Trace amounts of oil in blue crab larvae are cause for alarm.
“It would suggest the oil has reached a position where it can start moving up the food chain instead of just hanging in the water,” said Bob Thomas, a biologist at Loyola University in New Orleans. “Something likely will eat those oiled larvae … and then that animal will be eaten by something bigger and so on.”
Tiny creatures might take in such low amounts of oil that they could survive, Thomas said. But those at the top of the chain, such as dolphins and tuna, could get fatal “megadoses.”
And even if the crabs aren’t immediately killed by the oil, it could have a severe effect on their ability to reproduce, scientists say. If enough are impacted, it could cause a decline in the next generation — and if fishing is allowed to resume then, the population could be further exacerbated. These kinds of impacts support the claims of other researchers, who fear that the worst of the damage from the BP spill may be done to the strata of life that resides in the deep sea. Scientists do note that it’s good news that most of the larvae they’re collecting are alive, and they aren’t worried that blue crabs will be wiped out by the spill — they’re simply too abundant. But they raise the concern that diminished numbers of crabs may impact other animals who rely on them as a food source, and could harm other populations.