COSEWIC Assessment and Status Report on the Loggerhead Sea Turtle in Canada 2010 - Limiting Factors and Threats

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The life history of the Loggerhead Sea Turtle requires any threat analysis to consider not only each of its life stages, but also the various habitats it uses, regardless of the many political boundaries it crosses. For example, Loggerhead Sea Turtles do not come onto land in Canada; however, threats to their survival in the terrestrial environment in other countries directly affect individuals for which Canadian waters provide marine habitat. Also, a major limit for this species is its slow rate of recruitment as it has a late age of maturity, nests only once every 2–3 years, has a high rate of egg and hatchling mortality and demonstrates a high sensitivity by adult and late stage juveniles to even small, chronic changes in survivorship (Crouse et al. 1987; Crowder et al. 1994; Heppell et al. 1996, 2003a, 2003b).

The authors of the Recovery Plan for the Northwest Atlantic Population of the Loggerhead Sea Turtle (NMFS and USFWS 2008) undertook an exhaustive analysis of threats facing the turtles in each life stage. The threats were divided into seven major categories: fisheries bycatch, resource use (non–fisheries), construction and development, ecosystem alterations, pollution, species interactions, and other factors (such as climate change). Each of these was broken into a detailed list of threats (n=59; Table 2) and then adjusted for the annual mortality in number of adult females. Table 3 is the key used to assign annual mortality to each threat category, and Tables 4 and 5 are the summaries of this analysis (NMFS and USFWS 2008). Appendix 1 includes the complete set of threat tables created by NMFS and USFWS (2008). Threats that affect Loggerhead Sea Turtle habitat are also discussed in detail in the Habitat Trends section of this report.

Table 2. Detailed list of threats facing Loggerhead Sea Turtles in the northwest Atlantic as compiled by NMFS and USFWS (2008).
Category Threat Description
Fisheries Bycatch Bottom trawl Includes bottom trawl fisheries for blue crab, flounder, general finfish, scallop, shrimp, whelk, and the North Carolina flynet fishery for weakfish
Top/midwater trawl Includes trawls for sargassum and cannonball jellyfish
Dredge Includes dredge fisheries for scallops and whelk
Pelagic longline Includes longline fisheries for shark, swordfish, tuna and wahoo
Demersal longline Includes longline fisheries for black scabbard and shark
Demersal, large mesh gillnet Includes gillnet fisheries for black drum, dogfish, monkfish, shark, and southern flounder
Demersal, small mesh gillnet Includes gillnet fisheries for general finfish
Drift gillnet Includes drift gillnet fisheries for shark, swordfish, and tuna
Pound nets and weirs
Pot/trap fisheries Includes pot fisheries for blue crab, lobster, stone crab, and whelk
Haul seine
Channel net
Purse seine Includes purse seines for menhaden and tuna
Other hook and line (recreational)
Other hook and line (commercial) Includes commercial hook and line fisheries for snapper/grouper, Gulf reef fish, king and Spanish mackerel and sharks
Resource Use (non–fisheries) Legal harvest
Illegal harvest
Oil and gas activities
Vessel strikes
Beach cleaning
Human presence
Recreational beach equipment
Beach vehicular driving
Power generating activities
Conservation/research activities Includes harassment of nesting females and hatchlings, handling of eggs, etc.
Military activities
Salvage operations
Construction and Development Beach sand placement Includes beach nourishment, beach restoration, and inlet sand bypassing
Beach armouring Includes bulkheads, seawalls, soil retaining walls, rock revetments, sandbags, and geotextile tubes
Other shoreline stabilizations Includes groins, jetties, mesh groins (nets), and offshore breakwaters
Sand fences
Dredging
Storm–water outfalls
Coastal construction Refers to buildings on the coast
Channel blasting
Bridge blasting
Ecosystem Alterations Trophic changes from fishing activities E.g., bottom trawling
Trophic changes from benthic habitat alteration
Beach erosion (washouts) and accretion
Aquaculture
Eutrophication
Pollution Marine debris ingestion
Marine debris entanglement in derelict fishing gear
Marine debris entanglement in non–fishing gear
Beach debris Includes large items that can impede or trap hatchlings and/or nesting females
Oil pollution
Light pollution
Noise pollution
Thermal pollution Including from power plants
Chemical pollution
Species Interactions Predation
Disease and parasites
Harmful algal blooms
Predation by exotic species
Exotic dune and beach vegetation
Other Factors Climate change
Natural catastrophes
Cold water
Other (egg stage only) Includes root damage, disease events, infertile eggs, relocation mortality, and inundation
Table 3. Key used to assign estimated annual mortality to each threat category (Table 2). Taken from NMFS and USFWS (2008).
KEY
Estimated Annual Mortality Color Code Value
No evidence of mortality, based on best available information
Sub–lethal effects occur at this stage and may result in reduced fitness (e.g. reduced somatic growth rates, reduced hatching production, reduced prey abundance, reduced quality of nesting and/or foraging habitants)
> 0
Mortality has been documented or is likely to occur, however, data are insufficient to estimate mortality
1
1–10 3
11–100 30
101–1000 300
1001–10,000 3,000
10,001–100,000 30,000
100,001–1,000,000 300,000
Table 4. Annual mortality for each life stage and ecosystem for each threat category (Table 2) adjusted by relative reproductive equivalents. This table does not include sub–lethal effects. Estimates are based on the colour–coded scale (Table 3). Taken from NMFS and USFWS (2008).
LIFE STAGE ECOSYSTEM FISHERIESBYCATCH RESOURCE USE (NON–FISHERIES) CONSTRUCTION AND DEVELOPMENT ECOSYSTEM ALTERNATIONS POLLUTION SPECIES INTERACTIONS OTHER FACTORS
Nesting female Terrestrial Zone
Egg Terrestrial Zone
Hatchling stage Terrestrial Zone
Swim frenzy, transitional stage Neritic Zone
Juvenile stage Oceanic Zone
Adult stage Oceanic Zone
Juvenile stage Neritic Zone
Adult stage Neritic Zone
Table 5. Annual mortality for each threat within a threat category (Table 2) summed for all life stages and ecosystems, and adjusted for relative reproductive values for each. This table does not include sub–lethal effects. Estimates are based on the colour–coded scale (Table 3). Taken from NMFS and USFWS (2008).
THREAT CATEGORY SPECIFIC THREAT WITHIN A THREAT CATEGORY
Other Factors Climate change Natural catastrophes Cold water Other (egg stage only)
Species Interactions Predation by native species Disease and parasites Harmful algal blooms Predation by exotic species Exotic dune and beach vegetation
Ecosystem Alternations Trophic changes from fishery harvest Tropic changes from benthic habitat alteration Beach erosion (washouts) and accretion Aquaculture Eutrophication
Pollution Marine debris ingestion Marine debris entanglement in derelict fishing gear Marine debris entanglement in non–fishing gear Beach debris Oil pollution Light pollution Noise pollution Thermal pollution Chemical pollution
Construction and Development Beach sand placement Beach armoring Other shoreline stabilizations Sand fences Dredging Storm outfalls Coastal construction Channel blasting Bridge blasting
Resource Use (non–fisheries) Legal harvest Illegal harvest Oil and gas activities Vessel strikes Beach cleaning Human presence Recreational beach equipment Beach vehicular driving Power plant entrainment Conservation/
reseach activities
Military activities Salvage operations
Fisheries Bycatch Trawl (bottom) Trawl (trop/midwater) Dredge fisheries Longline (pelagic) Longline (demersal) Gillnet (demersal, lg. mesh) Gillnet (demersal, sm. mesh) Gillnet (drift) Pound nets and weirs Pot/trap fisheries Haul seines Channel net Purse seine Other hook & line (recreational) Other hook & line (commercial)

