Credits: Nariman Mosharrafa on unsplash
Empirical evidence shows global environmental changes producing poleward distributional expansions, equatorward contractions and depth migrations across marine biodiversity. As greenhouse gas emissions increase over time, so does the vulnerability of biodiversity. To timely address potential changes and accomplish the Sustainable Development Goals (2030 Agenda for Sustainable Development; UN), the Paris Agreement (UN Framework Convention on Climate Change) was outlined to provide a roadmap to limit global warming below 2°C above preindustrial levels. This major objective was based on climate change impact assessments (e.g., Intergovernmental Panel on Climate Change; IPCC) considering policy-relevant research quantifying biodiversity distributional shifts. Such quantifications have been mostly performed with Species Distribution Modelling, as established by our team, which allows comparing the distribution of species for present-day conditions with projections (future) made through time.
SDM projections rely of standardized environmental data from atmosphere-ocean general circulation models (AOGCMs) estimating environmental conditions under different concentrations of greenhouse gases. However, standardized data for SDM projections are not yet available under the new mitigation scenarios in line with the Paris Agreement, undermining policy-relevant assessments and up-to-date guidelines. Also, data for SDM projections miss important drivers beyond thermal, salinity and sea ice conditions . This might have produced misleading SDM quantifications since the distribution of marine organisms is strongly influenced by additional drivers like oxygen and nutrients. Most importantly, SDM projections have recurrently overlooked the crucial role of population connectivity / isolation through time, beyond environmentally suitable areas. Range expansions and contractions are highly determined by the ability of populations / individuals / genes to migrate (latitudinally or vertically) to new suitable areas. This is particularly important for low dispersive ecosystem structuring species, for which global changes coupled with strong isolation might strongly compress distributional ranges, erode entire genetic lineages (i.e., intraspecific biodiversity), and trigger cascading effects to the entire ecosystem.
The current proposal aims to address these limitations that might have strongly precluded previous conclusions and quantifications of marine biodiversity distributional shifts under global changes. Our main tasks are:
Estimate global connectivity patterns for major biodiversity groups;
Link projected distributional shifts with dispersal potential under global change scenarios;
Test how oceanographic patterns shape the distribution of populations at the intraspecific level;
Combine SDM projections with the estimates of global connectivity to provide realistic quantifications of the trajectory and pace of the future redistribution of marine biodiversity.
Our analyses will compare present-day patterns with contrasting future scenarios to provide key information for IPCC impact assessments, for the prosecution of the Sustainable Development Goals 9, 13 and 14 of the 2030 Agenda, and for well informed conservation and management policies. We hypothesize that the redistribution of biodiversity is positively correlated with anthropogenic greenhouse gas emissions, so that there is a substantial benefit to comply with the Paris Agreement, by limiting warming to 1.5°C above preindustrial levels.