NEW CASTLE — A bottlenose dolphin calf, who later died, was found stranded along the Delaware River on the Fourth of July.
“This was a very rare event,” said Suzanne Thurman, executive director at the Marine Education, Research & Rehabilitation Institute. “This would not be something we would expect to see … the majority of our strandings take place south of Slaughter Beach.”
The MERR Institute’s Lewes Response Team wasn’t able to respond as quickly as usual due to distance and holiday traffic, but the Goodwill Fire Company of New Castle and Delaware State Parks, along with some MERR volunteers from New Castle County, assisted in rescuing the dolphin before their arrival. The MERR Institute aided firefighters and volunteers in providing first aid and keeping the calf cool with wet towels.
“If it’s an abandoned or orphaned calf, the chances of survival are next to zero,” Ms. Thurman said. “We did want to evaluate it nonetheless. We want to determine the condition of the animal and he was already very debilitated from lack of nourishment and dehydration. So, immediately their organs start to be affected by that.”
Ms. Thurman noted they observed a few marks on the calf that could be from washing against the rocks for a time, but there were other marks that looked more severe that they intend to investigate.
“We do see this syndrome called ‘dolphin infanticide’ where male dolphins will attack the calves,” Ms. Thurman said.
Regardless, MERR says they are grateful to those who volunteered to help. Without rescue, the calf otherwise would have succumbed to a much more tragic death.
“The rescue efforts of everybody who participated kept that little dolphin from continuing to be pummeled by the rocks or being attacked by a shark while it was still alive, or just the long process of starving to death and being frightened the whole time because he didn’t have his mom there to take care of him.”
The calf, around 2 to 3 months old, would still be dependent on its mother for survival, but was likely separated from her in a more southern location.
The calf was disoriented after an unknown prolonged separation from nourishment and hydration provided by its mother, and ultimately would have continued to swim north, exhausting and starving itself, before likely washing up along Battery Park in New Castle. A calf as young as the one found can only survive a few days without its mother.
Ms. Thurman said there are many reasons that a calf could become separated from its mother in Delaware and surrounding waters.
“They are challenged every day to survive out there in the ocean, mostly due to human and water noise pollution because if the mother and calf cannot hear each other and communicate, then the calf will become separated from the mother,” Ms. Thurman said.
She added that dolphins can’t rely on their sight as well in murkier waters and noise pollution from ships can interfere with dolphins’ communication as well.
Fisheries interactions can have a large impact on marine life as well. Ms. Thurman said the mother also could have potentially been caught in a net and then separated from the calf.
According to the World Wildlife Fund, fishing gear accounts for roughly 10% of trash in the ocean; between 500,000 to 1 million tons of fishing gear are discarded or lost in the ocean every year. Discarded nets, lines and ropes now make up about 46% of the Great Pacific Garbage Patch.
To report living and deceased marine mammals or sea turtles 24 hours a day, contact the MERR Institute’s stranding hotline at 302-228-5029.