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Fish kill in Delaware Bay attributed to warm water

middletwp081210_optBY JOE TYRRELL

The state Department of Environmental Protection has been unable to definitively identify the cause of a major fish kill in Delaware Bay, but is continuing to investigate.

The DEP announced plans to take more water samples on Aug. 12, and analyze tissue samples from some of the thousands of dead menhaden first reported on Aug. 11 along an eight-mile stretch of shoreline.

In a statement released late Thursday afternoon, the DEP said the additional water tests "strongly suggest" low oxygen levels were responsible for the massive die-off.

"These low levels likely occurred a result of very warm weather and warm temperatures in the bay," Van Fossen said in an update. "The warmer water is, the less dissolved oxygen it is able to hold."

DEP gave approval to local officials to use heavy equipment to remove the dead fish from beaches and waterways, with the clean-up scheduled to begin Aug. 13.

In a statement, the agency said the massive die-off "appears to have been a natural event," but also cast doubt on initial theories.

"Right now, we do not have any indication that pollution or a toxic algae bloom such as red tide caused this large die-off," Bob Van Fossen, DEP manager for emergency management, said in an earlier statement.

The dead fish also did not seem to come from a broken commercial fishing net, he said. Initial surveys found the wash-up appeared to be concentrated at High's Beach in Middle Township.

But corpses were found from Kimbles Beach in Middle Township to the Villas in Lower Township, with additional shoreline surveys still taking place, according to the DEP.

Although not currently used for human consumption, menhaden has been vital to marine ecosystems and to American industry. In the 19th Century, the oily-fleshed fish replaced whale oil as a source of commercial and industrial lubricants.

In the modern era, menhaden are the major component of fishmeal, fed to chickens and farm-raised fish. Menhaden are also major sources of bait used in recreational fishing. They are commonly caught in large purse seines.

menhaden081210_optIn his 2007 book of the same name, Rutgers Professor H. Bruce Franklin labeled menhaden "The Most Important Fish of the Sea," calling the fish "the living keystone of the marine ecology of the Atlantic and Gulf coast," from Mexico's Yucatan Peninsula to Nova Scotia.

Franklin decried the near monopoly exercised by Omega Protein in the commercial fishing and production of menhaden products. He also described the fish's role in filtering water as the consume algae and microscopic plants, and as food sources for larger fish.

The DEP has theorized that predators could have driven large schools of small menhaden close to shore, where they depleted the supply of dissolved oxygen in the water. But initial water samples taken Aug. 11 showed acceptable oxygen levels, the DEP confirmed.

Joe Tyrrell may be reached at This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Comments (6)
6 Wednesday, 30 November 2011 13:39
To paranoid, so called friends of the environment:
Similar (natural) phenomena involving the same fish species happen almost every summer in this area; seasonally high nutrient loadings and warmth cause the proliferation of algae; these are in turn utilized as a food source by other organisms, which consume the dissolved oxygen. The estuaries and bays of this area are ‘restricted’. This physical condition is extremely important, since on one hand it offers shelter to the juvenile of these fishes but on the other it promote poor ventilation of bottom waters, which easily become completely devoid of oxygen. In addition, the decay of these high quantities of organic matter by bacteria at the seafloor produces hydrogen sulphide, which accumulates in bottoms waters in the absence of currents. This highly toxic substance may eventually return to the surface due to water column mixing, causing the fish kills (Luther et al., 2004 Estuaries). The main culprit is therefore increasing nutrient loadings, which are probably due to a combination of abusive usage of fertilizers and poorly controlled, man-made land use.
5 Tuesday, 07 September 2010 02:33
Cyndy T
I think if any area starts showing signs of dead fish, they had better start testing for Corexit. Do not expect the US goverment to test or tell you the truth if they do, You need to do like the people on the Gulf coast are doing and have the testing done yourselves . Be sure whoever is doing the testing is not connected to the gov. in any way.
And by all means...DO NOT EAT GULF COAST SEAFOOD!!!!
From The Gulf Stream To The Bloodstream - THE VIDEO BP DOESN'T WANT YOU TO SEE!
Blood Beach Blue Crab covered oil and Parasites 9/06/10
Please help us fight the goverment and demand they stand up for Americans First not corporations!!!
4 Tuesday, 17 August 2010 17:24
BP CoverUp
Anything to save face. These BP bastards are low life scum. They are environmental terrorists. To hell with their image. RIP Matt Simmons and Dr David Kelly.
3 Tuesday, 17 August 2010 12:34
Its the Corexit dispersant sprayed over the gulf till today that is responsible for this die-off.
In the weeks to come, this will get only worse!
God Bless Late. Matt Simmons for warning us.
2 Saturday, 14 August 2010 16:16
scott brady
I also think we should look for trace amounts of the dispersant s used in the gulf.
I think the predator theory sound fishy.
1 Thursday, 12 August 2010 17:37
Josh Spring
I think we should look for trace amounts of the dispersants used in the gulf.
The oceans are -after all - connected

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