Cystoseira scale-based biometric relationships

Scale-based biometric relationships of Cystoseira species were studied. All of the allometric relationships between size and biomass were significant (p < 0.001) and volume [estimated as the product of length (L) and circumference-squared (C-2)] was a better predictor of both wet biomass (WB) and dry biomass (DB) than L. The allometric exponent of the relationship between L and DB for five Cystoseira species (0.238-0.297) was found to be close to the allometric exponent suggested to be universal for primary producers (0.25). The relationship between Cystoseira spp. coverage (%; estimated in the laboratory for each species harvested within a reference quadrat in vertical projection) and WB was best expressed by a power function, while that between photographic cover (%; estimated in the field) and WB was asymptotic at 100% cover. The relationships between cover (%) (CVr) and coverage (%) (CVe) with WB pooled from an independent dataset were polynomial with comparable values up to 120 g WB. ANCOVA showed species-specific (e.g. between biomass and size) and species-independent (e.g. between biomass and coverage/cover, between DB and WB, and between DB and organic matter) relationships, indicating that non-destructive sampling in the genus is feasible when species and parameter are taken into account.