As usual, I am responsible for the brilliant? pun in the title but this time I have handed over to one of my residential volunteers to write this blog. Our volunteers come in all different 'shapes and sizes', with many different skills and backgrounds. However, they invariably have one thing in common: a real passion for nature and a strong desire to make a difference. So, I am delighted to introduce Robert, a marine biology student, and here is his blog on this week's Beachcomber Walk at New England Bay. His enthusiasm and knowledge is here for all to see:
The seashore is my favourite wild habitat to explore. It is such a complex habitat with countless nooks and crannies hosting an enormous diversity of life. About two thirds of animal diversity is found only in the sea and the seashore at low tide is one of the easiest ways to find many of these animals in the wild. It is one of the toughest habitats on earth. The animals and seaweeds that live there have to face extremes in temperature, salinity and moisture with fluctuations on a twice-daily basis. This leads to lots of unique and interesting adaptions and behaviours, many of which we saw on the latest RSPB beach combing walk which was guided by RSPB staff and volunteers and included lots of young explorers. Here’s my account of what we saw and learned.
Many of the inhabitants of the seashore are small and you have to look carefully to see them. At the start of the walk we turned over a dried piece of seaweed and watched the sand around it come alive with dozens of tiny sandhoppers all leaping like fleas. Sandhoppers are tiny crustaceans which use their tails to spring away from predators and clutching hands.
Nearer to the sea, the muddy sand was covered with the burrows and castes of the lugworms. Lugworms are found under the sand in U-shaped burrows and eat sand, removing the organic material before excreting it back to the surface. At the head end of the burrow the worm leaves a small pit where it has eaten the sand, at the tail end it leaves behind a caste. Every gardener knows how valuable earth worms are for turning over the soil and lugworms to the same for the sand on the beach, keeping the soil full of oxygen for animals to breath. This reminds us that many of the most important species in conservation are often the smallest and most easily overlooked.
At first glance the rocky shore can seem dead. It is littered with empty shells of all shapes and sizes. Topshells, periwinkles, whelks, mussels, clams and scallops are testament to the startling diversity of molluscs alone to be found on the sea shore, all the other animal groups.
However closer inspection revealed that many other organisms were still hanging on in this unforgiving habitat. Many of the scattered shells were in fact still occupied with a whole host of snail varieties from the harmless herbivores such as periwinkles and topshells to the ravenous predatory dog whelks and common whelks, which use their tongues to drill holes in the shells of other snails. All marine snails have a trap door which seals their shell shut when they retreat into it, helping them to avoid drying out at low tide.
Strands of seaweeds can be seen holding on tight to the rock with holdfasts and egg wrack and bladder wrack use gas filled floats to stay up near the sun when the tide is in. One type of seaweed, called Polysiphonia, looks like a red fuzz on the egg wrack. It hangs on to the much larger seaweed and uses it to shelter from the sun and stay moist when the tide is out.
Plenty of crabs could be found buried in the sand, sheltering from the birds. As we caught them, we learned to distinguish between male and female crabs by looking at the underside. We also found plenty of discarded crab shells and found out how crabs grow by regularly moulting their armour.
By lifting rocks we found beadlet anemones, sheltering from the sun. When the tide comes in, the anemone will spread its tentacles to capture drifting food, resembling a colourful marine flower.
There is not nearly enough space here to describe all of the exciting marine animals we saw on our beach walk, suffice to say that in a great team effort, a group of young explorers managed to catch a huge shore crab at the end of the walk. After admiring his large claws we returned him to his rock pool.
If this has got you interested, why not join our next RSPB beach walk at New England Bay - Wednesday 14 August, starting at 11am from the entrance to the caravan park.