Resilience and regime shifts in a marine biodiversity hotspot

Abstract

Complex natural systems, spanning from individuals and populations to ecosystems and social-ecological systems, often exhibit abrupt reorganizations in response to changing stressors, known as regime shifts or critical transitions. Theory suggests that such systems feature folded stability landscapes with fluctuating resilience, fold-bifurcations, and alternate basins of attraction. However, the implementation of such features to elucidate response mechanisms in an empirical context is scarce, due to the lack of generic approaches to quantify resilience dynamics in individual natural systems. Here, we introduce an Integrated Resilience Assessment (IRA) framework: a three-step analytical process to assess resilience and construct stability landscapes of empirical systems. The proposed framework involves a multivariate analysis to estimate holistic system indicator variables, non-additive modelling to estimate alternate attractors, and a quantitative resilience assessment to scale stability landscapes. We implement this framework to investigate the temporal development of the Mediterranean marine communities in response to sea warming during 1985–2013, using fisheries landings data. Our analysis revealed a nonlinear tropicalisation of the Mediterranean Sea, expressed as abrupt shifts to regimes dominated by thermophilic species. The approach exemplified here for the Mediterranean Sea, revealing previously unknown resilience dynamics driven by climate forcing, can elucidate resilience and shifts in other complex systems.

Modelling spatio-temporal patterns of fish community size structure across the northern Mediterranean Sea: an analysis combining MEDITS survey data with environmental and anthropogenic drivers

“…Notably, in the last few decades, landings of thermophile species in the Mediterranean have increased, contrasting with a general decrease in landings and a widely reported impact of increasing temperature on species and ecosystems (e.g. Vasilakopoulos et al 2017). However, the increasing trend of biomass in our case is observed also for non-thermophile species such as G. melastomus, S. smaris and, to a smaller extent, L. piscatorius and L. budegassa.…”

From Science to Evidence – How Biodiversity Indicators Can Be Used for Effective Marine Conservation Policy and Management

“…The bibliographic data were queried from the Web of Science database (accessed last Sept 18th, 2018). Beaugrand, 2005;Rochet et al, 2005;Blanchard et al, 2010;Shin et al, 2010; Lindegren et al, 2012;Cline et al, 2014 Baltic Sea; Global (lakes); Impact of an anthropogenic pressure on the ecosystem Shannon et al, 2010;Henriques et al, 2014;Coll et al, 2016 Global; Portugal; Global Ecosystem stability or resilience Samhouri et al, 2009;Vasilakopoulos et al, 2017 Global; Mediterranean Sea Oceans at different spatial scales Blanchard et al, 2010;Halpern et al, 2012;Coll et al, 2016;Uusitalo et al, 2016;Torres et al, 2017 Global; global; global; regional (European); single ecosystem (Baltic Sea)…”

Remotely Sensing the Biophysical Drivers of Sardinella aurita Variability in Ivorian Waters

“…The coefficient of regression is estimated to r = 0.92, p < 0.0001, which suggests that the interannual variability in the landings of S. aurita observed in the fishing zone of Abidjan (see box region location in Figure 2) is representative of the landings for the whole of the Ivorian waters. FAO datasets have been examined before in studies focusing on the links between fisheries trends and biophysical/climate factors (e.g., [50][51][52][53]). Trends in stock abundances are usually detected by analyzing catch or landings per unit of effort (CPUE or LPUE), rather than pure catch or landings data [54].…”