Combining Methods to Describe Important Marine Habitats for Top Predators: Application to Identify Biological Hotspots in Tropical Waters

PLoS One. 2014 Dec 10;9(12):e115057. doi: 10.1371/journal.pone.0115057. eCollection 2014.

Abstract

In tropical waters resources are usually scarce and patchy, and predatory species generally show specific adaptations for foraging. Tropical seabirds often forage in association with sub-surface predators that create feeding opportunities by bringing prey close to the surface, and the birds often aggregate in large multispecific flocks. Here we hypothesize that frigatebirds, a tropical seabird adapted to foraging with low energetic costs, could be a good predictor of the distribution of their associated predatory species, including other seabirds (e.g. boobies, terns) and subsurface predators (e.g., dolphins, tunas). To test this hypothesis, we compared distribution patterns of marine predators in the Mozambique Channel based on a long-term dataset of both vessel- and aerial surveys, as well as tracking data of frigatebirds. By developing species distribution models (SDMs), we identified key marine areas for tropical predators in relation to contemporaneous oceanographic features to investigate multi-species spatial overlap areas and identify predator hotspots in the Mozambique Channel. SDMs reasonably matched observed patterns and both static (e.g. bathymetry) and dynamic (e.g. Chlorophyll a concentration and sea surface temperature) factors were important explaining predator distribution patterns. We found that the distribution of frigatebirds included the distributions of the associated species. The central part of the channel appeared to be the best habitat for the four groups of species considered in this study (frigatebirds, brown terns, boobies and sub-surface predators).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aquatic Organisms* / physiology
  • Biodiversity
  • Charadriiformes* / physiology
  • Ecosystem*
  • Female
  • Food Chain
  • Male
  • Models, Theoretical
  • Oceans and Seas
  • Population Density
  • Tropical Climate*

Associated data

  • figshare/10.6084/m9.figshare.1246215

Grants and funding

This study was funded partly by Programme FREGATES (Appel d'Offre Eparses CNRS-INEE, TAAF). Laurie Thiers was funded by Conseil Régional Poitou Charentes and Fondation prince Albert 2 de Monaco. Maite Louzao was funded by a Juan de la Cierva post-doctoral contract (JCI-2010-07639, Ministerio de Cienciae Innovación) and a Marie Curie Career Integration Grant (PCIG09-GA-2011-293774). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.