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In the high seas, regional fishery management organisations are required to implement measures to prevent significant adverse impacts on vulnerable marine ecosystems (VMEs). Our objectives were to develop habitat suitability models for use in the spatial management of bottom fisheries in the South Pacific and to evaluate these and existing models using independent data from high‐quality seafloor imagery. Presence‐only models for seven VME indictor taxa were developed to complement previous modelling. Evaluation of habitat suitability models using withheld data indicated high mean True Skill Statistic scores of 0.44–0.64. Most habitat suitability models performed adequately when assessed with independent data on taxon presence and absence but were poor surrogates for abundance. We therefore advocate caution when using presence‐only models for spatial management and call for more systematically collected data to develop abundance models. [ABSTRACT FROM AUTHOR]

Parasitism is hypothesized to reduce reproductive success in heavily parasitized males because females may preferentially mate with less parasitized males (parasite-mediated sexual selection) or parasites may compromise male competitiveness. In marine systems, this hypothesis is largely unexplored. This paper provides the first confirmed record of a copepod ectoparasite (Caligus buechlerae Hewitt 1964) on the common triplefin (Forsterygion lapillum) and evaluates the hypothesis that males parasitized with C. buechlerae experience lower reproductive success than unparasitized males (as determined by the presence and area of eggs within male nests). We found that 38% of males we surveyed were infected with at least one C. buechlerae, with a median of two individuals per infected male. About 32% of males were defending eggs, with 62.5% of those males infected with at least one parasite. Males of greater total length (TL) were both more likely to be infected and more likely to be defending eggs. However, when statistically accounting for the effects of TL, parasite infection had no effect on the probability of defending eggs, or the average surface area of eggs when present. Positive covariation in fish length, the presence of eggs and parasite infection observed here potentially suggest that the importance of parasitic infection on reproductive success may depend upon the strength of selection for larger male body size. Our study is one of the few studies to investigate the effects of ectoparasites on reproductive success in reef fish and also provides a quantitative measure of infection for a widespread species within New Zealand., Introduction After the initial proposal by Hamilton and Zuk (1982) that suggested parasitism might strongly influence patterns of sexual selection, the role of parasites in mediating reproductive success has been [...]

Although the frequency and magnitude of sedimentation often varies across coastal landscapes creating patches with different mean sediment loads, duration of sedimentation and rates of sediment resuspension, few studies have documented the emergent effects of spatio-temporal variability in sedimentation. Here, we conducted two laboratory experiments to evaluate such effects on the establishment of Macrocystis pyrifera and Undaria pinnatifida spores. In the first experiment, spore establishment was significantly affected by sediment load (the effective dose required for a 40% reduction in establishment ranged between 16 and 60 mg sediment [l.sup.-1]) and sediment regime (relative sedimentation occurring before spore settlement, ~3 times more sediment was required for 20% reduction in spore establishment when sedimentation occurred after spore settlement). The second experiment demonstrated that the effects of sediment depended on sediment load (spore establishment was 2-4 times greater when sediment load was 200 mg [l.sup.-1] relative to 400 mg [l.sup.-1]), variability in sedimentation (spore establishment was 1.36 times greater with variable than fixed sediment loads), repeated pulses of sedimentation (pulsed sedimentation decreased spore establishment by 59-91% relative to a single sedimentation event) and timing of sedimentation relative to spore settlement (sedimentation before spore settlement decreased establishment by 51-95% relative to sedimentation after spore settlement). These results have important implications for ecologists and resource managers attempting to predict the consequences of sedimentation, suggesting that it is not only important to consider sediment load, but also fine-scale temporal variability in sedimentation relative to key life-history events of the impacted organisms., Introduction The consequences of increasing coastal sedimentation for changes in the functioning of rocky reef ecosystems are of significant concern worldwide (Airoldi 2003; McCulloch et al. 2003; Bellwood et al. [...]

Abstract: Marine organisms occasionally settle at exceptional densities, whereby thousands of individuals arrive concurrently. High levels of mortality, which has historically been attributed to predation or competition, often follow this [...]