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Stranded Marine Mammals Stir Tough DecisionsExperts propose guidelines for when to rehabilitate, release, and euthanize |
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| Enlarge ImageSeals entangled in fishing lines and gear may strand on beaches where they are noticed by people. Local stranding networks around the country send workers to evaluate the animals' condition and make difficult decisions about how to care for them. Here, a worker wraps and prepares to examine a badly entangled seal. (Photo courtesy of Cape Cod Stranding Network) |
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| Enlarge ImageSeals frequently congregate and rest on Billingsgate Shoal, Cape Cod, Mass. (Photo by Jim Canavan, Woods Hole Oceanographic Institution) |
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| Enlarge ImageWHOI biologist and marine mammal specialist Michael Moore was lead author of a recent article proposing a new method for making decisions about stranded marine mammals. (Photo by Jim Canavan, Woods Hole Oceanographic Institution) |
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| Enlarge ImageMichael Moore and co-authors have called for clear guidelines for marine mammal rehabilitation and release and have proposed a decision tree similar to this, with specific criteria for choices that stranding responders must make. (Tree courtesy of Michael Moore, redrawn by E. Paul Oberlander and Jeannine Pires, Woods Hole Oceanographic Institution) |
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A seal, sick or injured, is found stranded on a beach. What should be done?
That depends on whom you ask.
An
animal welfare advocate would urge efforts to help the disabled animal.
A scientist might want to rehabilitate it with another reason also in
mind: to release and track it, and learn about wildlife populations.
Veterinarians might welcome the rare opportunity to discover more about
wildlife diseases and physiology—though they would also be wary of
exposure to diseases that could be transmitted to humans.
The
range of perspectives doesn't end there. California or East Coast
fishermen might not shed a tear about losing one out of a proliferating
population of seals that they perceive to be eating into diminished
fish stocks, and fishermen’s profits. But if the seal were an
endangered species, saving each one would be critical from a
conservationist’s point of view. Unless, of course, releasing it back
into the wild could further endanger the species, by introducing a
novel pathogen acquired in a rehabilitation facility. The same seal,
endangered or not, would be considered fair game by another endangered
population, subsistence hunters, if it were found on a beach in Canada
or Alaska.
And then there’s the cost-factor debate: Should
limited marine mammal protection funds be spent to rehabilitate
animals, or to increase public education, law enforcement, or research
activities?
Six marine mammal specialists have now called for an
innovative method to help balance and sort out conflicting priorities
involved in strandings and forge compromises among competing interests.
In a review and position paper published in the October 2007 issue of
the journal Marine Mammal Science,
they outline a decision tree—a systematic framework to assess the
risks, benefits, costs, and probabilities that branch out from various
choices to euthanize, rehabilitate, and release stranded animals.
Joining
together to make the proposal were a range of experts spanning
research, conservation, veterinary medicine, public education,
rehabilitation facilities, and regional stranding networks: Michael
Moore (Woods Hole Oceanographic Institution), Greg Early (Mote Marine
Laboratory), Kathleen Touhey (Cape Cod Stranding Network), Susan Barco
(Virginia Aquarium), Frances Gulland (The Marine Mammal Center,
Sausalito), and Randall Wells (Chicago Zoological Society and Mote
Marine Laboratory).
“Rehabilitation of stranded marine mammals
elicits polarized attitudes,” the authors wrote. “The challenge is to
find the common ground and the greater good.”
When success creates problems
Decades
ago, few stranded animals could be saved, and those that could were
generally placed in zoos and aquariums and displayed for public
education. Over the last 25 years, though, veterinarians and curators
learned more about marine mammal physiology and medicine, making it
possible to keep more stranded animals alive. Eventually there were
more stranded animals than there was display space to permanently house
them.
“The issue is complex, but the math is simple,” said
co-author Early of the Mote Marine Laboratory. “One either releases
animals, or stops admitting them.”
