Greetings Marmamers On behalf of my coauthors, I am pleased to announce the publication of a new paper on the abundance of North Atlantic right whales.
The paper's citation is: Pace III RM, Corkeron PJ, Kraus SD. State–space mark–recapture estimates reveal a recent decline in abundance of North Atlantic right whales. Ecol Evol. 2017;00:1–12. https://doi.org/10.1002/ece3.3406 And the abstract is: North Atlantic right whales (Eubalaena glacialis Müller 1776) present an interesting problem for abundance and trend estimation in marine wildlife conservation. They are long lived, individually identifiable, highly mobile, and one of the rarest of cetaceans. Individuals are annually resighted at different rates, primarily due to varying stay durations among several principal habitats within a large geographic range. To date, characterizations of abundance have been produced that use simple accounting procedures with differing assumptions about mortality. To better characterize changing abundance of North Atlantic right whales between 1990 and 2015, we adapted a state–space formulation with Jolly-Seber assumptions about population entry (birth and immigration) to individual resighting histories and fit it using empirical Bayes methodology. This hierarchical model included accommodation for the effect of the substantial individual capture heterogeneity. Estimates from this approach were only slightly higher than published accounting procedures, except for the most recent years (when recapture rates had declined substantially). North Atlantic right whales' abundance increased at about 2.8% per annum from median point estimates of 270 individuals in 1990 to 483 in 2010, and then declined to 2015, when the final estimate was 458 individuals (95% credible intervals 444–471). The probability that the population's trajectory post-2010 was a decline was estimated at 99.99%. Of special concern was the finding that reduced survival rates of adult females relative to adult males have produced diverging abundance trends between sexes. Despite constraints in recent years, both biological (whales' distribution changing) and logistical (fewer resources available to collect individual photo-identifications), it is still possible to detect this relatively recent, small change in the population's trajectory. This is thanks to the massive dataset of individual North Atlantic right whale identifications accrued over the past three decades. Photo-identification data provide biological information that allows more informed inference on the status of this species. Ecology and Evolution is an Open Access journal, so the paper is freely available at: http://onlinelibrary.wiley.com/doi/10.1002/ece3.3406/abstract If you’d like the paper, please download it from the journal’s site. If the journal's site download isn't an option for you, the paper is also available via Researchgate at: https://www.researchgate.net/publication/319904432_State- space_mark-recapture_estimates_reveal_a_recent_ decline_in_abundance_of_North_Atlantic_right_whales I hope this is of interest. Peter -- Leader, Large Whale Team Protected Species Branch NOAA Northeast Fisheries Science Center 166 Water St Woods Hole MA 02543 phone: 508-495-2191 webpage: https://www.nefsc.noaa.gov/psb/psbStaff_PeterCorkeron.html ResearchGate: researchgate.net/profile/Peter_Corkeron Orcid: orcid.org/0000-0003-1553-125
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