On a typical dive off St. Abbs Head from the surface to a depth of about 30m,
you will go through a whole cross section of marine life zones. Firstly, attached
to the rocks is a thick band of shiny, greeny-brown kelp down to a depth of about
8m. These large plants stand erect and swaying in the current. With sunlight dappling
the rocks around their holdfast root systems and small fish darting around, it has
a beauty all of its own and it is easy to see why this zone is known as the kelp
forest. Kelp fronds are very slippery and only a few specialised animals such as
hydroids and sea mat can make a home on them. So too can one or two sea slugs which
prey on them. A large fish, the Ballan Wrasse, is often found amongst the kelp.
These are well accustomed to visiting divers and often will swim up to them looking
for hand outs.
The rocks between the kelp holdfasts can be a blaze of colour. Often it is a rich
mauve due to the encrustation of a brittle algae called lithothamnion but it will
be interspersed with other creatures of contrasting colours such as white and yellow
anemones, red sea squirts, yellow and green sponge and feathery hydroids.