While we know that Palau is connected to its neighboring countries by the ocean, we do not know the extent of this connectivity and whether fish and corals from nearby countries contribute to the populations here in Palau.
To answer these questions of how fish and coral larvae move around in the ocean, Palau International Coral Reef Center enlisted the assistance of Professor Eric Wolanski, an oceanographer from James Cook University, to work with its researchers to examine the connectivity of Palau with its neighbors.
Using a hydrodynamic modeling, PICRC researchers and Dr. Wolanski predicted movement of coral and fish larvae that reaches Palau from different countries. Dr. Wolanski provided satellite-derived water current data, recorded at 5-minutes intervals, from all over Micronesia between 1993 to 2015. This data was used to drive the larva oceanography model to study the movement of fish and coral larvae across Palau and Micronesia.
The initial results of the modelling work by PICRC researchers were unexpected. While there is connectivity from Yap to Palau, this connectivity is small. Most of the connectivity to Palau is with Asian countries such as the Philippines and Indonesia, especially Biak Island in Irian Jaya. These results explain why Palau is so much more diverse than other Micronesian Islands, with diversity similar to those of high biodiversity countries such as the Philippines and Indonesia.
The ocean current systems coming from Micronesian islands like Pohnpei, Chuuk, Kosrae and Guam, do not pass through Palauan waters. Instead, water from Indonesia and the Philippines are directly circulating into Palauan waters on and off via large-scale oceanic eddies.
The implications of the study are clear. While Palau needs to continue to work on conservation and management of its resources, it should also strengthen collaborations with neighboring islands. While Palau is part of the Micronesian region and should continue to work with other Micronesian islands, efforts need to expand to our neighboring countries of Indonesia and Philippines. We need to collaborate on efforts to minimize negative impacts to our reefs and fish populations.
The results of this study also support the creation of the Palau National Marine Sanctuary. Our exclusive economic zone (EEZ) is a pathway for many coral and fish larvae from our neighboring counties to reach Palau. Protecting this pathway is as important as protecting the source of these populations so Palau will continue to get it supplies of corals and fish from it neighboring countries. (PR)
This figure shows the source of fish larvae to Palau. The thickness of the arrow indicates the amount connectivity with thicker arrows indicating higher connectivity. [/restrict]