The dolphin that died in the Gowanus Canal in Brooklyn on Friday had many health problems, including a damaged kidney and stomach ulcers, and appeared to have stopped eating, all indicators of chronic illness, the biologist who performed the necropsy said Monday night.
While the findings are preliminary and tissue tests still need to be done, the necropsy did not turn up evidence of any damage to the animalcaused by the canalâs Superfund-level contamination, said the biologist, Kimberly Durham.
The polluted water âdidnât help,â said Ms. Durham, rescue program director for the Riverhead Foundation. But she added, âI think the fate of this animal would have happened regardless or whether it was in the canal or anywhere else.â
The animal, an older adult male common dolphin seven feet long, turned up in the filthy headwaters of the canal, more than a mile from the harbor, on Friday morning, and struggled for much of the day.
The Riverhead Foundation, the regionâs official marine-mammal rescue group, chose to wait for evening high tide to see if the dolphin returned to the harbor under its own power rather than try to capture the animal, a decision widely second-guessed by lay observers. The dolphin died in the canal about an hour befor! e evening high tide.
The necropsy, performed Sunday, turned up kidney stones, liver parasites, stomach ulcers and an empty gastrointestinal tract, adding up to a âchronically ill animal,â Ms. Durham said.
âI think you might have a situation where you have all of these things put together,â she said. The stomach ulcer was big enough that it had to have taken a while to form, she said. âThe dolphin was thin and hadnât been feeding, and this in itself can lead to an animalâs death. They stop eating and get dehydrated and they get renal failure - it can lead to a whole chain reaction.â
âAnytime I see something associated with a marine mammalâs kidneys,â she added, âthatâs something that could be in itself the sole reason why the animal succumbs.â
With regard to the canalâs waters, Ms. Durham said that fish, which breathe water through their gills, are much more quickly affected by water quality than dolphins, which do not ingest water directly (they get ther water from the food they eat). Damage from the polluted water would have taken the form of skin lesions or similar injuries, she said, and there was no sign of anything like that.
âAll I can tell you is that this animal was in poor health,â Ms. Durham said. She added that she expects a histopathologistâs report to yield more detailed findings and possibly - but not definitely - a specific cause of death.