Download Northern Atlantic cod spawning, nursing, migration, and refuge in

Northern Atlantic cod spawning, nursing, migration, and refuge in Smith Sound
Potentially Harmful Activity (X)
Bottom trawl
Fishing
Scallop dredges
Clam dredges
Midwater trawl
Gillnets (groundfish)
Gillnets (pelagic)
Long line
Scottish seining
Purse seining
Recreational cod fishery
Crab pots
Lobster pots
Whelk pots
Otter trapping
Other
Seal hunt
harvest
Seabird hunt
Seaweed harvest
Anchor drops/drags
Seabed
Ore spill
alteration
Fish offal dumping
Finfish aquaculture
Dredge spoil dumping
Dredging
Mining
Cables
Freshwater diversion
Subtidal construction
Coastal
Intertidal/coastal
alteration
construction
Other (specify)
Vessel traffic
Disturbance Ship strikes
Ecotourism
Marine construction
Seismic surveys
Navy sonar
Other (specify)
X
X
Potentially Harmful Stressor (X)
Oil pollution
Industrial effluent
Marine
Fishplant effluent
pollution
Sewage
Historic military waste
Long range transport of nutrients
Acid rain
Persistent Organic Pollutants (POPs)
Eutrophication
Ghost nets
Litter
Other contaminants (specify)
Ice distribution
Climate
Temperature change
Change
Sea-level rise
Ocean acidification
Current shifts
Increased storm events
Increased UV light
Oxygen depletion
Changes in freshwater runoff
Other (specify)
Green crab
Harmful
Membranipora
species
Golden Star Tunicate
Violet Tunicate
Vase Tunicate
Codium fragile
Clubbed Tunicate
Didemnum
Toxic Algal Blooms
Disease organisms (human waste)
Disease organisms (aquaculture)
Other harmful species (specify)
Other
X
X
X
X
X
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Gillnets (bottom):
Fishing mortality is considered the greatest threat to Smith Sound cod, and there is a risk that
fishing inshore may impede recovery of the entire stock (Fisheries and Oceans Canada,
2008). Following the discovery of dense aggregations of cod in Smith Sound in 1995, a
small (index) fishery directed at these inshore populations was introduced in 1998. Catch
rates declined and the fishery was closed in 2003. Catches during 2004-2005 were limited
mainly to bycatch (>600t) in the winter flounder fishery (Fisheries and Oceans Canada,
2008) and sentinel fisheries. Sentinel catch rates near Trinity Bay (southern 3K and northern
3L) have generally increased since 2002 and are currently above average for the time series.
A directed stewardship fishery was reopened in the inshore in 2006 to replace the index
fishery in 2006. Reported landings from the 2007 stewardship fishery were 2364t. In
addition, 182t were landed in the sentinel fishery. These fisheries largely utilize gillnets.
Bycatch in other directed fisheries, including winter flounder and lumpfish, which utilize
gillnets, are also significant.
Total fishing mortality is estimated at 20% of the biomass (Corey Morris, Biologist, Fisheries
and Oceans Canada, PO Box 5667, St. John’s, NL, A1C 5X1, “pers. comm.”). Stewardship
fishery catch rates in 2006-07 were slightly higher than in earlier fisheries between 1998 and
2002. A pre-recruit index suggests that the strength of the 2003-2006 year-classes will be
much lower than those that have supported recent fisheries (Fisheries and Oceans Canada,
2008). Gillnet fishing is clearly a major source of mortality and has been screened in for
further analysis. Screened in.
Recreational cod fishery:
Historically, cod has been an important part of the diet in Newfoundland, and access to a
winter supply of fish is considered a traditional right which residents took for granted until
the implementation of the groundfish moratorium. As a result, there was intense pressure to
open a food/recreational fishery when dense aggregations of fish were detected in Smith
Sound and adjacent coastal areas in 1995. In response to public pressure, a food fishery was
opened for a number of years, but was closed again in 2003 in response to declining inshore
stocks. The fishery was reopened in 2006.
Only handline and angling gear is permitted. Handlines include baited hooks, feathered
hooks and artificial lures. A maximum of three (3) hooks per line may be used. The season
dates are set each year, typically 3-4 weeks in late July/early August, and an additional 1-2
weeks in late September/early October, for a total of five weeks. Recreational fishers are
limited to five (5) groundfish per day (including cod), and 15 per boat trip.
Estimates of landings from the recreational fishery are variable. The 2007 DFO Survey
(BriLev Consulting Inc., 2008) estimated that anglers caught 1,128,635 fish in the 2007
recreational fishery, with 308,160 in Trinity Bay alone. This suggests that the recreational
catch was equivalent to that of the stewardship fishery (Fisheries and Oceans Canada, 2008),
and may be a significant stressor to Smith Sound cod. Screened in.
Ghost nets:
Ghost nets are fishing gear that have been lost or discarded at sea. Fishing, legal or
otherwise, involves an inherent risk of gear loss. Factors such as weather, currents, tides, sea
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state, depth, fishing intensity, presence of sea ice, the make up of the seafloor, the condition
of the gear, equipment and vessel all contribute to the risk of lost gear (Hareide, N-R. et al.,
2005; The British Ecological Society, 2000).
Since the 1960s, fishing nets have been constructed from highly durable plastic materials
such as nylon, polypropylene and polyethylene, which are largely impervious to
biodegradation- they are resistant to chemicals and abrasion (National Academy of Sciences,
2008). Unlike their natural predecessors, the new materials can last for years or decades in
the marine environment, and lost gear or even torn fragments of netting or line floating in the
sea, can continue to fish for considerable periods (The British Ecological Society, 2000).
Lost gillnets, traps, trawls and line fisheries are considered the most harmful (National
Academy of Sciences, 2008), and of those, gillnets are generally thought to be the most
problematic.
Set bottom gillnets, by virtue of their fixed, anchored framing, may remain fully deployed
and fishing long after they are lost or abandoned. As nets become fouled, they become more
visible, lose their vertical profile and their fishing capacity declines, but limited
investigations have shown that gillnets lost in deepwater (>400m) can fish for years after
they are lost because there is very little bio-fouling or water movement in depths below 400m
(National Academy of Sciences, 2008). Even when nets collapse, forming balls on the sea
floor, they continue to fish. Recent studies of nets on the seabed have shown that a typical
pattern of capture is observed. Over the first few days, catches decline almost exponentially
as the increasing weight of the catch causes the net to collapse. Then for the next few weeks,
the decay of captured animals attracts a large number of scavenger species such as crabs,
lobster and fish. This cycle of capture, decay and attraction continues for as long as the net
retains entanglement properties. Once on the bottom, monofilament nets may, once clear of
fish remains, disentangle, return to an upright position and resume fishing (The British
Ecological Society, 2000).
We have no data on the number of ghost nets in Smith Sound, but data from other areas
indicates that the problem is likely to be significant. The Northwest Straits Commission
estimates that there are nearly 3,900 gillnet remaining in Puget Sound from domestic salmon
fisheries from the 1970s and 1980s. In a recent survey of over 1,000 fish harvesters currently
operating within Placentia Bay, 67% reported experiencing loss of gear (FFAW, 2007), and
both DFO and industry recognized it as a major concern for Atlantic Canadian fish
harvesters. A ghost net retrieval program conducted in Placentia Bay in the 1990s retrieved
sixty ghost nets containing 30,000 lbs of rotting cod, as well as other species. Some 10,000
vessels, mainly small boat, inshore operations, fished monofilament gillnets in Atlantic
Canada prior to the northern cod moratorium. While it is difficult to quantify the amount of
lost gear, studies suggest that some 8,000 active gillnets were lost on average each year for a
number of years up to 1992. In a survey of 100 Atlantic Canada gillnet fish harvesters,
losses averaged 1-3 nets per fisher per year, with the exception of two fishers with vessels
greater than 65 feet that incurred an average loss of 19.2 nets per year (Memorial University
of Newfoundland & Fisheries and Oceans Canada, 1995).
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Gillnets are considered the most problematic gear in relation to fish mortality, and are the
most common gear used in Smith Sound. Smith Sound is a small, narrow, relatively
sheltered area where significant gear loss is unlikely to occur, but any lost gear is likely to
end up in one of the two deep trenches where dense aggregations of cod overwinter, and
significant mortalities could result. Screened in.
Temperature change:
Drinkwater (UNEP & UNFCCC, 2002) predicts a temperature increase of 2-4oC in Southern
Newfoundland waters by 2100 based on IPCC 2001 models. Temperature rise will likely not
be linear, but is expected to accelerate over time. Even given the worst case scenario, an
increase in 0.4oC is likely the most we can expect over the next ten years. Many believe that
temperature shifts were at least partially responsible for the poor recovery of over-fished cod
stocks in the 1990s (Rose, G. A., 2007). Drinkwater states that the range of cod may extend
northward with increasing temperature, and it is likely that spring migrations will occur
earlier, and fall returns will be later (Drinkwater, K. F., 2005). These responses of cod to
future climate changes are highly uncertain, however, as they will also depend on the
changes to climate and oceanographic variables besides temperature, such as stratification,
plankton production, the prey and predator dynamics, and industrial fishing. Temperature
changes are not likely to be significant over the next 10 years, and a small increase of 0.4oC
or less would likely be beneficial to cod in Smith Sound. Screened out.
Increased storm events:
Recent scientific evidence suggests a link between the destructive power, or intensity, of
hurricanes and higher ocean temperatures, driven in large part by global warming. Two
factors that contribute to more intense tropical cyclones, ocean heat content and atmospheric
water vapour, have both increased over the past several decades. As warm, moist air rises, it
lowers air pressure at sea level and draws the surrounding air inward and upward in a rotating
pattern, powering the storm. As the moist air spirals in and rises to higher altitudes, it cools
and releases heat as it condenses to rain (Union of Concerned Scientists, 2006).
Atlantic tropical cyclones are getting stronger on average, with a 30-year trend that has been
related to an increase in ocean temperatures, and are predicted to impact the NW Atlantic at a
high level of intensity relative to other areas of the globe (Elsner, J. B., Kossin, J. P., &
Jagger, T. H., 2008). The years 1995-2000 experienced the highest level of North Atlantic
hurricane activity in the reliable record (Goldenberg, S. B., Landsea, C. W., Mestas-Nunez,
A. M., & Gray, W. M., 2001). The largest increase in hurricanes reaching categories 4 and 5
occurred in the Pacific and Indian Oceans, but the highest increase in the number of cyclones
and cyclone days occurred in the North Atlantic (Webster, P. J, Holland, G. J., Curry, J. A.,
& Chang, H. A., 2005). The relationships between a warming environment and increasing
storm events is complex, and research results and predictions are variable, and more research
is clearly required (Emanuel, K., 2005; Emanuel, K. A., 2000; Goldenberg, S. B., Landsea,
C. W., Mestas-Nunez, A. M., & Gray, W. M., 2001; Webster, P. J, Holland, G. J., Curry, J.
A., & Chang, H. A., 2005).
Increased storm surges can potentially contribute to super-cooling events during severe
winter storms where the motion keeps seawater in a liquid state at temperatures well below -
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2oC and can lead to mass mortalities. A super-cooling event in Smith Sound several winters
ago resulted in mass mortality (~500,000 fish) of overwintering cod. Screened in.
Green crab (Carcinus maenas):
The European green crab is an aggressive and hardy invasive species that has significant
impact on eelgrass beds as a result of their burrowing activity, which has been well
documented in PEI, as well as North Harbour, Placentia Bay. Smith Sound has extensive
eelgrass beds in the shallow inner portion of the Sound, and since eelgrass is considered an
important nursery habitat for juvenile cod, green crab may potentially impact cod nursery
habitat in Smith Sound.
Green crab was first detected in North Harbour, Placentia Bay in 2007, and has since been
found in several sites in Placentia Bay as well as two sites on the west coast.
Green crab have not been detected in Trinity Bay, but since this invasive species was first
detected in North Harbour, Placentia Bay, it has expanded rapidly within Placentia Bay in
two years and was recently identified near Port aux Basques, and in the Bay St. George
region. Northern waters of the LOMA may be protected by colder water temperatures, but
green crab is unlikely to reach high concentrations in Trinity Bay in the near future.
Screened out.
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Lacey bryozoan (Membranipora membranacea):
Membranipora is an invasive species which was first detected by MUN Scientist Bob
Hooper in Bonne Bay in 2002, and has since spread to many coastal areas of the LOMA.
The map below shows survey areas where Membranipora has been detected:
This invasive colonial bryozoan of European origin grows on kelp, rockweed, eelgrass and
other marine plants, secreting a protective limestone covering which forms a tough, white
lace-like crust over the flexible, rubbery surface of the kelp blade. Kelp blades that are
heavily encrusted with Membranipora become brittle and more susceptible to breakage
during a storm surge. In high energy areas, encrusted blades are far more prone to break off.
In some areas this has led to the removal of entire kelp beds. Membranipora is expected to
have a significant impact on the structural habitat provided by kelp and to a lesser degree
rockweed, with implications for biodiversity and recruitment of juvenile fish such as cod
which utilize kelp beds as nursery habitat.
Mature kelp beds are being killed on the north coast of Newfoundland, while young and
mature kelp are affected on the south coast of the island. Water temperature is critical for the
growth of Membranipora with maximum growth at water temperatures reaching 15oC,
usually in August in most areas, with growth continuing until December. The impact on the
kelp peaks in November. Kelp on the west and south coasts have suffered major impacts as a
result of this AIS, with kelp basically going from a perennial to annual. On the Northeast
coast, Membranipora is present but the level of harm to kelp is much lower. Climate change
could potentially intensify the growth of this harmful species, but significant impacts on kelp
are not expected in Smith Sound over the next ten years. Screened out.
Key Activities/Stressors:




