Dear Colleagues,

My co-authors and I are very pleased to announce the publication of our paper 
in Conservation Biology:

Mannocci, L., Roberts, J.J., Miller, D.L., & Halpin, P.N. (2017) Extrapolating 
cetacean densities to quantitatively assess human impacts on populations in the 
high seas. Conservation Biology DOI: 10.1111/cobi.12856

The article is Open Access and can be downloaded from: 
http://onlinelibrary.wiley.com/doi/10.1111/cobi.12856/abstract

Abstract: As human activities expand beyond national jurisdictions to the high 
seas, there is an increasing need to consider anthropogenic impacts to species 
inhabiting these waters. The current scarcity of scientific observations of 
cetaceans in the high seas impedes the assessment of population-level impacts 
of these activities. We developed plausible density estimates to facilitate a 
quantitative assessment of anthropogenic impacts on cetacean populations in 
these waters. Our study region extended from a well-surveyed region within the 
U.S. Exclusive Economic Zone into a large region of the western North Atlantic 
sparsely surveyed for cetaceans. We modeled densities of 15 cetacean taxa with 
available line transect survey data and habitat covariates and extrapolated 
predictions to sparsely surveyed regions. We formulated models to reduce the 
extent of extrapolation beyond covariate ranges, and constrained them to model 
simple and generalizable relationships. To evaluate confidence in the 
predictions, we mapped where predictions were made outside sampled covariate 
ranges, examined alternate models, and compared predicted densities with maps 
of sightings from sources that could not be integrated into our models. 
Confidence levels in model results depended on the taxon and geographic area 
and highlighted the need for additional surveying in environmentally distinct 
areas. With application of necessary caution, our density estimates can inform 
management needs in the high seas, such as the quantification of potential 
cetacean interactions with military training exercises, shipping, fisheries, 
and deep-sea mining and be used to delineate areas of special biological 
significance in international waters. Our approach is generally applicable to 
other marine taxa and geographic regions for which management will be 
implemented but data are sparse.

Please note that all the results of this study can be downloaded from: 
http://seamap.env.duke.edu/models/AFTT-2015/

Cheers,

Laura Mannocci, PhD
Postdoctoral Associate
Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke 
University
https://mgel.env.duke.edu/

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