A nearly 400 pound thresher shark and an 800 pound tuna were some of the fish being caught at the Casco Bay classic fishing tournament in Maine this week.
This tournament is about more than sport, it's also about science.
In the Casco Bay competition, it's more important to conserve the fish than it is to keep them.
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The only sharks that can be kept are macos, porbeagles and threshers. All sharks are then tagged, so researchers at the University of New England can track them.
The organizers also donate tens of thousands of dollars to shark research.
While it may seem counterproductive, scientists say fishing sharks can help grow their population in the Gulf of Maine, since it's an opportunity to collect data about the different species that serves the population as a whole.
The tournament wraps up Saturday.