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Posted By: Marty Are whale sharks at risk? - 07/07/10 03:28 PM

Close Encounter with a Whale Shark in the Gulf of Mexico

Whale Shark, Rhincodon typus, feeding in the Gulf of Mexico.

Image: Gulf Coast Research Laboratory Whale Shark Research.


Despite being the largest fish species in the world, measuring over 40 feet in length and 35 tons in weight, whale sharks are quite mysterious. We know they are plankton filter feeders, and we recently learned that we can identify individuals by the pattern of dots and bars on their bodies, but otherwise, we know very little about these animals. For example, in just 1996, we learned that these sharks are ovoviviparous (their young grow in egg sacs inside the body but are born live) after capturing a female pregnant with 300 pups. But we still know almost nothing about them, including their population size. So to learn more about them, researchers are attaching satellite tags to whale sharks and taking a tiny tissue sample for DNA work. This video shows this process as it occurred with one whale shark feeding at the surface of the water in the Gulf of Mexico.

Swimming with a whale shark off the Alabama coast


Last week, scientists spotted a group of roughly 100 whale sharks in the Gulf last week, feeding on the surface over a deepwater area off Louisiana called the Ewing Bank that apparently is untainted by oil from the Deepwater Horizon. But this week, there is sad news that at least three whale sharks are swimming in oil just a few miles from the gushing wellhead.

"Based on all the information I'm getting, they are doing the normal things regardless of the oil. The idea that sharks have these evolved senses that will protect them -- well, they haven't evolved to detect oil," said [Eric Hoffmayer, the University of Southern Mississippi scientist who found the large aggregation last week.]

He tagged whale sharks on the Ewing Bank in June of last year. The satellite trackers showed that some of the animals spent that July migrating hundreds of miles toward the Alabama coast and Florida Panhandle. If they follow the same route this year, it would carry them straight through the heart of the spill [...]

"Last year we had two sighted off Florida and Alabama that were from Honduras and Belize," Hoffmayer said. "That means these oil impacts are not only for the Gulf population, but for the Caribbean and maybe even further. The implications are pretty big here." He said that high Gulf temperatures and the position of the offshore Loop Current mean conditions this year are similar to those that drew the sharks to the area last summer.

"If that migration pattern holds true this year, the sharks will have to travel through the oil to get to Alabama," Hoffmayer said. "That's a serious concern. These guys are surface feeders. They swim at the surface with their mouths open. Will they be ingesting oil?" [Ben Raines, Press-Register]

Oh, there is one more thing that we do know about whale sharks: Like all shark species, these magnificent animals lack swim bladders, so for example, when they die from ingesting oil, their carcasses sink to the bottom of the sea and are never seen -- no possibility of washing ashore -- so we have no way to determine how many are being killed by the BP disaster.

Unfortunately, these satellite tags are expensive: each costs $4,000, and they are the only way we can learn more about the movements and habits of whale sharks. This year, these tags will probably provide the only record of their exposure to oil.

"We're going to miss our window if we don't get our tags out soon," Hoffmayer said. "These animals are in peril."

I strongly encourage you to donate to support this vital research (donation links at bottom of that page). Whale shark sightings should be reported to Hoffmayer at 228-872-4257 and you can learn more about this research at the Gulf Coast Research Laboratory Whale Shark Research site.

Map depicting historic (2002-2009) whale shark sighting locations shown within the estimated boundaries of the Deepwater Horizon oil spill as of May 18, 2010.

Posted By: shuffles Re: Are whale sharks at risk? - 07/07/10 03:41 PM
I say YES they are in danger Whale sharks swim close to oil spill
Posted By: TrueLover Re: Are whale sharks at risk? - 07/07/10 04:10 PM
Facts we know about oil drilling and exploration show that the normal amount of negative impact is major even when there are no accidents whatsoever.

There is no way to determine the repercussions of this in the long term. Just too many variables to consider but we can be assured it's all bad.

Though we know that this situation in the Gulf of Mexico will do immeasurable damage to the whole region and many species that migrate or survive on what is produced in the region at some point, stage, season, what a similar situation would do anywhere near a major reef system might be catastrophic to the whole of the caribbean.

There needs to be International restrictions from all of this activity anywhere near a reef system in the world.

The Belize barrier reef would unlikely survive such a situation and by nature of configuration take thousands of years to recoup. Oil would be locked behind contaminating many habitats at the same time including sea grass, mangroves, estuaries in addition the the coral reefs, canyons, and other areas vital to the life cycles of every species including those already endangered.

