Dear MARMAM subscribers,
My coauthors and I are pleased to share with you the recent publication
of the article:
Pardo MA, Gerrodette T, Beier E, Gendron D, Forney KA, Chivers JS,
Barlow J, Palacios DM (2015) Inferring Cetacean Population Densities
from the Absolute Dynamic Topography of the Ocean in a Hierarchical
Bayesian Framework. PLoS ONE 10(3): e0120727.
doi:10.1371/journal.pone.0120727
Abstract
We inferred the population densities of blue whales (/Balaenoptera
musculus/) and short-beaked common dolphins (/Delphinus delphis/) in the
Northeast Pacific Ocean as functions of the water-column’s physical
structure by implementing hierarchical models in a Bayesian framework.
This approach allowed us to propagate the uncertainty of the field
observations into the inference of species-habitat relationships and to
generate spatially explicit population density predictions with reduced
effects of sampling heterogeneity. Our hypothesis was that the
large-scale spatial distributions of these two cetacean species respond
primarily to ecological processes resulting from shoaling and
outcropping of the pycnocline in regions of wind-forced upwelling and
eddy-like circulation. Physically, these processes affect the
thermodynamic balance of the water column, decreasing its volume and
thus the height of the absolute dynamic topography (ADT). Biologically,
they lead to elevated primary productivity and persistent aggregation of
low-trophic-level prey. Unlike other remotely sensed variables, ADT
provides information about the structure of the entire water column and
it is also routinely measured at high spatial-temporal resolution by
satellite altimeters with uniform global coverage. Our models provide
spatially explicit population density predictions for both species, even
in areas where the pycnocline shoals but does not outcrop (e.g. the
Costa Rica Dome and the North Equatorial Countercurrent thermocline
ridge). Interannual variations in distribution during El Niño anomalies
suggest that the population density of both species decreases
dramatically in the Equatorial Cold Tongue and the Costa Rica Dome, and
that their distributions retract to particular areas that remain
productive, such as the more oceanic waters in the central California
Current System, the northern Gulf of California, the North Equatorial
Countercurrent thermocline ridge, and the more southern portion of the
Humboldt Current System. We posit that such reductions in available
foraging habitats during climatic disturbances could incur high
energetic costs on these populations, ultimately affecting individual
fitness and survival.
The full article is freely available at:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0120727
Kind regards,
--
*Mario A. Pardo*
CICESE <http://www.cicese.edu.mx/> - Unidad La Paz <http://ulp.cicese.mx/>
Research Associate
Project CONACyT-SEP-2011-168034-T-1753
Miraflores 334, La Paz, BCS 23050, Mexico
Tel: +52(612)1213031 Ext. 28116
ResearchGate <https://www.researchgate.net/profile/Mario_Pardo2/> |
LinkedIn <http://mx.linkedin.com/pub/mario-a-pardo/4b/272/a1b> |
GoogleScholar <http://scholar.google.com/citations?user=EX8mZ9AAAAAJ&hl=en>
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