Minireview on macroalgal beds in fishing ports and their uses with special reference to their slipways

Abstract

On the coast of Japan, ca 3,000 fishing ports are present. The walls of mooring space and breakwater, slipways, bottom and blocks provide substrata for algae to attach, resulting in the formation of macroalgal beds (sometimes including sea grass). These beds have been paid attention to study algal succession, to use as nursery or feed of shellfish and to enlarge such algal beds by researchers in the field of phycology, ecology and coastal engineering. Among the above structures, slipways are the most convenient sites to observe vegetation because of its horizontal development of algal beds, safe accessibility and availability of clear vegetational images in aerial photographs. Macroalgal beds range from intertidal to upper subtidal zones on the slipways; zonation of canopy-forming species or commercial algae including nori and kelp, urchin barrens, or other positive and negative effects by the ambient factors such as sedimentation and waste charge. Our preliminary survey also found additional alteration of vegetation by presence of substructures of slipways including as slip bar, pit, corner, wall, and grooves of blocks. Sustainable, costless and easy monitoring of these beds may help local residents understand the important productive communities on their closest parts of their coasts.