Eugene weekly., November 16, 2017, Page 13, Image 13

Musseling Up
Mazzacano says Oregon’s freshwater mussels face a lot
of challenges, and some of them — like climate change and
habitat loss — they share with many other animal species.
In the case of climate change, rivers are heating up,
making it more difficult for the mussels’ host fish. In terms
of habitat loss, dams make it not only harder for the host
fish, which often can’t get past dams despite fish ladders
and even trucking, but also harder for mussels to have the
right river flows, substrate (the gravel, rock or sand they
dig into) and temperatures. Rivers below dams can be
starved for sediment, she says.
And then there are those host fish. Freshwater mussels
like the Western pearlshell have an “absolute dependence
on host fish,” Mazzacano says. They are “salmon
specialists” that need native salmonids to survive.
A mussel’s life cycle goes something like this: The
male mussels release sperm into the water, and the females
inhale it. Thus the name “bivalve” because mussels have
one valve that takes things in and another that sends it out.
Embryo mussels develop into larvae called “glochidia” and
are released by the female mussels. (Interesting side note:
It’s rare, but Western pearlshells can be hermaphrodites.)
Once released, the glochidia need the host fish. Blevins
says some glochidia have hooks. Some don’t, but they find
a way to grab onto a fish’s fins or gills, take a bite, hold on
and encyst. The fish swims away and “the glochidia hang
on for the ride,” she says.
While Western pearlshells need native fish like cutthroat
trout, Chinook, Coho and sockeye salmon, floaters tend to
be generalists when it comes to their fishy hosts. But all of
Oregon’s freshwater mussel species need to be parasites on
fish as part of their life cycles. Without the fish, the mussels
cannot reproduce.
Musseling In
Oregon is home to invasive Asian clams — possibly
brought here because people saw them as tastier than
Oregon’s native mussels, Mazzacano says.
Or possibly, according to Alexa Main, they came to
the Northwest via the Great Lakes, “as all the bad things
seem to,” she says, only half in jest. Main is a mussel and
Pacific lamprey biologist with the Confederated Tribes of
the Umatilla Indian Reservation.
Asian clams not only can compete with native mussels
for food, they may also consume larval or juvenile mussels.
Main points out that not only do dams limit the mussels’
access to native fish, but mussels are also up against
nonnative fish. Nonnatives will eat the host fish, and native
mussels are not interested in latching on to most nonnative
fish — similar, Mazzacano, says to caterpillars that only
like to munch on one type of plant.
And that’s not all that Oregon’s unobtrusive mussels are
up against. There are also invasive mussels — zebra and
quagga mussels, malignant little bivalves that have been
invading lakes and rivers across the country. They have not
made it to Oregon. Yet.
One economic assessment showed that a mussel
invasion would damage hydropower, irrigation, fish
hatcheries and municipal water facilities at a cost of $500
million annually to the Pacific Northwest.
“They don’t need a host fish; they shoot out the baby
mussels,” Mazzacano says of the invasives’ reproductive
technique.
And while Oregon’s native freshwater mussels take
years to grow up and reproduce, zebra and quagga mussels
mature quickly and could compete for mussel habitat.
But if Oregon’s mussels are in decline, you might think
the invaders could fill in the niche that mussels have in
filtering water. Unfortunately, zebra and quagga mussels
reproduce so quickly the filter feeding they do “almost
sterilizes the water,” Mazzacano says. Rather than benefit,
they damage the ecosystems they invade.
Mussels and First Foods
Thanks to the Confederated Tribes of Umatilla Indian
Reservation in northeast Oregon, mussels west of the
Continental Divide are the subject of the region’s only
effort to re-propagate freshwater mussels.
The Umatilla, however, came to the mussel quandary
and restoration differently. According to tribal member
Wenix Red Elk, the CTUIR mussel effort came about as a
result of the tribe’s First Foods policy.
