After a long day asking local Brazilians and museum staff for donations, a researcher sighed with relief. Someone had given them exactly what they had been looking for: a sawfish rostrum.
The critically endangered fish is difficult to find alive, so many researchers use the bones that grow along their long snouts, or rostra, to learn more about the elusive species, said Jens Hegg.
The UI College of Natural Resources alumnus has been selected for a Fulbright award to Brazil. Hegg will travel to the city of Belém, located in the state of Pará, Brazil, in July.
Hegg currently works as analytical lab manager of the Kennedy LIFE Lab under UI associate professor Brian Kennedy. Hegg “oversees collaborations and analytical services” at the lab, according to his biography on the lab’s website.
Hegg said he plans to stay in Brazil for four months, collecting data and finding information before returning to UI to analyze his findings at the lab.
The two fish Hegg will investigate — Atlantic tarpon and sawfish — are endangered species. Hegg’s work will help track their migration patterns so people can better predict where these populations will be at various times of the year. Hegg said he hopes this will minimize animals being unintentionally caught in fishing nets meant for other populations, known as by-catching.
“Their big threat is that they get caught in fishing nets. If you could figure out where they were during what period, you could maybe start to look at ways to minimize the effect of that by-catch of them getting caught in that fishing net.”
Hegg will investigate ear bones, or otoliths, of the fish to determine where they travel. He said they grow like the rings of a tree, except the bones grow rings of calcium deposits instead of bark.
When polished, scientists can determine how fast a fish grew, the age of the fish and the type of water the fish was in at the time of growth — all based on the size of the rings and which minerals they find in the otoliths, Hegg said. Hegg will use similar information from tarpon scales and sawfish rostral teeth — the teeth that line the fish’s long snout like a chainsaw — to learn about their migration patterns.
“We’re going to be looking at whether we can distinguish those movements and whether that might be a way to start to understand where they’re moving, when they’re moving,” Hegg said.
Hegg will work with two other Fulbright recipients in Brazil — Alex Fremier of Washington State University’s School of the Environment and Carson Jeffres of the University of California, Davis’ Center for Watershed Sciences. All three recipients will work with Tommaso Giarrizzo of the Federal University of Pará.
Hegg said he hopes his work will help bring awareness to these endangered species. He said if people know the fish are out there, they may begin to care more about them.
“Just knowing that there is this fish out there, that it’s this really cool cartilaginous fish — it looks like a shark with a hedge trimmer on its face and they can be 10, 15 feet long and over 1,000 pounds — knowing that even exists is something that most people don’t know,” Hegg said. “And knowing that they’re critically endangered — if I could get that word out — that’s a good start.”
Lex Miller can be reached at [email protected]