So, its now been 8 weeks since the Deepwater Horizon oil rig exploded in the Gulf of Mexico and oil started leaking at a rate now estimated to be 35,000 – 60,000 barrels a day, roughly 1,225,000 and 2,100,000 L every day. Those numbers aren’t even comprehendible anymore. If we assume an Olympic swimming pool contains two and a half million litres that means between 0.5 and 1 Olympic sized swimming pool, of oil, is leaking into the gulf every day!!!
Let’s be clear. This is no good. The benefits for any individual organism do not outweigh the costs incurred by the ecosystem. Having said that, guess who’s thriving…
According to a recent article in The Scientist evidence is mounting that surrounding the oil plumes, bacteria populations are gearing up for big boom. As awful as crude oil is for pelicans, bacteria (or at least those that can utilise it) view oil and hydrocarbon chains as tasty, tasty food. Whilst no direct evidence exists as yet for a bacteria population explosion (i.e. as far as I’m aware nobody has done a count) what has been detected is a drop in soluble oxygen within and around the oil plumes, arguably representative of bacterial respiration and growth.
Whilst this may seem awesome for the bacteria it throws up some very interesting problems. Traditionally bacteria occupy the lowest trophic level (lowest point in the food chain) in the environment. They are heavily involved in the decay and recycling of dead matter back into the food chain by consuming it themselves then being eaten by organisms higher up the food chain. But the bacteria have to pass through more ‘links’ in the food chain to reach the ‘higher’ animals than other resident of these low trophic levels. As only 10% (roughly) of the energy consumed by one link in the food chain is transferred to the next link in the chain this represents an enormous drop in the quality of the food for the ecosystem in the Gulf. Poor food quality requires increased consumption and often the loss of many species in the process.
The phytoplankton that normally fill the role of ‘bottom of the food chain’ can’t photosynthesise as efficiently in the oily water and so it’s expected that their numbers will drop, which is a major problem.
So what does this mean? Without the phytoplankton almost all the organisms in the Gulf will have no food.
However, one organism is expected to thrive alongside the bacteria. Jellyfish.
Jellyfish can feed directly off the bacteria and the bacteria can feed directly off the mucous secretions of the Jellyfish. Although it’s an outside possibility, if things get worse (and there’s every indication that they will) the ecosystem of the Gulf of Mexico could be forever altered and a new ecosystem that largely circumnavigates photosynthetic phytoplankton could be established. How this change could impact on higher members of the food chain (fish, water and predatory birds in particular) remains to be seen.
JB, taking it down a notch this Wednesday morning for ya…