Experimental treatments testing the predation effects of two intertidal crab species on <i>Crassostrea virginica</i>.

†<p>Indicates no cage.</p><p>Treatment codes shown: +/− indicates species inclusion/exclusion; Blue crab <i>C. sapidus;</i> Mud crab <i>P. herbstii</i>; Control − uncaged treatment. Crab species were included at densities typical of the region (<i>C. sapidus -</i> 1 per cage; <i>P. herbstii</i> – 4 per cage) (A.M. Knights, <i>pers. obs.</i> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035096#pone.0035096-Grabowski1" target="_blank">[32]</a>).</p

<i>Crassostrea virginica</i> abundance on caged (C), uncaged (UC) and procedural control (PC) tiles at sites characterised by high and low flow velocities.

<p>Cochran’s test, <i>C</i>  =  0.08, <i>ns</i>.</p><p>SNK test  =  << indicates p < 0.01.</p><p>Replicate tiles (<i>n</i>  =  12) were established at two sites nested within 3 locations (Murrells Inlet, North Inlet, Cape Romain) and 2 flow regimes (high, low).</p

Flow velocity characterization of locations and sites using gypsum dissolution.

<p>Shown are mean proportional dissolution rates (± SD) of gypsum at each of three locations and four sites per location in South Carolina (<i>n</i>  =  6). Post hoc test outcomes are shown by letters (a, b) and indicate groups of means that are indistinguishable from each other (where letters differ p < 0.01).</p

Predator identity effects on mortality of <i>Crassostrea virginica</i>.

<p><i>C. sapidus</i> (blue) and <i>P. herbstii</i> (mud) were caged either independently or in combination with 10 oysters per cage. Crabs were included in cages at densities typical of those seen in the region (AM Knights, <i>pers. obs</i>. and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035096#pone.0035096-Grabowski1" target="_blank">[32]</a>). Data are pooled from two sites at North Inlet (<i>n</i>  =  6, a total of 30 plots). Post hoc test outcomes are shown by letters (a, b) and indicate groups of means that are indistinguishable from each other (where letters differ p < 0.01).</p

Mean recruitment (± SE) of <i>Crassostrea virginica</i> onto predator exclusion (cage), procedural control and open access (control) tiles.

<p>Recruitment tiles were established at two sites in each of three locations in South Carolina characterised by high and low flow regimes (<i>n</i> = 12; a total of 432 plots). Post hoc test outcomes are shown by letters (a, b) and indicate groups of means that are indistinguishable from each other (where letters differ p < 0.01).</p

Flow velocity characterization of sites and locations by gypsum dissolution.

<p>Cochran’s <i>C</i>  =  0.207, <i>ns.</i></p><p>SNK test  =  << indicates p < 0.01.</p><p>Replicate gypsum dissolution clods (<i>n</i>  =  6) were haphazardly placed at each of four randomly chosen sites and three locations in South Carolina (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035096#pone-0035096-g001" target="_blank">Figure 1</a> for locations). SNK outcomes are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035096#pone-0035096-g002" target="_blank">Figure 2</a>.</p

Study locations (bold) on the eastern coast of the USA.

<p>Study locations (bold) on the eastern coast of the USA.</p

Proportional mortality of <i>Crassostrea virginica</i> in the presence or absence of <i>C. sapidus</i> (blue crab) and/or <i>P. herbstii</i> (mud crab) at two sites in South Carolina.

<p>Cochran’s test, <i>C</i>  =  0.27, <i>ns</i>.</p>**<p>signifies p < 0.01; * signifies p < 0.05.</p><p>SNK test  =  << indicates p < 0.01; ‘−’ signifies species absent, ‘+’ signifies species present.</p><p>A separate 1-factor ANOVA was used to compare mortality between control (uncaged oysters) and the treatment containing both blue and mud crabs. No significant differences were found (<i>F</i>_{1, 11}  =  0.16, <i>ns</i>).</p

Appendix A. Tables showing the sectors and activities considered, the pressure types generated by each sector, and the ecological characteristics of the ecosystem that are impacted by each pressure type, as well as short descriptions of sectors, activities, and pressure types.

Tables showing the sectors and activities considered, the pressure types generated by each sector, and the ecological characteristics of the ecosystem that are impacted by each pressure type, as well as short descriptions of sectors, activities, and pressure types

Recruit abundances of <i>Austrominius modestus</i> over time.

<p>(a) Mean recruit abundance (± SE) in 25 cm² control and cumulative plots every 2 wk (<i>n</i> = 10), (b) mean recruit abundance (± SE) in plots of difference area (cm²) (<i>n</i> = 10), and (c) mean recruit density per cm² in cumulative plots in plots of different sizes (<i>n</i> = 40). Letters over bars (a–d) indicate post-hoc comparison outcomes with the same letter indicating no significant difference between recruit abundance/density. All plots irrespective of initial clearance size are pooled in (b). The period when all cumulative plots were 100% colonised is shown (dotted line).</p