Climate change in the Bay of Biscay: Changes in spatial biodiversity patterns could be driven by the arrivals of southern species

Abstract

Under climate change, future species assemblages will be driven by the movements and poleward shift of local species and the arrival of more thermophilic species from lower latitudes. To evaluate the impacts of climate change on marine communities in the Bay of Biscay, we used the hierarchical filters modelling approach. Models integrated 3 vertical depth layers and considered 2 Intergovernmental Panel on Climate Change (IPCC) scenarios (Representative Concentration Pathway, RCP2.6 and RCP8.5) and 2 periods (2041-2050 and 2091-2100) to simulate potential future species distributions. Results predicted potentially suitable future ranges for 163 species as well as future arrivals of non-indigenous southern species. We aggregated these results to map changes in species assemblages. Results revealed that coastal areas would undergo the highest species loss among the Bay of Biscay species, depending on their vertical habitat (benthic, demersal, benthopelagic or pelagic). Benthic and demersal species were projected to experience a westward shift, which would induce a deepening of those species. In contrast, pelagic species were projected to shift northward. The potential ecological niche for half of the studied species, mostly benthic and demersal, was projected to decrease under climate change. In addition, a high rate of southern species arrivals is expected (+28%). Assessment of community composition showed high species replacement within the 0-50 m isobath, driven by the replacement of native species by southern ones. This could lead to a major reorganization of trophic networks and have socio-economic impacts.

European cephalopods distribution under climate-change scenarios

“…in the North and Yellow seas) [20][21][22] . According to these observed distributional and behavioural changes, recent predictions highlighted the potential capacity of cephalopods to extent their distribution towards the pole, suggesting a future range expansion of these species [23][24][25] . In addition, recent studies highlighted the major economic importance of fisheries for several European countries 26,27 .…”

European small pelagic fish distribution under global change scenarios

“…To cover the range of year‐2100 radiative forcing values found in the literature, that is from 2.6 to 8.5 W/m 2 , we used three RCPs scenarios: (a) the optimistic peak and decline (RCP2.6), the intermediate “stabilization” (RCP4.5) and the “business as usual” (RCP8.5) scenarios (Meinshausen et al, 2011; van Vuuren et al, 2011). We considered SSS as constant over time because its temporal variance is negligible in comparison with its spatial variance (Dickson et al, 1988; Faillettaz et al, 2019; Le Marchand et al, 2020). While the spatial variance of SSS allowed us to discriminate marine from brackish waters (e.g., from 35 to 15 between the west and the east of the Danish strait), its temporal variance is negligible: for the period 2016–2065, Lavoie et al (2019) report expected salinity trends of +0.063 per decade at the maximum, a value comparable to the rise of SSS observed since 1950 (Durack et al, 2012).…”

“…To cover the range of year-2100 radiative forcing values found in the literature, that is from 2.6 to 8.5 W/m 2 , we used three RCPs scenarios: (a) the optimistic peak and decline (RCP2.6), the intermediate "stabilization" (RCP4.5) and the "business as usual" (RCP8.5) scenarios (Meinshausen et al, 2011;. We considered SSS as constant over time because its temporal variance is negligible in comparison with its spatial variance (Dickson et al, 1988;Faillettaz et al, 2019;Le Marchand et al, 2020…”

Spatialized ecological network analysis for ecosystem-based management: effects of climate change, marine renewable energy, and fishing on ecosystem functioning in the Bay of Seine

“…Modeling the inflow of non-indigenous species due to CC in an open system like the Bay of Seine is a very hard task. The results are often hypothetical and subject to many modeling hypotheses (Morin and Thuiller, 2009;Beaugrand et al, 2018;Le Marchand et al, 2020). Moreover, the arrival of non-indigenous species is often modeled with new trophic groups (Libralato et al, 2015;Corrales et al, 2018), which change the system aggregation.…”