Evaluating substances that facilitate algal spore adhesion

Abstract

Non-toxic substances that enhance the adhesion of spores are of ecological and economic interest. When used as spore trappers, they may help to trace distributional changes of spore abundance in the water column. Spread over artificial substrata, they may enhance recruitment of economic seaweeds. Gastropod pedal mucus has been used as a substance that enhances adhesion, but its efficiency varies with the type and physiological state of the gastropod. In a search for adhesion promoting compounds, the attachment and germination effects of solutions of albumin (chicken), agar, gelatine (type B), glycerine and polylysine, on spores of Mazzaella laminarioides, Lessonia nigrescens and Ulva rigida, were compared. Polylysine was the only product significantly increasing the number of spores attached, as compared to uncoated controls. It did not affect germination rates of U. rigida or M. laminarioides but decreased the germination rates of L. nigrescens. Artificial substrata coated with polylysine retained 4-10 times more spores than uncoated controls, both in field-exposed and in nursery experiments.