Federal practices hamper study of Gulf dolphin deaths -- Nah, that couldn't be deliberate, could it? (Read contributed)

A federal agency's practice of returning weakened dolphins to deeper Gulf of Mexico waters is thwarting efforts to probe dolphin deaths after last year's BP oil spill, scientists said on Saturday.

The National Oceanic and Atmospheric Administration, meanwhile, confirmed that two dolphins stranded in low tide on the Louisiana coastline were returned to water deep enough for them to swim away.

"These animals had no signs of external oil and were deemed healthy and robust," NOAA spokeswoman Kim Amendola said, adding that beach releases are a viable option in some circumstances.

"The animals were pushed to deeper water by our stranding network partner, the Louisiana Department of Wildlife and Fisheries, and swam off on their own," Amendola said.

Researchers said weakened and stranded dolphins should instead be rescued and tested.

Moby Solangi, director for the Institute of Marine Mammal Studies in Mississippi, said returning the dolphins to deeper waters also was undermining efforts to determine who is responsible for the rash of sea animal deaths in Gulf waters.

"We are not able to conduct necropsies on these animals any more either," Solangi said. "This is all because of the BP criminal investigation."

The article continues on later:

Fifteen of the 406 dolphins that have washed ashore in the last 14 months had oil on their bodies, the oceanographic administration has said.

Deepwater Horizon oil was confirmed to be on six bottlenose dolphins, one had an unknown oil and two have not been tested. (read more)