Monitoring Winter and Summer Abundance of Cetaceans in the Pelagos Sanctuary (Northwestern Mediterranean Sea) Through Aerial Surveys

Systematic long-term monitoring of abundance is essential to inform conservation measures and evaluate their effectiveness. To instigate such work in the Pelagos Sanctuary in the Mediterranean, two aerial surveys were conducted in winter and summer 2009. A total of 467 (131 in winter, 336 in summer) sightings of 7 species was made. Sample sizes were sufficient to estimate abundance of fin whales in summer (148; 95% CI = 87–254) and striped dolphins in winter (19,462; 95% CI = 12 939–29 273) and in summer (38 488; 95% CI = 27 447–53 968). Numbers of animals within the Sanctuary are significantly higher in summer, when human activities and thus potential population level impacts are highest. Comparisons with data from past shipboard surveys suggest an appreciable decrease in fin whales within the Sanctuary area and an appreciable increase in striped dolphins. Aerial surveys proved to be more efficient than ship surveys, allowing more robust estimates, with smaller CIs and CVs. These results provide essential baseline data for this marine protected area and continued regular surveys will allow the effectiveness of the MPA in terms of cetacean conservation to be evaluated and inform future management measures. The collected data may also be crucial in assessing whether ship strikes, one of the main causes of death for fin whales in the Mediterranean, are affecting the Mediterranean population

Réserve Naturelle Nationale des prés salés d'Arès et de Lège-Cap Ferret (33) : connaissance et suivi des peuplements benthiques, supra-benthiques, ichtyologiques et des fonctions écologiques du compartiment tidal (programme de recherche Biamar 2012)

National audienceLes objectifs de cette étude étaient : • Le développement et l’expérimentation de méthodes réplicables pour l’étude du «couple» benthos/poissons, dans une optique à la fois de connaissance, de suivi et de gestion/conservation • La caractérisation des peuplements étudiés, en termes de richesses spécifiques, d’abondances relatives et de biomasses • L’étude de la dynamique spatio-temporelle (habitats/saisons) des peuplements étudiés • L’identification et la caractérisation des fonctions écologiques jouées par ces marais maritimes pour les poissons amphihalins

Biophysical correlates of relative abundances of marine megafauna at Ningaloo Reef Western Australia

© CSIRO 2007Changes in the relative abundance of marine megafauna (whales, dolphins, sharks, turtles, manta rays, dugongs) from aerial survey sightings in the waters adjacent to Ningaloo Reef between June 2000 and April 2002 are described. Generalised linear models were used to explore relationships between different trophic guilds of animals (based on animal sighting biomass estimates) and biophysical features of the oceanscape that were likely to indicate foraging habitats (regions of primary/secondary production) including sea surface temperature (SST), SST gradient, chlorophyll-a (Chl-a), bathymetry (BTH) and bathymetry gradient (BTHg). Relative biomass of krill feeders (i.e. minke whales, whale sharks, manta rays) were related to SST, Chl-a and bathymetry (model [AICc] weight = 0.45) and the model combining these variables explained a relatively large amount (32.3%) of the variation in relative biomass. Relative biomass of fish/cephalopod feeders (dolphins, sharks) were weakly correlated with changes in SST, whereas that of other invertebrate/macroalgal feeders (turtles, dugong) was weakly correlated with changes in steepness of the shelf (bathymetry gradient). Our results indicate that biophysical variables describe only a small proportion of the variance in the relative abundance and biomass of marine megafauna at Ningaloo reef.Jai C. Sleeman, Mark G. Meekan, Steven G. Wilson, Curt K. S. Jenner, Micheline N. Jenner, Guy S. Boggs, Craig C. Steinberg and Corey J. A. Bradsha