Gelidium commercial exploitation: natural resources and cultivation

The state of the Gelidium agarophyte resource was last reviewed in 1990 during the First International Workshop on Gelidium. The main objective of the present study was to gather and analyse the new information made available since then, with emphasis on the G. sesquipedale resource from the Iberian Peninsula and Morocco. Other Gelidium-based resources world-wide are also reviewed, as well as new attempts to cultivate Gelidium species in the sea. In general, since the late 1980s, G. sesquipedale yields have decreased in Portugal, and increased in Spain and Morocco. Current reported values, in dry weights, are ca. 670 t yr(-1) for Portugal (average 1995-1997), 5200 t yr(-1) in Spain, and 6950 t yr(-1) for Morocco (average 1994-1996). Efforts to develop cultivation of G. sesquipedale in the sea in Spain have yet to progress beyond the demonstration scale. Other important Gelidium-based agarophyte resources are located in: (i) South Africa where, in addition to G. pristoides, new species are being harvested, with total agarophyte landings of 140 t yr(-1) in 1996; (ii) Mexico, where G. robustum harvest averaged 750 t yr(-1) in 1987-1996; (iii) and Chile where harvest of Gelidium species yielded ca. 460 t yr(-1) in 1990-1992. Preliminary research on new techniques for commercial cultivation of Gelidium species is also reported from these countries.