Evaluating substances that facilitate algal spore adhesion

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. Ga stropod pedal mucus has been used as a substance that enhances adhesion, bu t its efficiency varies with the type and physiological state of the gastro pod. In a search for adhesion promoting compounds, the attachment and germi nation effects of solutions of albumin (chicken), agar, gelatine (type B), glycerine and polylysine, on spores of Mazzaella laminarioides, Lessonia ni grescens and Ulva rigida, were compared. Polylysine was the only product si gnificantly increasing the number of spores attached, as compared to uncoat ed controls. It did not affect germination rates of U. rigida or M. laminar ioides but decreased the germination rates of L. nigrescens. Artificial sub strata coated wit h polylysine retained 4-10 times more spores than uncoate d controls, both in field-exposed and in nursery experiments.