Gillnets (bottom)
Recreational cod fishery
Ghost nets
Increased storm events
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Reference List
1. BriLev Consulting Inc. (2008). 2007 Survey of the Recreational Cod fishery of
Newfoundland and Labrador.
2. Drinkwater, K. F. (2005). The response of Atlantic cod (Gadus morhua) to future
climate change. ICES Journal of Marine Science, 62, 1327-1337.
3. Elsner, J. B., Kossin, J. P., & Jagger, T. H. (2008). The increasing intensity of the
strongest tropical cyclones. Nature, 455, 92-95.
4. Emanuel, K. (2005). Increasing Destructiveness of Tropical Cyclones over the
past 30 Years. Nature, 436, 686-688.
5. Emanuel, K. A. (2000). A Statistical Analysis of Tropical Cyclone Intensity.
Mon.Wea.Rev., 128, 1139-1152.
6. FFAW (2007). Appendix C: Co-existence? Fishing Activity and Tanker Traffic in
Placentia Bay, June 2007 (Rep. No. Provincial Environmental Assessment,
Environmental Impact Statement, Volume 4, Socio-Economic Assessment,
Volume 2). Newfoundland and Labrador Refining Corporation.
7. Fisheries and Oceans Canada (2008). Stock Assessment of Northern (2J3KL) Cod
in 2008 (Rep. No. 2008/034). Canadian Science Advisory Secretariat Science
Advisory Report, Newfoundland and Labrador Region.
8. Goldenberg, S. B., Landsea, C. W., Mestas-Nunez, A. M., & Gray, W. M.
(2001). The Recent Increase in Atlantic Hurricane Activity: Causes and
Implications. Science, 293, 474-479.
9. Hareide, N.-R., Garnes, G., Rihan, D., Mulligan, M., Tyndall, P., Clark, M.,
Connolly, P., Misund, R., McMullen, P., Furevik, D., Humborstad, O. B.,
Høydal, K., & Blasdale, T. (2005). A preliminary Investigation on Shelf Edge
and Deepwater Fixed Net Fisheries to the West and North of Great Britain,
Ireland, around Rockall and Hatton Bank.
10. Memorial University of Newfoundland & Fisheries and Oceans Canada (1995).
Phase I: Prevention of ghost fishing in Atlantic Canada. Fisheries and Marine
Institute of Memorial University of Newfoundland in cooperation with
Fisheries Management, Fisheries and Oceans Canada.
11. National Academy of Sciences (2008). Tackling Marine Debris in the 21st
Century.
12. Rose, G. A. (2007). Cod: The Ecological History of the North Atlantic Fisheries.
Breakwater Books.
7
13. The British Ecological Society. Commercial fishing: the wider ecological
impacts. Moore, G. and Jennings, S. Ecological Issues , 1-66. 2000.
Ref Type: Serial (Book,Monograph)
14. UNEP & UNFCCC (2002). Climate Change Information Kit UNEP and
UNFCCC.
15. Union of Concerned Scientists (2006). Hurricanes and Climate Change:
Exploring the potential causes of increased storm intensity. Union of
Concerned Scientists, Global Warming. [Announcement posted on the World
Wide Web]. from the World Wide Web:
http://www.ucsusa.org/global_warming/science_and_impacts/science/hurrican
es-and-climate-change.html
16. Webster, P. J., Holland, G. J., Curry, J. A., & Chang, H. A. (2005). Changes in
Tropical Cyclone Number, Duration, and Intensity in a Warming
Environment. Science, 309, 1844-1846.
8
Northern Atlantic cod spawning, nursing, migration, and refuge in Smith Sound
Gillnets (bottom)
Magnitude of Interaction
Areal extent:
 Smith Sound is a small area which provides refuge for dense aggregations of mature cod
throughout the winter and spring. A deep (200m) trench provides over-wintering habitat
for pre-spawning fish, and as deep waters cool in the spring, warming surface layers
provide above zero waters if deep water should fall below optimal temperatures for
spawning and survival of cod. During the spawning season (April-July), cod may be seen
throughout Smith Sound.
 Some fish appear to remain in Smith Sound all year, but the majority migrate seasonally
in and out of the bay. Tagging studies indicate that migrating cod begin to move out of
the sound in April, into coastal waters and bays both north and south of Trinity Bay, with
some larger fish moving offshore (Corey Morris, Biologist, Fisheries and Oceans Canada,
PO Box 5667, St. John’s, NL, A1C 5X1, “pers. comm.”). In a normal year, migrating
cod return to Smith Sound in late fall or early winter when deep waters in the trench are
warm (3-5oC) (Rose, 2007).
 Extensive eelgrass beds at the head of the Sound and kelp beds within the Sound provide
nursery habitat for juvenile fish.
Figure 1. Cod distributions in Trinity Bay from acoustic surveys (O'Driscoll et al., 2000)

