Creatures of the coastline
Expert discusses the Solway species
Marine biologist Jim Logan gave a lecture called Between the Tides.
He aimed to give an overview of the variety of wildlife that can be found between the high and low watermarks on the Solway.
The area is particularly rewarding, partly because of the wide range of habitats – from mudflats through sand and shingle beaches to rocky shores – and partly because the tidal range, from six to nine metres, is the second largest in Britain.
Salinity can vary considerably, due to streams and rivers that discharge into the Solway. Mr Logan pointed out that some seaweeds, for example, can tolerate almost non-saline water, and also drying out, whereas others need a strictly marine environment.
Rock pools, which might seem to provide a good place to observe wildlife, can be a difficult habitat for marine species as in hot weather the pool dries and salinity rises, whereas heavy rain will dilute the seawater.
Mr Logan then described the types of molluscs to be found. These include the little winkle, which spends most of its life above the tideline but takes to the sea to breed, whereas the edible winkle needs daily immersion in seawater.
The familiar limpet grips to rocks using a huge foot muscle and scavenges weed by scraping the rock surface. Dog whelks feed on other sea creatures, such as mussels or barnacles, by first drilling a hole in the shell.
The native European oyster is no longer found on the Solway coast, but there is a thriving colony and oyster fishery in Loch Ryan.
Mr Logan moved on to describe crustaceans, which range from the large edible crab to the tiny pea crab, which lives inside mussels, feeding on material gathered by its host.
Barnacles, despite resembling small limpets, are in fact crustaceans which feed on plankton by opening up plates in the top of the shell.
Other intertidal creatures include starfish, sea anemones and sea urchins. Fish are generally observed in rock pools and species include the blenny, goby and butterfish, the last named because of its slippery skin.
Mr Logan ended by mentioning sea creatures that may become stranded on the shore. Most notable were various species of jellyfish, some of which were harmless but others, such as the lion jellyfish, could inflict a powerful sting.
The evening concluded with a question and answer session.