A seasonal carbon budget for a laminarian population in a Scottish sea-loch

Employing in situ SCUBA methods a seasonal carbon budget has been established for a Laminaria saccharina population in a Scottish sea-loch. Concurrent studies of photosynthesis, secretion rates, reserve fluctuations and frond growth were undertaken. Net annual production is in excess of 120 g C m^-2 yr^-1. Over 13% of gross carbon input is released as extracellular secretions (over 30% in autumn) and 40-50% is lost by distal decay, entering detrital food chains. The large concentrations of laminarin, synthesised in summer months, are nearly all lost in autumn-winter distal tissue loss and therefore not available for early spring growth. © 1977 Biologische Anstalt Helgoland.