Red algal farming in Chile: a review

Production of seaweeds in Chile has fluctuated between 74,000 and 322,000 w et metric tons/year during the last 14 years, involving different species o f Phaeophyta and Rhodophyta. Among Rhodophyta, the most important harvested species include the carrageenophytes Sarcothalia crispata, Mazzaella lamin arioides, Gigartina skottsbergii, Chondracanthus chamissoi, and the agaroph ytes Gracilaria chilensis and Gelidium lingulatum. Other less important tax a are Gel. rex, M. membranacea, Ahnfeltia plicata, Ahnfeltiopsis furcellata , Porphyra columbina, Callophyllis variegata, Mastocarpus papillatus and Ch ondrus canaliculatus. Chilean production comes mainly from wild stocks, as at present, cultivatio n on a commercial scale is restricted to Gin. chilensis. Total landings of Gracilaria currently stand at 120,000 wet tons. Large-scale cultivated biom ass of this species, on the other hand, has been the result of a sharp incr ease in the number of farms, from less than 10 in 1982 to almost 322 in 199 6. A basic understanding of key biological and ecophysiological aspects, as well as the availability of propagation methods, permitted the development of large-scale Gracilaria farming operations. However, during the cultivat ion process, new problems arose for the farmers, such as abrupt production decline, pests and pathogens. Similar key knowledge is lacking for other Chilean Rhodophyta, which create s a bottleneck that prevents the development of seaweed farming activities other than Gracilaria. This situation prevails in spite of the growing pres sure on wild stocks triggered by an increase in the demand for raw material by the industry, with the obvious danger of over-exploitation and the resu lting collapse of fisheries. Taking the above into consideration, an effort has been made in recent years to provide the basic knowledge necessary for the management and cultivation of some of the most valuable seaweed resour ces in Chile. Thus, the main objective of this contribution is to summarize the present situation of red seaweed cultivation in the country. We will a ddress this issue by reviewing the landing statistics of these resources, f ollowed by a summary of recent information that favours cultivation. These include propagation methods, culture conditions and techniques, product qua lity, pest management, strain selection and the diversification of seaweeds currently exploited in Chile. (C) 2001 Elsevier Science B.V. All rights re served.