Riverhead Foundation: Dead Seal In Southold Died Of Natural Causes

A dead seal that washed up on the town beach in Southold last weekend was actually a female adult gray seal, had recently been pregnant --and died of natural causes.

According to Kim Durham, rescue program director of the Riverhead Foundation for Marine Research and Preservation, a necropsy examination was completed Thursday on a female adult gray seal found in Southold on Saturday.

Initial reports indicated that the seal was an adult male.

Preliminary findings, Durham said, indicate postpartum; the seal had evidence of a recent pregnancy and lactation.

"The most prominent finding was respiratory disease," Durham said. "Examination of her lungs revealed extensive pneumonia. She also had evidence of an uterine infection as well as age-related changes within her liver and spleen."

The seal, Durham said, died of natural causes.

The Riverhead Foundation performed the necropsy after the dead seal washed up on the Southold shoreline and was found at approximately 10:45 a.m. on Saturday morning.

According to Rob DiGiovanni, executive director and senior biologist for the Riverhead Foundation for Marine Research and Preservation, the seal, about six-and-a-half feet long, appeared underweight and seemed to have died recently.

The Riverhead Foundation brought the seal in for a necropsy; the fact that it died recently was expected to help provide "a lot more information about the animal," DiGiovanni said.

While DiGiovanni said it is not necessarily unusual to have seals wash up on Long Island Sound beaches, over the past 30 years, "having an adult gray seal wash up is rare" because gray seals have not traditionally been known to frequent area waters.

However, over the past few years, an increasing gray seal population has been seen on Little Gull Island in the Long Island Sound, making the appearance of the gray seal less rare or unusual, he said.

When a seal is found, DiGiovanni said, researchers try to monitor if there is a major reason it has died -- if a number of animals have died and appeared on beaches in a short amount of time, meaning perhaps they might have become entangled, somehow, or that there may have been some other underlying connection.

The organization is volunteer-based and run through by donations and fund-raising efforts, DiGiovanni said, so the number of tests that can be done is limited. 

"The more samples we can run, and tests we can do -- we can determine contributory factors," DiGiovanni said. "It's like putting a puzzle together."