JANICE MATHISEN of the Seattle Aquairum sent this email update on SSWD:
Update on Sea star wasting from Seattle Aquarium
research:
In
response to inquiries from staff, volunteers and visitors, Dr. Lesanna Lahner
put together the following SSWD update, which will also be posted to our blog
this week.
Sea
star wasting disease continues to be a problem for sea stars along the west
coast of North America. Since it was first observed two years ago, many strides
have been made in understanding the disease including the isolation of a virus,
termed sea star-associated densovirus SSaDV, that may be associated with it.
More work is being done to understand the role this virus might play in the
disease process and the Seattle Aquarium is collaborating with Dr. Ian Hewson
from Cornell on this topic.
Other
research directed at better understanding SSWD has been done recently at the
Seattle Aquarium, with generous support from The Boeing Company. This past
summer, three interns worked with me on a variety of sea-star-related projects
including 1) the effects of ocean acidification conditions on the general health
of sea stars and on SSWD progression; 2) better understanding the coelomic fluid
of healthy and diseased sea stars; and 3) radiographic evaluations of healthy
and SSWD-affected stars. Evaluating coelomic fluid is like doing blood work on a
mammal. It tells us a lot about what is going on inside the sea star on a
physiologic level. The radiographic studies included fascinating diagnostics
like plain film radiographs (x-rays), computed tomography (CT scan), and
magnetic resonance imaging (MRI) of both healthy and diseased sea stars. These
radiographic studies gave us new insight into what's normal for sea stars and
what's happening in live stars affected with sea star wasting disease. These
valuable coelomic fluid and radiographic studies were made possible due to
generous support from collaborators including Dr. Nicole Stacy at The University
of Florida School of Veterinary Medicine and Dr. Tori McKlveen at the VCA
Specialty Clinic of Seattle.
The
Seattle Aquarium recently co-funded a dive survey of the San Juan Islands with
the SeaDoc Society and Reef Environmental Education Foundation (REEF) to look at
the population impacts of SSWD. Over 100 dives were done as part of this survey
by highly trained scientific divers. Before SSWD, between 20 and 30 sunflower
sea stars would be seen on a single dive. Unfortunately, the findings were quite
grim and not a single sunflower sea star could be found. Other areas are
reporting very low numbers of sea stars and increasing numbers of urchins. The
recruitment of young sea stars in most regions has been reported as low by
collaborators.
The
Seattle Aquarium continues to collaborate with many other institutions on SSWD
research and is dedicated to understanding SSWD for the conservation of our
marine environment. We will be hosting an international workshop in January of
2016 of sea star disease researchers to identify priorities for SSWD research
moving forward. Stay tuned for more updates!
Janice Mathisen
Seattle Aquarium
Seattle WA
