Oil’s effect on fish
Researchers say exposure hinders survival of fish by affecting cardiac health, cognition
University of Texas researchers studying effects of the Deepwater Horizon spill on fish find it decreases their ability to grow and impairs their cognitive function.
PORT ARANSAS — The immediate impact the 2010 Deepwater Horizon oil spill had on animals and marine life in the Gulf of Mexico was obvious.
Turtles and dolphins were pulled from the ocean coated in slick, brown oil. Brown pelicans and laugh gulls turned up dead at alarming rates. Coral reef colonies stretching from Alabama to Florida suffocated under the weight of millions of barrels of oil, their vibrant colors getting dimmer and dimmer as they died.
But the long-term impacts of the BP-leased oil rig explosion, which dumped about 4.3 million barrels of crude oil into the Gulf, are still being ferreted out.
Researchers at the University of Texas at Austin’s Marine Science Institute in Port Aransas are lending their expertise to this study, specifically looking at how oil impacts cardiac health in fish.
“Oil is a well-known inhibitor of cardiac performance, which can have a whole bunch of ecological consequences beyond just death,” said Andrew Esbaugh, an associate professor who studies fish physiology at the institute.
Those consequences are not good ones.
Compared to their healthy counterparts, oil-exposed fish grow and find food and other resources slower, Esbaugh said. They also struggle to swim at maximum capacity and, he added, they are two times more likely
to be become prey than healthy fish.
Research also shows oil exposure impairs the cognitive function of fish, making them take more risks and, therefore, increasing the chances they will become prey. These observations are preliminary, however, and institute scientists plan to examine this strange behavior in the future. Esbaugh began studying the oil spill impacts about four years ago with funding from the Gulf of Mexico Research Initiative. The initiative is an independent research board created to hand out the $500 million BP set aside for research programs after the spill, according to its website.
The institute is specifically looking at red drum fish — a game fish found in the Gulf of Mexico that the institute works with extensively. But a wide swath of marine life, from Mahi Mahi to crustaceans, is being examined for oilrelated consequences by other institutions, including the University of Miami in Florida.
In Miami, researchers have found that oil exposure results in poor vision and impaired cardiac performance in Mahi Mahi. It’s also negatively impacted the fish’s reproduction and swimming pattern, as well as their susceptibility to predators, according to the university’s website.
Back in Texas, Esbaugh also has found that even short term oil exposure has harmful impacts that can stretch for weeks, or even months. For example, 24 hours of oil exposure can have side effects that last two months, Esbaugh said.
The UT-Austin Marine Science Institute researchers will study these cardiac impacts for another year or so, he said. He hopes their findings will influence where oil rigs are built and, potentially, improve compensation calculations for commercial fishermen if and when another accident occurs, he added.
“Whenever you have oil development, despite the best engineering, you’re going to have spills,” Esbaugh said. “But if you know that early life stage animals are susceptible and if you know where their needed habitats are, you can say OK, maybe we shouldn’t do things in a certain area.”