Closing the Data Gap on Stock Assessments

The difficulty of obtaining reliable data, which vary across species, fleets, and regions, is a challenge for stock-assessment scientists in advising fisheries managers how to optimally manage tuna stocks.

Dr. Simon Hoyle, a scientist for the National Institute of Water and Atmospheric Research (NIWA) in New Zealand, developed a way to assess tuna stocks by catch-per-unit-of-effort, or CPUE. He first developed CPUE indices for tuna stock assessments in 2005. Since 2015, he has been developing joint longline indices in collaboration with scientists from distant water fishing nations.

Read his “Closing the Data Gap” blog post.


ISSF Resources for Stock Assessment

Stock Assessment Workshop Reports

ISSF convenes periodic workshops to review Regional Fisheries Management Organization (RFMOs) strategies for assessing tuna stocks. Workshop topics have included uncertainty in stock assessment and the adoption of harvest control rules.

Read all five workshop reports here.


Interactive Status of the Stocks Tool

We developed a data-visualization Web tool based on our long-running and widely followed Status of the Stocks report. You can use the tool to visualize tuna-stock health and catch by fishing method — including filtering data by stock area and exporting graphics.

Click here to use the tool on our website.


About the International Seafood Sustainability Foundation (ISSF)
The International Seafood Sustainability Foundation (ISSF) is a global coalition of scientists, the tuna industry and World Wildlife Fund (WWF) — the world’s leading conservation organization — promoting science-based initiatives for the long-term conservation and sustainable use of tuna stocks, reducing bycatch and promoting ecosystem health. Helping global tuna fisheries meet sustainability criteria to achieve the Marine Stewardship Council certification standard — without conditions — is ISSF's ultimate objective. To learn more, visit, and follow ISSF on TwitterFacebook and Instagram.