"If you think it’s not our fault, urine denial."
"A slender forked tail suddenly pokes through the surface of the shallow waters around Biscayne Bay, Florida, some 50 meters in front of where our small skiff is floating. The tail belongs to a bonefish, a skittish and elegant species with an elongated body roughly the length of an adult male’s forearm and so called because of its numerous little bones. The fish is busily using its slim snout to dig in the sediment and seagrass for crabs, shrimp, and other good things to eat. As it does so, the tip of its tail pops up, and Nicholas Castillo, a PhD candidate at Florida International University, calls excitedly, “It’s tailing.”
Jennifer Rehage, a fish ecologist and Castillo’s PhD supervisor, drops anchor near a mangrove island hosting a flock of snowy egrets, their snapping bills loudly clicking. Castillo, who is also an expert fisherman, selects a colorful artificial fly from his kit. He’s got one shot at catching the fish. If he makes a wrong move, the fish will take off at high speed—bonefish can swim up to 64 kilometers per hour. We all climb out of the boat, and I’m instructed to stay nearby and not make a sound. Castillo stealthily wades toward where we saw the tail, then stops and waits. He whips the line back and forth using a fly-fishing cast, then lands the fly expertly on the surface, where it slowly sinks. The bonefish bites on the first cast but fights hard against Castillo’s pull, thrashing and squirming in the water. It takes a minute or so, but in the end Castillo reels the fish in.
Castillo and Rehage are catching bonefish to investigate why the population has plummeted over the past 35 years around South Florida and areas in the Caribbean Sea. South Florida is world renowned for sportfishing, a reputation that was built, in part, on the size and number of bonefish that were once found there. Today, that population is halved and the fish are smaller. Precise numbers of bonefish are not known, but researchers use the average number of bonefish caught by anglers per month as a way of estimating the decline. The bonefish catch fell from a high of over 25 fish in the late 1980s to a low of around five from 2010 onward. Bonefish are having other problems, too. A healthy fish population typically has an equal number of males and females. But in his fieldwork, Castillo has seen many more males than females, and without large females the population produces fewer eggs and larvae, he explains. Castillo also suspects the population’s spawning behavior might be “out of whack.”"
Natasha Gilbert reports for Hakai magazine February 2, 2022.
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