Bycatch

The primary documented threat to Loggerhead Sea Turtles in Canadian waters is the pelagic longline fishery (DFO 2006; McAlpine et al. 2007; Brazner and McMillan 2008; CSTSD 2009). Given our current understanding of the distribution of Loggerhead Sea Turtles in Canadian waters, this is likely the only fishery that poses a threat at this time (DFO 2005; James pers. comm. 2009). However, bottom trawl, gillnet, dredge, pot, trap or seining fisheries would pose a threat if they were to operate in waters where Loggerhead Sea Turtles are present (NMFS and USFWS 2008).

Loggerhead Sea Turtles (n=701) were reported by the International Observer Program (IOP) as incidentally captured by the Canadian Atlantic pelagic longline fleet from 1999–2006 within the Canadian Exclusive Economic Zone. The turtles were found concentrated in offshore areas along the Western Scotian Shelf and Georges Bank off Nova Scotia, and near the Grand Banks off Newfoundland (Brazner and McMillan 2008). As noted earlier (Abundance), the incidental catch for the fishery as a whole during that period averaged 1,199 annually, a substantial number given the estimate of total adult females nesting annually in the Northwest Atlantic was only ~17,000 (NMFS and SWFSC 2008).

A direct comparison between bycatch of Canadian Loggerhead Sea Turtles in the Atlantic pelagic longline fishery and the bycatch in the American pelagic longline fishery is not published. However, the most recent data on Loggerhead Sea Turtle takes from the observed U.S. pelagic longline fishery (observer coverage ~8%) are: 2004 (n=734) (Garrison 2005); 2005 (n=274) (Fairfield–Walsh and Garrison 2006); 2006 (n=561) (Fairfield–Walsh and Garrison 2007); 2007 (n=542) (Fairfield and Garrison 2008); and 2008 (n=772) (Garrison et al. 2009).

