A lot of you have raised the question of what happens if the ocean "dies". That is to say, what if the ocean becomes unhealthy and marine wildlife populations decline too much? I wasn't sure on the answer to this question I too was wondering about but today I got the starts of my answer.
In ecology we've been watching a documentary series called Strange Days on Planet Earth. Today's episode had to do with what happens (and IS happening) due to fish population decline. Unfortunately this particular documentary did not cover the effects of Oil Spills long term but it shows the obvious need for keeping the ocean healthy.
Here is one of the first effects, you can watch it here: www.youtube.com/watch?v=HijeLf…
It's definitely interesting, especially if your concern revolves around african animals (and the narrator is Edward Norton in case any of you like him :'D )
That version is shortened, so I will mention that they also talked about the indirect effects of baboon overpopulation is that kids are being kept out of schools in order to protect the property from baboons and that baboons CAN spread diseases to humans.
The second effect had been going on for possibly 80 years (yet no one had studied until like just now...) and involved 1) a terrible rotting eggs smell to this one coastal town 2) the ocean near the town changed color to brown -> white -> yellow and of course 3) MILLIONS of fish would wash up dead.
What was happening?
Hydrogen Sulfide and Methane were being released from the seafloor in extraordinary eruptions when the atmosphere became low pressure (usually as storms passed over)
The Methane and Hydrogen Sulphide build up was caused by the decay of amazing amounts of phytoplankton. The gases created from the decay would be stored in the sediments until it became low pressure enough for them to escape.
The reason there are so many phytoplankton dying and getting to decay at all is because the area has been often over-fished and there was no longer a strong enough population of certain fish such as Sardines to eat the phytoplankton. And of course, because there are now poisonous gases being erupting from the seafloor, it's going to be even HARDER to bring sardines back to these areas.
The study was done because of one town and Namibia, but it was then discovered that these eruptions were not local. The eruptions were getting bigger and happening in extraordinary series along the coast. And of course the idea should pop into your head that what if populations of phytoplankton-eating fish decline elsewhere? It is likely that these eruptions could end up appearing in many other places.
I should also mention that Methane contributes to the greenhouse effect. And upon these giant eruptions of methane, you can expect they will contribute to global warming. kthx.
All of that isn't directly related to oil spills but either way it shows just the beginning of what it is like when the oceans "die". If the ocean becomes out of balance, expect more land animals to disappear to make up for the food loss. Expect it to contribute to global warming.