Red Elk explains, “When you lose a food source, you
lose the food source but you are also losing the entire
culture of that river area, that fish, that land” and the
culture, the language and family stories that went with it.
“It’s so much bigger than losing a species.”
UNEXPLAINED DIE-OFFS LIKE THESE ARE ANOTHER REASON FOR CONCERN ABOUT FRESHWATER MUSSELS
PHOTO COURTESY EMILIE BLEVINS, XERCES SOCIETY
First Foods, she says, are “natural, from that land, and
have always been there, at least for us. For us, First Foods
are the foods we were given by Creation.”
Tribal belief says the Creator asked the foods which of
them would take care of the people, and salmon was the
first to promise, then other fish and mussels lined up behind
salmon. The First Food serving ritual in the longhouse
follows that order. First Foods are water, salmon, roots,
berries, deer and elk.
While a Eurocentric viewpoint might try to save the
salmon, the First Foods-informed perspective means
mussels, lamprey and other key elements in the ecosystem
must be saved as well in order to save salmon.
The tribes have a reciprocal response to those foods,
Red Elk says. “The foods give life to us, and in turn, we
protect them.”
She says the tribes “have been doing this type of work
from time immemorial,” and they gather what they need,
whether it is salmon, willows or wood for teepee poles, in
such a way they come back more plentiful.
Elders tell stories of where mussels were and where
they were eaten, and that information — the knowledge of
the people — is brought to the scientists. “That’s what’s so
unique about us,” Red Elk says. “We put that oral history
first.”
This approach brings attention to species and ecological
processes that those outside the Umatilla reservation may
not recognize or value. Traditional ecological and cultural
knowledge is brought together with science.
“Our keystone river is the Umatilla River,” says Main
of the CTUIR mussel project. “First Foods takes the entire
river as whole, takes the pieces of what we want to see,
and breaks it down into individual components. Not just
a salmon run in 10 years, but everything that goes into a
healthy ecosystem.”
Back in the 1960s and ’70s, Main says, Western
pearlshells were made locally extinct in the Umatilla
River. The Umatilla, Cayuse and Walla Walla Indians used
pearlshells exclusively as a food source, and for jewelry
and tools.
“It’s really telling to see we’ve completely extirpated
that from an entire system,” she says.
Elizabeth Glidewell is the Freshwater Mussel Project
lead for the CTUIR. She says the project started in 2003
and, while it has gathered vast amounts of historical data,
she echoes the cry that there is still much to discover about
mussels, from where they are and how many are left to
their reproductive timing.
But, she says, the project is “close to being able to
address the long-term goal of restoration.”
Working with mussels, Glidewell tells me, is a way of
“cheering for the underdog.”
Knowing that the pearlshell uses salmonids, Glidewell
says that scientists can take the mussel larvae and attach
them to the fish, and give them time to metamorphose in a
lab setting. They can then be collected and released into the
river as juveniles or later on.
Aware of the argument that salmon raised on fish farms
are genetically inferior, and even stupider, and thus less
able to survive than wild salmon, I ask Glidewell if that is
a concern for something as small and seemingly brainless
as a mussel.
“We don’t think so,” she tells me. They are selecting for
traits that will let the mussels survive in the river and with
good genetics.
Main adds that the plan is to out-plant mussels into the
Umatilla River in 2018 or, at the latest, 2019.
Back in Eugene, on the banks of the Willamette,
Williams tells me that one thing those working on mussels
do know is that overall, Western pearlshells are declining.
Maybe, just maybe, he says, if enough information
about mussel distribution and abundance is collected, they
could be petitioned for listing under the federal Endangered
Species Act. “But right now,” he says, “I don’t know of
anyone working on that.” ■
To find out more about Willamette Riverkeeper’s efforts to document
mussels in the Willamette, go to willamette-riverkeeper.org. To see Xerces
Society’s mussel research, check out xerces.org. Find the CTUIR mussel
project via ctuir.org.
eugeneweekly.com • November 16, 2017
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