Changes in the queen conch (Strombus gigas L.) population structure at Banco Chinchorro, Quintana Roo, Mexico, 1990-1997
Changes in the queen conch population structure from 1990-1997 were analyzed. Density and length-frequency data were collected in four fishing sites within Banco Chinchorro, using four random sample units of 100 m2. All conchs contained in the sample unit were measured for shell length and returned to the bottom. Von Bertalanffy's growth parameters, natural mortality, and total mortality were calculated. There was a significant decrease in conch density over the years. The highest density (2.651 conchs m-2) occurred in 1992 at Cayo Norte and lowest occurred in 1994 (0.108 conchs m-2) and 1997 (0.006 conchs m-2) at Isla Che. There were significant differences in mean shell length (SL) between years. In 1994 mean SL was 229.30±2.07 mm; in 1997 mean SL was only 128.30 ± 3.23 mm and 99.31% of conchs were lesser than 200 mm SL. No significant differences in the L∞ were detected from 1990-1997, but K had higher values in 1997 (K = 0.45) indicating presence of a juvenile population, with a higher natural mortality (M = 1.06). Conch stock at Banco Chinchorro is overexploited and if the levels of harvesting continue the fishery is predicted to collapse in a short period. A total ban of five years is proposed and more conservative management measures are recommended in order to maintain a sustainable conch fishery.
| Main Authors: | , , |
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| Format: | Texto biblioteca |
| Language: | eng |
| Subjects: | Strombus gigas, Caracoles marinos, Población animal, Artfrosur, |
| Online Access: | http://www.ingentaconnect.com/content/umrsmas/bullmar/2003/00000073/00000001/art00020?crawler=true |
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