Harvesting Gracilariopsis heteroclada (Gracilariales, Rhodophyta) in Iloilo, Philippines

Abstract

Gracilariopsis heteroclada thalli were planted in a 1 m2 ditch along a drainage canal at Leganes, Iloilo, Philippines. Monthly growth rate and production were calculated to determine the effect of harvesting on the regeneration capacity of the plant. After 30-day growth period, all plants were harvested at 25%, 50%, 75%, and 100% of the total available biomass. Though highest growth rate was observed at 100% (8.7%), it took three months for the plants to regenerate and obtain a considerable biomass. Positive growths were obtained when plants were harvested at 75% (5.6%) during the entire growth period. Negative growth rates observed both at 25 and 50% harvests.