The thin, brown line where land meets sea has drawn beachgoers of every age since time immemorial. It offers an enticing insight into that watery world few of us will ever have the opportunity to explore. Representing a very visual marker of the tide’s highest point, strandlines aren’t just places to discover an immense variety of marine treasures, but also represent food and shelter for creatures such as sand hoppers, seaweed flies and all their attendant predators.
Essentially composed of debris that has been brought ashore by waves, before then being left by the ebbing tide, the bulk of most strandlines around the UK’s coast consist of detached or broken-up seaweed. Within this matted and tangled mass of gently rotting algae, items such as seashells, egg cases and marine mammal bones can also be uncovered. A depressingly large amount of man-made litter, primarily in the form of plastic waste and discarded fishing gear, is now being found in ever higher proportions as well.
The type of beach strongly impacts the volume of material deposited on the strandline. Sandy beaches tend to accumulate less seaweed because of the highly mobile nature of their offshore seabeds. By contrast, rocky coastlines will see their strandlines frequently piled high, due to harder, more stable seabeds offerin