Oiled birds and stranded boats have been some of the most compelling visual images of the devastation in Galveston Bay in the wake of an oil tanker collision that might have released up to 168,000 gallons of fuel oil into the Gulf of Mexico on Saturday.
But marine scientists and fishing industry officials worry that the spill poses longer-term dangers beneath the surface of the bay’s waters, which are among the most productive in the world and a key resource for a multibillion-dollar recreational and commercial fishing industry.
“An awful lot of things that are the most at risk are in the water” and out of sight to most observers, said Doug Rader, chief oceans scientist for the Environmental Defense Fund. “The health of the [seafood] populations is intimately tied to the health of the bay.”
In 2012, the most recent year for which data is available, nearly 5.8 million pounds of fish were commercially harvested from Galveston Bay, at a combined wholesale value of $16.4 million.
More than one-10th of that income comes from shrimp, which are among the most vulnerable species to the oil spill, in part because the brown shrimp’s spawning season is already underway, beginning in earnest near the end of March. The spawning happens in the Gulf of Mexico, but soon afterward the new shrimp larvae will spend days, if not weeks, drifting in the water toward the bay and shoreline marshes. That’s where they will metamorphose into baby shrimp, eventually maturing into adults and returning to the Gulf after several months.
During that journey, many shrimp may encounter clumps of the black, sticky oil that has sunk beneath the water’s surface. An even bigger concern to Greg Stunz, a biologist at the Harte Research Institute for Gulf of Mexico Studies at Texas A&M University-Corpus Christi, is what might happen when the shrimp larvae reach their destination, where even more of the difficult-to-remove oil is likely to have washed up.
“Once they start using the marshes, that is the defining moment of when everything’s got to be just right,” Stunz said. “The marshes are their homes and grocery stores. And if your home’s polluted, you’re not going to survive.”
Many other species that go through a similar process are also threatened, including blue crab and menhaden, a small fish that is valuable for fish oil products and as prey for other species. If they end up ingesting oil and surviving, the effects will continue up the food chain, potentially affecting human consumers. (Oysters are also a major product from Galveston Bay, but oystering has already been closed there for two weeks because of an algal bloom that could contaminate those fish.)
It could be years before the extent of the consequences to the food chain become clear, because scientists will have to wait for future spawning seasons and will have to test the current populations once they mature. Researchers will have to monitor the possible effects for as much as a decade into the future, Rader said.
In the meantime, fishing activity has been severely curtailed. While state health inspectors have not yet said fish harvested from Galveston Bay cannot be consumed, access to large portions of the bay are cut off, and those wishing to harvest fish farther offshore have no way to get to the Gulf. Recreational charter boats are unable to operate during the peak spring break season, and a number of charter boat business owners have already filed a class-action lawsuit against the operators of the oil barge and bulk carrier that collided, causing the spill.
Buddy Guindon, owner of a wholesale and retail seafood market in the Galveston Harbor, said his offshore boats were forced to reroute to Freeport, about 50 inland miles away. “That’s quite inconvenient and expensive,” he said.
Guindon said he won't harvest shrimp from Galveston Bay for now, and will buy more from Louisiana shrimpers.
“I just want to make sure that the all-clear is given to this stuff before we put seafood in the chain that’s contaminated,” he said. He employs 35 shrimpers, and business was ramping up as temperatures warmed up along the Gulf after a long, cold and unproductive winter season.
Consumers’ perceptions can also play a major role in determining how much the fishing industry suffers from the incident. After the Deepwater Horizon disaster in 2010, Guindon said he tested hundreds of harvested fish to prove they were safe, but the market shrank from concerns about the spill. His business lost hundreds of thousands of dollars, and he is still waiting on claims from BP.
It won’t help that a study with negative findings about the effects of that 2010 oil spill was released this week by an international group of marine scientists. The researchers found that the salmon, tuna and other species’ embryos were deformed by the spill, contributing to heart defects later in their lives.
Rader said the lessons from that study can be easily applied to the current oil spill. Scientists said the defects in the tuna and other fish occurred because they were spawning in the area where the spill occurred — a parallel situation to what could develop in Galveston Bay today.
“You have sensitive early life history stages that are being exposed to toxins,” he said.
In fact, the species in Galveston Bay could be even more vulnerable than those studied in the wake of the Deepwater Horizon disaster, Rader said. That’s because the crude oil that spilled in 2010 does not persist in the environment as long; its toxicity is more acute, but short-lived. The fuel oil that spilled last weekend could have much longer-term effects, he said.