PICRC Partners with BOFI to Study Tuna Spawning in the PNMS

The Palau International Coral Reef Center (PICRC) and Belau Offshore Fishers Incorporated (BOFI) have launched a new study of tuna spawning in the Palau National Marine Sanctuary (PNMS). To understand tuna’s reproduction in Palau’s waters and the PNMS, PICRC researchers are collecting gonad samples from BOFI’s catch.

Although tuna spend most of their lives migrating through the open ocean, they periodically gather together for reproduction and spawning. These gatherings, which are critical to maintaining the tuna’s population, also leave them vulnerable to overfishing.

“Sanctuaries like the PNMS are effective because as tuna migrate through them, they’re protected from fishing” said Dr. Louw Claassens, PNMS Science Officer/Researcher. “But the conservation value of a sanctuary is much higher if it also protects these critical spawning events, when the tuna are especially at risk.”

Domestic fishers like BOFI also benefit from protected spawning areas, as spawning events in the PNMS can replenish tuna stocks in the nearby Domestic Fishing Zone. 

“Through our work with BOFI, we’ll be able to measure the occurrence and frequency of tuna spawning events in the PNMS,” continued Dr. Claassens. “If we find extensive spawning activity, that’s a good indicator that the Sanctuary is acting as a source of tuna for our domestic fisheries.”

To measure spawning activity in the PNMS, PICRC researchers are collecting gonad samples from the tuna BOFI brings to market. By measuring the development of eggs in each sample, researchers can track when spawning events are occurring throughout the year.

“The partnership with BOFI has been an enormous help,” said King Sam, PNMS
Director. “Our study requires large numbers of gonad samples, which take a lot of time and resources to collect. But, by using the fish that BOFI is already bringing in, we have fresh samples to analyze every month. It’s a great example of how organizations can work together to get research done!” 

PICRC and BOFI will continue collecting gonad samples for at least the next year, building a clear picture of tuna spawning behavior in the PNMS over time. Ultimately, this study will demonstrate the importance of the PNMS for supporting domestic tuna fisheries, and reveal how Palau’s conservation efforts are impacting tuna populations throughout the Pacific.