Oil $$$$$$ has always won in the past but we can no longer allow them to act as it they own the reefs and oceans nor risk them as expendable towards their goals.

Especially ironic now that it seems clear to most anyone that Oil as fuel is in it's last days. Everyone need to care about this. Not just for the sake of the sea and all it's inhabitants but because this is where life began and if we destroy the source we risk destroying ourselves in the process.

Every year, a tremendous amount of money, time, and effort are spent to protect this endangered species or that particular whatever but here is one sin that potentially kills off them all.

NO OFFSHORE DRILLING EVER NEAR ANY REEF AND NO MORE ELSEWHERE TILL THEY CAN IMPROVE SYSTEMS THAT CAN INSURE MINIMAL RISK AND NEGATIVE IMPACT.
Posted By: Rigrat Re: Are whale sharks at risk? - 07/08/10 04:00 AM
Originally Posted by TrueLover
Facts we know about oil drilling and exploration show that the normal amount of negative impact is major even when there are no accidents whatsoever.

Can you please post some of these facts?

Originally Posted by TrueLover
There is no way to determine the repercussions of this in the long term. Just too many variables to consider but we can be assured it's all bad.
Why?

Originally Posted by TrueLover
Though we know that this situation in the Gulf of Mexico will do immeasurable damage to the whole region and many species that migrate or survive on what is produced in the region at some point, stage, season, what a similar situation would do anywhere near a major reef system might be catastrophic to the whole of the caribbean.

Is there any evidence yet that there will be long term damage to the Gulf? Every single year for the past hundreds of thousands of years the equivalent of two Exxon Valdez tanker worths has been released into the Gulf of Mexico from Natural seeps. Has this done long term damage? Or has nature learned how to take care of it? This current oil spill is minute compared to the amount of oil released, it is just a large amount in a short time. I will bet you that just a few months after the well is capped, that you will see nature doing some serious remediation.

Originally Posted by TrueLover
There needs to be International restrictions from all of this activity anywhere near a reef system in the world.
There are scores of drilling rigs near reef systems all over the world. The overwhelming amount of damage to reefs is caused by tourism and fishing. NOT drilling.

Originally Posted by TrueLover
The Belize barrier reef would unlikely survive such a situation and by nature of configuration take thousands of years to recoup. Oil would be locked behind contaminating many habitats at the same time including sea grass, mangroves, estuaries in addition the the coral reefs, canyons, and other areas vital to the life cycles of every species including those already endangered.

Where is your evidence for this? Sure if you smother a reef in oil it will be damaged. There are scores of scientific papers on it. But there has not yet been a single reef worldwide that has been killed, or damaged beyond repair by an oil slick. Also what makes you think that any oil spilled will be because a hole is drilled? Do you not think that your every day activities spill far more oil and reef killing toxins that an oil rig can ever hope to do?

Originally Posted by TrueLover
Oil $$$$$$ has always won in the past but we can no longer allow them to act as it they own the reefs and oceans nor risk them as expendable towards their goals.
Especially ironic now that it seems clear to most anyone that Oil as fuel is in it's last days. Everyone need to care about this. Not just for the sake of the sea and all it's inhabitants but because this is where life began and if we destroy the source we risk destroying ourselves in the process.
Oil is natural. It doesn't destroy nature. You think that oil as a fuel is in it's last days? You are wrong. You will still be using oil as a fuel until the day you die. And so will your ancestors.

Originally Posted by TrueLover
Every year, a tremendous amount of money, time, and effort are spent to protect this endangered species or that particular whatever but here is one sin that potentially kills off them all.
NO OFFSHORE DRILLING EVER NEAR ANY REEF AND NO MORE ELSEWHERE TILL THEY CAN IMPROVE SYSTEMS THAT CAN INSURE MINIMAL RISK AND NEGATIVE IMPACT.

Well they can insure minimal risk already, as well as minimal impact. By your own argument, drilling should commence immediately.
My argument however is that a lot of work needs to be done by the government before a request to drill is allowed. And I actually am in possession of real facts.
Posted By: Katie Valk Re: Are whale sharks at risk? - 07/08/10 02:17 PM
The people in possesion of the facts are quite concerned about the spills affect on the whale sharks and those that might migrate to our waters. Drs. Graham and McField from Belize have both expressed great concerns, as have marine biologists in the area. Listen to what they have to say.
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