Seasonal distribution and abundance of cetaceans within French waters- Part II: The Bay of Biscay and the English Channel

Laran, Sophie; Authier, Matthieu; Blanck, Aurélie; Dorémus, Ghislain; Falchetto, Hélène; Monestiez, Pascal; Pettex, Emeline; Stéphan, E.; Canneyt, Olivier Van; Ridoux, Vincent

doi:10.1016/j.dsr2.2016.12.012

Cited by 58 publications

(53 citation statements)

References 28 publications

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“…On the contrary, in years when warmer SST values were restricted to the inner part of the BoB the predicted relative abundances were lower (<600 individuals). Our abundance estimates are consistent with previous studies carried out in summer in the BoB such as CODA (Hammond et al, ) and SAMM (Suivi Aérien de la Megafaune Marine 2012; Laran et al, ), despite the different extension of the sampling areas.…”

Section: Discussionsupporting

confidence: 92%

“…Within the BoB, fin whale abundance was driven by both physiography and oceanography. Depth was the most important physiographic parameter as fin whales were found predominantly in deep off‐shore waters of the BoB at depths beyond 1,000 m, in accordance with previous studies (Laran et al, ). Additionally, SST had an important role with preferred fin whale habitat occupying intermediate temperature waters (20°C).…”

Section: Discussionsupporting

confidence: 91%

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Modelling the spatial abundance of a migratory predator: A call for transboundary marine protected areas

García‐Barón

Authier

Caballero

et al. 2019

Diversity and Distributions

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Aim During their migration, highly mobile species cross multiple jurisdictional boundaries and multiple not‐specific marine protected areas (MPAs). When identifying the critical habitats where individuals aggregate, these areas can be ideal candidates for MPAs. This study was focused on the endangered fin whale (Balaenoptera physalus) for which there is little knowledge on its distribution and abundance in non‐breeding temperate latitudes. Location Bay of Biscay (BoB). Methods Firstly, we modelled the relative abundance of fin whales by means of generalized additive models (GAMs) using data collected on the PELACUS (2007–2008) and JUVENA (2013–2016) oceanographic surveys during late summer. Secondly, we evaluated the reliability of the predictions by distinguishing environmental extrapolations and interpolations. Finally, we identified critical areas of highest predicted abundance and we assessed whether existing MPAs comprised within the Natura 2000 network and designated for other species offer protection to fin whales in the BoB. Results Fin whales were especially abundant in deep off‐shore waters, mainly associated with intermediate temperature water values in the inner part of the BoB. The years with the highest relative predicted abundances (an average of 1,500 whales) matched with years when warmer sea surface temperature extended into larger areas. In colder years, the average predicted abundance dropped to 400 whales. The main critical area for fin whales (defined by the highest 40% of abundance) was common for both surveys, and it was located in the south‐eastern part of the BoB. Main conclusions Our study contributes to the identification of important concentration areas of fin whales during late summer, based on reliable spatial predictions. The assessment of the current Natura 2000 network highlights the fact that only three MPAs marginally covered the critical area we have identified for fin whales. We propose a transboundary potential MPA to aid the conservation of the species in the BoB.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 91%

Modelling the spatial abundance of a migratory predator: A call for transboundary marine protected areas

García‐Barón

Authier

Caballero

et al. 2019

Diversity and Distributions

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“…Of course the results presented would benefit from a similar study to be implemented over the rest of the year. Indeed, previous study highlighted seasonal variations of habitat preferences and distribution of cetaceans and seabirds in the Bay of Biscay (Lambert et al, 2017a;Laran et al, 2017;Pettex et al, 2017), showing limited seasonal differences in distribution for bottlenose dolphins and northern fulmars, but large differences in distribution for black-legged kittwakes, auks and northern gannets between summer and winter. The small-sized shearwaters are completely absent from the study region during winter.…”

Section: Discussionmentioning

confidence: 98%

The persistence in time of distributional patterns in marine megafauna impacts zonal conservation strategies

