Small But a Big DealNot too surprisingly, the BP oil spill had a big impact on various ecosystems in the Gulf of Mexico, and that includes some of those that we can't see with the naked eye. Microbes might be small, but what they lack in stature they make up for in importance.
To figure out how coastal microbe communities were impacted by the oil, researchers took samples after the Deepwater Horizon oil rig blew up, but before oil had time to reach the shores, and then they took more samples after the oil got there. By analyzing the differences, they found something that "shocked" them.“In that short time period, we saw a drastic change in the microbial community,” says lead author Holly Bik, a postdoctoral researcher at UNH’s HCGS when the research was conducted, now at the Genome Center at the University of California, Davis. “We were shocked at how drastic the change was, pre- and post-spill.”
[They] found that the communities of microbial eukaryotes (organisms not visible to the naked eye whose cells contain nuclei) in the sediments shifted dramatically from highly diverse communities dominated by nematodes – “what you would expect on a beach,” says Bik -- to an almost exclusively fungal community.
What’s more, those post-spill fungi seem to have an appetite for oil. “The fungal taxa that were there were previously associated with hydrocarbons,” Bik says, noting that the group of fungi sampled post-spill from the Grand Isle sites are suspected to utilize hydrocarbons and thrive in hostile, polluted conditions that appear to be intolerable for other marine fungi. [...]
While nematodes and fungi are hardly charismatic and are unlikely to turn up on the dinner table, these little-understood yet abundant organisms are nonetheless important. “They underpin the entire ecosystem,” Bik says. “If you knock out the base of the food pyramid, you’re not going to have food higher up in the food chain.” Further, they are also important for nutrient cycling and sediment stability. [...]
“If you turned up at the beach in September and looked around, you would have had no idea there was an oil spill,” Bik says. “Yet our data suggest considerable hidden initial impacts across shallow Gulf sediments that may be ongoing.” Ongoing research and sampling will aim to determine whether fungi are thriving and persisting long-term and whether the shift in communities is an ephemeral, seasonal or a more permanent phenomenon.
So while it's not surprising that oil-eating micr-organisms thrived after the oil spill, what is of more concern is what will happen now that the communities of microbes that dominated the area before the spill are gone or almost so. Hopefully things will go back to a healthy equilibrium quickly, but that's not a sure thing.