Growth and reproduction of Macoma balthica (L.) on a mud flat in the Fraser River estuary, British Columbia

Publisher Website
Google Scholar
Abstract
Growth and reproduction of the bivalve, M. balthica (Linnaeus, 1758) was studied for 1 yr (April 1977-March 1978) on an intertidal mud flat in the Fraser River estuary, British Columbia. The maximum number of individuals (1830/m2) occurred in April, then steadily declined throughout the year. Spawning occurred between mid-June and late July but recruitment was slow and prolonged. Peak spatfall (age 0+ individuals) did not occur until the following March when a maximum density of only 410/m2 for newly settled spat was observed. The oldest animals found were 5+ yr of age. Maximum growth took place during April-July. The growth rate measured was one of the highest recorded for any M. balthica population. A direct relationship between high water temperatures, a fast growth rate, and reduced longevity was apparent. A regression of body weight on shell height was used to calculate a condition factor (CF), which reached its highest value during growth and its lowest value immediately after spawning. The mean annual biomass measured was 2.96 g dry wt/m2.