Epibenthic and mobile species colonisation of a geotextile artificial surf reef on the south coast of England.

Roger J H Herbert,Jenny Mallinson,Josephine Pegg,Alice E Hall,Leo Clarke,Tom Clements,Kathryn Ross,Ken Collins

doi:10.1371/journal.pone.0184100

Abstract

With increasing coastal infrastructure and use of novel materials there is a need to investigate the colonisation of assemblages associated with new structures, how these differ to natural and other artificial habitats and their potential impact on regional biodiversity. The colonisation of Europe’s first artificial surf reef (ASR) was investigated at Boscombe on the south coast of England (2009–2014) and compared with assemblages on existing natural and artificial habitats. The ASR consists of geotextile bags filled with sand located 220m offshore on a sandy sea bed at a depth of 0-5m. Successional changes in epibiota were recorded annually on differently orientated surfaces and depths using SCUBA diving and photography. Mobile faunal assemblages were sampled using Baited Remote Underwater Video (BRUV). Distinct stages in colonisation were observed, commencing with bryozoans and green algae which were replaced by red algae, hydroids and ascidians, however there were significant differences in assemblage structure with depth and orientation. The reef is being utilised by migratory, spawning and juvenile life-history stages of fish and invertebrates. The number of non-native species was larger than on natural reefs and other artificial habitats and some occupied a significant proportion of the structure. The accumulation of 180 benthic and mobile taxa, recorded to date, appears to have arisen from a locally rich and mixed pool of native and non-native species. Provided no negative invasive impacts are detected on nearby protected reefs the creation of novel yet diverse habitats may be considered a beneficial outcome.

Highlights

IntroductionColonisation of Boscombe artificial surf reef and whether developing assemblages are likely to interact with existing biodiversity [1,2,3]
From annual surveys between 2009 and 2014, including SCUBA and Baited Remote Underwater Video (BRUV) sampling, 180 taxa were recorded on the Artificial Surf Reef (ASR), comprising 132 species of macro-invertebrates and fish and 48 species of algae
Increasing both the depth and complexity of the ASR could be achieved by the deployment of rocks, bespoke artificial reef blocks or reef balls [119] at the seaward edges of the structure

Summary

Introduction

Colonisation of Boscombe artificial surf reef and whether developing assemblages are likely to interact with existing biodiversity [1,2,3]. This is especially important in the vicinity of protected areas and where new structures consist of novel materials, are of unique design, unusual location and have multifunctional objectives that might generate attributes and disturbances not usually observed in the natural environment. Of concern is the establishment of invasive species and the extent to which structures might provide stepping stones for their colonisation and spread [8,9,10,11], especially to nearby protected sites. This risk might be greater in the proximity of harbours and ports, which are known hot spots for invasive species [9]

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