Tropical seaweeds for human food, their cultivation and its effect on biodiversity enrichment

Abstract

article i nfo As a response to growing land and freshwater shortages and climate change, the use of seaweeds as food, their cultivation at sea and its effect on biodiversity are being researched on both the Caribbean and Pacifi cc oasts of Costa Rica. Native species, more plentiful on the Caribbean coast, were collected and pre-selected based on existing information and on criteria including ubiquity, abundance, growth and palatability. These species were then evaluated as food and subjected to floating long-line cultivation using vegetative propagules. After establishing postharvestprocedures, useasfood involvedmanypreparationstobe eatenfresh orafterdrying,in- cluding a dry-ground meal. Ten of these species, which had nutrient contents within expected values including 9.8% crude protein on a dry weight (dw) basis and high iron, were considered adequate as food, both directly and as part of recipes in quantities not exceeding 20% dw of a given dish. Higher concentrations either 'overwhelmed' traditional recipes or their taste was rejected by tested consumers. Near-coast cultivation was in general a simple matter, easily transferred to artisanal fishers. To a great extent due to herbivory and theft of ropes, yield (ranging from 51.7 to 153.2 t ha −1 yr −1 on a fresh weight basis) was quantified for only five spe- cies with a mean of 9.3 t ha −1 yr −1 dw, equivalent to 0.91 t ha −1 yr