Mussel fouling on the Celtic Sea Kinsale Field gas platforms

Fouling was investigated on Marathon Kinsale Field Alpha and Bravo platforms in the Celtic Sea between June 1978 and June 1981. In shallow depths, algae dominated, chiefly Polysiphonia brodiaei and Ulva lactuca. Mussels formed the dominant fouling organism between 6 and 20 m depth, below which were zones of Metridium senile and Alcyonium digitatum, serpulids and the deep water barnacle Balanus hameri. In September 1979 mussels exceeded 2500 m⁻² with a modal length of 42 mm. By June 1981, modal length had increased to 67 mm at −4 m and 73 mm at −18 m (maximum size 97 mm). Populations on Bravo were similar. Comparison is made with growth rates on North Sea platforms. On Alpha, percentage cover m⁻² in March 1980 was much greater at −4 m than at −18 m, but mean thickness was similar. At −18 m mussels were a heavier fouler on Bravo than Alpha. On Alpha mussel weight did not show a linear relationship with percentage cover.