Allometric relationships for intertidal macroalgae species of commercial interest

The demand for seaweeds has intensified in recentdecades and will most certainly continue to expand. Severalmethods exist to evaluate the biomass of seaweeds in the fieldbut most of them are destructive. The objectives of this studywere (1) to develop and evaluate allometric equations for es-timating seaweed biomass in the field for some harvested spe-cies and (2) to provide uniform calculated dry/wet biomassratios to estimate the relative water content of these seaweeds.Sampling and measurements of more than 350 seaweed indi-viduals were carried out for 8 species of commercial interest.Our models were fitted for both power and linear equationsand were tested for different explanatory variables. While thepower equation was found to be the best for predicting bio-mass of all species, we found that the best descriptive biomet-ric variable varies according to seaweed morphology. Specieswith a bushy morphology were best described by the volume,while long stringy species were best described by the lengthand flat species by the surface. This study attempts to providenondestructive tools that could be used by professional sea-weed harvesters, their employers as well as scientists and pub-lic regulators, to assess the harvest potential of a field of sea-weed in a nondestructive approach.