Although nobody knows exactly how the Gulf of Mexico oil spill will affect the ocean ecology, the body of a dead sperm whale found in the gulf has raised scientists suspicion that it was an oil spill related death. The corpse had been decaying for perhaps days and was within 77 miles of the oil spill. Video of the spill had shown sperm whales swimming through and surfacing in the oil, which is toxic to them. Usually only one body of a sperm whale is discovered in the gulf every year, so the finding is suspicious.
Much of the ecological damage from the BP oil spill has been hidden underneath hundreds of feet of water, in part because the source of the spill is on the ocean’s floor, and because BP is using a large volume of dispersants to keep the oil away from the shoreline.
Sperm whales are remarkable mammals, and because they dive deeper than 9,000 feet to catch fish and squid, they are also the deepest diving mammals in the world. They also produce the loudest sound that any mammal can make when it clicks mysteriously to perhaps signal other whales or as a form of sonar.
Sperm whales eat about 3% of their body weight in food each day. So I wonder if this sperm whale could have perhaps gotten lost in the gigantic oil plume and perhaps had trouble over the past month finding enough food to eat as the oil has been killing off the smaller organisms such as the squid and fish. Of course, direct toxicity from the oil is another possibility.
Having no natural predator, besides man, the death of a sperm whale near an environmental disaster such as an oil spill has raised concerns about the long term survival of the group of sperm whales living in the gulf. As sperm whales eat even more seafood than humans each year, their survival is even more closely linked to the effects of the oil spill.
In terms of survival of the species, sperm whales are notoriously very cosmopolitan whales and live in a number of locations around the world. However, more bad news for the sperm whales poured in this week as it was discovered that sperm whales from locations around the world had built up high levels of toxic metals in their blubber. This is blubber that is turned into milk for baby whales, thus meaning that future generations of sperm whales could eventually succumb to ever increasing levels of toxins such as chrome, cadmium, lead, and mercury to name a few.
Because the sperm whales are at the top of the food chain, toxic metals present in fish and squids at lower concentrations accumulate in the whale’s tissues and rich high concentrations. The bad news for humans is that we may be exposed to toxic metals in our seafood as well.
Sadly, this has a been a tough year for the sperm whales and it will take a global effort to help save the species, as well as to decrease the levels of toxic metals in the oceans which are coming from human pollution.