Quantifying the impact of this take on a population scale is difficult. In general, there is inadequate information to assess the size and status of the Loggerhead Sea Turtle stock. There is also insufficient information on the impact of foreign fisheries and other sources of mortality on this population (Lewison et al. 2004). Nonetheless, the significance of bycatch of juvenile Loggerhead Sea Turtles should not be underestimated (Crowder 2000; Lewison et al. 2004; Brazner and McMillan 2008; Mansfield et al. 2009). Mixed–stock analyses of juvenile Loggerhead Sea Turtles indicate that turtles from genetically distinct nesting assemblages mix extensively in oceanic habitats (Bowen et al. 2005; Bowen and Karl 2007). Juvenile Loggerhead Sea Turtles have the highest reproductive value to the species (Crowder et al. 1994). Therefore, longline and other fisheries capturing significant numbers of Loggerhead Sea Turtles per year may deplete some source populations throughout the region (Lewison et al. 2004; Bowen et al. 2005; Bowen and Karl 2007; Brazner and McMillan 2008; Alfaro Shigueto et al. 2008; Mansfield et al. 2009).

The literature on mitigation strategies as they apply to the United States pelagic longline fishery is extensive (e.g., Epperly and Boggs, 2004; Watson et al. 2005; Gilman et al. 2006), highlighting the usefulness of manipulating hook, gear type, and gear depth. In 2004, U.S. pelagic longline fleets switched from using primarily J–hooks to exclusively using 16/0– and 18/0–sized circle hooks. Although bycatch of Loggerhead Sea Turtles dropped in 2005, it has since rebounded to a level only slightly lower than pre–regulation period (Fairfield–Walsh and Garrison 2007; Fairfield and Garrison 2008; Garrison et al. 2009). Additional years of data are necessary to fully assess the impacts of these efforts to reduce Loggerhead Sea Turtle bycatch in the pelagic longline fishery (Fairfield–Walsh and Garrison 2007; Brazner and McMillan 2008; Fairfield and Garrison 2008; Garrison et al. 2009). Brazner and McMillan (2008) suggest that setting longlines on the cooler side of oceanic fronts might reduce Loggerhead Sea Turtle bycatch. Educating fishers about handling, dehooking, and release techniques is also an important measure in reducing post–hooking mortality (Martin and James 2005b; Ryder et al. 2006; Brazner and McMillan 2008).

Pollution

Loggerhead Sea Turtles ingest debris when it is mistaken for, or associated with, prey items. The effects can be lethal or non–lethal directly but also can have side effects that may increase probability of death (Balazs 1985; Carr 1987; McCauley and Bjorndal 1999; Witherington 2002; Mrosovsky et al. 2009). Side effects happen, for example, when non–nutritive debris replaces food in the gut; nutrient dilution occurs that may decrease somatic growth and reproduction (McCauley and Bjorndal 1999).

Offshore oil and gas production

Sea turtles at all life stages appear to be highly sensitive to oil spills, with effects including increased egg mortality; developmental defects; direct mortality due to oiling; impacts on the skin, blood, salt glands, and digestive and immune systems (Milton et al. 2003). Activities associated with offshore oil and gas production, including operational discharge (affecting water quality), seismic surveys, explosive platform removal, platform lighting and noise from drill ships and production activities are also known to impact Loggerhead Sea Turtles (Viada et al. 2008; Conant et al. 2009). Effects range from non–injurious (e.g., acoustic annoyance, mild tactile detection or physical discomfort) to non–lethal and lethal injuries (Viada et al. 2008). However, research in this area is still limited.

Climate change

Climate change and sea level rise have the potential to impact Loggerhead Sea Turtles in the marine environment, resulting in trophic level alterations that could affect the abundance and/or distribution of Loggerhead Sea Turtle prey (Chaloupka et al. 2008; Conant et al. 2009; Mazaris et al. 2009). Female Loggerhead Sea Turtles require at least a year to acquire sufficient fat stores necessary for reproduction as well as for the necessary energy required for migration. Cooler ocean temperatures are generally associated with increased productivity; a lag in productivity due to warmer temperatures can lead to reduced nesting and recruitment (Chaloupka et al. 2008; Mazaris et al. 2009).

North Pacific Population

Unfortunately, no exhaustive analysis of threats of the kind that exists for the northwest Atlantic population of Loggerhead Sea Turtles (NMFS and USFWS 2008) exists for the North Pacific population of Loggerhead Sea Turtles. Pacific Loggerhead Sea Turtles face many of the same threats as their counterparts in the northwest Atlantic. The following is an overview of primary threats based on available research for the North Pacific Loggerhead Sea Turtle population.

North Pacific Population: Terrestrial environment

Coastal development has reduced the habitat available for eggs and hatchlings in Japanese nesting colonies (Suganuma 2002; Kamezaki et al. 2003; Kudo et al. 2003). Coastal development includes building sea walls, dams and/or erosion control structures; removing sand and/or native vegetation from beaches; planting non–native vegetation on the beaches; as well as increasing beachfront lighting and vehicular and pedestrian traffic. (See detailed explanation for each of these threats in “Habitat Trends”). Unfortunately, there are no quantitative studies to determine the direct impact of these threats on Pacific Loggerhead Sea Turtle nesting populations (Kamezaki et al. 2003). Nonetheless, it is clear that nesting habitat has been impacted by these factors, which have contributed to unusually high mortality of eggs and pre–emergent hatchlings (Matsuzawa 2006). Beach debris also contributes to the deaths of hatchlings and nesting adults (Conant et al. 2009).

