Nitrogen from sewage-treatment plants, along with other nutrient
sources, are known to trigger plankton blooms that lead to
dangerous low-oxygen conditions in Puget Sound — a phenomenon that
has been studied for years.
Nitrogen sources used to
predict future water-quality in the Salish Sea Model
Map: Washington Department of Ecology
Now state environmental officials are working on a plan that
could eventually limit the amount of nitrogen released in sewage
effluent.
The approach being considered by the Washington Department of
Ecology is a “general permit” that could apply to any treatment
plant meeting specified conditions. The alternative to a general
permit would be to add operational requirements onto existing
“individual permits” issued under the National Pollutant Discharge
Elimination System, or NPDES.
The general permit would involve about 70 sewage-treatment
plants discharging into Puget Sound. Theoretically, an overall
nitrogen limitation would be developed for a given region of the
sound. Treatment plant owners could work together to meet that
goal, with the owner of one plant paying another to reduce its
share of the nutrient load.
In what is becoming an annual event, portions of Hood Canal have
changed colors in recent days, the result of a large bloom of
armored plankton called coccolithophores.
Coccolithophore from Hood
Canal’s Dabob Bay viewed with scanning electron microscope.
Image: Brian Bill, Northwest Fisheries Science
Center
Teri King, a plankton expert with Washington Sea Grant, has been
among the first to take notice of the turquoise blooms each year
they occur.
“Guess who is back?” Teri wrote in the blog
Bivalves for Clean Water. “She showed up June 24 in Dabob Bay
and has been shining her Caribbean blueness throughout the bay and
spreading south toward Quilcene Bay.”
Yesterday, I noticed a turquoise tinge in Southern Hood Canal
from Union up to Belfair, although the color was not as intense as
I’ve seen in past years.
The color is the result of light reflecting off elaborate
platelets of calcium carbonate, called coccoliths, which form
around the single-celled coccolithophores. The species in Hood
Canal is typically Emiliania huxleyi.
Hood Canal has changed colors again, shifting to shades of
bimini green, as it did in 2016, when satellite photos showed the
canal standing out starkly among all other waters in the
Northwest.
Hood Canal has changed colors
as a result of a plankton bloom, as shown in this aerial photo
taken in Northern Hood Canal.
Photo: Eyes Over Puget Sound, Washington
Ecology
The color change is caused by a bloom of a specific type of
plankton called a coccolithophore, which shows up in nutrient-poor
waters. The single-celled organism produces shells made of calcite,
which reflect light to produce the unusual color.
Observers are now waiting for the clouds to depart, so we can
get new satellite images of the green waters.
The plankton bloom started June 1 in Quilcene and Dabob bays,
according to Teri King of Washington Sea Grant. It came about a
week earlier than last year and has since spread through Hood
Canal. Observers in the Seabeck area reported seeing the bloom the
past few days. The bimini green color, which gets its name from an
island in the Bahamas, is especially noticeable when the sun comes
out.
In a way, some of Puget Sound’s most serious ecological problems
have been hiding in plain sight. I have been learning a lot lately
about plankton, an incredibly diverse collection of microscopic
organisms that drift through the water, forming the base of the
food web.
Sources of nitrogen in Puget
Sound (click to enlarge)
Graphic: Washington Department of
Ecology
To put it simply, the right kinds of plankton help to create a
healthy population of little fish that feed bigger fish that feed
birds and marine mammals, including the endangered Southern
Resident killer whales. On the other hand, the wrong kinds of
plankton can disrupt the food web, stunt the growth of larger
creatures and sometimes poison marine animals.
OK, that’s a bit of an oversimplification, but Puget Sound
researchers are just beginning to understand the profound
importance of a healthy planktonic community to support a large
part of the food web. That’s one of the main points that I try to
bring out in five stories published today in the Encyclopedia of Puget Sound. I
am grateful to the many researchers who have shared their knowledge
with me.
Average daily nitrogen coming
in from rivers and wastewater treatment plants (1 kg = 2.2
pounds)
Graphic: Washington Department of
Ecology
These stories tie together several major issues all related to
nutrients — mainly nitrogen — that feed the marine phytoplankton,
which use their chlorophyll to take energy from the sun as they
grow and multiply. In the spring and summer, too much nitrogen can
mean too much plankton growth. In turn, excess plankton can lead to
low-oxygen conditions, ocean acidification and other significant
problems.
