Right Whale Use of Southern New England Wind Energy Areas Increasing
NOAA
Two North Atlantic right whales, 2018.
Credit: NOAA Fisheries/Tim Cole
Southern
New England habitat is important to the North Atlantic right whale. With
offshore wind energy development planned in the region, working with
stakeholders to minimize potential impacts on right whales and other protected
species is crucial.
Right whales are increasing
their use of southern New England waters, including regions slated for offshore
wind energy development, according to aerial survey data collected during the
last decade. Offshore wind energy installations are proposed in waters off the
south coasts of Massachusetts and Rhode Island.
Understanding and minimizing the
potential impacts from construction noise, increased vessel traffic, and
habitat alteration will be crucial to protecting and conserving this endangered
species. This research supports the Administration’s goal
of deploying offshore wind while protecting biodiversity and promoting ocean
co-use.
The study
was published July 29 in Endangered Species Research. Marine
mammal researchers from NOAA Fisheries and colleagues at the New England
Aquarium and the Center for Coastal Studies examined aerial survey data
collected between 2011–2015 and
2017–2019.
The data was collected in offshore waters including the
Massachusetts and Rhode Island Wind Energy Area. The data from these two time
periods were used to quantify right whale distribution, residency,
demographics, and movements in the region.
“We found that right whale use of the region increased during the last decade, and since 2017 whales have been sighted there nearly every month, with large aggregations occurring during the winter and spring,” said Tim Cole, lead of the whale aerial survey team at the Northeast Fisheries Science Center and a co-author of the study.
Survey Data, Models Reveal Patterns
The New
England Aquarium conducted systematic aerial surveys in the
region. The Northeast Fisheries Science Center and the Center for
Coastal Studies conducted surveys directed to aggregations of right whales.
They collected photographs of individual right whales to
estimate the whales’ abundance and residency. Individual
right whales are identified by distinctive patches
of raised tissue on their
head, lips, and chin, and by scars on their body.
Photographs were matched to catalogued individuals in the North Atlantic Right Whale Consortium Sighting Database. A total of 327 unique right whales were photographed in the area by the teams over the study period.
Unique light colored patches of tissue on the whale's head help
identify each individual. Credit: NOAA Fisheries/Peter Duley
The study also found that the residence time for individuals in
the area during the winter and spring has increased to an average of 13 days
over the last decade. Age and sex ratios of the whales present in the study
area are similar to the species as a whole, with adult males the most
common.
A whale
movement model included in the study revealed that southern New England is an
important destination for right whales, including pregnant females.
Observations of feeding occurred in all seasons and years. Social behaviors
were observed mainly during the winter and spring in all years except
2011 and 2017.
First Indications of the Region’s Importance
The first
documentation of large numbers of right whales in southern New England waters
occurred on April 20, 2010. The Northeast Fisheries Science Center aerial
survey team identified 102 individual whales during a flight in the region. The
New England Aquarium then conducted visual and acoustic monitoring during
2011-2015.
They found consistent use of the region by more than
one-third of the population, including 30 percent of the reproductive females.
The use of the area by reproductive females is an important consideration for
the species’ conservation. Their overall population has declined
significantly in recent years in part due to reduced calving rates.
“Since a number of large commercial offshore wind
energy projects are proposed off southern New England,
construction and operation of wind farms are relevant to conserving the
species,” Cole said. “Considerable uncertainty still exists regarding
how the
development of the region could have an impact on right whales just as they are
becoming more reliant on the region.”
Increased Noise, Vessel Traffic, Habitat
Alterations Possible
Construction
and operation of hundreds of wind turbines is likely to introduce increased
ocean noise, vessel traffic and possibly habitat alteration. All of these
factors have the potential to affect right whales.
Increased
vessel traffic in the region will bring with it a greater risk of vessel
strikes, one of the leading causes of serious injury and death of right whales.
Increased
noise from wind turbine construction and operations and vessels could also
directly impact important whale behaviors and interfere with the detection of
critical acoustic cues. These types of impacts may also be associated with
physiological stress and could affect the whales’ use of the region.
The presence of wind turbine foundations may
impact oceanographic
and atmospheric conditions including potential changes in ocean stratification. This might alter the
formation of plankton aggregations and thus foraging opportunities for right
whales.
Mitigation Measures Will be Crucial
“Implementing
mitigation measures by all companies holding leases will be crucial, and should
be adapted and reevaluated continually in relation to the whales’ use of the
area,” Cole said. “Given the large-scale shifts that the species is
experiencing, a variety of studies will be needed to understand potential
changes in right whale distribution patterns and to inform appropriate
strategies for future wind energy development.”
NOAA
Fisheries utilizes the best available science and works closely with the Bureau
of Ocean Energy Management (the lead federal agency for offshore wind energy
development) and offshore wind energy companies. We evaluate mitigation
and monitoring measures and ensure compliance with the Endangered Species Act
and the Marine Mammal Protection Act.
Funding for
the study was provided by the Bureau of Ocean Energy Management and the
Massachusetts Clean Energy Center under Cooperative Agreement M17AC00002. NOAA
Fisheries funded publication of the study.