Egg harvesting of Loggerhead Sea Turtles no longer presents a problem in Japan (Kamezaki et al. 2003; Takeshita 2006). However, in northwestern Mexico, sea turtles are killed for human consumption despite a federal ban on turtle hunting and trade (Gardner and Nichols 2001; Nichols 2003). Sea turtles that are retrieved dead as bycatch are usually discarded; in general, only live turtles are retained or hunted for personal consumption or black market sale (Nichols 2003; Nichols and Safina 2004). Peckham et al. (2008) estimate Loggerhead Sea Turtle mortality due to human consumption (n=~50/year at a minimum), and indicate a need for further research to understand its effects on the population.

Climate change will increase the erosion rate along nesting beaches as a result of factors such as rising sea levels, and the increase of storm frequency and/or changes in prevailing currents (Antonelis et al. 2006; Baker et al. 2006). In low–lying nesting areas, erosion will cause the sea to inundate nesting sites and decrease available nesting habitat (Daniels et al. 1993; Fish et al. 2005; Baker et al. 2006). In addition, climate change may also affect Loggerhead Sea Turtle sex ratios because the species exhibits temperature–dependent sex determination. Increasing global temperatures may result in warmer incubation temperatures, and therefore, highly female–biased sex ratios (Mrosovsky and Provancha 1992; Davenport 1997; Glen and Mrosovsky 2004; Hawkes et al. 2009).

North Pacific Population: Marine environment

The greatest anthropogenic threat to this population is commercial fishing. It affects both juveniles and adults in the neritic zone. Coastal fisheries in Baja California Sur, Mexico, and Japan kill a significant number of turtles (Kamezaki et al. 2003; Peckham et al. 2007; Peckham et al. 2008). A large number (n=~1,500/year at minimum) die in Baja bottom–set gillnet/longline fisheries (Koch et al. 2006; Peckham et al. 2007; Peckham et al. 2008). There is also recorded fishery bycatch in the Western Pacific neritic foraging areas (Cheng and Chen 1997). Recent research suggests pound net fisheries off coastal Japan also pose a major threat (Conant et al. 2009).

Quantifying the magnitude of the threat to Loggerhead Sea Turtles posed by fisheries in the North Pacific is difficult because there is little observer coverage or investigation into bycatch conducted by countries that have large fishing fleets in the area. Lewison et al. (2004) tried to quantify the effect of longline fishing on Loggerhead Sea Turtles in the Pacific Ocean, analyzing data reflecting fishing effort for the year 2000. They estimated that between 2,600 and 6,000 Loggerhead Sea Turtles were killed annually through immediate or delayed mortality as a result of interacting with the gear. This suggests that vulnerable Loggerhead Sea Turtles in the region are taken as bycatch on average once every two years (Lewison et al. 2004).

Loggerhead Sea Turtles are killed or injured by collisions with boat hulls and propellers, though the population effect of this source of mortality has not been quantified (Conant et al. 2009). Impacts of oil and gas industries, climate change and sea level rise and marine pollution are similar to those described for the Atlantic populations.

The Loggerhead Sea Turtle is listed as threatened under the United States’ Endangered Species Act (USFWS and NMFS 1978) and as endangered by the International Union for Conservation of Nature (IUCN 1996). The species is a routine visitor to Atlantic Canadian waters; as a result, Canada plays a key role in the conservation of the northwest Atlantic population of Loggerhead Sea Turtles.

There is little information on the quantitative interaction of Loggerhead Sea Turtles with their environment or with other species (Bjorndal 2003). However, sea turtles have been employed worldwide as flagship species for conservation because of the widespread public support for these creatures (Frazier 2005; Martin and James 2005a; Martin and James 2005b).

Loggerhead Sea Turtles receive some protection from the Fisheries Act. The federal government fulfills its constitutional responsibilities for sea coast and inland fisheries through the administration of the Fisheries Act. The Act provides Fisheries and Oceans Canada (DFO) with powers, authorities, duties and functions for the conservation and protection of fish and fish habitat (as defined in the Fisheries Act) essential to sustaining commercial, recreational and Aboriginal fisheries.

The Loggerhead Sea Turtle is listed as “endangered” by the International Union for Conservation of Nature (IUCN) on its Red List (1996). It is an Appendix I species of the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES 2009), which prohibits the international trade of the species or its parts. Canada is signatory to CITES.

In the United States, the Loggerhead Sea Turtle was listed as threatened throughout its range on July 28, 1978, under the Endangered Species Act (USFWS and NMFS 1978).