Independent organizations
that respond to strandings proliferated and now total more than 400 in
the United States. When notified about stranded animals on public
beaches, organizations must respond; doing nothing is usually not an
option, from the perspective of animal or human welfare. They are faced
with making choices about the animals on the spot, in situations that
prompt strong public reactions.
Though governed by federal
regulations under the Marine Mammal Protection Act, the stranding
response groups mostly depend on local funding. As a consequence, they
reflect local priorities, are not well-coordinated, and sometimes
contradict each other’s goals.
For example, saving a stranded
dolphin can be gratifying to human responders, Moore and colleagues
said, but the situation is more complex. Responders must also take into
account whether nearby rehabilitation facilities exist; whether the
animal could, or should, ever be released to the wild; whether the
animal would suffer during treatment, and whether resources are
available for a lifetime of ongoing care.
It has cost as much as
$175,000 to rehabilitate a single dolphin, and between $400 and $50,000
to rehabilitate a seal, sea lion, or walrus, according to estimates
cited by the researchers. Emotion-charged decisions to rehabilitate can
lead organizations to begin to care for animals they have no assurance
of funds to support or treat; Moore and colleagues suggest this is
inappropriate. Even more difficult is weighing the relative
benefits of spending limited funds on rehabilitating individuals, or on
education, conservation, or research efforts.
Conflicts and contradictions
Making
rehabilitate-or-release decisions more difficult is that some risks
(transmitting pathogens to wild populations, for example) are supported
by scientific data; some (seals competing with fishermen) are
theoretical but unproven; and some—interfering with natural selection
by releasing less-fit animals to reproduce, for example—are “perceived’
risks unsupported by current data.
Further complicating the
situation are the federal guidelines themselves. The federal agency
charged with managing marine mammals—the National Marine Fisheries
Service (NMFS, part of NOAA, the National Oceanic and Atmospheric
Administration)—authorizes just three reasons for responding to marine
mammal strandings: protecting animal welfare, protecting public health,
and collecting scientific information to advance conservation of wild
populations. But these justifications can compete: For example, NMFS is
charged with protecting seals and sea lions, as well as preserving
endangered salmon stocks that the marine mammals prey on. NMFS
guidelines don’t identify, or provide a way to decide, priorities.
Even
the term “rehabilitation” is problematic, because many existing
rehabilitation organizations do not agree on what it means, and federal
regulations don’t make the meaning clear, Moore and colleagues said. It
can be interpreted as returning an animal to full health (which may not
be possible, if the animal has other health problems), or returning it
to basic functioning (which may not be wise, if the animal might suffer
a slow death from a pre-existing condition). “The vagueness of even
this most basic concept,” the authors wrote, “adds to the conflicting
values and options within which the stranding organizations work.”
As
a result, the authors wrote, “marine mammal rehabilitation is an effort
that currently lacks a coherent central set of core values, ethics, or
goals. After more than a quarter-century, the effort remains
inconsistent, poorly supported, and fractious.”
A method to make decisions
Hence
the call for a decision tree—a cascading series of assessments and
choices designed to “identify at what point an activity should cease
because the cost or risk to subjects is too great to continue.” Moore
and colleagues called on federal managers to consult with veterinary,
conservation, animal welfare, and other experts to develop clear
ethical, scientific, and legal criteria for each decision branchpoint
on the tree.
The tree would provide consistent guidelines for
decisions and “remove the burden of inherently unpopular decisions from
the responder and transfer it to government management agencies,” they
said. “Rehabilitation efforts should be evaluated on whether the likely
benefits to science, nature, or knowledge outweigh the potential harm
to individuals or populations.”
“The issue of what’s
appropriate to do with mammals is hugely difficult,” Moore said. “We
have to take a hard look at the situation in the context of the real
political pressures we’re all under.”
—Kate Madin
The WHOI Ocean Life Institute provided funding for Moore’s work.
Posted: December 20, 2007 [top] |
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