MEPS prepress abstract  -  DOI: https://doi.org/10.3354/meps12390

Artificial reefs create distinct assemblages: a study of fish assemblage response to the deployment of artificial patch reefs

Kade A. Mills*, Paul A. Hamer, Gerry P. Quinn

*Email: kadem@vnpa.org.au

ABSTRACT: We conducted a before-after-control-impact (BACI) experiment to evaluate the effects of deploying small-scale artificial patch reefs on fish assemblages in a temperate bay (Port Phillip Bay) in south eastern Australia. Three replicate artificial reef treatments were placed on sandy substratum and the response of the fish assemblage was compared with three control sites with no reef, and three nearby natural reef comparison sites. All habitats were sampled using Baited Remote Underwater Video (BRUV) and Underwater Visual Census (UVC) multiple times 6 months before and 22 months after artificial reefs deployment. Fish species rapidly colonised artificial reefs, with 30 species detected in the first-year post deployment and only four in the following year. Both sampling methods captured a shift in assemblage structure, albeit with different species compositions, as individual species numbers varied dependent upon method used. BRUV provided better estimates of the important recreational species (family Sparidae) Chrysophrys auratus (Snapper), with more snapper recorded on artificial and natural reefs compared to sediment. The artificial reef assemblages were dominated by species that favour the reef/sediment interface. Several reef-associated species were detected in the juvenile stages, however, adults of obligate reef species were not observed on artificial reefs. Sediment-associated species present before artificial reefs deployment persisted within the artificial patch reef area over the course of the study. Overall, the deployment of patchwork artificial reefs increased local species diversity and abundance of fish, and did not impact existing sediment fish assemblages.