Northern Rock Barnacle

(Semibalanus balanoides)

Introduction

	Abstract: The location of the study in fall of 2008 was in Nahant, Massachusetts, where the study focused on the Northern Rock Barnacle (Balanus balanoides) and its distribution along the coastline. Random locations along the South and South-east facing coastlines were chosen, where the barnacles were mainly found, and an area was isolated with a .25x.25m quadrat. Then the temperature, texture, slope, sizes of the barnacles, number of barnacles, exposure, and direction of the area were recorded. Significant correlations were found between the size of the barnacles and the slope and exposure of the rock. Also, the correlation between the area covered by the barnacles and the exposure was found to be significant.
Introduction: Barnacles are crustaceans found from the mean water line up to, on very rare occasions, a depth of up to 45 m, along coast lines. (Johannesson, 2000) They feed on small copepods and even algae using fan-like projections called cirria that essentially wave the water into their mouths. Barnacles are most commonly found on the rocks on the coast lines, but can also be found attacked to wood and many man made objects that are in the water. Because the barnacles are sessile organisms (Gaines, 1992) they are exposed to all of the natural forces that surround coasts. In this way barnacles have to withstand large fluctuations in temperature, strong impatcs of waves, and even errosion. In some areas the wave action may be so intense that it leaves a strip of bare rock, called a bare belt, where no organisms are found. (Johannesson, 2000) Despite the harsh environments surrounding the barnacle habitats, there always seems to be a dense layer of barnacles on the coastlines.