Researchers at the Palau International Coral Reef Center (PICRC) are investigating the movement patterns of fish between open ocean and coral reef environments, in order to better gauge the connectivity between the Palau National Marine Sanctuary (PNMS) and areas open to fishing.
The study, which involves examining fish muscle tissue of open ocean species such as sharks and tunas, is meant to determine how these fish travel from the protected area, where their numbers are supposed to be rejuvenating, to areas accessible to local fishermen.
Researchers at PICRC, along with researchers from Stanford University, have collected 174 tissue samples from 16 open water species, which are being chemically analyzed to determine how these species move between the deep waters and the shallow waters. PICRC has also received 1,139 tissue samples from 25 reef-fish species from the Coral Reef Research Foundation for chemical analysis.
Many of the species being studied are predatory species which move between the open ocean and coastal waters to feed.
The PNMS was founded on the concept that closing off 80% of Palau’s waters will spur a “spillover effect”, in which fish repopulating the closed zones will also replenish those zones which are open to fishing, such as the near-shore zones and the commercial fishing zone. With upcoming elections placing more stress on the large protected area to prove its long-term benefits, the study hopes to gain more insight into if and how this spillover will take place.
The study is also aimed at evaluating the impacts of phenomena like climate change on marine environments and shifting fishing pressures from reef-fish to pelagics.