The Deepwater Horizon disaster continues to provide examples of why offshore drilling should be more tightly regulated than in the past. The latest:

• The once prosperous dolphin population in Barataria Bay south of New Orleans has been racked by a sudden dramatic increase in diseases since BP’s oil flowed into that estuary, according to an on-going study by the National Oceanic and Atmospheric Administration.

• Oil from BP’s blown well is taking a heavy toll of deep sea coral in the area of the spill, according to research published in the Proceedings of the National Academies of Sciences.

The dolphin study involved intensive physicals given to 32 live dolphins last summer. Preliminary results showed “many of the dolphins were underweight, anemic, had low blood sugar and/or some symptoms of liver and lung disease. Nearly half also had abnormally low levels of the hormones that help with stress response, metabolism and immune function.”

“The results presented today only reflect what we know about the health of dolphins in Barataria Bay area of Louisiana,” NOAA spokesman Ben Sherman said in a news release following a teleconference announcing the results. “They may provide possible clues to other dolphins exposed to oil in the northern Gulf of Mexico. However, it is too soon to tell how the Barataria Bay findings apply to the overall (unusual mortality event) or to the health implications for other dolphins exposed to oil in the Gulf of Mexico.”

Since February 2010, more than 675 dolphins have been stranded from Franklin County, Florida, to the Louisiana/Texas border, a much higher rate than the usual average of 74 dolphins per year.

The Barataria Bay study is part of the on-going Natural Resource Damage Assessment, required under the Oil Pollution Act of 1990. Government agencies, called “trustees” – work with the “responsible parties,” in this case BP, to assess the harm cause to the environment, and settle on the cost of repairing the damage. That bill is separate from fines levied for polluting public waters under the Clean Water Act, a sum expected to be around $20 billion.

While the strategy of using dispersants at the underwater source of the blowout has been considered helpful in preventing waves of intact oil from soaking the great estuary of the Mississippi River, the decision was controversial among marine biologists. They said the tactic merely kept the polluting hydrocarbon components in the Gulf, a decision that could have impacts for the health of a wide range of species as the years go by.