Gillnet fishing within Smith Sound may include directed sentinel and stewardship
fisheries, and winter flounder and lumpfish fisheries. There are no restrictions on the
locations of these fisheries within the Sound, therefore, we have assumed that the entire
EBSA is subject to gillnet fishing.
Score 10
Contact:
 In relation to bottom gillnet, Quantitative Fishing Gear Scores (Fisheries and Oceans
Canada, 2007) for “contact” are high (75-100%) for bony fish species.


Since there is a directed fishery for cod in Trinity Bay and adjacent waters where
migrating cod from Smith Sound may occur, we have given a score of 100%.
A component of the CP is nursery habitat which is not affected by gillnet fisheries, so the
score has been reduced by 25%.
Score 7.5
Duration:
 Cod occur in Smith Sound throughout the year, but aggregations are greatest from
November through April.
 The main directed fisheries for cod using bottom gillnet occur in the late summer or fall
(September- October), including the stewardship and sentinel fisheries. Bycatch of cod
may occur in other gillnet fisheries including the winter flounder fishery (August), and
the turbot and lumpfish fisheries which typically takes place in June-July. The turbot
fishery does not take place within the bay, but may impact migrating cod.
 June-October = 5months/12months = 42%.
Score 4.2
Intensity:
 Halpern et al. (2008) have developed maps showing the global intensity of several
anthropogenic stressors including ‘demersal non-destructive fishing with high bycatch’,
which includes bottom gillnet fisheries (see Figure below). This map can be used to
provide guidance in scoring the intensity of a stressor in relation to maximum intensity in
a global context, in accordance with the scale provided below.
 This map shows a medium (yellow) intensity relative to global levels for a score range of
40% to 60% for the LOMA.
Map colour
Red
Orange
Yellow
Light Blue
Dark Blue
Intensity
80-100%
60-80%
40-60%
20-40%
0-20%
Figure 2. Global intensity of bottom gillnets, adapted from (Halpern et al., 2008).