The United States is party to the Inter–American Convention for the Protection and Conservation of Sea Turtles (IAC), the only binding international treaty dedicated exclusively to marine turtles (IAC 2003). The objective of the IAC is to “promote the protection, conservation and recovery of sea turtle populations and of the habitats on which they depend, based on the best available scientific evidence, taking into account the environmental, socioeconomic and cultural characteristics of the Parties” (IAC 2001).

The United States is also signatory to the Protocol Concerning Specially Protected Areas and Wildlife (SPAW) to the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region (Cartagena Convention), which lists Loggerhead Sea Turtles in Annex II. Annex II prohibits the “taking, possession or killing (including, to the extent possible, the incidental taking, possession or killing) or commercial trade in [listed] species, their eggs, parts or products; [and] to the extent possible, the disturbance of such species, particularly during periods of breeding, incubation, aestivation or migration, as well as other periods of biological stress" (NOAA 2009).

Loggerhead Sea Turtles are listed in Appendices I and II of the Convention on Migratory Species (CMS 2006), where they are protected by (a) the Memorandum of Understanding on the Conservation and Management of Marine Turtles and their Habitats of the Indian Ocean and South–East Asia; and (b) the Memorandum of Understanding Concerning Conservation Measures for Marine Turtles of the Atlantic Coast of Africa. Canada and the United States are not signatory to the CMS.

Caretta caretta
Loggerhead Sea Turtle tortue caouanne
Range of Occurrence in Canada: Atlantic Ocean
Demographic Information
Generation time Age at maturity is still disputed and estimates range from ~16–35 years. The mean of these is used here = 25 years. Gen Time = AM + (1 + 1/Annual rate of mortality) = 25 + (1 +1/0.05) = 25 +1 + 20 = 46 years (see p. 20 for more detail). 46 years
Is there an observed or projected continuing decline in number of mature individuals? Yes, observed and projected

Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]
(a) based on 1.6% decline calculated by (NMFS and USFWS) for the Peninsular Florida Recovery Unit (PFRU) using data collected from 1989–2008. PFRU chosen because 80% of all nesting in the Atlantic Ocean occurs there.
(b) based on 2.6% decline calculated by (TEWG 2009) for the PFRU using data collected from 1983–2005.

a) 7.7% [calculated over 5 years]; 77.3% [calculated over 2 generations, or 92 years]

(b) 12.3% [calculated over 5 years]; 91.1% [calculated over 2 generations, or 92 years]

[Observed percent reduction in total number of mature individuals over the last [10 years, or 3 generations].
(a) based on 9.1% calculated by TEWG considering only the last 10 years of data (1997–2007) for PFRU

(a) 9.1% [calculated over the last 10 years]
93% [calculated over 100 years]

[Projected or suspected] percent [reduction] in total number of mature individuals over the next [10 years, or 3 generations].
(a) based on 1.6% decline calculated by (NMFS and USFWS) for the Peninsular Florida Recovery Unit (PFRU). PFRU chosen because 80% of all nesting in the Atlantic Ocean occurs there.
(b) based on 2.6% decline calculated by (TEWG 2009) for the PFRU.
(c) Data not available for North Pacific population.

(a) 14.9% [calculated over 10 years]; 80.1% [calculated over 100 years]

(b) 23.2% [calculated over 10 years]; 92.8% [calculated over 100 years]

[Estimated percent reduction in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.
(a) based on 1.6% decline calculated by (NMFS and USFWS) for the Peninsular Florida Recovery Unit (PFRU). PFRU chosen because 80% of all nesting in the Atlantic Ocean occurs there.
(b) based on 2.6% decline calculated by (TEWG 2009) for the PFRU.

(a) 14.9% [calculated over 10 years]; 80.1% [calculated 100 years]

(b) 23.2% [calculated over 10 years]; 92.8% [calculated over 100 years]
Are the causes of the decline clearly reversible and understood and ceased?
Some causes of decline are understood and in some parts of the range of the species mitigation measures have been implemented. Fishing (bycatch) continues in Canadian waters. Bycatch in other areas continues. Loss of nesting habitat continues.
No
Are there extreme fluctuations in number of mature individuals? No
Extent and Occupancy Information
Estimated extent of occurrence Unknown
Index of area of occupancy (IAO)
(Always report 2x2 grid value; other values may also be listed if they are clearly indicated (e.g., 1x1 grid, biological AO)).
Unknown
Is the total population severely fragmented? No
Number of “locations * N/A
Is there an [observed, inferred, or projected] continuing decline in extent of occurrence? No
Is there an [observed, inferred, or projected] continuing decline in index of area of occupancy? No
Is there an [observed, inferred, or projected] continuing decline in number of populations? No
Is there an [observed, inferred, or projected] continuing decline in number of locations? No
Is there an [observed, inferred, or projected] continuing decline in [area, extent and/or quality] of habitat? Yes observed, inferred and projected
Are there extreme fluctuations in number of populations? No
Are there extreme fluctuations in number of locations*? No
Are there extreme fluctuations in extent of occurrence? No
Are there extreme fluctuations in index of area of occupancy? No
Number of Mature Individuals (in each population)
Population N Mature Individuals
One population in Atlantic Canadian waters, consisting of individuals from several nesting populations; Mean annual number of nesting females ~17,000 for the Northwest Atlantic population Unknown
Total Unknown
Quantitative Analysis
Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years]. N/A
Threats (actual or imminent, to populations or habitats)
In Canadian waters:
Fisheries bycatch (identified in the Atlantic pelagic longline fleet), marine debris, offshore oil and gas production, and climate change.

