Secrets of the seashore brought to life

REMEMBER the days when we were all a bit hardier, or is that just imagination playing tricks? Back then we landlocked folk didn’t necessarily wait for a glorious day to go the seaside. If we were set on going, we just got on the train or into the car and did it. Unless, of course, there actually was ice underfoot or a thunderstorm in progress.

And if we were on a week or fortnight’s beach holiday, we turned out to pick over the driftwood, build castles and collect shells on the bleakest of days. The greatest fun to be had, apart from trying to bodysurf the waves in pelting rain, was climbing over rocks at low tide and exploring the mysterious world of those warm pools between them. Hours would slip by as we hunkered down, dipped in our nets, and pulled out little slithery fish, crabs, winkles and clumps of seaweed to throw at one another. Bucketloads of trophies were collected, and later we’d try to smuggle this pongy cargo home with us, only to be told we had to put it back on the beach. You still see little ones having tantrums at home time, when they are made to part with their fishy-smelling booty.

Imagine being paid to “play on the beach”, studying coastal life in all its rich variety and measuring the profusion of species, as well as the ever-evolving coastline itself as it adapts to global warming and other threats, manmade or otherwise. Obviously “playing on the beach” is a foolish and simplistic view of what Dr Sue Hull and Dr Magnus Johnson do (they are lecturers in marine biology and ecology at Hull University), as their work is actually very serious. But such is their energy and enthusiasm for it that they turn a masterclass in understanding the shoreline into a couple of hours of tremendous fun that bring back all the joy of discovering rockpools for the first time.

Magnus brings along his sons, seven-year-old Alfie and Eddie, who seems entirely happy to be spending part of his sixth birthday pottering about on Filey Brigg, the rocky promontory that stands just north of the east coast town. It’s late morning and the tide is almost at its lowest. The mad 12 hours of submarine activity – moving about, feeding and mating – have been halted by the retreat of the sea, marooning all kinds of life for a dozen hours on the beach, the rocks or in hundreds of shallow pools along the front and back of the mile-long Brigg.

Sue’s like a little goat. She leaps ahead, talking all the while. “Look, zonation!” This is a clearly demarcated area at the back of the shore next to the cliffs, where certain tough species live because they are well adapted to spending more time out of water rather than by the sea where there is more competition for food. Across the steep Jurassic cliff behind are similar ecological “bands” of life forms that are cleverly specialised in living in different positions in relation to the ebb and flow of the tide. It must be amazing to understand everything you’re looking at in this seething mass of biology. Sue used to come over here as a child from her home at Elland, near Halifax, and spend hours studying evolution – even if she didn’t quite realise at the time that was what she was doing. At the far end of the Brigg she first saw grey seals and an octopus.

Eddie and Alfie are confidently but carefully picking green shore crabs out of pools and examining them with furrowed brow. “This is a lady one,” shouts Eddie knowingly, waving a crab in my face. And how does he know this, I ask. “Her bottom’s bigger!” It’s true the triangular area encasing her reproductive tackle is a wider triangle than the male’s. To help crabs do what comes naturally, the male has two penises and the female has two vaginas, says Magnus. Well, I never. Not only that, did you know that there are left-handed and right-handed crabs?

A hermit crab scuttles by, looking slightly unbalanced. Sue explains how one species of seaweed harbours all sorts of other seaweeds and “lodgers” when the tide is out, and she picks up one of a zillion mussels to point out its beard. “It secretes two proteins which solidify on contact with each other and stick the mussel to the rock like Araldite.

The ancient-looking limpets that sit seemingly unbudgingly on every available surface are so much more exciting than they look, too. What I thought were a simply an annoying feature of the coastline that makes it difficult to clamber about in bare feet, now have my undying admiration and respect.

Each limpet has its own little niche in a “home” rock. When the tide is in, the limpet sets off randomly trundling, foraging for food and leaving a trail of mucus behind it which acts like a paper trail. When it senses it is time get back to base before low tide leaves it exposed and vulnerable to predators, the limpet follows the path it laid down earlier and snuggles down into place until the next tide, having feasted and hydrated itself and probably worn itself out from roaming up to two metres away from its nook. Genius. A limpet can live 11 years, by the way, and the big ones are always female. She likes to be fertilised by a nice, neat, virile younger man.

Sue has a shallow white specimen tray with her, and picks out of it a dogwhelk, a little creature hidden inside a curly-wurly shell. Inoffensive-looking, yes, but it has a lethal weapon which it projects and uses to drill for around three days into the shell of a barnacle before devouring the creature inside.

This coastline is constantly changing, says Sue. “The cod has gone, and the dogfish has gone. But this is a very healthy area of shoreline. The last survey found 70 different seaweeds and in all 450 species of animal and plant, although there are lots that still need identification. There’s little indication of things dying out.”

Back to crabs. Budding biologist Alfie picks up a velvet swimming crab – a great hulk of a beastie next to the cute little green ones that proliferate here. Handling a velvet is not really recommended unless you are quite expert, says Magnus. They can deliver a nasty nip and have been known to break a pencil. The crab’s clearly feeling narky, so Alfie pops it back in a large pool where it disappears into a cloud of sediment that’s washed down from the cliffs.

It’s easy to see why Sue and Magnus love their job.

“I can honestly say I adore studying the shoreline, and am never happier than when I’m mooching about here,” says Sue. Luckily she lives close by. “Teaching young people about the ecosystems here is also incredibly rewarding. I like nothing better than bringing them down here for the first time and hearing them say ‘Wow!’”

If this has whetted your appetite for exploring the shoreline, Sue and Magnus have put together a few tips on safe and responsible rockpooling and shoreline adventures:

Check the tide timetables – beaches usually have display boards – and take care that you keep an eye on the tide all the time, as it can come in behind and cut you off

Binoculars will help you to spot porpoises and other creatures like grey seals and waders; a good guidebook to the shoreline will help you to identify species

If you turn boulders over to see what’s beneath them, make sure to turn them back

If something isn’t in a rockpool when you find it, don’t put it into one

Don’t take any of the plants or animals home and don’t put anything from the shore into freshwater

Don’t prise anything off the rocks, such as limpets and barnacles – you can kill them

Don’t let your dog chase sea birds feeding on the shore

Do bring a shallow tray, in which to put a little sea water and examine anything you find – then put it back

When you turn a rock in a rockpool over, stop and wait, look very carefully – all sorts of things can be camouflaged and not easily spotted at first

Despite the need for care and consideration, do come and look – rocky shores are home to a wonderfully condensed and fascinating ecology

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