The electrofishing boat, which biologists once used to find out which fish species were present in a body of water, is becoming outmoded now that identification is possible through fish DNA present in the water itself.
CHARLESTON, W.Va. -- To biologists, the answers to life's mysteries seem cut and dried -- at least until someone proves they aren't.Decades ago, fisheries biologists didn't think twice about taking fish from one part of the country and stocking them into another. To determine which fish species were present in a body of water, biologists simply cordoned off an area with nets, poisoned everything within it, and took the fish back to the lab for study.Times have changed. Biologists seldom approach their work in such blunt-edged fashion anymore, mainly because they've discovered better and more effective ways to accomplish what they set out to do.Chris O'Bara, a fish biologist for more than 30 years, has seen what he calls "a dramatic change" in the way he and his colleagues conduct their affairs.
"Back when I got started, fish biologists were more like naturalists than scientists," O'Bara said. "To survey a population, we collected specimens by shocking or netting or seining or poisoning them. We looked at what we had, tried to make some sense of it, and tried to figure out what to do about it."For example, when walleyes began disappearing from West Virginia rivers and lakes during the late 1950s through the 1960s, Division of Natural Resources biologists did what colleagues in other states were doing -- they brought in walleyes from the Great Lakes and stocked them."We now realize that was a mistake," said O'Bara, who heads up the DNR's fisheries research arm."The reason we know that is because advances in genetics research showed us that the Great Lakes fish have a different genetic makeup from walleyes that were native to our rivers."Armed with that knowledge, DNR officials are now able to identify native-strain walleyes, breed them in the state's two warm-water hatcheries, and stock them instead of Great Lakes fish.
O'Bara said many of the methods and gadgets fisheries biologists use today were originally used in other areas of biological and biomedical research."What we have done is borrow, steal and use approaches that were pioneered in other disciplines," he said.Gene research, he added, has had a particularly strong influence."With the techniques developed in the field of molecular genetics, we are able to tell why some strains of fish do better than others. It started in the early 1980s when people started studying Florida-strain largemouth bass, and it just exploded from there. Nowadays a lot of people are looking at a lot of species, and are applying their findings to fisheries management."Advances in medical pathology have helped biologists better understand how disease can affect both wild and hatchery-grown fish populations.
"Early on, the only diseases we worried about were those that affected the fish we were growing in our hatcheries," O'Bara said. "We never thought about diseases in wild populations. We figured most fish kills were caused by environmental problems."
That began to change when scientists trained in medical pathology started applying their expertise to fish."Now a lot of the people studying fish diseases are 'fish veterinarians.' They're giving us medications and techniques we can use to control disease in our hatcheries and, as a result, stock healthier fish," O'Bara said.Some of the cutting-edge work seems almost like science fiction. O'Bara said biologists are now able to visit a body of water, take a few water samples, and determine which fish species are present by the DNA they find."It's called environmental DNA, or eDNA," he explained. "It's very good for detecting the presence of invasive species such as Asian carp. It's also good for helping us find rare species that are difficult to collect."I can foresee a day when, instead of going out with gill nets and electrofishing boats, we'll just go out and collect water samples to see what fish are there. We could use the same techniques for finding diseases, too."O'Bara likened modern fisheries research to the work done by forensic pathologists on TV shows such as "CSI" and "Bones."
"What we do is not much different from that," he said. "We use many of the same techniques crime labs do."Even with all the advances, O'Bara believes future generations of biologists will look back on today's techniques and laugh."Technology will push the way we do our business," he said. "I've had kids ask why we did things the way we did, putting cyanide in the water to sample fish. Well, it was the breaking edge of technology at the time. Twenty-five years later, we wonder what the heck we were thinking about."O'Bara said the biologists of the future will need to be far better communicators than biologists of his generation were."Kids now are getting their information from smartphones, websites, blogs and the like," he said."I think biologists 25 years from now won't even have offices. They'll work off some gadget that's like a smartphone, only 100 times smarter. Information will fly back and forth from one biologist to the other. The beneficiaries will be the sportsmen, who will have better and healthier fisheries because of the work those biologists will be doing."Reach John McCoy at firstname.lastname@example.org or 304-348-1231.