Lambert

eacutemus

Ridoux

2019

Preprint

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The main type of zonal conservation approaches corresponds to Marine Protected Areas (MPAs), which are spatially defined and generally static entities aiming at the protection of some target populations by the implementation of a management plan. For highly mobile species the relevance of an MPA over time might be hampered by temporal variations in distributions or home ranges. In the present work, we used habitat model-based predicted distributions of cetaceans and seabirds within the Bay of Biscay from 2004 to 2017 to characterise the aggregation and persistence of mobile species distributional patterns and the relevance of existing MPA network. We explored the relationship between population abundance and spatial extent of distribution to assess the aggregation level of species distribution. Specific core areas of distributions were determined, based on predicted distributions, as the smallest spatial extent including 50% of the population present in the Bay of Biscay and their persistence was calculated over the 14 studied years. The relevance of MPA network was assessed regarding aggregation and persistence. The potential to zonal conservation was confirmed for spatially aggregated and persistent species, as bottlenose dolphins or auks. We showed that aggregation level alone is not sufficient to determine candidates to zonal conservation, since some species might be aggregated in space, but poorly persistent in time (black-legged kittiwake). Nonetheless, some loosely distributed species with strong persistence might not benefit from existing zonal conservation due to poor overlap between existing MPA networks and their core areas of distribution (great skuas). We thus have demonstrated that both aggregation and persistence have potential impact on the amount of spatiotemporal distributional variability encompassed within static MPAs. Our results exemplified the need to have access to a minimal temporal depth in the species distribution data when aiming to designate new site boundaries for the conservation of mobile species.

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“…Our results suggested that competitive relationships can occur between commercial-size meagre and other predator species such as hake and sea bass, two abundant commercial high trophic level fish in European Atlantic waters (Mahé et al, 2007;Spitz et al, 2013), or common dolphin (Meynier et al, 2008), the most abundant cetacean in the Bay of Biscay (Laran et al, 2017). Meagre have probably one of the lowest spawning biomass among this top predator community, hence this species should be more sensitive to direct trophic interactions with competitor species which could limit access to this resource.…”

Section: Implications For Eafmentioning

confidence: 99%

Trophic ecology of commercial-size meagre, Argyrosomus regius, in the Bay of Biscay (NE Atlantic)★

Hubans

Chouvelon

Bégout

et al. 2017

Aquat. Living Resour.

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-In the north-eastern Atlantic, meagre (Argyrosomus regius) is one of the largest fish living on the shelf and this species has important commercial interest. Over the past two decades, large variations in meagre abundance have been observed with pluri-annual cycles but the factors involved in such variations are still unclear. Trophic interactions between meagre and other species (both prey and competitors) might be one explanatory variable of the observed variations in meagre recruitment and abundance. In the present study, we described the diet of commercial-size meagre in the Bay of Biscay from stomach content and stable isotope analyses, and explored its dietary ontogeny. We found that commercial-size meagres were mostly piscivorous with a diet dominated by clupeiform fish (mainly anchovy and sardine) completed by demersal fish (mainly pout and whiting). Cannibalism also accounted for a non-negligible part of the diet. Interestingly, stable isotope and stomach content analyses showed only a very slight increase in prey length and trophic level during the ontogeny of large meagre after 50 cm of total length and despite a 3 fold-change of the individual length in our sampling. Our results suggested that specific trophic interactions (i.e. bottomup control by clupeiform fish on meagre population, competitive effects on piscivorous populations or topdown control by meagre on clupeiform fish populations) may occur in the Bay of Biscay and can impact meagre abundance dynamics. Our study underlined the interest to enhance ecological knowledge of preypredator relationships in the development of ecosystem-based approach to understand trophic controls impacting aquatic living resources and fishery economy.

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Seasonal distribution and abundance of cetaceans within French waters- Part II: The Bay of Biscay and the English Channel

Cited by 58 publications

References 28 publications

Modelling the spatial abundance of a migratory predator: A call for transboundary marine protected areas

Modelling the spatial abundance of a migratory predator: A call for transboundary marine protected areas

The persistence in time of distributional patterns in marine megafauna impacts zonal conservation strategies

Trophic ecology of commercial-size meagre, Argyrosomus regius, in the Bay of Biscay (NE Atlantic)★

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