Gillnets are the dominant gear impacting cod within the inshore, with landings of cod
(including bycatch) estimated at 2500t in 2007. Although landings are greatly reduced
compared to historical levels, landings are significant in relation to the estimated biomass
of inshore stocks (10%). Fishing intensity is minimal during the spawning period (AprilJuly). We have therefore selected the lowest score within the range.
Score 4
Magnitude of Interaction: (10 x 7.5 x 4.2 x 4)/1000 = 1.3
Sensitivity
Sensitivity of the CP to acute impacts:
 In relation to bottom gillnet, Quantitative Fishing Gear Scores (Fisheries and Oceans
Canada, 2007) for “harm” are high (75-100%) for bony fish species in 3NO.
 Bottom gillnets were also given a “high impact” rating in relation to groundfish based on
ecological impact (Fuller et al., 2008).
 Directed fisheries (sentinel and stewardship) which predominantly use bottom gillnets are
responsible for significant mortality (up to10% of biomass) of inshore cod which utilize
Smith Sound at some stage in their life cycle for spawning, refuge, nursery and/or
migration.
 Since there is a directed gillnet fishery targeting cod, we have selected a moderate score
in the high range – score 9.
 Since juvenile (nursery) fish are not directly targeted by gillnet the score has been
reduced by 25%.
Score 6.8
Sensitivity of the CP to chronic impacts:
 Smith Sound cod belong to the Newfoundland and Labrador population of Atlantic cod
which was assessed by COSEWIC in 2003 and designated endangered. The Status
Report lists fishing (including legal, illegal, and unreported catches) and fishing-induced
changes to the ecosystem as key threats to cod recovery.
 Inshore components of the stock appear more productive than offshore components.
Stewardship fishery catch rates in 2006-07 were slightly higher than in earlier fisheries
between 1998 and 2002, and sentinel fisheries catch rates near Trinity Bay (southern 3K
and northern 3L) have generally increased since 2002 and are currently above average for
the time series.
 A pre-recruit index suggests that the strength of the 2003-2006 year-classes will be much
lower than those that have supported recent fisheries (Fisheries and Oceans Canada,
2008).
 Clearly, significant fishing mortality can affect the long-term stability of the stock, and
therefore we have selected a moderate score (5).
 Atlantic cod are listed in the CP document as a ‘depleted and rare species’, and will
therefore rank higher on this scale than other CPs because they are already in need of
recovery (add one point).
Score 6
Sensitivity of ecosystem to harmful impacts to the CP:
 Smith Sound cod belong to the Newfoundland and Labrador population of Atlantic cod,
one of two major cod stocks within the LOMA.







Cod have historically had a huge influence on the ecosystem of the LOMA, mainly
because of their large biomass and broad distribution compared to other species, and their
significant role as both predator and prey at all trophic levels as they grow and move
from one trophic level to another. Even though they are currently at less then one percent
of their former biomass, they still represent a significant component of the total goundfish
population.
Since the sharp decline in cod biomass in the 1990s, stocks of invertebrates such as
shrimp and crab have expanded to record highs in what has been termed a trophic
cascade. These changes have been blamed on over-fishing resulting in perturbations to
the predator-prey systems, and although environmental change may have had a
contribution, it is clear that the role of Atlantic cod in the ecosystem is highly significant
to its structure and function.
Coastal bays provide significant spawning, nursery and over-wintering habitat for
Atlantic cod within the LOMA. Since the collapse of the cod stocks in the early 1990s,
much of the remaining biomass has been concentrated in coastal regions. Although cod
were historically known to over-winter and spawn in these coastal areas, the recent
concentration of cod in coastal bays, in contrast to the dearth of fish in adjacent shelf
regions, may be without precedent (Lawson & Rose, 2000). Bay stocks are seen by many
as a key component in the recovery of cod stocks within the LOMA as a whole.
Smith Sound is an important overwintering area for the severely depleted population of
Northern cod. The very dense aggregation of fish in the relatively small geographical
area of Smith Sound during the winter not only represents the largest group in terms of
numbers of fish, but the fish are also very large in size and hence very fecund, and can
potentially contribute significant numbers of eggs to Smith Sound and adjacent areas.
Smith Sound is considered the largest remaining spawning area for Northern Cod.
Extensive eelgrass beds at the head of the Sound provide high quality nursery habitat.
Much of the currently known spawning that occurs along the northeast coast appears to
originate from migrating subgroups of cod which overwintered in Smith Sound
(Templeman, 2007).
Smith Sound cod aggregations may be critical to the recovery of the population
(Templeman, 2007), although the potential role of bay stocks such as those in Smith
Sound in rebuilding the offshore stocks is unknown (Rose, 2007).
Given the importance of this population to one of the two major stocks within the
LOMA, we have selected a score of 6.
Atlantic cod are listed in the CP document as an ‘ecologically significant species’ (add
one point).
Score 7
Sensitivity: (6.8 + 6 + 7)/3 = 6.6
Risk of Harm: MoI x S = 1.3 x 6.6 = 8.6
Certainty Checklist
Answer yes or no to all of the following questions. Record the number of NO’s to the 9
questions, and record certainty according to the scale provided below:
1
No’s = High certainty
2- 3 No’s = Medium certainty
>4
No’s = Low certainty
Y/N
N Is the score supported by a large body of information?
Y Is the score supported by general expert agreement?
Y Is the interaction well understood, without major information gaps/sources of error?
Y Is the current level of understanding based on empirical data rather than models,
anecdotal information or probable scenarios?
N Is the score supported by data which is specific to the region, (EBSA, LOMA, NW
Atlantic?
Y Is the score supported by recent data or research (the last 10 years or less)?
Y Is the score supported by long-term data sets (ten years or more) from multiple surveys
(5 years or more)?
Y Do you have a reasonable level of comfort in the scoring/conclusions?
N Do you have a high level of confidence in the scoring/conclusions?
Certainty Score: Medium
Reference List
1. Fisheries and Oceans Canada (2007). Draft proceedings of the Workshop on
Qualitative Risk Assessment of Fishing Gears. In Government of Canada.
2. Fisheries and Oceans Canada (2008). Stock Assessment of Northern (2J3KL) Cod in
2008 (Rep. No. 2008/034). Canadian Science Advisory Secretariat Science Advisory
Report, Newfoundland and Labrador Region.
3. Fuller, S. D., Picco, C., Ford, J., Tsao, C.-F., Morgan, L. E., Hangaard, D. et al. (2008).
How we fish matters: Addressing the Ecological Impacts of Canadian Fishing Gear
Ecology Action Centre, Living Oceans Society, and Marine Conservation Biology
Institute.
4. Halpern, B. S., Walbridge, S., Selkoe, K. A., Kappel, C. V., Micheli, F., D'Agrosa, C.
et al. (2008). A Global Map of Human Impact on Marine Ecosystems. Science, 319,
948-952.
5. Lawson, G. L. & Rose, G. A. (2000). Seasonal distribution and movements of coastal
cod (Gadus morhua L.) in Placentia Bay, Newfoundland. Fisheries Research, 49, 6175.
6. O'Driscoll, R. L., Rose, G. A., Andersdon, J. T., & Mowbray, F. (2000). Spatial
association between cod and capelin: a perspective on the inshore-offshore dichotomy
(Rep. No. 2000/083).
7. Rose, G. A. (2007). Cod: The Ecological History of the North Atlantic Fisheries.
Breakwater Books.
8. Templeman, N. D. (2007). Placentia Bay-Grand Banks Large Ocean Management
Area Ecologically and Biologically Significant Areas (Rep. No. 2007/052). Canadian
Science Advisory Secretariat Research Document, Fisheries and Oceans Canada.
Northern Atlantic cod spawning, nursing, migration, and refuge in Smith Sound
Recreational cod fishery
Magnitude of Interaction
Areal extent:
 Smith Sound is a small area which provides refuge for dense aggregations of mature cod
throughout the winter and spring. A deep (200m) trench provides over-wintering habitat
for pre-spawning fish, and as deep waters cool in the spring, warming surface layers
provide above zero waters if deep water should fall below optimal temperatures for
spawning and survival of cod. During the spawning season (April-July), cod may be seen
throughout Smith Sound.
 Some fish appear to remain in Smith Sound all year, but the majority migrate seasonally
in and out of the bay. Tagging studies indicate that migrating cod begin to move out of
the Sound in April, into coastal waters and bays both north and south of Trinity Bay, with
some larger fish moving offshore (Corey Morris, Biologist, Fisheries and Oceans Canada,
PO Box 5667, St. John’s, NL, A1C 5X1, “pers. comm.”). In a normal year, migrating
cod return to Smith Sound in late fall or early winter when deep waters in the trench are
warm (3-5oC) (Rose, 2007).
 Extensive eelgrass beds at the head of the Sound and kelp beds within the Sound provide
nursery habitat for juvenile fish.
Figure 1. Cod distributions in Trinity Bay from acoustic surveys (O'Driscoll et al., 2000)

