Artificial Reefs Project : final report of scientific studies (2004–2006)

Abstract

A study was undertaken to assess the environmental impact of four artificial reef units on the soft sediment marine benthic assemblages and fish fauna in their vicinity, and to evaluate the reefs’ potential as a habitat. Another aim of the study was to assess whether the two different materials used to construct the reefs – native Globigerina limestone and a concrete mixture that incorporated Globigerina debris – had different effects on the benthic biota and fish fauna. To assess the impact of the artificial reefs on the soft sediment benthic fauna, five replicate sediment cores (diameter: 10 cm) were collected from each of five stations positioned at incremental distances (1, 2, 5, 10, 20 and 50 m) along each of two transects located on opposite sides (west and east) of each of two artificial reef locations. Five replicate samples were also collected from each of two control sites that had similar seabed characteristics as the reef sites. Additionally, three sediment cores were collected from the reef and reference stations to measure the mean grain-size and percentage organic carbon content of the sediments. Samples for benthic faunal analysis and physico-chemical attributes were collected from the designated reef sites during winter 2003/2004 before deployment of the artificial reefs, and during winter/spring 2005 following deployment of the reefs.