The scene unfolded near Union and Nevins Streets in the Gowanus section of Brooklyn. The dolphin was first spotted in the canal on Friday morning.
The dolphin appeared to be about 7-feet long. It surfaced periodically and managed to shake loose black gunk from its snout in the water.
The Riverhead Foundation for Marine Research and Preservation and the NYPD responded to scene a short time later.
Officials said that nothing appeared to be physically wrong with the dolphin. However, according to Riverhead Foundation, it is very unusual for a dolphin to be that far up the canal. That usually indicates that there may be something wrong with the dolphin's health.
It was thought that the dolphin may have been trapped because the water was too shallow. Marine officials had hoped that high tide would have allowed the dolphin to escape.
The next high tide is at 7:10 p.m. but the dolphin was reported dead by 6:30 p.m.
The canal is a Superfund site, where for years factories and fuel refineries operated. It runs through an industrial zone near some of Brooklyn's wealthiest neighborhoods.
Marine experts had planned to help the dolphin on Saturday morning if it didn't get out of the canal during high tide. They had decided to hold off intervening Friday because of the stress the dolphin might have experienced in being captured.
Experts plan to conduct a necropsy to determine why the dolphin died.
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