My collaborators and I are pleased to announce the publication of our
right whale density model. The paper and all results are open access,
freely downloadable, and reusable under a CC-BY License.
Download the paper: https://doi.org/10.3354/meps14547
Download the model: https://seamap.env.duke.edu/models/Duke/EC/
North Atlantic right whale density surface model for the US Atlantic
evaluated with passive acoustic monitoring
Jason J. Roberts, Tina M. Yack, Ei Fujioka, Patrick N. Halpin, Mark F.
Baumgartner, Oliver Boisseau, Samuel Chavez-Rosales, Timothy V. N. Cole,
Mark P. Cotter, Genevieve E. Davis, Robert A. DiGiovanni Jr., Laura C.
Ganley, Lance P. Garrison, Caroline P. Good, Timothy A. Gowan, Katharine
A. Jackson, Robert D. Kenney, Christin B. Khan, Amy R. Knowlton, Scott
D. Kraus, Gwen G. Lockhart, Kate S. Lomac-MacNair, Charles A. Mayo,
Brigid E. McKenna, William A. McLellan, Douglas P. Nowacek Orfhlaith
O’Brien, D. Ann Pabst, Debra L. Palka, Eric M. Patterson, Daniel E.
Pendleton, Ester Quintana-Rizzo, Nicholas R. Record, Jessica V. Redfern,
Meghan E. Rickard, Melanie White, Amy D. Whitt, Ann M. Zoidis
Abstract: The Critically Endangered North Atlantic right whale Eubalaena
glacialis entered a population decline around 2011. To save this species
without closing the ocean to human activities requires detailed
information about its intra-annual density patterns that can be used to
assess and mitigate human-caused risks. Using 2.9 million km of visual
line-transect survey effort from the US Atlantic and Canadian Maritimes
conducted in 2003-2020 by 11 institutions, we modeled the absolute
density (ind. km-2) of the species using spatial, temporal, and
environmental covariates at a monthly time step. We accounted for
detectability differences between survey platforms, teams, and
conditions, and corrected all data for perception and availability
biases, accounting for platform differences, whale dive behavior, group
composition, and group size. We produced maps of predicted density and
evaluated our results using independently collected passive acoustic
monitoring (PAM) data. Densities correlated positively (r = 0.46, ρ =
0.58, τ = 0.46) with acoustic detection rates obtained at 492 stationary
PAM recorders deployed across the study area (mean recorder duration =
138 d). This is the first study to quantify the concurrence of visual
and acoustic observations of the species in US waters. We summarized
predictions into mean monthly density and uncertainty maps for the
2003-2009 and 2010-2020 eras, based on the significant changes in the
species’ spatial distribution that began around 2010. The results
quantify the striking distribution shifts and provide effort- and
bias-corrected density surfaces to inform risk assessments, estimations
of take, and marine spatial planning.
For those of you already familiar with this model, the paper documents
"version 12.2" of the model, which is the most recent version. Version
12 was first released for management use on 14 February 2022. On 27 May
2023, we released version 12.1, which included a supplementary report
giving technical details of the model but did not change the model's
density predictions. On 20 March 2024, we released 12.2 in conjunction
with this publication, and again did not change the model's density
predictions. If you downloaded version 12 or 12.1 and performed an
analysis with it, your analysis does not need to be redone at this time,
and it is OK to say your analysis was conducted against the latest right
whale model (version 12.2) available at this time.
This project builds upon the efforts of the hundreds of people involved
in conducting line transect surveys in the eastern United States over
the past 25 years. Thanks for the opportunity to analyze the data you
helped collect. I hope you will find this project a worthy outcome of
your efforts.
All the best,
Jason Roberts
[email protected]
Duke Marine Geospatial Ecology Lab
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