1995/01/01 by I.D. Marsden, Marsden, I. D., R. M. Pilkington +1
Earth and Planetary Sciences · Environmental Science · #Marine Biology and Ecology Research #Aquatic Invertebrate Ecology and Behavior #Marine Bivalve and Aquaculture Studies
paper · pdf · doi:10.26021/700
Weight relationships ofthe cockleAustrovenus stutchburyi were investigated from 9 low tide sites within the Avon-Heathcote estuary in December 1990.The condition index varied significantly between sites.Mean condition index increased with both higher salinity and increased chlorophyll a levels, measured during low tide periods.Results from a 15 month sampling programme showed seasonal patterns in the condition index and dry tissue weights of cockles collected from a marine and a more estuarine site.Highest values were recorded in Spring and lowest values in January and February.Cockles from the more estuarine site showed delayed onset of weight gain and a smaller maximal size than those from the marine site.It is suggested that estuarine cockles show reduced reproductive potential and reduced growth rates compared with the more marine population.The role of reduced salinity as a limiting factor affecting growth in cockles is discussed.