Maryland offshore wind farm could become stop-over for migrating
sturgeon, striped bass

Date:
June 26, 2020
Source:
University of Maryland Center for Environmental Science
Summary:
For the endangered Atlantic sturgeon and the commercially important
striped bass, the Delaware-Maryland-Virginia coastal shelf serves as
an important spring and fall migratory route. Researchers suggest
that the development of wind farms on the DelMarVa coastal shelf
may alter the migratory behavior of these fish as new wind turbines
in this otherwise featureless region could create habitat around
which fish linger.



FULL STORY ==========================================================================
For the endangered Atlantic sturgeon and the commercially and
recreationally important striped bass, the Delaware-Maryland-Virginia
coastal shelf serves as an important spring and fall "flyway." Typically thought of as an established aerial route used by migratory birds to
travel between feeding and breeding grounds, a recent study by scientists
at the University of Maryland Center for Environmental Science applies
the term to fish species of concern. Authors suggest that the development
of wind farms on the Delmarva coastal shelf, 17-26 miles from Ocean
City's shoreline, may alter the migratory behavior of these fish as new
wind turbines in this otherwise featureless region could create habitat
around which fish linger.


========================================================================== Studies within the Maryland Wind Energy Area -- the coastal shelf waters
leased by the Bureau of Ocean Energy Management for offshore wind farms
-- prior to construction activities reveal that Atlantic sturgeon and
striped bass are frequent visitors. Seasonal trends lead scientists to
believe that the wind energy area lies within an important migration
corridor for both species.

Atlantic sturgeon were most commonly observed moving through the area
during the spring and fall, while striped bass had an increased migratory presence in spring and winter. The Atlantic sturgeons' "flyway" tended
to favor shallower, warmer waters, while striped bass were more likely
to be found at great depths and cooler conditions.

Both species spent longer periods of time in the corridor during the
autumn and winter. This trend was particularly strong for striped bass,
with many individuals prolonging their presence on the outer shelf
during winter.

However, during the summer, Atlantic sturgeon were rarely detected and
striped bass were absent.

The construction of an off-shore wind farm creates loud noises and
increased activity that can disrupt typical animal behaviors. The low occurrence of these important fish species during the summer months
suggests a potential window for wind turbine construction, when impacts
could be minimized.

"Scientists have learned a lot about the Atlantic sturgeon and striped
bass' seasonal patterns of habitat selection within spawning rivers,
estuaries, and shelf foraging habitats," says study author Ellie
Rothermel, who recently received her master's degree from the University
of Maryland Center for Environmental Science. "During these times,
we know where the fish are likely to be and when to expect them there,
but information on the location and timing of key coastal migrations is limited. Coastal waters have been largely inaccessible to scientists. Our
study uses acoustic telemetry to understand the critical migratory
periods in the lives of these fish species." Rothermel compares acoustic telemetry to the E-ZPass system used for vehicles.

When a car with E-ZPass is driven over the Bay Bridge, a toll booth
collects its identification number, along with the time and date. Just
like toll booths and the E-Z Pass system, scientists use acoustic
receivers and tags to track where fish go, and when they go there.

After catching and determining the size, weight and sex of a striped bass, scientists surgically implanted an acoustic tag into the fish prior to releasing it. An acoustic tag is a small device, about the size of a
thumb, that has a unique ID and makes a "ping" sound every few seconds.

Scientists also deployed 20 acoustic receivers in the Maryland Wind Energy Area. When a tagged fish swims past a receiver, a listening device about
the size of a liter soda bottle, the receiver records the "ping" sent out
by the tag. Each "ping" transmits its unique ID and the depth at which
the fish was swimming to the receiver, which also records the time and
date. The array of receivers allows scientists to monitor the movements
of tagged fish. During the study, "pings" from 352 individual Atlantic
sturgeon and 315 individual striped bass were recorded by receivers.

Scientists believe that Maryland's future offshore wind farm could
become a stop-over region where striped bass and sturgeon might
linger longer. The DelMarVa coastal shelf is a fairly barren area. The development of high relief wind turbines would provide structure around
which fish may gather and linger during migrations.

"To extend the highway travel metaphor, the wind farm that will be built
in the area off-shore from Ocean City may become a 'rest stop' where fish
and sharks can grab a bite to eat and take a break before resuming their travels," says study co-author Dave Secor of the University of Maryland
Center for Environmental Science.

As wind farms are developed and operated offshore of the Mid-Atlantic and Southern New England regions, which together comprises a multispecies
"flyway," scientists could use the telemetry array design to monitor
potential impacts.

Cooperation among researchers, expanded scale of acoustic telemetry
arrays, and increased incorporation of oceanographic data will improve understanding of how fishes will respond to wind energy development in
the northwest Atlantic Ocean.


========================================================================== Story Source: Materials provided by University_of_Maryland_Center_for_Environmental_Science.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Ella R. Rothermel, Matthew T. Balazik, Jessica E. Best, Matthew W.

Breece, Dewayne A. Fox, Benjamin I. Gahagan, Danielle E. Haulsee,
Amanda L. Higgs, Michael H. P. O'Brien, Matthew J. Oliver, Ian
A. Park, David H.

Secor. Comparative migration ecology of striped bass and Atlantic
sturgeon in the US Southern mid-Atlantic bight flyway. PLOS ONE,
2020; 15 (6): e0234442 DOI: 10.1371/journal.pone.0234442 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200626092724.htm

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