The 1995 Code of Conduct for Responsible Fisheries (the Code) of the Food and Agriculture Organization of the United Nations (FAO) calls for the sustainable use of aquatic ecosystems and requires that fishing be conducted with due regard for the environment. The Code also promotes the maintenance, safeguarding and conservation of biodiversity of ecosystems by minimizing fisheries impacts on non-target species and the ecosystem in general. A great deal of concern has been expressed by fishery managers and conservation/environmental groups that by-catch and discards may be contributing to biological overfishing and altering the structure of marine ecosystems. Such claims are frequently based on observations of large numbers of discards and high discard ratios or rates, but infrequently on detailed population assessments of impacted stocks. This is perhaps because comprehensive and historical datasets involving discards have generally been unavailable to demonstrate such claims, although a growing body of literature does support the conclusion that for some species and regions of the world, biological and ecological impacts are discernible. For this reason there has been increasing interest in addressing by-catch issues, and a joint meeting of the tuna Regional Fisheries Management Organisations (tRFMOs) in Brisbane 2010 as part of the KOBE process, specifically focused on this topic.
By-catch issues have become particularly important for long-lived marine megafauna such as sharks, sea turtles, seabirds, and marine mammals. Individual fishers often underestimate the cumulative effect of all fishing activities because by-catch of these species may be a relatively rare event and represents a small fraction of the total by-catch biomass. However, given the life history characteristics of most marine megafauna (slow growth, low reproductive rates, high adult survival), relatively low levels of by-catch can have a large effect on population viability. Many of these species are threatened (sensu International Union for Conservation of Nature, IUCN), having suffered declines as a result of excessive incidental mortality caused by fisheries.
In order to improve the knowledge on by-catch species the SCRS recommended that a short-term by-catch coordination study be conducted with the objectives of: (a) creating a meta-database of reports and publications providing information about by-catch species from tuna and related fisheries; (b) developing a database for unprocessed and aggregated by-catch data for priority species such as marine mammals, turtles, sea birds, and many sharks, rays and teleost fish that are not subjected to stock assessment by ICCAT; (c) establishing interaction with scientists leading national observer programmes to obtain previously unreported data and to make an inventory of past and current observer programmes; and (d) developing forms and protocols for the collection of more and higher quality by-catch data in the future. The study was completed in 2010.
In 2012, the ICCAT Secretariat hired a By-catch Coordinator to harmonise and analyse fishery datasets related to by-catch species of tuna fisheries in the ICCAT area. As part of his tasks, The By-catch Coordinator is in charge of updating and maintaining the ICCAT by-catch meta-database.
Identification Guides for by-catch species
The seabird by-catch identification guides drafted by the Agreement on the Conservation of Albatrosses and Petrels (ACAP) can be downloaded here.