The recreational cod fishery occurs throughout Smith Sound wherever cod are found.
Score 10
Contact:
 Since there is a directed recreational fishery for cod in Trinity Bay, we have given a score
of 100%.
 A component of the CP is cod nursing (juvenile fish) which is not affected by the
recreational cod fishery, so the score has been reduced by 25%.
Score 7.5
Duration:
 The cod are widely distributed in Smith Sound throughout the year.
 The recreational cod fishery is conducted in the fall, although dates are variable. The
2007 fishery was open for five weeks (35 days): July 25 to August 19 and September 29
to October 7.
 35 days/365 days = 9.5%
Score 1
Intensity:
 Halpern et al. (2008) have developed maps showing the global intensity of several
anthropogenic stressors including ‘demersal non-destructive fishing with low bycatch’,
which includes handline fisheries (see Figure below). This map can be used to provide
guidance in scoring the intensity of a stressor in relation to maximum intensity in a global
context, in accordance with the scale provided below.
 This map shows a medium-low (light blue) intensity for the EBSA and other coastal areas
of the LOMA relative to global levels, for a score range of 20% to 40%.
Map colour Intensity
Red
80-100%
Orange
60-80%
Yellow
40-60%
Light Blue 20-40%
Dark Blue
0-20%
Figure 2. Global intensity of handline fisheries, adapted from (Halpern et al., 2008).


Landings of cod in Trinity Bay by the recreational cod fishery were the highest of any
area in the region, amounting to 308,160 fish in 2007, almost 40% of the total landings
within the LOMA.
These landings are significant (equivalent to that of the commercial fishery), and were
particularly high in Trinity Bay compared to other areas of the LOMA, so we have
selected highest score in the global range (20-40%).
Score 4
Magnitude of Interaction: (10 x 7.5 x 1 x 4)/1000 = 0.3
Sensitivity
Sensitivity of the CP to acute impacts:




Since there is a directed recreational fishery for cod in Trinity Bay, we have given a score
in the high range.
Landings of cod in Trinity Bay by the recreational cod fishery were the highest of any
area in the region, amounting to 308,160 fish in 2007, almost 40% of the total landings
within the LOMA.
These landings are significant (equivalent to that of the commercial fishery), and were
particularly high in Trinity Bay compared to other areas of the LOMA, so we have
selected highest score in the high range (Fisheries and Ocean Canada, 2007).
A component of the CP is nursery habitat which is not affected by the recreational cod
fishery, so the score has been reduced by 25%.
Score 7.5
Sensitivity of the CP to chronic impacts:
 Smith Sound cod belong to the Newfoundland and Labrador population of Atlantic cod
which was assessed by COSEWIC in 2003 and designated endangered. The Status
Report lists fishing (including legal, illegal and unreported catches) and fishing-induced
changes to the ecosystem as key threats to cod recovery.
 Inshore components of the stock appear more productive than offshore components.
Stewardship fishery catch rates in 2006-07 were slightly higher than in earlier fisheries
between 1998 and 2002, and sentinel fisheries catch rates near Trinity Bay (southern 3K
and northern 3L) have generally increased since 2002 and are currently above average for
the time series.
 A pre-recruit index suggests that the strength of the 2003-2006 year-classes will be much
lower than those that have supported recent fisheries (Fisheries and Oceans Canada,
2008).
 Fishing mortality associated with the recreational fishery was particularly high in Smith
Sound, although not extreme, and this level of fishing may affect the long term stability
of the stock so we have selected a score at the low end of the high range (7.5).
 Atlantic cod are listed in the CP document as a ‘depleted and rare species’, and will
therefore rank higher on this scale than other CPs because they are already in need of
recovery (add one point).
Score 8.5
Sensitivity of the ecosystem to harmful impacts to the CP:
 Smith Sound cod belong to the Newfoundland and Labrador population of Atlantic cod,
one of two major cod stocks within the LOMA.
 Cod have historically had a huge influence on the ecosystem of the LOMA, mainly
because of their large biomass and broad distribution compared to other species, and their
significant role as both predator and prey at all trophic levels as they grow and move
from one trophic level to another. Even though they are currently at less then one percent
of their former biomass, they still represent a significant component of the total goundfish
population.
 Since the sharp decline in cod biomass in the 1990s, stocks of invertebrates such as
shrimp and crab have expanded to record highs in what has been termed a trophic




