Using large scale surveys to investigate seasonal variations in seabird distribution and abundance. Part I: The North Western Mediterranean Sea

Pettex, Emeline; David, Léa; Authier, Matthieu; Blanck, Aurélie; Dorémus, Ghislain; Falchetto, Hélène; Laran, Sophie; Monestiez, Pascal; Canneyt, Olivier Van; Virgili, Auriane; Ridoux, Vincent

doi:10.1016/j.dsr2.2016.11.008

Cited by 12 publications

(16 citation statements)

References 36 publications

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“…The Channel region, as part of the Greater North Sea, which comprises the entire North front as far as the North sea (92,875 km², hereafter noted "Channel"), the metropolitan French Atlantic region from Brittany to the South of the Bay of Biscay (282,141 km², noted "Atlantic") and the Northwestern Mediterranean region including the Gulf of Lion up to the North of Sardinia and the Italian waters in the Pelagos sanctuary (181,377 km², noted "Mediterranean"). The total length of transect measured 11,629 km in winter and 10,887 km in summer on the Channel side, 20,814 km in winter and 22,977 km in summer on the Atlantic side, and 13,762 km in winter and 18,451 km in summer on the Mediterranean side (Pettex et al, 2014).…”

Section: Study Area and Data Collectionmentioning

confidence: 93%

“…Empirical data collected by ship and aerial surveys may 6 yet provide valuable information in order to evaluate and locate sensitive zones, by targeting the areas where turtles and debris spatially overlap. In this study, we explore data collected during the Marine Megafauna Aerial Survey (SAMM) campaign carried out in winter and summer 2011-2012 on the 3 fronts of the French metropolitan maritime domain, during which sea turtles and marine debris were recorded (Pettex et al, 2014). We evaluated (i) debris and sea turtle spatial distributions and overlap, (ii) the probability of sea turtles to be exposed to debris and (iii) the quantity of debris surrounding them at close distances, i.e.…”

Section: Introductionmentioning

confidence: 99%

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Risk assessment reveals high exposure of sea turtles to marine debris in French Mediterranean and metropolitan Atlantic waters

Darmon

Miaud

Claro

et al. 2017

Deep Sea Research Part II: Topical Studies in Oceanography

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Debris impact on marine wildlife has become a major issue of concern. Mainy species have been identified as being threatened by collision, entanglement or ingestion of debris, generally plastics, which constitute the predominant part of the recorded marine debris. Assessing sensitive areas, where exposure to debris are high, is thus crucial, in particular for sea turtles which have been proposed as sentinels of debris levels for the Marine Strategy Framework Directive and for the Unep-MedPol convention. Our objective here was to assess sea turtle exposure to marine debris in the 3 metropolitan French fronts. Using aerial surveys performed in the Channel, the Atlantic and the Mediterranean regions in winter and summer 2011-2012, we evaluated exposure areas and magnitude in terms of spatial overlap, encounter probability and density of surrounding debris at various spatial scales. Major overlapping areas appeared in the Atlantic and Mediterranean fronts, concerning mostly the leatherback and the loggerhead turtles respectively. The probability for individuals to be in contact with debris (almost 100% of individuals within a radius of 2 km) and the density of debris surrounding individuals (up to 88 items within a radius of 10 km) were very high, whatever the considered spatial scale, especially in the Mediterranean region and during the summer season. The comparison of the observed mean debris density with random distribution suggested that turtles selected debris areas. This may occur if both debris and turtles drift to the same areas due to currents, if turtles meet debris accidentally by selecting high food concentration areas, and/or if turtles actively seek debris out, confounding them with their preys. Various factors such as species-specific foraging strategies or oceanic features which condition the passive diffusion of debris, and sea turtles in part, may explain spatio-temporal variations in sensitive areas. Further research on exposure to debris is urgently needed. Empirical data on sea turtles and debris distributions, such as those collected aerially, are essential to better identify the location and the factors determining risks.

