Science Response 2019/032

Assessment of Leatherback Sea Turtle (Dermochelys coriacea) Fishery and Non-Fishery Interactions in Canadian Waters: 2018 Update

Context

The Leatherback Sea Turtle (Dermochelys coriacea) was listed as Endangered under the Species at Risk Act (SARA) in 2003, a recovery strategy for the species in Atlantic Canadian waters was published in 2007 (Atlantic Leatherback Sea Turtle Recovery Team 2006), and a proposed action plan was posted in 2018 (DFO 2018). An objective of the recovery strategy is to identify and understand anthropogenic threats to Leatherback Sea Turtles in Canadian waters. This includes synthesizing and evaluating existing data on commercial fishing and other human activities that may impact recovery. The recovery strategy commits to undertaking a scientific review of the sources and rates of human-induced mortality every five years. The previous review was held in 2012 (DFO 2012a), so the Species at Risk Management Division in the Maritimes Region requested an update of this information in 2017. The information generated will be used by Fisheries and Oceans Canada (DFO) to inform continued efforts to protect and recover the Leatherback Sea Turtle.

The objective of this Science Response is to assess the levels of Leatherback Sea Turtle interactions with fisheries in Atlantic Canadian waters, as well as to assess other non-fisheries related interactions. This assessment aims to answer the following questions:

1. What are the current sources of fisheries interactions with Leatherback Sea Turtles in Atlantic Canadian waters?
2. What are the current sources of non-fisheries interactions with Leatherback Sea Turtles in Atlantic Canadian waters?

This update considers new information on anthropogenic impacts to Leatherback Sea Turtles in Atlantic Canadian waters available following the publication of a more detailed Canadian Science Advisory Secretariat (CSAS) review of this topic in 2012 (DFO 2012a). Confirmed threats to Leatherbacks in Canadian waters include ingestion of marine debris and vessel strikes; however, no substantive new information is available on these phenomena. Oil and gas exploration and development, including associated noise, has been posited as threat to this species, yet data specific to the Canadian context is also currently lacking. Therefore, the present summary focuses on Leatherback-fishery interactions. A review of various data sources, including Species at Risk Act (SARA) logbooks, fishery observer program records, and recently published turtle-fishery interaction data from citizen science networks suggest that Leatherback Sea Turtle interactions with Atlantic Canadian fisheries have been historically underestimated. The present results indicate that, in addition to pelagic longline fisheries, fixed fishing gear presents a regular hazard to Leatherback Sea Turtles. While this review provides new details on threats to this species in Atlantic Canada, the broad spatial and temporal distribution of Leatherback Sea Turtles in this region makes them challenging to monitor, and estimation of the true incidence of turtle-fishery interactions and accompanying rates of injury and mortality here remain uncertain.

This Science Response Report results from the Zonal Science Response Process of March 29, 2018, on the Assessment of Leatherback Turtle Fishery and Non-Fishery Interactions in Atlantic Canadian Waters.

Science Response 2019/032 (PDF, 632 KB)

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