Continental-scale patterns in benthic invertebrate diversity: insights from the MacroBen database

Abstract

Latitudinal clines in species diversity in limnic and terrestrial habitats have been noted for well over a century and are consistent across many taxonomic groups. However, studies in marine systems over the past 2 to 3 decades have yielded equivocal results. We conducted initial analyses of the MarBEF (EU Network of Excellence for Marine Biodiversity and Ecosystem Function) database to test for trends in local and regional diversity over the latitudinal extent of European continental-shelf waters (36°to 81°N). Soft-sediment benthic macrofauna exhibit little evidence of a latitudinal cline in local (α-) diversity measures. Relationships with water depth were relatively strong and complex. Statistically significant latitudinal trends were small and positive, suggesting a modest increase in diversity with latitude once water-depth covariates were removed. These results are consistent regardless of whether subsets of the database were used, replicates were pooled, or component taxonomical groups were evaluated separately. Local and regional diversity measures were significantly and positively correlated. Scientific cooperation through data-sharing is a powerful tool with which to address fundamental ecological and evolutionary questions relating to large-scale patterns and processes.

Broad-scale patterns in local diversity of marine benthic harpacticoid copepods (Crustacea)

“…Some of regional studies have failed to detect this pattern (e.g. peaks in diversity at midlatitude in both Atlantic and Pacific gastropods, Roy et al 1998); or even showed regionally opposite trends (Renaud et al 2009 and references therein). It is unclear whether these differences are caused by regional peculiarities or by the restricted geographical range of stations sampled (Renaud et al 2009).…”

“…It is unclear whether these differences are caused by regional peculiarities or by the restricted geographical range of stations sampled (Renaud et al 2009). Furthermore, regional diversity shows consistently stronger and steeper latitudinal gradients than local (α) diversity (Clarke & Lidgard 2000, Hillebrand 2004, thus posing the question of systematic variation in β diversity (see below).A nonlinear (unimodal) diversity−depth relationship is generally considered as the common pattern that has been reported for both macrobenthos (bivalves, gastropods, amphipod crustaceans, and other groups; Stuart et al 2003, McClain et al 2009, Renaud et al 2009, and references therein) and meiobenthos (nematodes and harpacticoids; Vanhove et al 1999, Lambshead & Boucher 2003, Muthumbi et al 2004, Baguley et al 2006, although the depth of peak diversity varies tremendously among taxa and basins. Explanations of this unimodal pattern are many, involving complex interactions among productivity, disturbance regime, speciation rates, habitat heterogeneity, and patch dynamics, all of which are related to depth.…”

“…A nonlinear (unimodal) diversity−depth relationship is generally considered as the common pattern that has been reported for both macrobenthos (bivalves, gastropods, amphipod crustaceans, and other groups; Stuart et al 2003, McClain et al 2009, Renaud et al 2009, and references therein) and meiobenthos (nematodes and harpacticoids; Vanhove et al 1999, Lambshead & Boucher 2003, Muthumbi et al 2004, Baguley et al 2006, although the depth of peak diversity varies tremendously among taxa and basins. Explanations of this unimodal pattern are many, involving complex interactions among productivity, disturbance regime, speciation rates, habitat heterogeneity, and patch dynamics, all of which are related to depth.…”

“…peaks in diversity at midlatitude in both Atlantic and Pacific gastropods, Roy et al 1998); or even showed regionally opposite trends (Renaud et al 2009 and references therein). It is unclear whether these differences are caused by regional peculiarities or by the restricted geographical range of stations sampled (Renaud et al 2009). Furthermore, regional diversity shows consistently stronger and steeper latitudinal gradients than local (α) diversity (Clarke & Lidgard 2000, Hillebrand 2004), thus posing the question of systematic variation in β diversity (see below).…”

Regional patterns of continental shelf polychaete diversity: examples for the North Sea, English Channel, Irish Sea and Outer Bristol Channel areas

“…There have been many studies investigating diversity patterns, with special emphasis on how biodiversity varies with depth and latitude (Mokievsky & Azovsky 2002;Gage et al 2004;Renaud et al 2009), most of which have identified an increase in diversity with water depth through the bathyal zone (Rex 1981;Levin et al 2001). On the other hand, the latitudinal gradient in species richness is a well-known biogeographical pattern in terrestrial ecology, where there is an observed increase in species diversity from high to low latitudes (from the poles to the tropics) (Pianka 1966;Gray et al 1997;Gaston & Blackburn 2000).…”