Faunal response to fragmentation in seagrass habitats: implications for seagrass conservation

Effects of propeller scarring on macrofaunal use of the seagrass Thalassia testudinum

“…The authors suggested that scallops trade off higher predation rates for the significantly higher growth rates obtained at seagrass edges (Bologna & Heck 1999). Bell et al (2001) reported significantly reduced densities of the infaunal polychaete, Kingbergonuphis simoni, at T. testudinum edges (1 m from the sand -grass interface) compared to densities 9 m from the interface in Tampa Bay, Florida. In contrast with our study, Bologna & Heck (2002) found that pagurid crabs exhibited no significant density differences between natural seagrass bed edges and interiors.…”

“…Faunal responses to natural seagrass edges are a current theme in the seagrass literature (Bologna & Heck 1999, Frost et al 1999, Bell et al 2001), but there is little information on the responses of fauna to scarring, although Bell et al (2002) found few large-scale differences in fauna between scarred and unscarred areas. The paucity of data concerning this phenomenon leads to the question of whether individual scars and their associated edges are large enough to shift faunal distributions.…”

Biodiversity, Species Interactions and Ecological Networks in a Fragmented World

“…They are affected by fragmentation through dredging and boating effects, eutrophication, extreme weather events, urchin grazing and wasting disease (Bostrom et al, 2006;Orth et al, 2006;Rasmussen, 1977; Continued BOX 1 Habitat Fragmentation in Aquatic Ecosystems-cont'd McComb, 1992;Walker et al, 2006). While many studies suggest that fragmentation of seagrass meadows has limited (Frost et al, 1999;Hirst and Attrill, 2008;MacReadie et al, 2009), inconsistent (Bell et al, 2001) or even positive (Eggleston et al, 1998;Hovel and Lipcius, 2001) impacts on epifaunal diversity and abundance, fragmentation beyond a threshold level can lead to rapid declines in species diversity and abundance (Reed and Hovel, 2006).…”

Habitat size, flora, and fauna: Interactions in a tidal saltwater marsh

“…This correlation between seagrass density and patch size can confound experiments involving faunal species that focus on either grass density (or structural complexity) or patch size (e.g. Bell et al, 1987;Worthington et al, 1992;Irlandi, 1997;Bell et al, 2001;Hovel and Lipcius, 2002), because both are frequently important . Thus, it is important to design experiments to distinguish between direct effects of habitat size (i.e.…”