversely, earlier lay
dates (e.g., 2009-13; Figure 29) were linked to better productivity, indicating that an earlier
start to breeding can lead to higher breeding success.
Diet
The 35-year diet time series for Cassin’s auklets is dominated by euphausiids, including 2015
(Figure 31). The diet in 2005-06 deviate greatly from the other years, as mysids (shrimp-like
marine invertebrates) comprised the entire diet of the few diet samples collected in those
years. This also led to breeding failure (Figure 30), revealing the importance of euphausiids in
this species’ diet, as well as the lack of euphausiids in the region during 2005 and 2006. Since
the breeding failures of 2005-06, euphausiids have increased in the auklet diet, and breeding
success has also rebounded. In addition, the size class of euphausiids consumed matters. In
warm water years, adult euphausiids that are consumed by auklets are smaller (Figure 26)
and have less lipid content compared to the larger euphausiids available during cold water
years.
Standardized anomaly (days)
60
40
20
0
-20
-40
-60
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
Figure 29. Cassin’s auklet annual median egg lay dates on SEFI, 1972-2015.
Standardized productivity
anomaly
1.0
0.5
0.0
-0.5
-1.0
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
Figure 30. Cassin’s auklet breeding success anomalies on SEFI, 1971-2015. Solid black line
represents 45-year mean, and dotted red lines represent ±80% confidence intervals.
100%
60%
40%
20%
Other
Pisces
Mysids
Amphipods
2015
2010
2005
2000
1995
1990
1985
1980
1975
0%
1970
Percent by number
80%
Euphausiids
Figure 31. Cassin’s auklet diet composition (through regurgitation analysis) on SEFI, 19712015.
Common murres
Brief species account
The common murre is a frequently-observed seabird in the study region and breeds on the
Farallon Islands. They are an omnivorous seabird feeding mainly on fish, but they also consume
zooplankton.
Abundance
In 2015, common murres were observed in lower abundances compared to 2014, with the
highest number counted in July (Figure 32). Since 2004, the highest number of murres were
seen in July 2010 (2405 murres) and April 2005 (2264 murres). This species was abundant in
2004 and early 2005, then declined in abundance in 2006. Counts of murres gradually
increased over the next few years, followed by a decline since 2010. In general, this species
was present in higher number in spring and summer (i.e., May-Jul, the breeding months) than
in the fall months.
2000
1500
1000
500
2004
2005
2006 2007 2008
2009
Jul
Sep
Jun
Jul
Sep
Jun
Jul
Sep
Jun
Sep
Jun
Sep
May
Sep
May
Jul
May
Jul
May
Feb
Sep
0
May
Total number observed
2500
2010 2011 2012 2013 2014 2015
Figure 32. Abundances of common murres observed during each cruise, 2004-15.
Distribution
In 2015, common murres were observed on the shelf (between SEFI and Cordell Bank), as well
as in nearshore waters (Figure 33). This is similar to most years (e.g., 2004-06, 2008, 2010-11,
not shown; 2012-13, Figure 33). In some years, this species was more dispersed, with more
observations in the northern parts of the study area (e.g., 2005 and 2009, not shown) or
further nearshore to the southeast area of SEFI (e.g., 2007-08, not shown). Note that
distributions shown here represent adult murre distributions; common murre chicks do not
start appearing in the waters of the sanctuaries until July and after.
2013
2012
2014
2015
Figure 33. Common murre distributions during May or June, 2012-15.
NOTE: July 2014 is shown here, as the June survey only covered a small area.
Common murres
Timing of breeding
Median egg laying date in 2015 was 8 days later than the long-term average (Figure 34). Similar
to the Cassin’s auklet, we observed that common murres have later lay dates in poor ocean
condition years (e.g., 1983, 1992, 1998, 2015). Since 2004, the annual median lay date has
hovered close to the long-term mean, with some years showing earlier lay dates (e.g., 2004,
2007, 2008, 2013) and some years showing later dates (e.g., 2005, 2006, 2009-11). There has
been a slight trend in earlier lay dates through time, although this is not significant.
