Rurprosjektet

Framgangsmåte for utføring av feltundersøkinga, fyrste år

1. Choose a convenient site. Everyone seems to have relatively easy access to sheltered rather than open coast sites, so I suggest a sheltered but non-estuarine site (to avoid salinity complications). This will also minimise problems of people accidentally looking at cthamalids! Please avoid using sites close to street lighting or other bright lights as this may inhibit fertilization.Choose sites with plenty of cover of barnacles.
2. For this first year, only sample from the middle of the Semibalanus band (ie not at low water or at the highest distribution on the shore).
3. Scrape Semibalanus off the rock surfaces (either singly or in small groups) with a penknife and inspect the underside of each barnacle with a handlens. At the start of the season you will see soft, amorphous pale yellow masses on either side of the barnacle. Use a mounted needle to prod the masses. Before fertilization they will be fluid to the touch of the needle, and it will not be possible to remove the masses with the needle. After fertilization the masses are a little darker in colour, but the main and very obvious difference is that they become defined rather than amorphous, and can be flipped out of the barnacle as whole, relatively hard egg masses.
4. Mike Burrows and I estimate that it takes about 20 minutes to investigate 50 barnacles. I feel that the technique is so simple that it can easily be delegated. I'm certainly going to train a couple of our technicians, so that sampling can continue if I'm away or ill.
5. Stop sampling when all egg masses are hard on two successive sampling trips.