Mike Dilger’s wildlife watching
Take a wander along the strandlines to spot an array of fascinating life.
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 offering the opportunity for large seaweed forests to gain a much firmer foothold. The origin of the other deposited material will also depend on a combination of coastal location, the geology of the adjacent seabed and offshore currents. On those beaches close to estuaries or river mouths, a higher percentage of the strandline’s content will have emanated from local or even inland sources. Identifying any mermaid’s purses washed ashore can help pinpoint the spawning grounds of our inshore breeding sharks, rays and skates, while the presence of
washed-up eelgrass would certainly indicate the close proximity of some seagrass beds.
However, on beaches facing the ocean, such as those along Britain’s western coast, more mysterious and exciting long-haul debris is encountered. Finds from further afield can help us understand how ocean currents operate, particularly when the item’s origin is either already known or can be traced. The heart-shaped beans from the monkey ladder vine, for example, sporadically turn up along our Atlanticfacing strandlines.
It was finding these exotic, longdistance sea beans from the New World that supposedly provided Christopher Columbus with the inspiration to set
forth from Europe in search of lands further west.
Though you can beachcomb at any time of the year, undoubtedly the richest strandline pickings are to be found following stormy weather, when larger waves and bigger swells may dislodge any creatures far happier on the seabed. Also, strandline-spotting immediately following spring tides should ensure that you have a good chance of discovering anything that has been temporarily left high and dry before it is pilfered by either a hungry gull or the next high tide.
When accruing items, it’s important not to be greedy. Collecting sparingly will ensure that plenty of natural resources will be left for the creatures and the birds so dependent on this ephemeral habitat. Do also bear in mind that beaches can be exposed places in October, and with little shelter from the wind, sun and rain, warm clothes are a necessity. Finally, a quick check of the local tide table beforehand will ensure your feet remain reassuringly dry throughout your visit.
On beaches along the western coast, more mysterious and exciting long-haul debris is encountered.