The complex interplay of planktonic species with larger life
forms in Puget Sound is still somewhat of a mystery to researchers
trying to understand the food web. As part of the effort, the
Washington Department of Ecology is working on a computer model to
show how excess nitrogen can trigger low-oxygen conditions in the
most vulnerable parts of the Salish Sea, such as southern Hood
Canal and South Puget Sound.
Areas of Puget Sound listed as
“impaired” for dissolved oxygen (click to enlarge)
Graphic: Washington Department of
Ecology
Stormwater is often cited as the most serious problem facing
Puget Sound, and we generally think of bacteria and toxic chemicals
flowing into the waterway and causing all sorts of problems for the
ecosystem. But stormwater also brings in nitrogen derived from
fertilizers, animal wastes and atmospheric deposits from burning
fossil fuels. Stormwater flows also pick up natural sources of
nitrogen from plants and animals that end up in streams.
Sewage treatment plants are another major source of human
nitrogen. Except for a few exceptions, not much has been done to
reduce the release of nutrients from sewage-treatment plants, which
provide not only nitrogen but also micronutrients such as vitamins
and minerals. Some experts suspect that nutrients other than
nitrogen help to determine which types of plankton will dominate at
any given time.
I plan to follow and report on new scientific developments
coming out of studies focused on the base of the food web.
Meanwhile, I hope you will take time to read this package of related
stories:
Does Puget
Sound need a diet: An overview of the nutrient problem with its
biological, legal and practical implications.
Automated equipment installed Monday off the Washington Coast
will track concentrations of six species of plankton that could
become harmful to humans and marine species.
The Environmental Sample Processor, or ESP, collects discrete
samples of water and processes them for analysis. Imbedded modules
can test for DNA and antibodies to identify the organisms picked up
in the seawater. Concentrations of the plankton and their toxins
are sent to shore-based researchers via satellite.
The equipment was installed by scientists with the National
Oceanic and Atmospheric Administration and the University of
Washington. The device was developed at the
Monterey Bay Aquarium Research Institute. Stephanie Moore of
NOAA’s Northwest Fisheries Science Center explains the benefits of
the device in the first video on this page. The second video
provides a few more technical details with graphic depictions of
the device.
The ESP was deployed in the Juan de Fuca eddy, a known pathway
for toxic algae 13 miles off the Washington Coast near LaPush. The
remote, self-operating laboratory will operate about 50 feet
underwater.
One of the primary targets of the monitoring is
Pseudo-nitzschia, a harmful algae capable of producing
domoic acid. This toxin can accumulate in shellfish and can cause
diarrhetic shellfish poisoning, which can progress to severe
illness. Last year, a massive bloom of this toxic algae canceled
scheduled razor clam seasons on Washington beaches with untold
economic consequences.
The harmful algal bloom (HAB) affected the entire West Coast,
from California to Alaska. It was the largest and longest-lasting
bloom in at least 15 years, according to NOAA’s National Ocean
Service.
“Concentrations of domoic acid in seawater, some forage fish and
crab samples were among the highest ever reported in this region,”
says a factsheet
from the service. “By mid-May, domoic acid concentrations in
Monterey Bay, California, were 10 to 30 times the level that would
be considered high for a normal Pseudo-nitzschia
bloom.”
“Other HAB toxins were also detected on the West Coast.
Shellfish closures in Puget Sound protected consumers from
paralytic shellfish poisoning and diarrhetic shellfish
poisoning.”
Paralytic shellfish poisoning is associated with a group of
plankton called Alexandrium, typically Alexandrium
catenella in the Puget Sound region.
In addition to sampling for Alexandrium and four
species of Pseudo-nitzchia, the ESP is monitoring for
Heterosigma akashiwo, which is associated with massive
fish kills, including farmed salmon.
Early warning of toxic algal blooms can assist state and local
health officials in their surveillance of toxic shellfish.
“Anyone can access the data in near-real-time,” UW oceanographer
and NANOOS Director Jan Newton told Hannah Hickey of
UW News and Information. “It’s an early warning sentry.”
We just completed another group of stories in the ongoing series
we’re calling “Taking the Pulse of Puget Sound.” This latest story
package is about
marine water quality and marine sediments. (The stories
themselves require a subscription.)
Noctiluca, a type of
plankton that could disrupt the food web, has grown more prevalent
in recent years.
