Back in the early 1950s, the only commercial sources of cysts originated from the coastal saltworks in the San Francisco Bay (SFB) in California and an inland biotope, the GSL in Utah. Artemia were marketed for the aquarium pet trade at a low price, i.e. less than US$ 10/kg (Bengtson et al. 1991). Cyst prices increased considerably in the mid-1970s as the combined result of increased demands from the emerging hatchery activity, decreased harvests from GSL and possibly simulated shortages by certain commercial companies.
At the 1976 Food and Agriculture Organization (FAO) Technical Conference on Aquaculture in Kyoto (Japan), Sorgeloos (1979) launched the idea that the cyst shortage was a temporary problem and could be overcome by the exploration and development of new Artemia resources and by the application of improved methods for cyst processing and use. By 1980 the situation had improved, with several new commercial products from natural (e.g. Argentina, Australia, Canada, China, Colombia, France) and man-managed (e.g. Brazil, Thailand) Artemia production sites. However, cyst quality in terms of hatching rate and nutritional composition proved to be highly variable, not only among the various strains and species of Artemia, but also among various batches from the same location (Leger et al. 1986). During the 1980s, new methods for evaluating and manipulating the hatchability of cysts and the nutritional composition of nauplii were adopted, mainly thanks to the efforts of the research group 'International Study on Artemia'. At the same time there was an important improvement of the harvesting technology applied at the GSL. Artemia were collected from the surface of the lake instead of from the shore and, together with airplane spotting of the cyst streaks, it resulted in a 10-fold increase in yield (>200 t/yr of processed product) combined with an improved hatching quality. Consequently, there was a dominant presence of GSL cysts on the world market from the mid-1980s onwards. More than 90% of the world's commercial harvests of brine shrimp cysts was derived from the GSL and sufficient high hatching product was available to fulfil the needs of the market. Bengtson et al. (1991) warned that this development presented a critical situation, since a bad harvest year at the GSL would have a major impact on the provision and price of Artemia cysts for the global larviculture industry.
In the meantime, cyst consumption had increased exponentially as a result of the booming shrimp and fish hatchery industry. In 1997, some 6000 hatcheries required over 15001 of cysts annually. Approximately 80 to 85% of total Artemia cyst sales were destined for shrimp hatcheries; the remaining part mainly went to marine fish larviculture in Europe and East Asia, as well as the pet fish market. Still, the GSL was able to supply that demand by increased harvesting efforts: more companies appeared, more harvesting permits were granted, and very efficient and cost-effective harvesting/processingtechniques were developed (Lavens & Sorgeloos 1998). In the 1990s, the remaining part (10%) of the world's provision of cysts derived from a number of locations with a limited production or harvesting/processing capacity, mainly natural sites in North and Central China and South Siberia and semi-natural or managed sites in the SFB, South Vietnam, Colombia and Northeast Brazil.
This resulted in a vulnerable situation of dependence on virtually one resource. Until then, the GSL produced on average about 40001 per season of raw, wet cyst material. Processing reduces this raw harvest to approximately 12001 of processed, commercial product of good hatching quality. However, since the lake is a large natural ecosystem, climatic and other environmental changes evidently interfere with its productivity, which results in large, often unpredictable, fluctuations in the annual harvests. Indeed, over the last 17 years the GSL harvest has ranged from less than 2000 to almost 9000t of raw product (Fig. 6.1). Environmental changes may furthermore influence the dormancy capacity and thus final hatchability of the cysts produced (Lavens & Sorgeloos 1987).
Instigated by these large fluctuations and the increasing cyst prices, several Artemia resources were revisited and/or explored with respect to their commercial potential. By now, various non-franciscana Artemia species and strains
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Lets start by identifying what exactly certain boats are. Sometimes the terminology can get lost on beginners, so well look at some of the most common boats and what theyre called. These boats are exactly what the name implies. They are meant to be used for fishing. Most fishing boats are powered by outboard motors, and many also have a trolling motor mounted on the bow. Bass boats can be made of aluminium or fibreglass.