My co-authors and I are pleased to announce the publication of a new
manuscript in PLoS ONE:
Virgili, A., Hedon, L., Authier, M., Calmettes, B., Claridge, D., Cole,
T., ... & Ridoux, V. (2021). Towards a better characterisation of
deep-diving whales’ distributions by using prey distribution model
outputs?. PloS one, 16(8), e0255667.
https://doi.org/10.1371/journal.pone.0255667
Abstract:
In habitat modelling, environmental variables are assumed to be proxies
of lower trophic levels distribution and by extension, of marine top
predator distributions. More proximal variables, such as potential prey
fields, could refine relationships between top predator distributions
and their environment. In situ data on prey distributions are not
available over large spatial scales but, a numerical model, the Spatial
Ecosystem And POpulation DYnamics Model (SEAPODYM), provides simulations
of the biomass and production of zooplankton and six functional groups
of micronekton at the global scale. Here, we explored whether
generalised additive models fitted to simulated prey distribution data
better predicted deep-diver densities (here beaked whales Ziphiidae and
sperm whales Physeter macrocephalus) than models fitted to environmental
variables. We assessed whether the combination of environmental and prey
distribution data would further improve model fit by comparing their
explanatory power. For both taxa, results were suggestive of a
preference for habitats associated with topographic features and thermal
fronts but also for habitats with an extended euphotic zone and with
large prey of the lower mesopelagic layer. For beaked whales, no
SEAPODYM variable was selected in the best model that combined the two
types of variables, possibly because SEAPODYM does not accurately
simulate the organisms on which beaked whales feed on. For sperm whales,
the increase model performance was only marginal. SEAPODYM outputs were
at best weakly correlated with sightings of deep-diving cetaceans,
suggesting SEAPODYM may not accurately predict the prey fields of these
taxa. This study was a first investigation and mostly highlighted the
importance of the physiographic variables to understand mechanisms that
influence the distribution of deep-diving cetaceans. A more systematic
use of SEAPODYM could allow to better define the limits of its use and a
development of the model that would simulate larger prey beyond 1,000 m
would probably better characterise the prey of deep-diving cetaceans.
This publication is open-access and can be found at this link:
https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0255667&fbclid=IwAR3F7LprXYeHAvTOPndlaSnOsxUenhiSrcIgFeZs78NT08rCyxy7Wy6wO44
Enjoy your day!
--
Dr Auriane VIRGILI
Ingénieure de recherche
Observatoire Pelagis UMS 3462 CNRS/La Rochelle Université
5 Allées de l'Océan, 17000 La Rochelle
Tél : 05 16 49 67 20
Standard: 05 46 44 99 10
E-mail : [email protected]
http://observatoire-pelagis.cnrs.fr/
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