Breeding success
Common murre breeding success in 2015 was just below the 44-year mean (Figure 35). Similar
to the Cassin’s auklet, anomalously low productivity years (e.g., 1983, 1992, 1998) that
punctuate the time series correspond to El Niño years, as well as years with late median lay
dates (Figure 34). However, recent years of extremely low breeding success (i.e., 2006 and
2009) had relatively late median lay dates but were not El Niño years. Earlier lay dates (e.g.,
1988; Figure 34) were linked to better productivity in some years, but this was not consistent;
annual median lay dates for 2006 and 2009 were earlier compared to 2005, yet breeding
success was worse. Some of these discrepancies in lay dates and productivity can be explained
by low feeding rates to chicks, as observed in 2009.
Diet
In 2015, common murre chicks on SEFI were fed mostly juvenile rockfish and anchovy/sardine
(Figure 36). Prey items being brought to common murre chicks have varied over time, with
rockfish being the main diet items in the 1970s and 1980s, then anchovy and sardine becoming
the dominant prey in the 1990s. This changed again in the early 2000s when rockfish became
the dominant prey, then back to anchovy/sardine in the 2004-08 period. Since 2009, rockfish
has been more important in the diet, although anchovy/sardine have become a larger part of
the diet in 2015. Historically, El Niño years corresponded to years with a low percentage of
rockfish in the diet; these were also years of late timing of breeding (Figure 34) and low
breeding success (Figure 35). However, 2005 and 2006 were not El Niño years, yet these years
of poor ocean conditions yielded late breeding, low breeding success, and few rockfish in the
murre diet. The 2009 results have been exceptional, as murres were eating a lot of rockfish, yet
breeding success was one of the lowest years on record; as mentioned previously, low chick
feeding rates can help explain the low productivity in this year.
Standardized anomaly (days)
40
30
20
10
0
-10
-20
-30
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2010
2015
Figure 34. Common murre annual median egg lay dates on SEFI, 1972-2015.
Standardized productivity
anomaly
1.0
0.5
0.0
-0.5
-1.0
1970
1975
1980
1985
1990
1995
2000
2005
Figure 35. Common murre breeding success anomalies on SEFI, 1972-2015.
Solid black line represents 44-year mean, and dotted red lines represent ±80% confidence
intervals.
100%
60%
40%
20%
Other
Anchovy/Sardine
Rockfish
Figure 36. Common murre chick diet composition on SEFI, 1973-2015.
2015
2010
2005
2000
1995
1990
1985
1980
1975
0%
1970
Percent by number
80%
Brandt’s cormorant
Brief species account
Brandt’s cormorants are piscivorous birds found throughout the coastal areas of California. They are
one of the breeding seabirds monitored on SEFI.
Abundance
Since 2008, Brandt’s cormorants were observed in very low numbers, and this trend has continued in
2015 (Figure 37). Numbers of Brandt’s cormorants have declined through the time series, with the
peak in October 2004 (273 cormorants); since this cruise, numbers have been less than half of this
high count. The October 2004 peak was later in the year compared to the high counts of other years,
which generally occurred during the summer months (i.e., the breeding season). The low
abundances observed in 2008-12 correspond to poor productivity for this species in these years
(Figure 38).
250
200
150
100
50
2004
2005
2006 2007 2008
2009
Jul
Sep
Jun
Jul
Sep
Jun
Jul
Sep
Jun
Sep
Jun
Sep
May
Sep
May
Jul
May
Jul
May
Feb
Sep
0
May
Total number observed
300
2010 2011 2012 2013 2014 2015
Figure 37. Abundances of Brandt’s cormorants observed during each cruise, 2004-14.
Distribution
In 2014, Brandt’s cormorants were observed in nearshore waters near San Francisco Bay and the
Point Reyes peninsula, which could be explained by the later season (July) distribution compared to
earlier distributions shown for other years (Figure 38). Brandt’s cormorants have been observed near
SEFI in most other years (Figure 36). In some years, this species was more scattered and observed in
smaller groups or as individual birds in waters closer to shore (e.g., 2007 and 2010 (not shown), and
2012).
2012
2013
2014
2015
Figure 38. Brandt’s cormorant distributions during May or June, 2012-15.
NOTE: July 2014 is shown here, as the June survey only covered a small area.
