Some Alabama fish populations increase dramatically after Gulf oil spill

[Barrett808]

Dauphin Island--Since the oil spill in the Gulf of Mexico, marine scientists have come upon a surprising finding: more fish. Researchers at the Dauphin Island Sea report dramatic increases in some species. But as Gigi Douban reports, the seafood industry is responding to the news with a wave of skepticism.

Student researchers at the Dauphin Island Sea Lab load up a boat with some essentials. It's about two hours to their destination in the Gulf of Mexico: T-35, so named because the water's 35 meters deep. They're going to collect thousands of samples of tiny arthropods (shrimp and crabs are an example), then count them at the lab.

Counting marine life isn't anything new. But when the BP oil spill hit, the Sea Lab ramped things up. They expected fewer sea creatures, a marine life wasteland. But instead, they found something very different.

"For a number of species there was as much as 300% increases in the numbers of fishes we were catching," says John Valentine, chair of university programs at the Dauphin Island Sea Lab. "Tiger sharks and sandbar sharks increased dramatically in the last six months or so. Croaker, spots, speckled trout, things like that are also increasing in abundance in our area." ...

Some Alabama fish populations increase dramatically after Gulf oil spill

We have other reports of increases in fish populations following the Deepwater Horizon disaster. I've been assuming that the oil/dispersant mixture selectively removed predator species and, possibly, entire trophic levels from the ecosystem, allowing some prey species to reproduce with greatly reduced predation pressure. Time will tell.

[Ozymanithrax]

1. Not the Tiger Sharks and Sandbar sharks...they've increased.

So your theory is either flawed or doesn't take some things into account.

[Barrett808]

2. Indeed, and the other two theories are simpler:

1. The oil spill drove these fish to Alabama;
2. Reduction in fishing pressure enabled populations to recover.

Or some combination of all of these (and other) factors.

[tabatha]

3. Or predator deaths.

However, I wish it were your #2 - good data for establishing marine reserves.

[Hell Hath No Fury]

4. Rachel Maddow interviewed -

a scientist that said certain fish stocks would increase after the spill due to the rapid, nutrient-rich breakdown of all the destroyed plant matter. He said that it would appear that everything was OK, no harm done to the fish. But, he also said that those same stocks would then dramatically fall once the plant die off was finished and there was no new plant material to provide the needed nutrition. That was when you would see the real damage of the spill. :(

[Barrett808]

6. Upward trophic cascade, eh?

Sounds plausible.

[OnlinePoker]

5. I'm curious as to marine mammal and bird populations in the area

I remember constant pictures and video of oil soaked birds and animals washed ashore along the coast, and since a majority of their food comes from fish and crustaceans, this could be one factor in the increase of fish stocks.