Seeing the amounts of debris and particularly the fine fragments of broken up plastic on some Welsh beaches facing the SW wind or where the tidal surges have swept debris up inlets, one is reminded of the poetic musings of the Walrus and the Carpenter, as they walked along a beach before over-exploiting the local stock of oysters. Verses 4 & 5 of the poem as told to Alice in Lewis Carroll’s Through the Looking Glass were as follows:-
One consequence of the prolonged sequence of depressions swept across the Atlantic by the jet stream may have been a reduction in the “standing stock” of litter actually washing to and fro out at sea with more of it landing up on the shore. Back of envelope calculations would suggest that 40 days or so, with winds as they have been, might have swept ashore most of the litter from about 700 – 1000 nautical miles out in the ocean. Looking at the organisms growing on the litter, it was noticeable that while the lost whelk pots and other items thrown up from the near-shore seabed by the early storms had the usual range of barnacles and saddle oysters on them, the floating litter coming up then had few attached organisms. Debris floating in the open ocean for long enough usually gets colonised by things like stalked or goose barnacles (Lepas spp.). The occurrence of such organisms can give clues as to whether a proportion of the litter has come from out in the open ocean or from more local sources in and around the Irish Sea. It was interesting to see that photographs showed Lepas on the bottom of the boat on which the Mexican fisherman apparently survived, drifting across the Pacific for many months.
|Lepas pectinata, which can be distinguished by |
the obvious radial ribbing on the shell plates