Terms of Reference

Assessment of Incidental Catch in the Atlantic Canadian Swordfish/Other Tuna Longline Fishery

Regional Peer Review - Maritimes Region

February 24-25, 2016
Dartmouth, Nova Scotia

Chairperson: Kristian Curran

Context

Incidental by-catch and discarding of non-targeted species occur in many fisheries. Discarding of targeted species also occurs for regulatory reasons or licence restrictions as, for example, undersized fish. An objective of sustainable fisheries management is to manage discard mortality for targeted species and to control the incidental mortality for non-targeted species. In the context of the longline fishery for Swordfish and other tunas (Bigeye Tuna, Yellowfin Tuna and Albacore) this requires a comprehensive plan for monitoring fishing activity, measuring the discard mortality, and establishing suitable references to indicate when that mortality is unacceptable.

Fisheries and Oceans Canada (DFO) Resource Management, Maritimes Region, in conjunction with the DFO Science Branch, Maritimes Region, initiated the ‘Work Plan to Address Incidental Catch in the Atlantic Canadian Swordfish/Other Tuna Longline Fishery’. The comprehensive work plan consists of a number of projects with three main objectives:

1. Examining appropriate levels of observer coverage;
2. Managing discards for all targeted species; and
3. Controlling incidental mortality for non-targeted species.

This science assessment meeting is a follow-up to a meeting previously held on this topic in July 2011 entitled ‘Incidental Catch in Canadian Large Pelagic Fisheries’ (DFO 2011).

The Work Plan focuses on seven species that are caught as incidental catches in the Swordfish/other tuna longline fishery: Bluefin Tuna, Porbeagle, Shortfin Mako, Blue Shark, Leatherback and Loggerhead turtles, and undersized Swordfish.

Objectives

• Document factors associated with discarding of the target species and provide estimates of juvenile swordfish discards.
• Determine if observer sampling is representative of the fleet and appropriate for the seven species identified in the ‘Work Plan to Address Incidental Catch in the Atlantic Canadian Swordfish/Other Tuna Longline Fishery’ (i.e., undersized Swordfish, Bluefin Tuna, Porbeagle, Shortfin Mako, Blue Shark, Leatherback Turtle, and Loggerhead Turtle).
• Identify potential strata for the purpose of improving precision of discard estimates. In addition, investigate alternative methods for discard estimation.
• Summarize available information on the habitat use of marine turtles in Canadian waters; areas of potential and/or documented  turtle-fishery interaction; how ecophysiology can influence species’ distribution and occurrence; and how the distribution of observer coverage can enhance the collection of valuable data pertaining to turtle biology and incidental capture.
• Assess the change (+/-) in encounters per species to be detected with 95% certainty and estimate the level of annual observer coverage needed to detect this change.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document

Participation

• DFO Science
• DFO Fisheries and Aquaculture Management
• DFO Species at Risk Management
• DFO Policy and Economics
• Aboriginal communities / organizations
• Provincial (NS and NB) governments
• Industry / non-government organizations

Reference

DFO. 2011. Considerations for the Estimation of Incidental Catch in the Eastern CanadianSwordfish/Other Tunas Longline Fishery. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2011/057.