3. Development and characteristics of shrimp farmingSAGARPA/CONAPESCA (2002) report the total area dedicated to shrimp farming is 52,648 ha, of which 51,059 ha (97%) are located around the Gulf of California; Baja California, 190 ha; Baja California Sur, 128 ha; Sonora, 9951 ha; Sinaloa, 37,390 ha; and Nayarit, 3400 ha (Fig. 1).The range size of farms in the Gulf of California region vary from 4 to 1200 ha, with a mean estimated at 150 ha. The pond size also is variable (<2 and 40 ha), 2 – 15 ha being predominant. The more common management system in the region is the semi-intensive type which occurs in 89% of the farms, while intensive and extensive types comprise 2% and 9%, respectively. The mean stock density for intensive shrimp farms is 58 postlarvaem2 (PLm2), for the semi-intensive 13 PLm2, and for extensive 7 PLm2; 39% of the farms stocks blue shrimp (L. stylirostris), 37% stock white shrimp (L. vannamei) and 24% stock both shrimp species (Lyle-Fritch et al., 2001). During 1999, in Sinaloa 74 % of shrimp farms operated two cycles per year, and the rest only one. However, in 2001 and 2002 the tendency has been to reduce the number of cycles per year due to the decreased crops during cold months. The duration of the cycles fluctuates between 120 and 140 days depending on season, marketing demand, and diseases. More details on the management and characteristics of shrimp ponds are summarized in Table 1.
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