Postdoc Spotlight: Seven Seas Sound Off

The state of Florida is often called the fishing capital of the world, with more than 10,000 miles of rivers for both the pro and rookie anglers. However, this has led to overfishing of multiple fish species, including the commercially and ecologically important grouper, according to Ali Ibrahim, postdoctoral fellow in the Harbor Branch Oceanographic Institute (HBOI), who is eavesdropping on these threatened species to help find ways to protect them.

Born and raised in Iraq, Ibrahim studied electrical engineering and obtained both his undergraduate and master's degrees in the country. In 2014, he came to the United States to earn his doctorate degree in electrical engineering and began his work at FAU where he examines sound to study the spawning behavior of grouper.

Spawning aggregations are large gatherings of fish and typically monitored using scuba divers in the water, though surveying is limited by sea conditions and geography. So, little is known about when and where these aggregations occur, Ibrahim said.

Using sound is best suited for tracking fish such as the red and yellow fin grouper, black grouper, and the Nassau grouper, which Ibrahim is researching, because these fish make noises when they reproduce. Using innovative technology and machinery, he extracts the features of their noises picked up by underwater passive acoustic monitoring devices, to identify and classify the different species. This allows him to identify where each species spawns. "We can protect the fish in these areas and prevent overfishing."

"The main idea of the project is to support spawning aggregation, because over a longer time period, the fish will begin to come back," Ibrahim said.

Ibrahim also applies these passive acoustic monitoring techniques to better study the critically endangered North Atlantic right whale, which migrate through Florida every winter up to their feeding grounds. The whales wind up entangled in fishing gear and are also hit by large commercial ships, said Ibrahim. Only about 360 of these whales remain in the world. By listening to their vocalizations, he can learn more about their movement patterns and build models that can help conservation efforts. "These models predict where the whales will be traveling based on their sound, so we take them to commercial ships in order to avoid collisions between ships and whales."