Scientists at Penn State University have discovered two new coral reefs near the site of BP’s historic 2010 oil spill in the Gulf of Mexico, and the impacts to those reefs from the spill have been greater than expected, according to research released Monday.
The two additional reefs found by the PSU team were both farther away and deeper than the one coral reef that had previously been found to have been impacted by the spill. That indicates not only that marine ecosystems may be more greatly affected, but that some of the 210 million gallons of oil that BP spilled into the Gulf is making its mark in the deep sea.
“The footprint of the impact of the spill on coral communities is both deeper and wider than previous data indicated,” PSU biology professor Charles Fisher, who led the study, said.
ThinkProgress spoke with Fisher to find out more about what the study says, what it means, and whether or not the findings spell trouble for the future of the Gulf.
TP: Your research noted that not all coral reefs surrounding the Macondo well were impacted by the spill. Can you explain, in your own words, what you found with regard to the corals that were actually impacted?
CF: The corals we found that were impacted were all within about 22 km of the spill site, and we could tell they were impacted by the appearance. Partially dead colonies were covered with growths of things that don’t normally grow on coral.
We know this impact was linked to the Macondo well, and that has to do with another study that we did in 2010. We found one [coral] site in 2010, and when we found it, the corals still had brown goo on it. The oil on those matched the chemical fingerprint of the oil from BP’s spill. We returned to that site and have followed the progress. So we know what a coral looks like that was impacted in 2010 looks like in 2011, and so on.
You don’t see this anywhere else, so all the rest of the corals that we found had the exact same characteristics. Things happened in a very predictable way.
How does your research compare to what we already knew about the BP spill’s impact on coral in the Gulf?
Before this study, we had only found one impacted site that was 14 km southwest of the spill. Now we’ve found two more, one of which is 22 km to the east. So this defines a larger circle of impact.
There was an oil plume from the spill detected at the time that modelers said predominantly moved away to the southwest at depths of like 1000 to 1400 meters. To find another impact to the east, and much deeper than that suggested means one of two things. Either the plume went further afield in different directions than some models suggested and deeper, or that there was a second mechanism that might have impacted the corals.
That second mechanism could be from sinking oil that was on a slick on the surface that either naturally emulsified and started to sink, or it could be that there was dispersant applied, and the dispersant started to sink. That’s nicknamed “toxic marine snow,” and that is a possibility. Sinking marine snow with these toxins in it could have reached the deep sea and impacted the corals.
How big were these reefs? How ecologically important are they?
Now, those are two different questions.
As for size, they’re mostly kind of tennis-court size. One of the two new communities we found has two areas, and each one is the size of a tennis court, and they’re a couple football fields apart.
As for whether they’re ecologically important, that’s a tough question to answer. The problem is that we don’t know much about the deep sea. So it’s hard for me to tell you exact connections. We do know that sharks lay their egg cases this deep on these corals. And there are lots of other fish and crabs there when we go to these sites. But we go there with bright lights and loud machines, so stuff that can swim off might swim off.
This isn’t just about corals. Corals are a great indicator species, because if something happens to them on the sea floors, they don’t just die and wash away. They’re attached to the sea floor and their skeleton stays there. So they are an indicator that this impact from the oil spill reached that far away.
If fish had died, we wouldn’t know because they wouldn’t be there by the time we got there. The corals are the evidence that there are impacts at those sites.
So because of the mystery of the deep sea, we don’t know how ecologically important this is. What are the implications of the fact that we don’t know these impacts?
What we’ve demonstrated here are what I would call acute impact to corals. In other words, corals that were impacted so hard that parts of the colony immediately died and then were colonizes by these hydroids. Things are starting to break off.
What we still don’t know, and what we need to all keep in mind, is that there’s the potential for sub-acute impact. In other words, things that might have happened to the corals’ reproductive system — slower acting cancers, changes in the fitness of the animal. These are very hard to detect and they’ll take a long time for us to see whats going on.
It seems like its been along time [since the spill], but the deep sea is a slow-moving environment. the water temperature down there is 4 degrees Celsius. These corals, some of them are 500 years old. Things change slowly. So it could be a while before things are fully recognized in the wider Gulf.
Are you worried?
About the deep sea? Sure I am.
There are many different stressers being applied to the oceans right now. In addition to energy extraction and metal extraction that’s coming upon us very quickly with people wanting to mine deep sea metals, there’s increased fishing pressure. We’ve got climate change and the effects of that, runoff and everything else.
The ocean is under a lot of pressure, and the shallows have already felt it very seriously, with a serious decline in coral all over the world. And the deep sea is starting to feel it as well. So yes, I’m concerned.
What do we need to do now that we know this?
We’re continuing to monitor, because we’re really not sure how it’s going to turn out in the end. We’re going to continue to see whether these corals going to recover or if this means death to these colonies.
Corals have a real value as monitors [of the state of the deep sea]. And I recognize very much how little we knew about the deepwater corals when we started doing this. So we’ve found that this has been very helpful.
We need to learn more about the deep sea and learn what a healthy deep sea looks like so we can more easily recognize impacts as man continues to expand its presence into the deep sea.
These answers have been edited for clarity and brevity.