Prediction of primary physical measures for cost-effective management of artificial seaweed reefs

Abstract

Seaweed plays a central role in supporting good habitats and spawning grounds for a number of fisheries resources. Artificial seaweed reefs (ASRs) should provide firm, stable substrates for seaweed. Hence, it is desirable to propose a physical measure of seaweed spore settlement, which can be characterized by the surface area of an ASR and its wake region characteristics. In this study, a so-called seaweed spore settlement contributor was proposed, 34 ASRs were characterized by their primary physical measures (contributors and wake volumes) and secondary measure (efficiency indices), and linear regression equations were obtained to predict the primary measures. It is found that the average values of the primary measures are 61.96 m2 (contributor) and 4.79 m3 (wake volume), and reef structures provoking the water flow blocking mechanism are critical to these parameters. The results also demonstrated that the effect of the seabed slope on the primary measures should be considered for reefs having a narrow top and wide bottom. We found that it is desirable to predict the primary physical measures for preinstallation and cost-effective management of ASRs.