cascade. These changes have been blamed on over-fishing resulting in perturbations to
the predator-prey systems, and although environmental change may have had a
contribution, it is clear that the role of Atlantic cod in the ecosystem is highly significant
to its structure and function.
Coastal bays provide significant spawning, nursery and over-wintering habitat for
Atlantic cod within the LOMA. Since the collapse of the cod stocks in the early 1990s,
much of the remaining biomass has been concentrated in coastal regions. Although cod
were historically known to over-winter and spawn in these coastal areas, the recent
concentration of cod in coastal bays, in contrast to the dearth of fish in adjacent shelf
regions, may be without precedent (Lawson & Rose, 2000). Bay stocks are seen by many
as a key component in the recovery of cod stocks within the LOMA as a whole.
Smith Sound is an important overwintering area for the severely depleted population of
Northern cod. The very dense aggregation of fish in the relatively small geographical
area of Smith Sound during the winter not only represents the largest group in terms of
numbers of fish, but the fish are also very large in size and hence fecundity, and can
potentially contribute significant numbers of eggs to Smith Sound and adjacent areas.
Smith Sound is considered the largest remaining spawning area for Northern Cod.
Extensive eelgrass beds at the head of the Sound provide high quality nursery habitat.
Much of the currently known spawning that occurs along the northeast coast appears to
originate from migrating subgroups of cod which overwintered in Smith Sound
(Templeman, 2007). Smith Sound cod aggregations may be critical to the recovery of the
population (Templeman, 2007), although the potential role of bay stocks such as those in
Smith Sound in rebuilding the offshore stocks is unknown (Rose, 2007).
Given the importance of this population to one of the two major stocks within the
LOMA, we have selected a score of 6.
Atlantic cod are listed in the CP document as an ‘ecologically significant species’ (add
one point).
Score 7
Sensitivity: (7.5 + 8.5 + 7)/3 = 7.7
Risk of Harm: MoI x S = 0.3 x 7.7 = 2.3
Certainty Checklist
Answer yes or no to all of the following questions. Record the number of NO’s to the 9
questions, and record certainty according to the scale provided below:
1
No’s = High certainty
2- 3 No’s = Medium certainty
No’s = Low certainty
>4
Y/N
N Is the score supported by a large body of information?
Y Is the score supported by general expert agreement?
Y Is the interaction well understood, without major information gaps/sources of error?
Y Is the current level of understanding based on empirical data rather than models,
anecdotal information or probable scenarios?
N Is the score supported by data which is specific to the region, (EBSA, LOMA, NW
Atlantic?
Y Is the score supported by recent data or research (the last 10 years or less)?
Y Is the score supported by long-term data sets (ten years or more) from multiple surveys
(5 years or more)?
Y Do you have a reasonable level of comfort in the scoring/conclusions?
N Do you have a high level of confidence in the scoring/conclusions?
Certainty Score: Medium
For interactions with Low certainty, underline the main factor(s) contributing to the
uncertainty
Lack of comprehensive data
Lack of expert agreement
Predictions based of future scenarios which are difficult to predict
Other (provide explanation)
Suggest possible research to address uncertainty:
Improved monitoring of recreational fishery
Reference List
1. Fisheries and Ocean Canada (2007). Conservation Harvesting Plan (CHP), Atlanticwide for Mobile Gear Vessels 65-100', February 8, 2007 (unpublished) Fisheries and
Oceans Canada, Newfoundland & Labrador Region.
2. Fisheries and Oceans Canada (2008). Stock Assessment of Northern (2J3KL) Cod in
2008 (Rep. No. 2008/034). Canadian Science Advisory Secretariat Science Advisory
Report, Newfoundland and Labrador Region.
3. Halpern, B. S., Walbridge, S., Selkoe, K. A., Kappel, C. V., Micheli, F., D'Agrosa, C.
et al. (2008). A Global Map of Human Impact on Marine Ecosystems. Science, 319,
948-952.
4. Lawson, G. L. & Rose, G. A. (2000). Seasonal distribution and movements of coastal
cod (Gadus morhua L.) in Placentia Bay, Newfoundland. Fisheries Research, 49, 6175.
5. O'Driscoll, R. L., Rose, G. A., Andersdon, J. T., & Mowbray, F. (2000). Spatial
association between cod and capelin: a perspective on the inshore-offshore dichotomy
(Rep. No. 2000/083).
6. Rose, G. A. (2007). Cod: The Ecological History of the North Atlantic Fisheries.
Breakwater Books.
7. Templeman, N. D. (2007). Placentia Bay-Grand Banks Large Ocean Management
Area Ecologically and Biologically Significant Areas (Rep. No. 2007/052). Canadian
Science Advisory Secretariat Research Document, Fisheries and Oceans Canada.
Northern Atlantic cod spawning, nursing, migration, and refuge in Smith Sound
Ghost nets (derelict fishing gear)
Magnitude of Interaction
Areal extent:
 Adult and juvenile cod are widely distributed throughout Smith Sound, depending on the
season and the life stage. The approximate dimensions of Smith Sound are 37 km x 2.5
= 92.5 km2.
 As a result of the steep bathymetry, any lost nets are most likely to accumulate in the
deep trenches where cod aggregate in winter. The approximate dimensions of the
trenches are 11 km x 1 = 11 km2 (Corey Morris, Biologist, Fisheries and Oceans Canada,
PO Box 5667, St. John’s, NL, A1C 5X1, “pers. comm.”).
 As a result, the area of overlap is likely in the low range (11/92.5 = 12%), with most of
the nets located in ~12% of the Sound. We have selected a slightly high score since some
nets may be distributed in other areas of the Sound.
Score 1.5
Contact:
 Contact with adult cod, particularly overwintering and migrating cod is considered high
(8).
 Contact with juvenile cod is low, and spawning cod in Smith Sound are often reported to
be high in the water column where water is warmer in spring, and contact would low.
 Overall, contact is therefore considered to be in the medium range.
Score 4
Duration:
 Since the 1960s, fishing nets have been constructed from highly durable plastic materials
such as nylon, polypropylene and polyethylene, which do not biodegrade. When exposed
to the sun for a period of years, photo-degradation will weaken these materials releasing
fragments of plastic. On the sea bottom, however, where they are protected from UV
radiation, there is no evidence that these nets weaken or degrade over time. As a result,
lost nets accumulate in the environment, and are present 100% of the time.
Score 10
Intensity:
 Since we have no data on the density of ghost nets or the frequency of gear loss within
the EBSA, we have based our intensity scores on data related to sources of ghost nets
(gillnet fishing) and environmental factors (rough bottom, wind speed, wave action).
 Halpern et al. (2008) have developed maps showing the global intensity of several
anthropogenic stressors including ‘demersal non-destructive fishing with high bycatch’,
which includes bottom gillnet fisheries (see Figure 2 below). This map can be used to
1

This map shows a medium (yellow) intensity relative to global levels for a score range of
40% to 60% for the LOMA.
Map colour Intensity
Red
80-100%
Orange
60-80%
Yellow
40-60%
Light Blue 20-40%
Dark Blue
0-20%
Figure 2. Global intensity of bottom gillnets, adapted from (Halpern et al., 2008).


Gillnets are among the most common gear types used inshore, and since Smith Sound is
known for its dense aggregations of fish, intensity is likely higher than average.
Based on these factors we have selected the highest score within the range indicated for
the LOMA.
Score 6
Magnitude of Interaction: (1.5 x 4 x 10 x 6)/1000 = 0.36
Sensitivity
Sensitivity of the CP to acute impacts:
 Set gillnets, by virtue of their fixed, anchored framing (held in position by buoys on top
and lead rope on bottom), may remain fully deployed and fishing long after they are lost
or abandoned. As nets become fouled, they become more visible, lose their vertical
profile and their fishing capacity declines (National Academy of Sciences, 2008). Even
when nets collapse, forming balls on the sea floor, they have been observed to self bait
such that predators and scavengers attracted to entangled animals are themselves
entangled, thereby perpetuating the cycle of destruction.
 Based on available data, impacts are considered significant, but relative to fishing
mortality are likely minor for a score of 3.
Score 3
Sensitivity of the CP to chronic impacts:
 Although overall mortality of cod from ghost nets may be relatively minor in Smith
Sound, the chronic, cumulative nature of the threat is a greater concern. Fishing activity
can be reduced as required to conserve stocks, but once ghost nets are lost, retrieval is
very difficult and expensive, and mortalities can continue for decades (minor, long term).
2

