Go rockpooling this weekend!


Make the most of the gorgeous weather. Relatives of what we keep at home can be found in our rock pools. Richard Aspinall reveals why he loves to be beside the seaside.

As my interest in reefkeeping has grown and my bank account has shrunk proportionately, I’ve rediscovered rock pools. These wonderful features of our tidal and rocky shores that are neither land nor sea cradle a wealth of life inhabiting our inshore waters.

We can also meet some of the distant and slightly more rugged relatives of the creatures we keep in our reefs back home.

My interest in the sea started when I was young, but growing up in a northern mill town did not offer many opportunities to explore reefs — except for that one miraculous week of the year when we packed ourselves on a train and headed coastward.

 

For kids and adults alike, rockpooling consists of stuffing as many crabs as possible into a small and rapidly overheating bucket. That kind of rockpooling wasn’t for me though.

Crabs were of little interest. I was looking for blennies, anemones, starfish, fan worms, swimming crabs, snails, Sea hares and so on...

I’ve met a few fishkeepers who’ve loved getting their hands wet around our British coastline, but for those of you who haven’t sampled this fascinating, largely free and only mildly perilous activity, here’s a quick introduction to some of the critters you can find in these pockets of water.

Fish
Dozens of fish species inhabit our rocky shores, with wrasses such as the Ballan (Labrus bergylta), Corkwing (Crenilabrus melops) and Painted (C. tinca) being equally as colourful as many tropical species.

The average rockpooler though is more likely to come across marooned bottom dwellers. Blennies such as Parablennius gattorugine  — the Tompot (above) — are common and remarkably attractive.

Southern coasts may reward the pooler with Butterfly blennies (B. ocellaris), a species having a gorgeous ‘eye-spot’ on its dorsal fin, or Montagu’s blenny (Coryphoblennius galerita).

Crustaceans
Crabs regularly feature in the trade, though we usually offer homes to smaller, herbivorous or detrivorous species such as Mithrax or species from the Porcelain crab group — not forgetting our beloved hermits.

Parting the seaweed and carefully lifting it aside, however, could reveal several much bigger and equally interesting species — more often than not the common Green shore crab, but occasionally rarer species such as the small Hairy crab (Pilumnus hirtellus) or tiny Pea crabs (Pinnotheres sp.) that live commensally in the shells of bivalves. There’s also the exquisitely marked Marbled swimming crab (Liocarcinus marmoreus).  

After the shore crab the most commonly found are small specimens of the Edible crab (Cancer pagurus) and the dapper Velvet swimming crab (Necora puber). This is a splendid creature with red eyes, shot through with blue on the legs and with flattened oar-like rear legs (periopods) to help it move at considerable speed through the water.

One of the joys of rockpooling is the chance to meet larger versions of creatures we wouldn’t entertain in a captive reef.  

A big crab is a nightmare to house and feed — and hard to love — but just catch one, briefly and carefully, and marvel at its construction. It has remarkably ‘engineered’ joints and pincer pivots, wonderful detail in its eyes and a breathtaking complexity of scores of separate ‘plates’ that make up its skeleton.

Our waters also offer a wealth of hermit crabs, which can usually be found in pools as smaller specimens inhabiting the shells of shallow water molluscs such as the Common periwinkle (Littorina littorea). Shells of deeper water molluscs, such as the Common whelk (Buccinum undatum), are much sought after below the low water mark.

The larger crustaceans don’t represent all of the order. Amphipods, ostracods and isopods can found by the more enthusiastic pooler, while several Palaemonid, Hippolytid and Alpheid shrimps can be found around our coastline, though the commercially valuable and very common Brown shrimp (Crangon crangon) is often found in the greatest numbers.

Occasionally, extreme low tides may reveal a Squat lobster (Munida sp., Galathea sp.) or even a Common lobster
(Homarus grammarus).  

Divers often take ‘lobbies’ for the table but, if you must do so, research first and ensure you take only older larger specimens that have had chance to breed — and that you are legally able to do so. These amazing animals should be left well alone!

Corals and anemones
We often associate anemones with warm tropical seas and colourful clownfish, but our temperate waters are replete with anemones, some exceptionally beautiful. The commonest and most easily spotted in the rock pool is the vivid red Beadlet anemone.

This resilient species can survive many hours of exposure to air, baking sunlight and freezing winds, before the tide returns and this small 5-8cm/2-3” creature opens its tentacles to feed in the manner we are all familiar with.

Warmer coastlines on the south and west of the UK might reveal a Daisy anemone (Cereus pedunculatus) buried with its foot in the sand, while, below the low water mark, rocks and harbour sides can be covered in Dahlia anemones (Urticina felina), Plumose anemones (Metridium senile) and one of our few stony corals — the Devonshire cup-coral (Caryophyllia smithii).

Soft coral species are limited in number, but not necessarily in biomass. Alcyoniums, such as the Dead Man’s Fingers often inhabit kelp forests and may cover many acres of shallow water all around the British coastline.

Echinoderms
Poolers are likely to come across several starfish species, from the Common (Asterias rubens) to some Cushion stars from the familiar genus of Asterina.

Extreme low tides may reveal some rarer and larger starfish, such as the very spiny and quite large Marthasterias glacialis or the smaller and attractively coloured Henricia starfish.

Several species of Brittle stars can be found in British rock pools — Amphiura brachiata, A chiajei and A. filliformis being common smaller species.      

Sea urchins are not commonly found alive in rock pools, but the remains of their ‘shells’ are common and intact skeletons are likely to be found in those seaside curio shops.

Molluscs
Nearly every genus of creatures we keep in our tanks has representatives in UK rock pools and this is much the same with the molluscs. You’ll be lucky to find turbos (order Turbinidae) as the few species in Europe favour warmer waters, but you will find cowries, trochids (Top shells), a cerith or two and nassarids such as the Dog whelks (Hinia sp.) and, if really lucky, a Sea hare.

Most are grazers, such as limpets, winkles and top shells. Look out for the chitons — small, oval, flattened grazers with shells made from eight plates that allow the creature to flex as it moves across the rock.  I’ve found the occasional one on live rock but never managed to keep them alive, suggesting their dietary needs are more complex than grazing algae and diatoms.  

Also look out for Blue-rayed limpets (Helcion pellucidum). These tinies are often found attached to the stalks of large sea weeds and have neon blue spots arranged in ‘rays’ radiating across the shell.

Rockpooling dos…

  • Check tide times.  
  • Be patient. Move seaweed and rocks aside slowly and watch for movement.
  • Put rocks and seaweed back where you found them. Many creatures will survive under seaweed when the tide is out, but not in full sun.
  • Make sure you put back anything you catch promptly and carefully.
  • Take care underfoot. Falling over on a rock covered in barnacles will not help you maintain your beach beautiful body.

…but don’t

  • Wander out to the furthest pool you can find as the tide starts coming in.

 

10 great places to go rockpooling

  • Cresswell Shore Nature Reserve, Northumberland
  • Flamborough Head, Yorkshire
  • Thanet, Kent
  • Samphire Hoe, Kent
  • Seven Sisters Country Park, Sussex
  • Charmouth, Dorset
  • Shoalstone Beach, Devon
  • Helford Passage, Cornwall
  • Portrush Nature Reserve, Northern Ireland
  • Rockcliffe, Kirkcudbrightshire, Scotland

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