Threats to other life history stages outside of Canadian waters:

Northwest Atlantic Ocean
Threats (n=59) are detailed in Table 2. Major threats include fisheries bycatch (particularly in bottom trawl, pelagic and demersal longline, dredge fisheries and gillnets); ecosystem alteration (beach erosion and accretion); pollution (light pollution, marine debris, oil pollution); construction and development (beach armouring, beach sand placement, coastal construction, and dredging); and non–fisheries resource uses (legal and illegal harvest of eggs and nesting females, vessel strikes, and oil and gas activities).
Rescue Effect (immigration from outside Canada)
Status of outside population(s)?
Decreasing in U.S. waters
Is immigration known or possible? Yes
Would immigrants be adapted to survive in Canada? Yes
Is there sufficient habitat for immigrants in Canada? Yes
Is rescue from outside populations likely? Shared stock with the U.S. Rescue is unlikely because the Northwest Atlantic population as a whole is declining
Current Status
COSEWIC: Endangered (April 2010)
Status and Reasons for Designation
Status:
Endangered
Alpha–numeric code:
A2b+4b
Reasons for designation:
This species is declining globally and there are well documented, ongoing declines in the Northwest Atlantic population from which juveniles routinely enter and forage in Atlantic Canadian waters. The Canadian population is threatened directly by commercial fishing, particularly bycatch in the pelagic longline fleet, and by loss and degradation of nesting beaches in the southeastern USA and the Caribbean. Other threats include bycatch from bottom and midwater trawls, dredging, gillnets, marine debris, chemical pollution and illegal harvest of eggs and nesting females.
Applicability of Criteria
Criterion A: Meets Endangered A2b+4b. The decline (based on the number of nesting females) over the past 3 generations (100 years) exceeds 50% and causes have not ceased nor are they well–understood. A continued decline in the Canadian Northwest Atlantic population of the species is suspected due to continued (unmitigated) fisheries bycatch interactions and ongoing development and loss of nesting habitat.
Criterion B: Does not meet criterion. EO and IAO values are not available, but they are estimated to exceed thresholds.
Criterion C: Does not meet criterion as number of mature individuals likely exceeds thresholds (although technically all individuals in Canadian waters are juveniles).
Criterion D: Does not meet criterion for the same reasons as criterion C.
Criterion E (Quantitative Analysis): Not available.

* See definition of location.

The report writer is grateful for the help of Sean Blaney (Atlantic Canada Conservation Data Centre); Laura Bennett (Canadian Sea Turtle Network); Sheryan Epperly (National Marine Fisheries Service); Matthew Godfrey (North Carolina Wildlife Resources Commission); Michael James (Dalhousie University); Jack Lawson (Fisheries and Oceans Canada); Don McAlpine (New Brunswick Museum); Tara McIntyre (Fisheries and Oceans Canada); Sean Smith (Fisheries and Oceans Canada); Lisa Spaven (Fisheries and Oceans Canada); Katrina Stipec (B.C. Conservation Data Centre); Nancy Thompson (National Marine Fisheries Service); Christie Whelan (Fisheries and Oceans Canada); Blair Witherington (Florida Fish and Wildlife Conservation Commission); and Jeanette Wyneken (Florida Atlantic University) in preparing this report. The report writer is also grateful for the astute and helpful comments of the anonymous reviewers of this report. And, as always, the report writer is grateful for the pioneering work of Sherman Bleakney (Acadia University), who first drew scientific attention to the presence of marine turtles in Canada.

Sean Blaney
Botanist and Assistant Director
Atlantic Canada Conservation Data Centre
Sackville, New Brunswick

Kevin Davidson
Head, Endangered Species and Protected Areas
Environment Canada
Sackville, New Brunswick

Sheryan Epperly
Research Fishery Biologist, Sea Turtle Team Leader
National Marine Fisheries Service
Miami, Florida
United States

Gloria Goulet
COSEWIC Secretariat
Canadian Wildlife Service
Ottawa, Ontario

Dr. Matthew Godfrey
North Carolina Wildlife Resources Commission
Beaufort, North Carolina
United States

Dr. Michael James
Department of Biology
Dalhousie University
Halifax, Nova Scotia

Lisa Spaven
Fisheries Technician
Fisheries and Oceans Canada
Nanaimo, British Columbia

