Risk and reward – the Roa Island shore walk 2019

September 2nd, 2019
Sand mason worms against the sunset at Roa, August 31 2019. By Barry

The drive up to Roa on Saturday was not very promising, with periods of torrential rain it was no surprise that only a few made the effort… In the event, however, other than a strong wind, the evening was very pleasant. We spent the first little while, however, spelling one of the lifeboat crew watching some kayakers to make sure they reached Piel Island safely!

Due to the wind we spent a little more time than usual to the West of the lifeboat jetty. The mud flats here are the home of a large number of sand mason worms (pictured above), and scattered with common starfish, which have been stranded by the tide as they hunt for cockles in the mud. Starfish have a hydrostatic skeleton, so are completely incapacitated in the absence of water. It is clear from the sad, deflated bodies, that a few do not survive exposure, but for many the chance of a meal must be worth the risk…

The visit also allowed me to take a plankton sample, which looks very different to the one I took on the dive in July, when there were no phytoplankton, and few zooplankton. The rougher weather recently may have helped spur some activity, as the sample from Saturday had high concentrations of phytoplankton, and lots of zooplankton and larvae, to recolonise the Bay. A few weeks can make a massive difference!

Barry Kaye

Posted in Marine science update, Shore walks