The geographic position of the Marine Reserve means that it benefits from a flow of
Atlantic water entering the North Sea around the northern tip of Scotland but
also from a cooler Arctic influence. This results in a diverse mix of marine
species from both cold and relatively warm water. For instance, the Devonshire
cup coral which is very common on western shores is found here in small numbers
but probably does not exist much further south in the North Sea. Similarly,
species such as the beautiful Bolocera anemone and the Wolf-fish are primarily
Arctic species but they are found off the Berwickshire coast in good numbers.
The Marine Reserve is situated well away from major centres of population and
industry and consequently, effluent discharges into the sea are minimal. Water
quality is improving as new sewage treatment plants are being installed up and
down the coast at various locations and as a result, the underwater visibility
in the area can be excellent. Spring tides, on-shore winds and plankton blooms
can affect this but ten to twelve metres visibility occurs regularly whilst at
some point each year, twenty metres visibility can be found.