Thursday, April 25, 2019

A look at the Marine Mammal Stranding Network

One of the first efforts to aid a stranded marine mammal was documented by the PTMSC in 1986, when a stranded harbor seal pup, nicknamed Itti-Vik, was cared for by a group of 20 PTMSC volunteers.
Itti-vik, meaning “spirit of the sea,” was brought to the PTMSC in 1986.
That same love for animals and dedication to science has fueled the PTMSC’s volunteer-driven MMSN program ever since.

Not all stranded mammals are found alive. But even in death, stranded marine mammal bodies can provide important information about the Salish Sea ecosystem.

Such was the case with a male northern elephant seal that was reported on Marrowstone Island on October 31, 2018.

Michael Siddel, Citizen Science Educator AmeriCorps Member, and PTMSC 
Citizen Science Coordinator Betsy Carlson examine the front flipper of the
northern elephant seal found on Marrowstone Island in 2018.
Measuring over 13 feet from the tip of his head to the tip of his tail – not counting his rear flippers – the size of the animal was impressive. In addition to collecting quantitative data, the team of PTMSC staff, AmeriCorps and volunteers sought clues for the cause of the elephant seal’s death.

Permission to conduct a necropsy (an autopsy performed on an animal) was given by the National Oceanic and Atmospheric Administration and a team was immediately assembled under the guidance of the Washington Department of Fish and Wildlife. The scientific value of a necropsy is indispensable in the evaluation of an animal’s life cycle as well as its death.*

As an added benefit, the PTMSC was allowed to preserve the full skeleton as a tool for future study, education and display.

Since November 2018, the remains of the elephant seal were allowed to naturally decompose underneath the Aquarium pier in a process called open-water maceration. This allowed microorganisms in the sea water to “clean” the bones of soft tissue. Marine mammals tend to have oily skeletons, so the bones were next boiled and degreased. Then they were soaked in a hydrogen peroxide solution to whiten them for display. Finally -- five months after the dead elephant seal was first reported -- the process of drying the bones in open air and sunshine began. 

AmeriCorps Volunteer Program Educator Mandi Johnson showing 
off a vertebrae in the steam. Photo by Johanna King.
The preservation of the northern elephant seal skeleton was a major undertaking for the PTMSC’s staff and volunteers. But it was not the first time.

In April 2016, a juvenile female gray whale died in central Puget Sound and the PTMSC was a key player in the subsequent necropsy and controlled decomposition of the carcass. Its skeleton will be articulated for educational use in classes and exhibits in the same manner as the skeleton of Hope, the orca, which hangs from the ceiling in the Museum.

The PTMSC is especially grateful to the following volunteers who contributed their time and energy to the northern elephant seal project: Bruce and Andrea Carlson; Wade Crouch; Wendy Feltham; Mario Rivera; Stefanie Worwag; Howard Teas.

The team of PTMSC staff and volunteers participating in the northern elephant seal necropsy.


The West Coast Marine Mammal Stranding Network was created in the early 1980s by the National Oceanic and Atmospheric Administration under the 1972 Marine Mammal Protection Act. And the Port Townsend Marine Science Center was one of the earliest response organizations in the Pacific Northwest. 

There are many reasons why a marine mammal might strand itself on shore. Among them are disease, parasite infection, harmful algal blooms, entanglements, pollution, malnutrition, weather events and injuries due to predation, ship strikes or direct human interaction. Because the presence and condition of marine mammals are important indicators of ocean health, each stranding case can reveal scientific clues about the stranded species and the marine environment.

*The necropsy revealed the elephant seal died of internal injuries from an impact, although there were no external wounds visible.

No comments:

Post a Comment

Want to leave us a comment? Just type in your message below; we'd love to hear from you!