Effects of Flow Rate on Balanus glandula Feeding Rates

Abstract

Environmental changes can affect the abundance and community structure of various intertidal organisms. Water flow rate is a determining factor in food abundance and settling rate of food particles. For this study, we used the acorn barnacle, Balanus glandula, to study the effects of water flow on feeding rate. Many studies have been conducted involving beating rate, that is, how often barnacles extend their cirri. However little research has been done on how flow rates can affect the actual feeding rates of barnacles, meaning the rate at which they obtain food using their cirri. We predicted that in faster moving water barnacles would be able to obtain more food particles due to the flux of food around them. We also predicted that in slower moving water barnacles feeding rate would be lower because settling rate would be higher. These predictions led to the hypothesis that there must be an optimal flow rate at which feeding rate is highest. Our results showed that settling rates of food particles were highest in slower moving water, however, we were unable to obtain enough data about how feeding rates would vary with changing flow rates. In the future, more tests should be done using the improved methods we have developed in order to determine differences in barnacle feeding rates.