Bluefin Tuna Larval Survey - Oceana USA

Report | December, 2009

Bluefin Tuna Larval Survey


The Oceana-MarViva project represented a new effort in the Mediterranean in defense of the North Atlantic bluefin tuna (Thunnus thynnus) (BFT), one of the most important commercial species living in the Mediterranean Sea1. According to the last stock assessments carried out by the Standing Committee on Research and Statistics (SCRS) of the International Commission for the Conservation of Atlantic Tunas (ICCAT), the bluefin tuna stock in the East Atlantic is still in critical condition. Furthermore, the Mediterranean Sea constitutes a hot spot because, while important spawning grounds are located here, this sea also constitutes the main fishing grounds for the industrial fleet of purse seiners that catches BFT during the critical spawning season.

This report presents the preliminary results of the first-ever larval survey carried out by NGOs. The summer 2008 Oceana-MarViva campaign focused on providing further evidence of active spawning sites for bluefin tuna and other associated species. Larval samples were taken in some of the most relevant bluefin tuna spawning areas in the Mediterranean Sea, including southwest Malta, the southern Tyrrhenian Sea and the Aegean Sea, onboard the research vessel Marviva-Med, from 15 July to 11 August. Ichthyoplankton samples from 52 stations were taken using a bongo 90 net for surface plankton tows. The species found included the larvae of several tunas and tuna-like species such as bluefin tuna, albacore, frigate tuna and skipjack tuna, as well as swordfish larvae.