Testing the Influence of Seascape Connectivity on Marine-Based Species Distribution Models

Giorgia Cecino,Roozbeh Valavi,Eric A Treml

doi:10.3389/fmars.2021.766915

Giorgia Cecino, Roozbeh Valavi + Show 1 more

Open Access

https://doi.org/10.3389/fmars.2021.766915

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Abstract

Species distribution models (SDMs) are commonly used in ecology to predict species occurrence probability and how species are geographically distributed. Here, we propose innovative predictive factors to efficiently integrate information on connectivity into SDMs, a key element of population dynamics strongly influencing how species are distributed across seascapes. We also quantify the influence of species-specific connectivity estimates (i.e., larval dispersal vs. adult movement) on the marine-based SDMs outcomes. For illustration, seascape connectivity was modeled for two common, yet contrasting, marine species occurring in southeast Australian waters, the purple sea urchin, Heliocidaris erythrogramma, and the Australasian snapper, Chrysophrys auratus. Our models illustrate how different species-specific larval dispersal and adult movement can be efficiently accommodated. We used network-based centrality metrics to compute patch-level importance values and include these metrics in the group of predictors of correlative SDMs. We employed boosted regression trees (BRT) to fit our models, calculating the predictive performance, comparing spatial predictions and evaluating the relative influence of connectivity-based metrics among other predictors. Network-based metrics provide a flexible tool to quantify seascape connectivity that can be efficiently incorporated into SDMs. Connectivity across larval and adult stages was found to contribute to SDMs predictions and model performance was not negatively influenced from including these connectivity measures. Degree centrality, quantifying incoming and outgoing connections with habitat patches, was the most influential centrality metric. Pairwise interactions between predictors revealed that the species were predominantly found around hubs of connectivity and in warm, high-oxygenated, shallow waters. Additional research is needed to quantify the complex role that habitat network structure and temporal dynamics may have on SDM spatial predictions and explanatory power.

Highlights

Conservation of biodiversity is a priority in management plans for conservation scientists and managers
For this study we selected two representative and widely distributed species of the south-eastern Australian coast, the Australasian snapper, Chrysophrys auratus formerly known as Pagrus auratus, and the purple sea urchin, Heliocidaris erythrogramma, both usually associated with rocky reefs habitats (Vanderklift and Kendrick, 2004; Pederson and Johnson, 2006; Ling et al, 2010; Harasti et al, 2015; Terres et al, 2015)
All centrality measures showed some spatial consistency within species, identifying similar areas of high and low values, revealing that hubs of connectivity, populations stepping-stones and critical nodes largely matched and were clustered in similar locations

Summary

Introduction

Conservation of biodiversity is a priority in management plans for conservation scientists and managers. Understanding species’ spatial distribution patterns is critical to identify important habitats and improve management strategies (Monk et al, 2010; Foltête et al, 2012). Classic strategies used in conservation to manage species include the establishment of protected areas and reserves around key habitats. Species distribution modeling approaches have been used to address different marine-related research goals (Robinson et al, 2017), for instance describing essential fish habitat (Monk et al, 2010), assessing the impact of climate change (Jones and Cheung, 2015), understanding habitat distribution shifts (Gormley et al, 2015), studying the spread of invasive species (Báez et al, 2010) or better designing conservation strategies (Adams et al, 2016)

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