Atlantic cod are listed in the CP document as a ‘depleted and rare species’, and will
therefore rank higher on this scale than other CPs because they are already in need of
recovery (add one point).
Score 3
Sensitivity of ecosystem to harmful impacts to the CP:
 Smith Sound cod belong to the Newfoundland and Labrador population of Atlantic cod,
one of two major cod stocks within the LOMA.
 Cod have historically had a huge influence on the ecosystem of the LOMA, mainly
because of their large biomass and broad distribution compared to other species, and their
significant role as both predator and prey at all trophic levels as they grow and move
from one trophic level to another. Even though they are currently at less then one percent
of their former biomass, they still represent a significant component of the total goundfish
population.
 Since the sharp decline in cod biomass in the 1990s, stocks of invertebrates such as
shrimp and crab have expanded to record highs in what has been termed a trophic
cascade. These changes have been blamed on over-fishing resulting in perturbations to
the predator-prey systems, and although environmental change may have had a
contribution, it is clear that the role of Atlantic cod in the ecosystem is highly significant
to its structure and function.
 Coastal bays provide significant spawning, nursery and over-wintering habitat for
Atlantic cod within the LOMA. Since the collapse of the cod stocks in the early 1990s,
much of the remaining biomass has been concentrated in coastal regions. Although cod
were historically known to over-winter and spawn in these coastal areas, the recent
concentration of cod in coastal bays, in contrast to the dearth of fish in adjacent shelf
regions, may be without precedent (Lawson & Rose, 2000). Bay stocks are seen by many
as a key component in the recovery of cod stocks within the LOMA as a whole.
 Smith Sound is an important overwintering area for the severely depleted population of
Northern cod. The very dense aggregation of fish in the relatively small geographical
area of Smith Sound during the winter not only represents the largest group in terms of
numbers of fish, but the fish are also very large in size, and hence fecundity, and can
potentially contribute significant numbers of eggs to Smith Sound and adjacent areas.
Smith Sound is considered the largest remaining spawning area for Northern Cod.
Extensive eelgrass beds at the head of the Sound provide high quality nursery habitat.
Much of the currently known spawning that occurs along the northeast coast appears to
originate from migrating subgroups of cod which overwintered in Smith Sound
(Templeman, 2007). Smith Sound cod aggregations may be critical to the recovery of the
population (Templeman, 2007), although the potential role of bay stocks such as those in
Smith Sound in rebuilding the offshore stocks is unknown (Rose, 2007).
 Given the importance of this population to one of the two major stocks within the
LOMA, we have selected a score of 6.
 Atlantic cod are listed in the CP document as an ‘ecologically significant species’ (add
one point).
Score 7
3
Sensitivity: (3 + 3 + 7)/3 = 4.3
Risk of Harm: 0.36 x 4.3 = 1.5
Certainty Checklist
Answer yes or no to all of the following questions. Record the number of NO’s to the 9
questions, and record certainty according to the scale provided below:
1
No’s = High certainty
2- 3 No’s = Medium certainty
>4
No’s = Low certainty
Y/N
N Is the score supported by a large body of information?
N Is the score supported by general expert agreement?
N Is the interaction well understood, without major information gaps/sources of error?
Y Is the current level of understanding based on empirical data rather than models,
anecdotal information or probable scenarios?
N Is the score supported by data which is specific to the region, (EBSA, LOMA, NW
Atlantic?
Y Is the score supported by recent data or research (the last 10 years or less)?
N Is the score supported by long-term data sets (ten years or more) from multiple surveys
(5 years or more)?
Y Do you have a reasonable level of comfort in the scoring/conclusions?
N Do you have a high level of confidence in the scoring/conclusions?
Certainty Score: Low
For interactions with Low certainty, underline the main factor(s) contributing to the
uncertainty
Lack of comprehensive data
Lack of expert agreement
Predictions based of future scenarios which are difficult to predict
Other (provide explanation)
Suggest possible research to address uncertainty:
Improved enforcement and analysis of data in relation to reporting lost nets
4
Reference List
1. Halpern, B. S., Walbridge, S., Selkoe, K. A., Kappel, C. V., Micheli, F., D'Agrosa, C.
et al. (2008). A Global Map of Human Impact on Marine Ecosystems. Science, 319,
948-952.
2. Lawson, G. L. & Rose, G. A. (2000). Seasonal distribution and movements of coastal
cod (Gadus morhua L.) in Placentia Bay, Newfoundland. Fisheries Research, 49, 6175.
3. National Academy of Sciences (2008). Tackling Marine Debris in the 21st Century.
4. Rose, G. A. (2007). Cod: The Ecological History of the North Atlantic Fisheries.
Breakwater Books.
5. Templeman, N. D. (2007). Placentia Bay-Grand Banks Large Ocean Management
Area Ecologically and Biologically Significant Areas (Rep. No. 2007/052). Canadian
Science Advisory Secretariat Research Document, Fisheries and Oceans Canada.
5
Northern Atlantic cod spawning, nursing, migration, and refuge in Smith Sound
Increased storm events
Magnitude of Interaction
Areal extent:
 Smith Sound is a small area which supports a very dense aggregation of cod. A deep
(200m) trench provides over-wintering habitat for pre-spawning fish, and as deep waters
cool in the spring, warming surface layers provide above zero waters if deep water should
fall below optimal temperatures for spawning and survival of cod. Thus, during the
spawning season, cod may be seen throughout Smith Sound.
Figure 1. Cod distributions in Trinity Bay from acoustic surveys (O'Driscoll et al., 2000)

Increased storm events are an escalating stressor related to climate change which is
predicted to impact the LOMA.
Score 10
Contact:
 Storm events affect the entire water column in shallow coastal areas, and therefore
contact will be high for CPs associated with coastal areas (Fisheries and Ocean Canada,
2007)
Score 10
Duration:
 The majority of cod return to Smith Sound during the winter (November-April), although
some fish remain in the sound year-round (6 months). Juvenile fish remain in eelgrass
beds at the head of the Sound, or in other suitable nursery habitat such as kelp beds
throughout the year. Since this CP refers to the entire life cycle of cod in Smith Sound
we have consider the CP to be present 12 months of the year.


Super-cooling events resulting from storm mixing are most likely in the spring of the year
when ice cover (which prevents wind related mixing) is gone, but surface waters are
below 0oC (March-April)- but these events are not expected to occur annually.
Chronic stressors which are unlikely to occur annually are scored in the low range. We
have selected a score at the low end of the range to reflect the anticipated low frequency
and duration of the stressor.
Score 1
Intensity:
 Atlantic tropical cyclones are getting stronger on average, with a 30-year trend that has
been related to an increase in ocean temperatures, and are predicted to impact the NW
Atlantic at a high level of intensity relative to other areas of the globe (Elsner et al.,
2008).
 The years 1995-2000 experienced the highest level of North Atlantic hurricane activity in
the reliable record (Goldenberg et al., 2001).
 The largest increase in hurricanes reaching categories 4 and 5 occurred in the Pacific and
Indian Oceans, but the highest increase in the number of cyclones and cyclone days
occurred in the North Atlantic (Webster et al., 2005). The relationships between a
warming environment and increasing storm events is complex, and research results and
predictions are variable, and more research is clearly required (Emanuel, 2005; Emanuel,
2000; Goldenberg et al., 2001; Webster et al., 2005).
 Based on the available information we have selected a score at the low end of the high
range.
Score 7.5
Magnitude of Interaction: (10 x 10 x 1 x 7.5)/1000 = 0.75
Sensitivity
Sensitivity of the CP to acute impacts:
 It is not clear exactly what factors contribute to making Smith Sound a unique spawning
area for northern Atlantic cod, but the abundance of prey, particularly capelin, refuge
from the intense fishing effort that led to the decline of offshore stocks, as well as the
deep (200m) trench within a sheltered sound which offers over-wintering habitat for prespawning aggregations, are likely important factors.
 Spawning in Smith Sound begins in early April and continues into the summer, with
spawning observed as late as July in some years (Rose, 2007). Some fish appear to
remain in Smith Sound all year, but the majority migrate seasonally in and out of the bay.
In a normal year, migrating cod return to Smith Sound in late fall or early winter when
deep waters in the trench are warm (3-5oC). As spring approaches, deep waters cool, but
temperatures are still above 0oC when cod begin to spawn in early April. By late May,
temperatures in deep waters may dip below 0oC and the fish either move up into the
warming surface waters or out into adjacent areas (Rose, 2007).