Katrina Stipec
British Columbia Conservation Data Centre
Victoria, British Columbia

Christie Whelan
Science Advisor, Fish Population Science
Fisheries and Oceans Canada
Ottawa, Ontario

Dr. Blair Witherington
Florida Fish and Wildlife Conservation Commission
Fish and Wildlife Research Institute
Melbourne Beach, Florida
United States

Dr. Jeanette Wyneken
Florida Atlantic University
Boca Raton, Florida
United States

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Kathleen Martin, Hon. B.A. with Distinction (University of Toronto), M.A. (Queen’s University), is Executive Director of the Canadian Sea Turtle Network, a non–profit group dedicated to conserving the endangered leatherback turtle. She has worked with the group since it began in 1997. Martin was previously a lecturer in the communications department at Acadia University, and is currently adjunct professor in the School for Resource and Environmental Studies at Dalhousie University.

Martin has an extensive background as a writer and editor. She has published peer–reviewed articles on the potential for resource users to become dedicated stewards of the environment and has routinely written, edited and adapted academic scientific content for a variety of audiences. She is a member of the Atlantic Leatherback Turtle Recovery Team, and has prepared a range of documents for Fisheries and Oceans Canada. She is also author of seven science books for children (Lerner Publishing Group, Minneapolis, MN) and is an award–winning journalist. In 2007, she shared the Gold Canadian Environment Award for Conservation.

Canadian Sea Turtle Network, Halifax, Nova Scotia.

Appendix 1. The following seven tables are the results of the north Atlantic Loggerhead Sea Turtle threat analysis conducted by the NMFS and USFWS (2008). They address each of the threats described in Table 2.
Detailed information used to derive estimated annual mortality is available: www.nmfs.noaa.gov/pr/recovery/plans.htm#turtles.
The colour coding matches Table 3.

