Known existing artificial reefs may be effective in encouraging the population of some fish species. However crustacean habitats favourable to crustaceans and abalone differ significantly from habitats favoured by other marine species. For example, existing artificial reefs provide for the fish to swim through. However, research to the behaviour of crustaceans has determined that crustaceans and abalone look for areas to harbour, a feature not provided by artificial reefs.Therefore an artificial reef module is provided comprising a readily assembled housing having harbourages adapted to harbour crustaceans or abalone, the harbourages having closed tapered form.
