Carbon, nitrogen and phosphorus ratios in seawater and seaweeds of Saurashtra, north west coast of India

Abstract

The concentrations of C, N and P in seaweeds vary from 19.72-41.01%, 1.19-3.60% and 0.0857-0.2482% (dry wt) respectively. The atomic ratio of N:P in seawater is 12.6:1. C:N:P ratio for seaweeds is 550:35:1. Lower ratios of C:N are observed in the green seaweeds (10.28 ± 1.29) especially of upper part of the intertidal zone than in brown (16.05 ± 1.07) and red seaweeds (13.42 ± 2.56) growing at lower part of the intertidal zone. Slightly higher N:P atomic ratios are observed in green (38.50 ± 5.20) and brown (35.84 ± 6.87) seaweeds than in red seaweeds (32.19 ± 9.82). Thus the nutrient turn over in benthic systems has C:P and relationships different from Redfield ratio.