Brandt’s cormorants
Timing of breeding
The median egg lay date for Brandt’s cormorants on SEFI in 2015 was 9 days later than the 44year average (Figure 39). Timing of breeding in Brandt’s cormorants isn’t as clearly linked to
ocean conditions as in Cassin’s auklets or common murres; El Niño years (e.g., 1983, 1992, and
1998, 2015) do not show anomalously late lay dates. There has been a slight trend in later lay
dates through time, although this is not significant. Since 2004, this species began breeding
early for three years (2004, 2006-07), and then bred late in 2005 and extremely late in 2008-12.
The return to average median egg laying dates in the past three years has corresponded to
improved breeding success (see below).
Breeding success
Breeding success of Brandt’s cormorants on SEFI in 2015 was slightly above the long-term
average (Figure 40). Most of the annual productivity estimates for Brandt’s cormorants fall
within the 80% confidence intervals around the long-term mean, similar to auklets and murres;
however, unlike auklets and murres, Brandt’s cormorants have experienced several years of
extremely low productivity, usually corresponding to El Niño years (e.g., 1983, 1992). In looking
at breeding success data since 2004, above average breeding success was observed in the first
four years (2004-07), then extremely low productivity in 2007-12, very high in 2013-14, and
now closer to average.
Diet
Brandt’s cormorants on SEFI in 2015 consumed almost exclusively rockfish (Figure 41). The diet
of Brandt’s cormorants on SEFI has consisted of forage fishes (i.e., northern anchovy, Pacific
sardine), various benthic species (i.e., sculpins, gobies, rockfish, and flatfish), and cephalopods.
Years with high percentages of anchovy and sardine in the diet (e.g., 1994, 2005-07)
corresponded to years of high productivity, although higher breeding success has also
correlated with high percentages of rockfish (e.g. 2013-14; Figure 40). Recent breeding success
increases may be attributed to the increased abundance of more offshore-distributed rockfish
species which were likely absent during the poor productivity years (Elliott et al. 2015).
Standardized anomaly (days)
40
30
20
10
0
-10
-20
-30
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
Figure 39. Brandt’s cormorant annual median egg lay dates on SEFI,
1972-2015.
Standardized productivity
anomaly
2.0
1.0
0.0
-1.0
-2.0
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
Figure 40. Brandt’s cormorant breeding success anomalies on SEFI,
1971-2015. Solid black line represents 45-year mean, and dotted red lines represent
±80% confidence intervals.
100%
60%
40%
20%
Cephalopods
Anchovy/Sardine
Rockfish/Sculpin
Flatfish
2015
2010
2005
2000
1995
1990
1985
1980
1975
0%
1970
Percent by number
80%
Other
Figure 41. Brandt’s cormorant diet composition on SEFI, 1994-2015.
NOTE: Data for years 1973-77 from Ainley et al. 1981. Years 1999, 2004 and 2006 have
low sample sizes.
Mammals
Overview
Marine mammals are top marine predators that feed on a variety of marine organisms. Some
species breed within our study area, while other species migrate great distances to spend
their non-breeding period in the central California Current. The abundances and distributions
of marine mammals have been linked to bathymetric and hydrographic features which
aggregate prey; many marine mammals live in or travel to the central California Current
because of the highly-productive waters common to the region.
Relative composition
There were 20 species of marine mammals observed during at-sea cruises since 2004 (Table
2). The top fifteen most abundant marine mammal species include two known SEFI residents:
California sea lion and Steller sea lion; both of these species are piscivorous. Risso’s dolphin,
Dall’s porpoise, northern right whale dolphin, and Pacific white-sided dolphin all consume
fish and squid, and are known to inhabit offshore waters. The two whale species (humpback
and blue) are both euphausiid-consuming whales that are common to coastal and shelf
waters.
In the following sections, more detailed information will be provided on the two common
migrant whales observed in the region: humpback whale and blue whale.
Table 2. Marine mammal species and average densities per cruise, 2004-15.