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Section: Study Area and Data Collectionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Risk assessment reveals high exposure of sea turtles to marine debris in French Mediterranean and metropolitan Atlantic waters

Darmon

Miaud

Claro

et al. 2017

Deep Sea Research Part II: Topical Studies in Oceanography

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“…The eastern basin is oligotrophic, but the north-western basin exhibits the highest productivity of the whole Mediterranean, showing similarities with the eastern North Atlantic regarding its marked seasonality [9]. The NWMS is home to a diversified and abundant community of cetaceans and seabirds (see [10,11] this issue). Cetacean populations are mostly confined to the Mediterranean, whereas seabird populations include species with a permanent presence in the basin, as well as populations that predominantly use the area either during their breeding season, or conversely during non-breeding or inter-nuptial periods of their life cycles [12].…”

Section: Introductionmentioning

confidence: 97%

How does ocean seasonality drive habitat preferences of highly mobile top predators? Part I: The north-western Mediterranean Sea

Lambert

Laran

David³

et al. 2017

Deep Sea Research Part II: Topical Studies in Oceanography

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“…To date, the assessment of French Mediterranean bottlenose dolphin population required by the EU are established using the DS data (Laran et al 2017). Aerial surveys provide crucial information on marine megafauna taxa, and on human pressures to fill several criteria of the Marine Strategy Framework Directive (Laran et al 2017; Pettex et al 2017; Lambert et al 2020). However, in the Mediterranean context, several monitoring programs are available and SIM makes it possible to include existing datasets that have been discarded so far to inform public policies (Cheney et al 2013; Isaac et al 2019).…”

Section: Discussionmentioning

confidence: 99%

“…To date, assessing bottlenose dolphin population of French Mediterranean Sea for the EU reporting only focuses on the DS data (Laran et al, 2017). Aerial surveys provide crucial information on marine megafauna taxa, and on human pressures to fill several criteria of the Marine Strategy Framework Directive (Laran et al, 2017; Pettex et al, 2017; Lambert et al, 2020). However, funding constraints make the aerial monitoring hardly applicable at a high frequency, and it is planned to be implemented every 6 years.…”

Section: Discussionmentioning

confidence: 99%

Integrated spatial models foster complementarity between monitoring programs in producing large-scale bottlenose dolphin indicators

Lauret

Labach

Turek

et al. 2021

Preprint

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Over the last decades, large-scale conservation projects have emerged that require collecting ecological data over broad spatial and temporal coverage. Yet, obtaining relevant information about large-scale population dynamics from a single monitoring program is challenging, and often several sources of data, possibly heterogeneous, need to be integrated. In this context, spatial integrated models combine multiple data types into a single analysis to quantify population dynamics of a targeted population. Using available information at different spatial or temporal scales, spatial integrated models have the potential to produce detailed ecological estimates that would be difficult to obtain if data were analyzed separately. So far, these models are available for open populations to estimate demographic parameters (survival, recruitment), therefore requiring data collected in long-term monitoring programs. In conservation biology however, we often need to quantify population abundance and density in closed populations. In this paper, we showcase the implementation of spatial integrated models to closed populations in a conservation context. We analyzed spatial capture-recapture data together with distance-sampling data to estimate abundance and density. Focusing on the Mediterranean bottlenose dolphins (Tursiops truncatus) as a case study, we combined 21,464 km of photo-identification boat surveys collecting spatial capture-recapture data with 24,624 km of aerial line-transect following a distance-sampling protocol. We compared the performances of the spatial integrated model, with that of the distance sampling model, and the spatial capture-recapture model separated. We discussed the benefits of using a spatial integrated model in the context of the assessment of French Mediterranean bottlenose dolphin conservation status to inform continental scale public policies. Overall, we emphasize the usefulness of spatial integrated model to make the most of available datasets in a conservation context. Spatial integrated models are widely applicable and relevant to conservation research and biodiversity assessment at large spatial scales.

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Using large scale surveys to investigate seasonal variations in seabird distribution and abundance. Part I: The North Western Mediterranean Sea

Cited by 12 publications

References 36 publications

Risk assessment reveals high exposure of sea turtles to marine debris in French Mediterranean and metropolitan Atlantic waters

Risk assessment reveals high exposure of sea turtles to marine debris in French Mediterranean and metropolitan Atlantic waters

How does ocean seasonality drive habitat preferences of highly mobile top predators? Part I: The north-western Mediterranean Sea

Integrated spatial models foster complementarity between monitoring programs in producing large-scale bottlenose dolphin indicators

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