The damages from the Deepwater Horizon spill just keep piling on. Added to the oil-laden birds, sick mammals and dead sea corals caused in the short-term, and the general decline in fish and wildlife populations in the long-term, a new study demonstrates how commercial fish exposed to crude oil while they're just embryos go on to develop potentially lethal heart defects and other deformities.
And according to the New York Times, that too will figure into the total amount for which BP will be held responsible.
The Verge describes the study, which used actual oil samples from the Gulf spill:
To study the effects of the BP oil disaster, scientists recreated the oceanic environment that yellowfin amberjack, yellowfin tuna and bluefin tuna larvae would have encountered in 2010 in the lab. They did so by introducing the larvae to Deepwater Horizon oil samples at environmental conditions that matched those of the spill. Fish are extremely vulnerable during development, so studying fish larvae is the most direct way of demonstrating the effect of noxious compounds.
The researchers found that the fish exhibited a number of heart defects including slower heart rates, fluid accumulation, and arrhythmia — a condition characterized by an irregular heartbeat. In the areas where the oil concentrations were the highest, the oil would have caused the larvae to die of heart failure, says John Incardona, research toxicologist at the National Oceanic and Atmospheric Administration and co-author of the study. Fish larvae that were located further away probably survived, but if these heart defects mean that "they can't swim as fast, so they are either going to get eaten or they won't be able to eat enough," he says. "That leads to reduced survival."
The researchers can't say for sure how the Gulf's fisheries will be impacted, but particularly for the bluefin tuna, that's one more thing threatening an already threatened species (overfishing and water pollution have taken their toll as well).
BP maintains that "the paper provides no evidence to suggest a population-level impact on tuna, amberjack, or other pelagic fish species in the Gulf of Mexico" because "oil concentrations used in the lab experiments were rarely seen in the Gulf during or after the Deepwater Horizon accident." That, however, contradicts the methodology described by the peer-reviewed paper (and backed up by several unaffiliated scientists).
As study author John P. Incardona, of the National Oceanic and Atmospheric Administration’s Northwest Fisheries Science Center, told the Verge, "we will find out eventually."