By Carl Safina, Elizabeth Brown
The island nation of Palau is a legendary tropical coral paradise, with perhaps the most farsighted fisheries management in the Pacific. Palau has protected its reef fishes from the export business that has destroyed fish populations on many reefs for the limitless demand in China. That’s why Palau remains a favorite destination for divers. The fish stay in Palau and the money comes to them.
But divers have to eat. And they like to order fish. So in the last few years, conservationists have been concerned by signs that the fish are declining. But how do you count fish on complex coral reefs? No one’s ever figured out how. Plus monitoring fish populations typically requires years of data collection and a lot of money – something Palau and many other developing nations often lack. So it’s hard to assess the effects of fishing.
But now scientists with the Nature Conservancy organization have come up with a clever new way. Instead of counting the number of fish in the water, the idea is to determine the proportion of the population capable of breeding for each fish species. And to use fishermen to collect the data, so it costs very little money! Thescientists teamed up with the fishermen of Palau to try it out. The scientists trained fishermen on how to measure the length of the fish they catch. They also showed them how to cut open the fish’s stomach and inspect their gonads to determine the sex and if it’s sexually mature or an immature juvenile. This information will tell them if enough fish are breeding to repopulate and sustain the fish populations, and if the fish are growing to their adult size.
Between August 2012 and June 2013, trained Palau fishermen were able to collect information on the species, size, and maturity of 2,800 fish!
The data revealed that 60% of the fish they are catching are juveniles, meaning they have not yet had the chance to breed or grow to full size. And for some of the most common caught reef fish, they found that only a very small amount of the population was breeding. The data clearly show Palau’s fish are in decline and risk of collapse. More....