By 2050, Palau is predicted to lose 25% of its fisheries catch potential due to climate change alone. The unrelenting demand for fish, joined by the threats of a changing climate and continually advancing technology, require more sophisticated and effective conservation measures. For Palau, this means that, in addition to ensuring community and leadership support for the nearshore Protected Areas Network (PAN), we need more expansive and progressive management approaches than what we have done in in the past to implement bul. Establishing the Palau National Marine Sanctuary (PNMS) located far away from our traditional nearshore fishing grounds is an example of this forward-thinking approach. However, the distance and scale of this offshore marine protected area necessitates management that is guided by information and supported by research.
Since December 2018, the Palau International Coral Reef Center, in collaboration with the National Geographic Society and the University of Hawaii, has been carrying out a project called, Examining the potential effects of climate change on the distribution, long-term movements and local fisheries productivity of pelagic and nearshore resources in the Palau National Marine Sanctuary. This project is funded by the Government of Italy. There are four components of this project:
1) Determining whether or not Palau’s waters are nursery habitats for tuna. This is done by analyzing the fish otolith (fish bone near the brain) using stable isotopes. The isotope analysis can tell us where the fish was born and where it lived every year of its life. This research will tell us whether juvenile tuna recruited in Palau’s waters remain within the PNMS, and thus part of the nation’s domestic fisheries.
2) Determining whether or not the movement of tuna within the PNMS is being influenced by climate change. A satellite tag is attached to the fish and stays on for about a year. After a year, the tag will automatically release from the fish. Once it is released, it will send the data by satellite, where PICRC researchers will access them. With this information, researchers can analyze where the fish has been, as well as determine preferred water temperatures, depths and patterns followed throughout the year. Together, this information can inform how the fish movement pattern changes in response to climate change. Despite their ability to swim large distances, pelagic fish may spend significant portions of their life within the managed MPA for reproduction and feeding and this analysis will shed light on whether the movements of this species are retained within the PNMS.
3) Determining ideal locations of Fish Aggregating Devices (FADs) by using acoustic tags to monitor the movement of the fish around and among the FADs. In addition to showing movement of tuna within the PNMS, the data will also reveal which FADs perform better than others and establish the factors that substantiate why some FAD locations are better than others. The tags will last about two years, thus giving information over multiple seasons.
4) Monitor reef fish stocks to determine the effectiveness of PNMS to reduce pressures on reef fish, and shift demand of reef fish to pelagic species. Reef fish surveys will continue to be conducted in one hundred seventy-six sites around Palau using diver operated stereo-video system. The stereo-video system’s advanced features enable it to not only capture the number of fish but also very accurate measurement of fish sizes.
The importance of this research is significant because not only are the global pelagic fisheries already in decline, but also, because climate change is predicted to redistribute the world’s fisheries over the next few decades. In addition, other climate-related factors are also already playing a part in contributing to this oceanic change, including bleaching from increasing temperatures and storms, ocean acidification, and the decrease in oxygen concentration.
By establishing the PNMS, and thus potentially increasing the density of marine life inside the country’s EEZ, Palau is committing to better management of its fisheries, especially tuna, to ensure food security for its people. At the same time, the PNMS prioritizes tuna for local consumption as opposed to the already fragile reef fisheries. The PNMS protects 500,000 km2 of ocean, which is 80% of Palau’s EEZ. This measure will ensure long-term local food security and biodiversity conservation within Palauan waters and establishes Palau as a world leader in marine conservation.