PRODUCTIVITY AND LIFE-HISTORY OF LAMINARIA-LONGICRURIS AT ITS SOUTHERN LIMIT IN THE WESTERN ATLANTIC-OCEAN

At Long Island Sound, Connecticut, linear growth rates were minimal during August and September, subsequently increased through the remainder of the year and reached a maximum (2.5 cm d-1) in May. Productivity per plant (fresh weight) was maximal January to May (11.4-15.7 mg g-1d-1); productivity m-2 was maximum in May (110.53 g m-2 d-1 in 1986 and 413.32 t m-2 d-1 in 1987). Production was 10.6 kg m-2 in 1986 and 46-50 kg m-2 in 1987. Maximum standing crop was observed in May (1986: 24 kg m-2; 1987: 47 kg m-2). Maximum densities of new recruits were 1000 ind. m-2. Densities of plants with blades >50 g were 92 and 167 plants m-2 in January and May, respectively. Highest percentages of fertile plants were observed during October to December. Succession in generations of plants behaving as either annuals or biennials is discussed. -from Authors