A Cameron County marine expert says he believes a bull shark is likely responsible for the Fourth of July shark attacks at South Padre Island that injured four people in one day.

“The shape of the bite marks on the people, it looked very similar,” Tony Reisinger, the Cameron County extension agent with Texas Sea Grant at Texas A&M University, said. 

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The shark that bit two people and injured two others during the Fourth of July shark attacks didn't leave behind any teeth, making official identification harder.

Bull sharks are the third most likely shark species to bite people, according to the shark attack file program at the Florida Museum of Natural History. 

A new study shows the number of bull sharks in the Gulf of Mexico is growing.

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Research done over the last 20 years shows the population of bull sharks has gone up five times in one part of the Gulf, and there's evidence that the population may also be rising in the rest of the Gulf as well.

Lindsay Mullins with Mississippi State University was the lead researcher on that project. 

Mullins and her colleagues looked at fish surveys done by the Alabama Department of Conservation and Natural Resources that showed the number of bull sharks counted increased year after year.

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Mullins says previous research in Texas shows the same trend.

"I definitely suspect that this is something that is not going to be just affecting the coast of Alabama, it's going to be a Gulf-wide thing wherever bull sharks are found,” Mullins said.

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