Photo by Christopher Krembs, Eyes Over Puget
Sound
For all my years of environmental reporting, I have to say that
I’ve never really understood the meaning of water quality. Keeping
the water free of chemicals and fecal bacteria is one thing. Safe
levels of oxygen, temperature, acidity and suspended sediment are
other important factors.
But in the real world, you never find ideal conditions. You take
what you get: physical conditions dictated by weather, climate and
bathymetry; a strange brew of toxic chemicals; and a mix of
nutrients and organic material, all drifting through complex cycles
of life and death.
Water quality means nothing without the context of living
things. More than 1,000 species of tiny organisms live in or on the
mud at the bottom of Puget Sound. In many areas, sensitive species
have disappeared. We are left with those that can tolerate harsher
conditions. Why are they dying off? What can be done about it?
Some plankton species are becoming more dominant, and the
effects on the food web are unknown. When water quality is poor,
Jellyfish are displacing forage fish, disrupting the food supply
for larger fish.
We know that toxic chemicals are spilling into Puget Sound in
stormwater and getting into the food web, first touching the
tiniest organisms and eventually causing havoc for fish, marine
mammals and humans. Compounds that mimic hormones are affecting
growth, reproduction and survival for a myriad of species. Because
of biomagnification, some chemicals are having serious effects at
concentrations that could not be measured until recently.
Puget Sound can’t cleanse itself by flushing its chemicals and
waste out to sea, as most bays do. Puget Sound is long and narrow
and deep, and the exchange of water takes a long time. Most of the
bad stuff floating in the water just sloshes back and forth with
the daily tides.
We can’t forget that some of the good stuff floating around are
microscopic plants that feed the food web, along with a variety of
larvae that will grow into fish, shellfish and many other
creatures. But many of these planktonic life forms are vulnerable
to chemicals, which can reduce their ability to survive against
predators, tipping the balance in unknown ways.
Understanding water quality is not so much about measuring what
is in the water as understanding the effects on living things.
Which species are missing from a given area of Puget Sound, and
what killed them off?
Biological monitoring has been around for a long time, but we
may be entering a new phase of exploration in which we begin to
connect the dots between what takes place on the land, how
chemicals and nutrients get into the water, and what that means for
every creature struggling to survive.
We have some brilliant people working on this problem in the
Puget Sound region. I would like to thank everyone who has helped
me gain a better understanding of these issues, as I attempt to
explain these complexities in my stories.
—–
While I was looking into the sediment story, Maggie Dutch of
Ecology’s sediment monitoring team introduced me to a huge number
of benthic invertebrates. In a blog she calls
“Eyes Under Puget Sound,” she talks about the monitoring
program and offers a slideshow of some of the bottom creatures. See
also Ecology’s
Flickr page.
For some
amazing shots of polychaete worms, check out the work of marine
biologist and photographer Alex Semenov who took these colorful pix
in Russia and Australia.
Eyes Over Puget Sound shot
some amazing plankton blooms this week, including this one between
Bainbridge Island and Seattle. / Photos courtesy of
EOPS
Team members for Eyes Over Puget Sound, a Washington Department
of Ecology program, were excited to discover and report on a second
major plankton bloom during their flight this week.
“The real show came at the end of the day when we got to Edmonds
and started to see a bright orange Noctiluca bloom. It was huge! It
persisted all the way to South East Passage. It was the most
extensive bloom I have ever seen. Every direction you looked, there
it was. It’s as if Puget Sound was on fire!
“The size of this bloom made me wonder … Why is it happening in
the Main Basin and not in South Sound? Why is it happening again?
Why don’t we know more about its appearance and ferocious appetite
for phytoplankton? Could it be that our imprint on Puget Sound is
artfully surfacing to remind us of our daily connection to the
Sound? Could these large blooms be a clue of a shift in the food
chain?”
The report provides all kinds of good information, which I will
review more carefully when I get the chance. General observations
include red-brown blooms in Port Townsend Bay, Discovery Bay and
Bellingham Bay. Large mats of accumulated plankton were seen in
Samish Bay. Clusters of jellyfish were spotted in Budd, Totten and
Eld Inlets, all in South Puget Sound.
EOPS provides aerial observations of sea surface conditions
between landings, when water is sampled for a variety of
conditions. Weather and general oceanographic conditions also are
reported after each flight.
