OC Waves Vol 3.6

small mesh size to sample without destroying
the gelatinous bodies of the jellies. A ring net,
aptly named for its ring-shaped opening, is also
deployed to collect even smaller zooplankton.
On those mornings that I was running late, my
saving grace was that sampling can be described
as a “hurry up and wait” kind of process on the
Langseth. When MOCNESS was sent over the
side of the ship, it took around 30 minutes to
reach the sea floor and return to the ship’s deck.
Then there was a burst of action as samples
were hauled into the lab for processing. A net’s
contents were poured into clear glass casserole
dishes with lights housed below, illuminating
the collection of organisms as scientists crowded
around to point out interesting specimens worthy
of being photographed or bountiful enough to
be sent for elemental analysis. It is within these
casserole dishes that I began to see the tiny world
of gelatinous zooplankton.
Gelatinous zooplankton come in a range of
shapes, sizes and behaviors. Some are round and
flat and look like ornate or fine china. Others are
long and skinny with many leg-like protrusions,
which allow them to swim incredibly fast. Among
all these unique animals, there was one group that
captured the attention of the entire science party
and crew.
The gelatinous zooplankton the Sutherland Lab is interested in are small, but in the words of Dr. Terra Hiebert, “…
just because something is difficult to see doesn’t mean that it isn’t extremely relevant in many ways.”
Most zooplankton are translucent, with some
tan or yellow organs, but Doliolids stand out due
to their colorful purple banding. A single barrelshaped
Doliolid doesn’t have enough pigment to
really be that interesting, but in mass aggregations
of thousands of individuals, they produce a
vibrant plum color.
Doliolids weren’t collected at every site, but they
could consistently be found at sites over 50 miles
offshore. Where they were found, they were the
most abundant gelatinous zooplankton, and their
purple hue indicated their abundance in the ring
net long before it was poured into our dishes.
Despite their eye-catching appearance, Doliolids
aren’t well known by most marine scientists
or general audiences. While they haven’t been
extensively studied, limited, existing literature
suggests that warming sea temperatures will
promote Doliolid populations to bloom due to
the increase in their food source, phytoplankton.
Understanding how different conditions may
impact zooplankton composition is central to
the work being done by the Sutherland Lab.
All sampling was done in combination with an
instrument that collects information on the water’s
salinity and temperature at different depths. This
helps researchers see patterns in the distribution
of specific zooplankton, and while some trends are
noticed during sampling, like where Doliolids can
be found, most of the work is done back on land.
Kevin Du Clos (left) and Alejandro Damian Serrano guide the ring net full of diatoms (dark substance) back on
deck. Diatoms are single-celled algae that make samples denser and more difficult to filter and sort through.
eager to get back to their families and also into
the lab to start processing the data collected
from all 28 sites sampled. Processing will take a
couple years, and the sampling isn’t done there.
This winter, the Sutherland Lab will again be out
at sea to introduce another factor, seasonality,
to their research. By overlaying ocean conditions
and seasonality onto sampling data, the lab
hopes to create predictive models of zooplankton
composition in response to climate change.
While climate change continues to impact our
marine ecosystems, the types of organisms you
find washed up on our beaches will likely change.
Most people who walk along beaches will usually
find an assortment of jellies, like pacific sea nettles
or comb jellies, but Doliolids aren’t often found
washed ashore. When Doliolids do find their way
to land, it is in masses.
beachgoers may start to see more of these purpledbanded,
barrel-shaped organisms, something that
previously seemed unattainable unless you found
yourself abroad a ship collecting zooplankton.
While these purple jellies are fascinating to
observe, these blooms are also a cue to what is
happening in the environment. There are changes
occurring to our marine ecosystems, and this is
one obvious indication of that.
The Sutherland Lab’s goal of creating
zooplankton composition models will take a couple
years, and our understanding of how increasing
Doliolid populations may affect the larger food
web will take even longer. For now, next time they
start to wash up on Oregon beaches, take some
time to investigate their tiny world and appreciate
gelatinous zooplankton at their most colorful. I
know I will be.
After two weeks at sea, the science party was
As these blooms become more common,
BY CARMEN SANCHEZ-REDDICK
OC WAVES • VOL 3.6
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