An increase in storm surges can potentially led to super-cooling events during severe
winter storms where the motion keeps seawater in a liquid state at temperatures well
below -2oC and can lead to mass mortalities.
In the spring of 2003, the normal cooling of the deep waters accelerated quickly in early
April, trapping cod in sub-zero waters deep in the Sound, and about 5% (500,000 fish)
froze to death in the super-cooled water (Rose, 2007). This type of event is rare,
occurring when specific environmental conditions coincide, and may never occur again,
but increased storm events may increase the risk of reoccurrence, although the additional
risk is considered low (3).
Score 3
Sensitivity of the CP to chronic impacts:
 Smith Sound cod belong to the Newfoundland and Labrador population of Atlantic cod
which was assessed by COSEWIC in 2003 and designated endangered. The Status
Report lists fishing (including legal, illegal and unreported catches) and fishing-induced
changes to the ecosystem as key threats to cod recovery.
 Inshore components of the stock appear more productive than offshore components.
Stewardship fishery catch rates in 2006-07 were slightly higher than in earlier fisheries
between 1998 and 2002, and sentinel fisheries catch rates near Trinity Bay (southern 3K
and northern 3L) have generally increased since 2002 and are currently above average for
the time series.
 A pre-recruit index suggests that the strength of the 2003-2006 year-classes will be much
lower than those that have supported recent fisheries (Fisheries and Oceans Canada,
2008).
 Mortality from the 2003 super-cooling event were significant (500,000 fish), but are
sustainable (5% of biomass) provided other mortality sources are adjusted in
consideration of the loss for the year in which the event occurred (score 2).
 Atlantic cod are listed in the CP document as a ‘depleted and rare species’, and will
therefore rank higher on this scale than other CPs because they are already in need of
recovery (add one point).
Score 3
Sensitivity of ecosystem to harmful impacts to the CP:
 Smith Sound cod belong to the Newfoundland and Labrador population of Atlantic cod,
one of two major cod stocks within the LOMA.
 Cod have historically had a huge influence on the ecosystem of the LOMA, mainly
because of their large biomass and broad distribution compared to other species, and their
significant role as both predator and prey at all trophic levels as they grow and move
from one trophic level to another. Even though they are currently at less then one percent
of their former biomass, they still represent a significant component of the total goundfish
population.
 Since the sharp decline in cod biomass in the 1990s, stocks of invertebrates such as
shrimp and crab have expanded to record highs in what has been termed a trophic
cascade. These changes have been blamed on over-fishing resulting in perturbations to




the predator-prey systems, and although environmental change may have had a
contribution, it is clear that the role of Atlantic cod in the ecosystem is highly significant
to its structure and function.
Coastal bays provide significant spawning, nursery and over-wintering habitat for
Atlantic cod within the LOMA. Since the collapse of the cod stocks in the early 1990s,
much of the remaining biomass has been concentrated in coastal regions. Although cod
were historically known to over-winter and spawn in these coastal areas, the recent
concentration of cod in coastal bays, in contrast to the dearth of fish in adjacent shelf
regions, may be without precedent (Lawson & Rose, 2000). Bay stocks are seen by many
as a key component in the recovery of cod stocks within the LOMA as a whole.
Smith Sound is an important overwintering area for the severely depleted population of
Northern cod. The very dense aggregation of fish in the relatively small geographical
area of Smith Sound during the winter not only represents the largest group in terms of
numbers of fish, but the fish are also very large in size and hence fecundity, and can
potentially contribute significant numbers of eggs to Smith Sound and adjacent areas.
Smith Sound is considered the largest remaining spawning area for Northern Cod.
Extensive eelgrass beds at the head of the Sound provide high quality nursery habitat.
Much of the currently known spawning that occurs along the northeast coast appears to
originate from migrating subgroups of cod which overwintered in Smith Sound
(Templeman, 2007). Smith Sound cod aggregations may be critical to the recovery of the
population (Templeman, 2007), although the potential role of bay stocks such as those in
Smith Sound in rebuilding the offshore stocks is unknown (Rose, 2007).
Given the importance of this population to one of the two major stocks within the
LOMA, we have selected a score of 6.
Atlantic cod are listed in the CP document as an ‘ecologically significant species’ (add
one point).
Score 7
Sensitivity: (3 + 3 + 7)/3 = 4.3
Risk of Harm: MoI x S = 0.75 x 4.3 = 3.2
Certainty Checklist
Answer yes or no to all of the following questions. Record the number of NO’s to the 9
questions, and record certainty according to the scale provided below:
1
No’s = High certainty
2- 3 No’s = Medium certainty
No’s = Low certainty
>4
Y/N
N Is the score supported by a large body of information?
N Is the score supported by general expert agreement?
N Is the interaction well understood, without major information gaps/sources of error?
N Is the current level of understanding based on empirical data rather than models,
anecdotal information or probable scenarios?
N Is the score supported by data which is specific to the region, (EBSA, LOMA, NW
Atlantic?
N Is the score supported by recent data or research (the last 10 years or less)?
N Is the score supported by long-term data sets (ten years or more) from multiple surveys
(5 years or more)?
Y Do you have a reasonable level of comfort in the scoring/conclusions?
N Do you have a high level of confidence in the scoring/conclusions?
Certainty Score: Low
For interactions with Low certainty, underline the main factor(s) contributing to the
uncertainty
Lack of comprehensive data
Lack of expert agreement
Predictions based of future scenarios which are difficult to predict
Other (provide explanation)
Suggest possible research to address uncertainty:
Improved regional monitoring
Reference List
1. Elsner, J. B., Kossin, J. P., & Jagger, T. H. (2008). The increasing intensity of the
strongest tropical cyclones. Nature, 455, 92-95.
2. Emanuel, K. (2005). Increasing Destructiveness of Tropical Cyclones over the past 30
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Summary Table: Northern Atlantic cod spawning, nursing, migration, and refuge in Smith
Sound.
Certainty
Key
as
cs
es
a
c
d
i
S
MoI
Risk
Activity/Stressor
(a x c x d x i)
(as+cs+es) of
1000
3
Harm
Gillnets
10 7.5 4.2 4
6.8 6
7
1.3
6.6
8.6
Med
(groundfish)
Recreational
10 7.5 1
4
7.5 8.5 7
0.3
7.7
2.3
Med
cod fishery
Ghost nets
1.5 4
10 6
3
3
7
0.36
4.3
1.5
Low
Increased
10 10 1
7.5 0.75
3
3
7
4.3
3.2
Low
storm events
Cumulative CP Score 15.6