Common
California sea lion
Risso's dolphin
Humpback whale
Pacific white-sided dolphin
Dall's porpoise
northern right whale dolphin
unidentified whale
unidentified otariid
unidentified dolphin
short-beaked common dolphin
blue whale
unidentified pinniped
Steller sea lion
northern fur seal
harbor porpoise
killer whale
northern elephant seal
harbor seal
unidentified cetacean
common minke whale
unidentified porpoise
Guadalupe fur seal
unidentified sea lion
gray whale
common dolphin (undifferentiated)
unidentified seal
sperm whale
fin whale
bottlenose dolphin
Average density (number of animals
observed per km of survey distance)
0.26036
0.13576
0.13294
0.11476
0.09134
0.06549
0.04283
0.02942
0.02092
0.01739
0.01565
0.01366
0.00840
0.00833
0.00654
0.00371
0.00280
0.00193
0.00068
0.00060
0.00050
0.00046
0.00044
0.00039
0.00027
0.00018
0.00010
0.00009
0.00008
Humpback Whale
Brief species account
Humpback whales are found in groups along the coast of western North America. The North
Pacific population spends the summer months along the coast from Alaska to California, moving
west and south (e.g., Hawai’i and Mexico) during the winter. This species feeds mainly on
euphausiids but will also consume fish.
Abundance
Humpback whale abundance in 2015 was slightly higher compared to 2014, with a peak in June
of 78 whales (Figure 42); while peak numbers of this species are typically seen in the fall
(September-October), the warm-water conditions in the region in 2015 may have led to an
earlier peak for these whales (as well as in 2010, 2011, and 2014). The highest number of
humpback whales was sighted in July 2010 with 204 whales. The poor ocean conditions in 200506 could explain why there were relatively fewer whales. The improved conditions in 2007-12
have led to more sightings of this species, while fewer numbers were observed in 2013-14.
200
150
100
50
2004
2005
2006 2007 2008
2009
Jul
Sep
Jun
Jul
Sep
Jun
Jul
Sep
Jun
Sep
Jun
Sep
May
Sep
May
Jul
May
Jul
May
Feb
Sep
0
May
Total number observed
250
2010 2011 2012 2013 2014 2015
Figure 42. Humpback whale abundances, 2004-15.
Distribution
Humpback whales were sighted near the shelf break between SEFI and Cordell Bank in 2015, as
well as nearshore areas outside the entrance to San Francisco Bay (Figure 43). In 2004-06 (not
shown) and 2014, this species congregated on the shelf and near SEFI in earlier months (MayJuly), and then expanded north to Cordell Bank and near the 200 m isobath in the fall
(September-October). In 2007-09 (not shown), the distributions changed; humpback whales
were consistently observed on the shelf throughout the study area, with some aggregations in
inshore areas and near SEFI. In 2010-11 (not shown) and 2012-13, small numbers of this species
were observed in early months (mainly near the shelf break), while greater numbers of whales
were observed over Cordell Bank and on the shelf in later months (Figure 43); 2012 was an
exception, with higher numbers observed in June in nearshore areas.
2012
2014
2013
2015
Figure 43. Humpback whale annual distributions, 2012-15.
Blue Whale
Brief species account
The blue whale is the largest animal on earth, and it feeds on euphausiids (and occasionally
other invertebrates). This species is found in all the oceans, and calves found in tropical and
subtropical waters during winter months. This species is found off the coast of California during
the summer.
Abundance
2004
2005
2006 2007 2008
2009
Jul
Sep
Jun
Jul
Sep
Jun
Jul
Sep
Jun
Sep
Jun
Sep
May
Sep
May
Jul
May
Jul
May
Feb
Sep
28
24
20
16
12
8
4
0
May
Total number observed
The highest number of blue whales in our time series (25) were observed in June 2015 (Figure
44). In contrast, later that year, only 1 blue whale was observed during surveys in September
2015. In most years, blue whales have peaked in abundance in late summer and early fall
months (July-October). The delayed upwelling in 2005 may have led a delay in peak numbers,
and the lack of blue whales in 2006 was evidence to the poor ocean conditions. Despite the
improved conditions in 2007-09, observations of this species remained relatively low, but then
increased in 2010-11; abundances declined in 2011-14.
2010 2011 2012 2013 2014 2015
Figure 44. Blue whale abundances, 2004-15.
Distribution
In 2015, blue whales were observed near SEFI in June, then north of Cordell Bank (near the
shelf break) in July (Figure 45). These results are consistent with most other years. Blue whales
have been found in the northern part of the study area (over Cordell Bank) in 2004-05 (not
shown), and 2013; this species was observed closer to SEFI in 2007, 2009-11 (not shown). Blue
whale sightings were scattered on the shelf in 2012. The sightings for 2014 were similar to
2015, except in fewer numbers of whales.
