The Indian Ocean Tuna Commission (IOTC) is the main regional fisheries management organisation mandated to manage tuna and tuna-like species in the Indian Ocean and adjacent seas. While its primary objective is to assure the conservation and optimum utilisation of fish stocks, the IOTC has paid increasing attention in recent years to the impacts of its fisheries on other marine species, such as marine turtles, seabirds and sharks. IOSEA and IOTC have developed a good working relationship, which has included collaboration in the production of regular status reports on marine turtles, the development of turtle ID cards for fishermen and, most recently, co-funding of the production of a region-wide Ecological Risk Assessment (ERA) for marine turtles.
Membership of IOTC is open to coastal countries and to countries or regional economic integration organisations that are fishing for tuna in the Indian Ocean. There is a substantial overlap in the respective memberships of IOTC and IOSEA. Indeed, twenty-three of the 31 IOTC Contracting Parties and two Cooperating Non-Contracting Parties (collectively known as CPCs) are also signatories to IOSEA. Many are also members of the Convention on Migratory Species, the parent organisation of IOSEA. This might help to explain, in part, why IOTC has been receptive to substantive discussions about fisheries interactions with non-target migratory species.
The annual meeting of the IOTC Scientific Committee includes on its agenda a presentation and review of national reports submitted by CPCs.1 These reports cover such topics as: background/general fishery information, fleet structure, catch and effort by species and gear, recreational fishery, ecosystem and bycatch issues, national data collection and processing systems, national research programmes, and implementation of IOTC recommendations and resolutions relevant to the Scientific Committee.
These reports are a rich source of information on fisheries potentially interacting with marine turtles in the Indian Ocean, as well as on monitoring programmes and bycatch mitigation measures that may have been implemented by IOTC members. They include, for example, data on the size and coverage of longline and purse seine fleets, as well as trends in fishing effort and shifts in the geographic distribution of fishing fleets. Such information could eventually be useful in helping to identify areas where marine turtles may be more or less prone to interactions with fisheries. The reports also contain information that may be used to assess the extent of compliance with various IOTC resolutions and recommendations pertaining to mitigation of marine turtle bycatch.
Incidentally, the reports also contain some data on the incidence of turtle bycatch, however this aspect is generally incomplete and based on very limited observation and reporting. Indeed, the IOTC Scientific Committee has expressed concern in the past “that the lack of data from Contracting Parties and cooperating non-contracting Parties (CPCs) on the interactions and mortality of marine turtles from fisheries under the mandate of the IOTC undermines the ability to estimate levels of turtle bycatch and consequently IOTC’s capacity to respond and manage adverse effects of fishing on marine turtles”.
Until now, the IOTC national reports have never been analysed systematically from the standpoint of assessing their potential contribution to the understanding of marine turtle bycatch in the Indian Ocean and of the efficacy of bycatch mitigation measures undertaken by IOTC members. The following analysis does just that, by compiling and summarising information from all of the national reports submitted to the 15th Scientific Committee meeting held in Seychelles in December 2012.