I am familiar with the commonly occurring horizontal stripes of rocky shore zonation where organisms are distributed between the tide levels according to their tolerance of exposure to air – but I wonder what influences the distribution and arrangement of different species of seashore creatures to result in the irregular patchwork pattern as found on the intertidal rocks at Fall Bay in Gower. The sloping flat surfaces of the limestone strata can be covered with a complete encrusting layer of mussels, limpets, and barnacles, organised by colour, shape, and size to make a patterned carpet.
A wide and shallow river flows over the sandy beach at Ventry Bay on the Dingle Peninsula in Ireland. I do not know its name. Characteristic ripple marks are made in the wet sand around the margins of its wandering channels, showing the influence of the freshwater currents modified by the sea water tides. As you walk away from the fast flowing water, the overlapping ‘leaf’ patterns made by the river currents gradually transition into the parallel ridges of wave-induced ripples that are more typical of the intertidal shore .
The soft smooth almost liquid muds that flow down the cliffs at Seatown after rain, pool and sink into the shingle on the beach. It doesn’t take long to see amazing networks of tracks and trails on the mud surface. These are made by a myriad of small invertebrate seashore creatures like worms, snails, and sandhoppers as they walk across, burrow, and tunnel into it, foraging for food and seeking shelter from exposure. The number of distinct track marks is amazing and I have no idea which mark was made by which animal (that is a whole new project requiring the collection of some mud samples for identification of the occupants of this habitat). Large bird footprints from crows and gulls show that these areas are also good places for them to feed on the creatures in the mud.
Images can be seen in greater detail by clicking on any photograph to view in the gallery, and then clicking “View full size” below the picture.