Taken over Winslow on
Bainbridge Island, this photo shows a Noctiluca bloom with the
Bainbridge Island ferry in the background. / Photo by
Christopher Krembs, Ecology
Plankton blooms reported last week from numerous locations in
Puget Sound were confirmed and examined from the air Monday by
Christopher Krembs and his colleagues at Eyes Over Puget Sound.
The marine monitoring group for the Department of Ecology
reported notable Noctiluca blooms, as I reported in a story in
Friday’s Kitsap Sun. The blooms are relatively harmless and not
unexpected, given the mild weather and freshwater flows that bring
nutrients into Puget Sound. They are earlier than in recent years,
however.
Christopher also observed heavy sediment flows coming out of the
Fraser River near Vancouver and moving south along the Canadian
border. These and many other observations can be reviewed by
downloading the latest
report on Ecology’s website.
A brightly colored plankton
called Noctiluca was observed last week along the shore of
Bremerton’s Evergreen-Rotary Park. / Kitsap Sun photo
by Meegan M. Reid.
I just completed the second part of a yearlong series I’m
writing about the Puget Sound ecosystem and the 21 “vital signs”
indicators chosen by the Puget Sound Partnership to measure the
health of the sound.
This second part, published in
Sunday’s Kitsap Sun, consists of stories about the food web,
including plankton and eelgrass; forage fish, including herring;
and bulkheads, which are generally considered a threat to the
nearshore ecosystem.
I was trying to cover the lower half of the food web, to build a
foundation for the other parts to come.
I talked to a lot of experts on these issues and ended up
writing one of the largest story packages I’ve ever written. Still,
I barely touched the surface of these topics. I guess I’ll have to
return later to dig a little deeper.
Scientists often say, the more they know, the more they realize
what little they know, or something like that. I’ve always tried to
help people understand the complexities of environmental science,
but there are no simple answers.
That’s why the Puget Sound Partnership is an important bridge
between policymakers and scientists. We have enough tools to know
what should be done to save Puget Sound, but how do we know what
projects should come before others? What can we afford to do? And
how do we measure success or failure? Those are the questions
challenging the partnership at the moment.
I would like to thank all the researchers willing to give their
time to this project as well as Kitsap Sun staffers who helped
crunch the numbers and produce the graphics for the story package,
as well as the editors who offered ideas along the way.
Sinclair Inlet last August
was awash in colorful plankton. This photo was taken over Port
Orchard, looking toward Gorst.
Photo by Christopher Krembs, Eyes Over Puget
Sound
Southern Hood Canal is back to its dirty tricks again, as
dissolved oxygen concentrations have dropped to dangerous levels
even at the surface. Numerous researchers are watching to see how
these conditions play out.
A giant Pacific octopus,
which should be hiding, clings to a rock wall Saturday at Sund
Rocks Marine Preserve.
Photo by Pat Lynch
The mechanism that causes the oxygen to decline is a little
complicated, but it’s pretty well understood. It involves nitrogen,
sunlight, plankton, heavy sea water and south winds. See the story
I wrote for
today’s Kitsap Sun for a brief explanation, or check out a
story from April 12, when I described findings from a
scientific panel about the sources of nitrogen in the canal.
The graph below shows the oxygen levels at three depths near
Hoodsport. As you can see from the blue line, oxygen levels near
the surface declined rapidly over the past five days, a period when
winds blew out of the south. Levels below 2.5 milligrams per liter
are considered highly stressful for sea life.
At Hoodsport, oxygen levels rose at the 10-foot mark starting
about midday yesterday. They declined again this morning, starting
after midnight. Being close to the surface, oxygen levels in these
waters are greatly influenced by winds and waves.
Waters at 66 feet deep stayed low in oxygen but fairly stable,
as shown by the green line. Fish tend to swim into shallow waters
to avoid those low-oxygen levels. A huge mass of low-oxygen water
lies in this mid-range area.
Meanwhile, the low-oxygen waters in the middle layers are being
pushed upward by heavy seawater coming in from the ocean. That deep
ocean water contains more oxygen than the layer above it, as shown
by the red line.
To follow these changes in close to real time, go to the
Nanoos website and
click on “Click here to view all assets” then on “regions” in the
left column and “Puget Sound.” You can get information from most of
these buoys. Hoodsport is the closest to the action in southern
Hood Canal.
