Fig. 4

Mytilus edulis. Size frequency distributions (Percentage of total number of measured individuals) of mussels in mixed samples taken at several places within a ∼1,100 m² bed (located near transect-9 and -10, Fig. 1), annually in late summer or autumn. a August 1969 (n = 197, estimated number present ∼10⁷), b September 1970 (n = 489, ∼7 × 10⁶), c September 1971 (n = 118, ∼3 × 10⁶), d October 1972 (n = 245, ∼10⁶), e October 1973 (n = 158, ∼2 × 10⁶), and f September 1974 (n = 372, 10⁶); black columns the strong cohorts of 1969 and 1973