Algal populations controlled by fish herbivory across a wave exposure gradient on southern temperate shores

摘要: Consumers that forage across habitats can affect communities by altering the abundance and distribution of key species. In marine communities, studies trophic interactions have generally focused on effects herbivorous predatory invertebrates benthic algae mussel populations. However, large mobile consumers move habitats, such as fishes, strongly community dynamics through consumption habitat-dominating species, but their often vary over environmental gradients. On temperate rocky shores, fishes are a small part fish fauna compared to tropics, there is sparse evidence they play major direct role in algal dynamics, particularly brown dominate many reefs. New Zealand, however, wide-ranging fish, Odax pullus, feeds exclusively macroalgae, including Durvillaea antarctica, low-intertidal fucoid reaching 10 m length 70 kg mass. four experiments we tested extent herbivory how it was affected canopy structure gradient wave exposure at multiple sites. Exclusion showed impacts greatly reduced cover biomass these decreased with increasing stress cover, effectively restricting alga exposed conditions. Almost all plants were entirely removed where sheltered semi-exposed sites, significantly less grazing Recruit beneath canopies grazing, grew slowly. Successful natural recruitment, therefore, occurred almost shores outside escaped severe growth maturity far greater than elsewhere. Such local regional populations vertebrate rare mediated an plant density, both which interact demographics. The study highlights that, even though diversity may be low, particular species still high, cool waters usually considered minimal.