Our third annual visit to Conger Rock was on Saturday 21st September, the early morning start being made very much more bearable by the rare appearance of some sunshine! Our walks are nice social occasions, but also allow us to check on the state of the honeycomb worm reefs which can grow to be substantial structures close to extreme low water.

The photo above by Lewis shows one of the honeycomb worm reefs with Conger Rock, and other members of the group, in the background. The reefs close to Conger Rock were rather smaller than on previous years, few being more than 10cm tall. More substantial reefs, up to 40cm tall were present closer to the the extreme low water mark.

The reefs are relatively short-lived structures – probably reaching a maximum size, with a height over half a meter, and extending for many tens of meters, after four or five years growth. After this time the rate of erosion from winter storms starts to dominate over the slow growth of the reef, perhaps as the founding worm population gets older, or simply that the larger reef size becomes unstable in the face of winter storms.

Barry Kaye, Sept. 28th 2024