Of the total commercial tuna catch worldwide, about 87% comes from stocks at “healthy” levels of abundance, according to the March 2025 International Seafood Sustainability Foundation (ISSF) Status of the Stocks report, and that percentage is similar to findings shared in the previous November 2024 report. Overfished stocks account for 2% of the total catch — down eight percentage points from the last report. The percentage of the catch that came from stocks at an intermediate level of abundance is 10% — an eight-percentage-point increase from November 2024 findings.
Changes in stock status ratings since the November 2024 report are limited to Indian Ocean yellowfin tuna. The abundance or spawning biomass (SSB) rating for Indian Ocean yellowfin improved from orange to yellow, and the exploitation rate or fishing mortality (F) rate for the stock improved from orange to green.
New for this year’s report is more detail in the color ratings table for each tuna stock. The color ratings table, which appears at the end of each tuna stock summary, now contains a more detailed rationale for the stock’s SSB and F ratings. This additional information provides important context, especially when ISSF ratings for a stock are not identical to the RFMO science body ratings, as currently is the case for Indian Ocean yellowfin and Pacific Ocean bluefin.
According to the March 2025 report, these stocks are considered overfished and/or subject to overfishing:
- The Indian Ocean bigeye stock is overfished and subject to overfishing, unchanged since the November 2024 report.
- Pacific Ocean bluefin is overfished, also unchanged since the November 2024 report.
For each stock, ISSF assigns color ratings (green, yellow or orange) using a consistent methodology based on two factors: stock abundance and fishing mortality. Each stock is rated separately and color-coded to indicate not only the severity of the problem but also the likelihood that the problem will continue in the future. Additional details on the protocol used and the color ratings decision table can be found on pages 16 and 17 of the report.
ISSF publishes its signature Status of the Stocks report several times yearly using the most current scientific data on 23 major commercial tuna stocks. Related infographics for the March 2025 report are available here and here.
Key Statistics in the New Status of the Stocks Report
- Abundance or SSB levels: Globally, 65% of the 23 stocks are at a healthy level of abundance—unchanged since the November 2024 report. Additionally, 9% of the stocks are overfished—marking a decrease of four percentage points since the previous report. Since the November 2024 report, the percentage of stocks at an intermediate level has increased by four percentage points, reaching 26%.
- Fishing mortality levels: 91% of the 23 stocks are not experiencing overfishing — an improvement of four percentage points from the November 2024 report. About four percent are experiencing overfishing — around five-percentage-point decrease since the previous report. Also, about 4% are at an intermediate level—unchanged since November 2024.
- Tuna production by fishing gear: 66% of the catch is made by purse seining, followed by longline (9%), pole-and-line (7%), gillnets (4%) and miscellaneous gears (14%).
- Largest tuna catches by stock: The five largest catches in tonnes — all unchanged since the previous report — are Western Pacific Ocean skipjack, Western Pacific Ocean yellowfin, Indian Ocean skipjack, Indian Ocean yellowfin, and Eastern Pacific Ocean skipjack.
- Total catch: The catch of major commercial tunas was 5.2 million tonnes in 2023, a 1% decrease from 2022. Fifty-seven percent of it was skipjack tuna, followed by yellowfin (31%), bigeye (7%) and albacore (4%). Bluefin tunas accounted for 1% of the global catch.
The Status of the Stocks report is reviewed by the ISSF Scientific Advisory Committee (SAC), which provides advice on its content and ratings, following the agreed ISSF methodology. The report does not advocate any particular seafood purchase decisions.
About the Status of the Stocks Report
There are 23 stocks of major commercial tuna species worldwide—six albacore, four bigeye, four bluefin, five skipjack and four yellowfin stocks. The Status of the Stocks summarizes the results of recent scientific assessments of these stocks and the current management measures adopted by the RFMOs, as of March 2025.
Produced several times each year, the Status of the Stocks presents a comprehensive analysis of tuna stocks by species. The Evaluation of the Sustainability of Global Tuna Stocks Relative to MSC Criteria provides scores for the stocks and RFMOs based on MSC assessment criteria. Together, these tools help define the continuous improvement achieved and the areas and issues that require more attention.
In addition, ISSF maintains a data visualization tool based on its Status of the Stocks report. The “Interactive Stock Status Tool” is located on the ISSF website and accessible through the Status of the Stocks overview page. Users can easily toggle through tuna abundance and exploitation health indicators by catch or stock, filter by location and species, and see the share of total catch by species/stocks and gear types.