Table A1. Results of the threat analyses for fisheries bycatch.
LIFE STAGE ECOSYSTEM TRAIL
(BOTTOM)
TRAIL (TOP/
MID–WATER)
DREDGE FISHERIES LONGLINE
(PELAGIC)
LONGLINE (DEMER–SAL) GILLNET (DEMER–SAL, LG, MESH) GILLNET (DEMER–SAL, SM, MESH) GILLNET (DRIFT) POUND NETS AND WEIRS POT/TRAP FISHERIES HAUL SEINES CHANNEL NET PURSE SEINE OTHER HOOK & LINE (RECREATIONAL) OTHER HOOK & LINE (COMMERCIAL) SUM RRV TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (#OF ADULT FEMALES)
Nesting female Terrestial Zone 0 1,000 0
Egg Terrestial Zone 0 0.004 0
Hatching stage Terrestial Zone 0 0.004 0
Swim frenzy, transitional stage Neritic Zone 1 1 0.004 0
Juvenile stage Oceanic Zone 30,000 1 1 30,002 0.029 870
Adult stage Oceanic Zone 1 1 2 0.789 2
Juvenile stage Neritic Zone 30,000 1 300 1 3,000 3,000 300 30 30 30 1 1 1 30 30 36,755 0.235 8,637
Adult stage Neritic Zone 300 1 30 1 300 300 30 3 3 30 1 1 1 3 3 3,707 0.789 2,925
TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (#OF ADULT FEMALES) 9,417 1 94 872 942 942 94 10 9 31 1 1 1 9 9
Table A2. Results of the threat analyses for resource use (non-fisheries).
Life Stage Ecosystem LEGAL HARVEST ILLEGAL HARVEST OIL AND GAS ACTIVITIES VESSEL STRIKES BEACH CLEANNIG HUMAN PRESENCE RECREATIONAL BEACH EQUIPMENT BEACH VEHICULAR DRIVING POWER GENER. ATINGACTIVITIES CONSERVATION RESEARCH ACTIVITIES MILITARY ACTIVITIES SALVAGE OPERATIONS SUM RRV TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (# OF ADULT FEMALES)
Nesting female Terrestial Zone 3 1 4 1.000 4
Egg Terrestial Zone 3,000 1 1 1 300 1 3,304 0.004 13
Hatching stage Terrestial Zone 1 1 1 1 1 1 6 0.004 0
Swim frenzy, transitional stage Neritic Zone 1 1 0.004 0
Juvenile stage Oceanic Zone 30 30 1 1 62 0.029 2
Adult stage Oceanic Zone 1 1 2 0.789 2
Juvenile stage Neritic Zone 3,000 300 30 300 3 3 1 3,637 0.235 855
Adult stage Neritic Zone 300 30 3 300 3 3 1 640 0.789 505
TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (#OF ADULT FEMALES) 943 107 10 308 0 0 0 3 3 4 2 0
Table A3. Results of the threat analyses for construction and development.
Life Stage Ecosystem BEACH SAND PLACEMENT BEACH ARMORING OTHER SHORELINE STABILIZATIONS SAND FENCES DREDGING STORM-WATER OUTFALLS COASTAL CONSTRUCTION CHANNEL BLASTING BRIDGE BLASTING SUM RRV TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (# OF ADULT FEMALES)
Nesting female Terrestial Zone 1 3 1 1 6 1.000 6
Egg Terrestial Zone 3,000 30,000 1 1 3,000 36,002 0.004 144
Hatching stage Terrestial Zone 3,000 1 1 1 1 3,004 0.004 12
Swim frenzy, transitional stage Neritic Zone 1 1 0.004 0
Juvenile stage Oceanic Zone 0 0.029 0
Adult stage Oceanic Zone 0 0.789 0
Juvenile stage Neritic Zone 30 30 0.235 7
Adult stage Neritic Zone 3 3 0.789 2
TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (#OF ADULT FEMALES) 25 123 1 0 9 0 13 0 0
Table A4. Results of the threat analyses for ecosystem alternations.
Life Stage Ecosystem TROPHIC CHANGES FROM FISHERY HARVEST TROPHIC CHANGES FROM BENTHIC HABITAT ALTERNATION BEACH EROSION (WASHOUTS) AND ACCRETION AQUA-CULTURE EUTROPHI-CATION SUM RRV TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (# OF ADULT FEMALES)
Nesting female Terrestial Zone 6 1.000 0
Egg Terrestial Zone 300,000 300,000 0.004 1,200
Hatching stage Terrestial Zone 0 0.004 0
Swim frenzy, transitional stage Neritic Zone 0 0.004 0
Juvenile stage Oceanic Zone 0 0.029 0
Adult stage Oceanic Zone 0 0.789 0
Juvenile stage Neritic Zone 0 0.235 0
Adult stage Neritic Zone 0 0.789 0
TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (#OF ADULT FEMALES) 0 0 1,200 0 0
Table A5. Results of the threat analyses for pollution.
Life Stage Ecosystem MARINE DEBRIS INGESTION MARINE DEBRIS ENTAGLEMENT IN DERELIC FISHING GEAR MARINE DEBRIS ENTAGLEMENT IN NON- FISHING GEAR BEACH DEBRIS OIL POLLUTION LIGHT POLLUTION NOISE POLLUTION THERMAL POLLUTION CHEMICAL POLLUTION SUM RRV TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (# OF ADULT FEMALES)
Nesting female Terrestial Zone 3 3 1.000 3
Egg Terrestial Zone 1 1 2 0.004 0
Hatching stage Terrestial Zone 1 1 300,000 300,002 0.004 1,200
Swim frenzy, transitional stage Neritic Zone 30,000 1 1 30,000 1 1 60,004 0.004 240
Juvenile stage Oceanic Zone 1 1 1 1 5 0.029 0
Adult stage Oceanic Zone 1 1 1 1 5 0.789 4
Juvenile stage Neritic Zone 1 300 30 30 1 362 0.235 85
Adult stage Neritic Zone 1 30 30 3 1 65 0.789 51
TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (#OF ADULT FEMALES) 122 95 32 0 130 1,203 0 0 2
Table A6. Results of the threat analyses for species interactions.
Life Stage Ecosystem PREDATION BY NATIVE SPECIES DISEASE AND PARASITES HARMFULALGAL BLOOMS PREDATION BY EXOTIC SPECIES EXOTIC DUNE AND BEACH VEGETATION SUM RRV TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (# OF ADULT FEMALES)
Nesting female Terrestial Zone 0 1.000 0
Egg Terrestial Zone 300,000 see comment 30,000 4 330,001 0.004 1,320
Hatching stage Terrestial Zone 3,000 1 4 3,002 0.004 12
Swim frenzy, transitional stage Neritic Zone 300,000 300,000 0.004 1,200
Juvenile stage Oceanic Zone 1 1 2 0.029 0
Adult stage Oceanic Zone 1 1 2 0.789 2
Juvenile stage Neritic Zone 1 1 30 32 0.235 8
Adult stage Neritic Zone 1 1 30 32 0.789 25
TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (#OF ADULT FEMALES) 2,414 0 31 120 0
Table A7. Results of the threat analyses for other factors.
Life Stage Ecosystem CLIMATE CHANGES NATURAL CATASTROPHES COLD WATER OTHER (EGG STAGE ONLY) SUM RRV TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (# OF ADULT FEMALES)
Nesting female Terrestial Zone 0 1.000 0
Egg Terrestial Zone 1 see comment 300,000 300,001 0.004 1,200
Hatching stage Terrestial Zone 1 1 2 0.004 0
Swim frenzy, transitional stage Neritic Zone 1 1 2 0.004 0
Juvenile stage Oceanic Zone 1 1 0.029 0
Adult stage Oceanic Zone 0 0.789 0
Juvenile stage Neritic Zone 30 30 0.235 7
Adult stage Neritic Zone 0 0.789 0
TOTAL ESTIMATED ADJUSTED ANNUAL MORTALITY (#OF ADULT FEMALES) 0 0 7 1,200

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