USE OF PHOTOGRAPHY AND IMAGE-ANALYSIS FOR IN-SITU MONITORING OF GROWTH-RATES OF INTERTIDAL FUCOID ALGAE

A combination of photography and subsequent image analysis of the phot ographs has been used to measure maximum length, perimeter length and total area of fronds of tagged Fucus serratus L. as part of a study of the growth of this species on the Yorkshire coast. Maximum mean growt h rate of 0.26 cm d-1 was observed during June-July. Minimum mean grow th rate of 0.01 cm d-1 was observed during October-March. The method i s relatively quick and convenient, and has the advantage that in addit ion to apical growth of the longest and/or other branches, lateral gro wth and total growth in surface area can all be recorded, while loss o f tissue can also be determined. A further advantage is that a photogr aphic record is obtained of the history of each individual plant.