Study of the migratory pattern and habitat of the silky shark (Carchahinus falciformis) in the Indian Ocean

Grande M, Onandia I, Erauskin-Extramiana M, et al (2022) Study of the migratory pattern and habitat of the silky shark (Carchahinus falciformis) in the Indian Ocean. AZTI

In 2018, the Echebastar purse seine fishery for skipjack in the Indian Ocean was certified against the MSC Standard for Sustainable Fishing. One of the components comprising the Standard relates to the impact of the fishery om ETP species. We did not meet the standard for PI 2.3.3 leading to a condition to certification being defined requiring demonstration “that information is adequate to measure trends and support a strategy to manage impacts on ETP species”. This condition did not refer to a specific ETP species, rather the need to have sufficient observer data. The work of the Echebastar Sustainability Group allowed this condition to be closed at the third annual audit in mid-2022, albeit after some delay due to various issues related to the COVID pandemic.

The main ETP species taken as a by catch by our vessels is silky shark. However, the number of these taken as a by catch is relatively low and does not hinder recovery of the species. That being said, we remain strongly aware of our obligation to minimise the impact of our fishing activities on other elements of the ecosystem. In the past, this has led us to adopt a number of mitigation measures such as non-entangling FADs, reduced number of FADs, double conveyor belts on some of its fishing vessels and the application by the crews of good handling practises.

While these activities have proven to be sufficient to meet the MSC Standard, the our stated policy is to go beyond those requirements wherever possible and to further strengthen our sustainability credentials. In relation to silky shark, a two-step approach was adopted.

- Firstly, to examine the post capture survival of silky shark released from our vessels.

- Secondly, to improve understanding of the migratory patterns and habitat of silkies in the expectation that this could lead to further mitigation measures.