{"id":633,"date":"2013-12-15T11:01:00","date_gmt":"2013-12-15T16:01:00","guid":{"rendered":"http:\/\/ncseagrant.ncsu.edu\/coastwatch\/?page_id=633"},"modified":"2024-07-02T12:20:49","modified_gmt":"2024-07-02T16:20:49","slug":"gutting-edge-science-fish-stomachs-help-identify-atlantic-pelagic-food-web","status":"publish","type":"post","link":"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/gutting-edge-science-fish-stomachs-help-identify-atlantic-pelagic-food-web\/","title":{"rendered":"GUTTING-EDGE SCIENCE: Fish Stomachs Help Identify Atlantic Pelagic Food Web"},"content":{"rendered":"\n\n\n\n\n
Catching fish is the most important part of fishing. Gutting is a messy step to cook what is landed. For seafood lovers and anglers, fish guts and gonads are rarely of any value. Most often, they land in the trash.<\/p>\n\n\n\n
But Stephen Poland, a marine biology master’s student at the University of North Carolina Wilmington, has spent many months collecting the cast-offs from large pelagic fish \u2014 such as wahoo, tuna, mahimahi and marlin \u2014 caught in the Atlantic Ocean off the coasts of North and South Carolina. Pelagic fish live far off in the sea and travel widely rather than stay close to land.<\/p>\n\n\n\n
“It is not something one should talk about right before dinner,” Poland admits. However, he adds that removing stomachs and studying their contents gives researchers the best chance of understanding predator-prey relationships among these fish.<\/p>\n\n\n\n
Poland and his graduate advisor, Frederick Scharf, who teaches biology and marine biology at UNCW, say these discarded fish guts hold the key to understanding the complex ecological relationships between large Atlantic pelagic predators and their prey.<\/p>\n\n\n\n
“There is not a lot known about the prey species that large pelagic fish are dependent upon and their basic life history even though we know they are central to the Atlantic marine ecosystem,” Scharf says.<\/p>\n\n\n\n
Funded by North Carolina Sea Grant, Scharf and Poland are analyzing the stomach contents of these fish to answer half-understood questions such as: What do the predator fish eat? How much of it do they eat? How do their diets change throughout the year? How does it influence their reproductive output?<\/p>\n\n\n\n
The project depends heavily on the catch from commercial and recreational fishermen and charter boats. This is an example of successful citizen science research, where fishermen collect the samples that researchers then analyze.<\/p>\n\n\n\n
“The research has the potential to open doors for many other research endeavors. It will help answer a lot of questions and generate many others,” Poland says. The scientists hope that these findings and the resulting database will help create an ecological map and a comprehensive food web of the pelagic environment in the South Atlantic.<\/p>\n\n\n\n
“Without such data and a bigger ecological map, it would be difficult to identify and avoid any future conflicts or tradeoffs in fisheries management,” Scharf adds. For example, he notes that it is hard to know how actions, such as fishing and harvesting a stock, might affect the fish population in the sea and alter the ecological balance of the Atlantic.<\/p>\n\n\n\n
Researchers know that top pelagic predators are capable of affecting community dynamics in offshore marine ecosystems. However, “sampling the species that large pelagic fish feed on has been traditionally difficult,” Scharf says.<\/p>\n\n\n\n
Most of the prey often are not targeted by fisheries operating in the region, so sampling of these fishes is restricted to their occurrence in the diets of fish that are caught, Poland explains.<\/p>\n\n\n\n
Stomach contents of predatory fish caught by commercial and recreational fishermen provide a viable and credible way of throwing light on the gaps in the Atlantic food web. This is why Poland spends most of his time collecting and analyzing fish innards.<\/p>\n\n\n\n