2012
2014
2013
2015
Figure 45. Blue whale annual distributions, 2012-15.
Blue whales and euphausiid abundance
Annual estimates of blue whale abundance in the core area of our time series (i.e. lines 1-7)
generally follow patterns in the abundance of euphausiids, their main prey, as estimated
through acoustics (Figure 46). Some years agree for predator and prey (e.g. 2007, 2010),
while other years show discrepancies with euphausiids in deeper waters (e.g. 2006) and
euphausiids in shallower waters (e.g. 2013, 2015). Euphausiid estimates for 2006 are likely
unreliable due to the high abundance of jellies, which produce a similar acoustic signal to
masses of euphausiids.
Blue whale density
(individuals/km2)
0.016
0.012
0.008
0.004
Mean euphausiid areal density
(g/m2)
0
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2000
30m krill
1500
200m krill
1000
500
0
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
Figure 46. Blue whale (top) and euphausiid (bottom) densities in the core ACCESS study
area (lines 1-7), 2004-15.
Conclusions
In 2015, the ACCESS partnership completed its 12th year of monitoring, with a total of 43 cruises
to date. While the transition to the upwelling season in 2015 was on-time, warm water
conditions prevailed during the spring and summer. Nutrients and primary production were
low. While the June 2015 acoustics results showed high euphausiid abundance, euphausiids
were smaller and less abundant for the year. The low ocean productivity led to low to moderate
numbers of seabirds observed. Similar to the acoustics results for euphausiids, whale
abundance was highest in June then declined through the remainder of the year.
Although our study region is influenced by localized upwelling, extreme coast-wide events also
have an effect on this region’s productivity. NOAA declared El Niño conditions were present in
March 2015 through spring 2016 (at the time this report was being written). In addition, an
unprecedented warm water event named “The Blob” began in the Gulf of Alaska in 2014 and
extended down the coast of North America to Baja by the summer of 2015. The ACCESS dataset
has illustrated the responses to these conditions through oceanographic measurements,
estimating prey availability, and monitoring the distribution and abundance of top marine
predators. ACCESS data have also captured observations of unusual species (e.g. common
dolphins, which are rarely found north of Southern California), presence species last observed
during the 82/83 El Niño event (e.g. pelagic red crab), and the absence of typical species (e.g.
Pacific white-sided dolphins). In combination with regional efforts documenting other unusual
events (e.g. juvenile common murre die-off, juvenile California sea lion strandings), managers
have used ACCESS data to understand how the marine ecosystem is responding to changing
ocean conditions. ACCESS data help us gauge the severity of large scale phenomena (e.g. The
Blob, El Niño) on our local marine resources.
This dataset demonstrates the importance of long term monitoring to evaluate annual and
interannual trends over variable ocean conditions. Climate change is bringing unprecedented
changes in temperature, sea level rise, and ocean chemistry, making long-term datasets critical
to monitoring changes in marine protected areas, sanctuaries, and beyond.
The ACCESS data is being used to provide timely, relevant ecosystem data for management
issues in our national marine sanctuaries. In recent years, ACCESS data have been used to: 1)
inform ship strike reduction efforts in the San Francisco shipping lanes, resulting in a voluntary
speed reduction request to large ships in 2014 and 2015; 2) help reduce wildlife impacts
(including whale entanglements) by targeting the removal of out-of-season crab pots in 2015;
3) document effects to the ecosystem by the anomalous Pacific Ocean conditions in 2014-15,
including contributing to the regional effort led by NANOOS to document these responses; 4)
develop a regional model to facilitate cost-effective ocean acidification monitoring; and 5) help
determine the extent and magnitude of harmful algal blooms, the cause of the 2015 crab
fishery closure in California. In addition, ACCESS collaborates with local universities (San
Francisco State University, UC Davis), mentors graduate students, and publishes results in peer
reviewed scientific journals.
The ACCESS science team raises awareness of ocean issues and inspires stewardship of marine
resources through the ACCESS website (accessoceans.org), social media
(www.facebook.com/ACCESS.Partnership), and regular outreach activities at local science
museums (The Exploratorium, California Academy of Sciences). Looking ahead, ACCESS will
begin the 13th year of monitoring in 2016 with three cruises planned in May, July, and
September.
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