10 MARINE MAMMALS AND SEA TURTLES - Hebron Project

Hebron Project Comprehensive Study Report
Marine Mammals and Sea Turtles
10.3.3.1 Fisheries and Oceans Canada Sighting Database
DFO in St. John‘s (J. Lawson 2007, pers. comm.) is compiling a database of
sea turtle sightings in waters around Newfoundland and Labrador. These
data provide some indication of what species can be expected to occur in the
area, but they cannot, at this point in the development of the database,
provide any fine-scale quantitative information as the database typically does
not include observation effort. However, no additional sea turtle observations
were reported in the Nearshore or Offshore Study Areas that were not
already described in the offshore monitoring of seismic activity in Jeanne
d‘Arc Basin or in the sea turtle entrapment records maintained by the Whale
Release and Stranding Group (see Section 11.3.2.6).
10.3.3.2 Species Profiles
Loggerhead Sea Turtle
Loggerhead sea turtles occur in temperate and tropical areas of the Atlantic,
Pacific, and Indian Oceans, with the majority of nesting occurring along the
western rims of the mid- and equatorial Atlantic and Indian Oceans (Spotila
2004). Globally, there are an estimated 43,000 to 45,000 nesting females
(Spotila 2004). There is an unknown number using Canadian waters, but
loggerheads are thought to occur off eastern Newfoundland during summer
and fall. Loggerhead sea turtles have not been considered by COSEWIC and
have no status under SARA, but are listed as Endangered on the Red List of
Threatened Species (IUCN 2009).
Adult loggerheads are known to migrate considerable distances between
nesting areas along the central Atlantic coast and temperate foraging areas
(Hawkes et al. 2007). Some individuals move with the Gulf Stream into the
Canadian Atlantic. Loggerheads found in Canadian waters are generally
smaller than those found in coastal US waters, suggesting that they are
younger animals (Witzell 1999). Nesting in the western Atlantic occurs from
late April to early September, while they are typically found in higher latitudes
during summer and fall (Spotila 2004).
Witzell (1999) described incidental captures of loggerheads during 1992 to
1995 in the U.S. pelagic longline fishery, which ranged from the Caribbean to
Labrador. The majority of loggerheads (70 percent) were captured on or east
of the Grand Banks and from June to November; catches were highest in
September. However, loggerhead catches mirrored the distribution of fishing
effort. None were sighted during summer and fall monitoring programs in the
Jeanne d‘Arc Basin, although one was observed 237 km south of that area in
early September 2008 (Abgrall et al. in prep.). While the available information
suggests that loggerhead sea turtles could occur in the Offshore Study Area,
their presence is likely to be rare and occur only during late summer to early
fall.
There are no records or reports of loggerhead sea turtles occurring in Trinity
Bay, or any other nearshore area of Newfoundland. It is possible that
10-30 June 2010