OJMS  Vol.1 No.3 , October 2011
An Evaluation of the Management Effectiveness of a Stock Re-Building Strategy for a Multi-Species Demersal Trap Fishery in Abu Dhabi, United Arab Emirates
ABSTRACT
The off-shore demersal trap fishery in the southern Arabian Gulf has been managed by gear regulations and effort constraints which were aimed at rebuilding depleted stocks. In order to evaluate the success of these regulations, a variety of selectivity and other fishery metrics were compared for the key species (Diagramma pictum, Epinephelus coioides and Lethrinus nebulosus) before and after their introduction. With the exception of a minor increase in the mean age at first capture from 1.3 yrs to 1.9 yrs for E. coioides, there were no significant changes in the values or trends in juvenile retention, mean size or the mean sizes and ages at first capture. The comparison of selectivity ogives with data derived independently through an experimental fishing program indicated that the failure of juvenile escape panels to modify the selectivity characteristics of the fishery could not be attributed to a lack of compliance. Furthermore, there were no significant changes in fishing mortality rates, harvest rates, catch, effort, yield per recruit and relative spawner biomass per recruit following the introduction of the management regulations. Age structures were highly truncated and the management measures had failed to increase the relative proportion of older age classes. Stock status indicators suggested that all species were heavily over-exploited with evidence of both growth and recruitment over-fishing. Given the failure of existing regulations to modify gear selectivity, reduce effort and rebuild stocks, the results of the study suggest that management authorities should consider alternative measures including a moratorium on the use of traps in the off-shore demersal fishery of Abu Dhabi.

Cite this paper
E. Grandcourt, T. Al Abdessalaam, S. Hartmann, F. Francis and A. Al Shamsi, "An Evaluation of the Management Effectiveness of a Stock Re-Building Strategy for a Multi-Species Demersal Trap Fishery in Abu Dhabi, United Arab Emirates," Open Journal of Marine Science, Vol. 1 No. 3, 2011, pp. 82-97. doi: 10.4236/ojms.2011.13009.
References
[1]   E. M. Grandcourt, “Fish and Fisheries,” In: T. Z. Al Abdessa-laam, Ed., Marine Environment and Resources of Abu Dhabi, Motivate Publishing, Dubai, 2008, pp. 200- 225.

[2]   B. Shal-lard, “Distribution and Abundance of Demersal Fish Stocks in the UAE. Technical Report 1. Fish Resources Assessment Survey Project of Abu Dhabi and UAE Waters,” Environmental Research and Wildlife Development Agency, Government of Abu Dhabi, Abu Dhabi, 2003, p. 211.

[3]   E. M. Grandcourt, T. Z. Al Abdessalaam, A. T. Al Shamsi and F. Francis, “Biology and Assessment of the Painted Sweetlips (Diagramma pictum (Thunberg, 1792)) and Spangled Emperor (Lethrinus nebulosus (Forssk?l, 1775)) in the Southern Arabian Gulf,” Fisheries Bulletin, Vol. 104, No. 1, 2006, pp. 75-88.

[4]   E. M. Grand-court, T. Z. Al Abdessalaam, F. Francis and A. Al Shamsi, “Population Biology and Assessment of the White-Spotted Spinefoot, Siganus Canaliculatus (Park, 1797), in the southern Arabian Gulf,” Journal of Applied Ichthyology, Vol. 23, No. 1, 2007, pp. 53-59. doi:10.1111/j.1439-0426.2006.00796.x

[5]   E. M. Grandcourt, T. Z. Al Abdessalaam, F. Francis and A. Al Shamsi, “Biology and Stock Assessment of the Sparids, Acanthopagrus Bifasciatus and Argyrops Spini- fer (Forssk?l, 1775), in the Southern Arabian Gulf,” Fisheries Research, Vol. 69, No. 1, 2004, pp. 7-20. doi:10.1016/j.fishres.2004.04.006

[6]   H. Al Masroori, H. Al Oufi, J. McIlwain and E. McLean, “Catches of Lost Fish Traps (ghost fishing) from Fishing Grounds near Muscat, Sultanate of Oman,” Fisheries Research, Vol. 69, No. 3, 2004, pp. 407-414. doi:10.1016/j.fishres.2004.05.014

[7]   E. M. Grandcourt, T. Z. Al Abdessalaam, A. T. Al Shamsi and F. Francis, “Population Biology and Assessment of the Orange-Spotted Grouper, Epinephelus coioides (Ha- milton, 1822), in the Southern Arabian Gulf,” Fisheries Research, Vol. 74, No. 1, 2005, pp. 55-68. doi:10.1016/j.fishres.2005.04.009

[8]   R. J. Beamish and D. A. Fournier, “A Method for Comparing the Precision of a Set of Age Determinations,” Canadian Journal of Fisheries and Aquatic Sciences, Vol. 38, No. 8, 1981, pp. 982-983. doi:10.1139/f81-132

[9]   W. E. Ricker, “Computation and Interpretation of Biological Statistics of Fish Populations,” Bulletin of the Fisheries Research Board of Canada, Vol. 191, 1975, pp. 2-6.

[10]   R. J. H. Beverton and S. J. Holt, “On the Dynamics of Exploited Fish Populations,” Chapman and Hall, London, 1957, p. 179.

[11]   F. C. Gayanilo Jr. and D. Pauly, “FAO-ICLARM Stock Assessment Tools, Reference Manual, ICLARM,” Food and Agricultural Organization of the United Nations, Rome, 1997.

[12]   D. Pauly, “Length-Converted Catch Curves: A Powerful Tool for Fisheries Research in the Tropics (Part 1),” Fishbyte, Vol. 1, No. 2, 1983, pp. 9-13.

[13]   R. J. H. Beverton, “Patterns of Reproductive Strategy Parameters in Some Marine Teleost Fish,” Journal of Fish Biology, Vol. 41, No. B, 1992, pp. 137-160.

[14]   E. M. Grandcourt, T. Z. Al Abdessalaam, F. Francis, A. T. Al Shamsi and S. A. Hartmann, “Reproductive Biology and Implications for Management of the Orange-Spotted Grouper, Epinephelus coioides (Hamilton, 1822), in the southern Arabian Gulf,” Journal of Fish Biology, Vol. 74, 2009, pp. 820-841. doi:10.1111/j.1095-8649.2008.02163.x

[15]   K. Patterson, “Fisheries for Small Pelagic Species: An Empirical Approach to Management Targets,” Reviews in Fish Biology and Fisheries, Vol. 2, No. 4, 1992, pp. 321-338. doi:10.1007/BF00043521

[16]   R. R. Sokal and F. J. Rohlf, “Biometry,” The Principles and Practice of Statistics in Bio-logical Research, 3rd Edition, W. H. Freeman and Co, New York, 1995.

[17]   C. D. Buxton, “The Application of Yield-per-Recruit Models to Two South African Sparid Reef Species, with Special Consideration to Sex Change,” Fisheries Research, Vol. 15, No. 1-2, 1992, pp. 1-16. doi:10.1016/0165-7836(92)90002-B

[18]   S. E. Campana, “Accuracy, Precision and Quality Control in Age Determina-tion, Including a Review of the Use and Abuse of Age Valida-tion Methods,” Journal of Fish Biology, Vol. 59, No. 2, 2001, pp. 197-242. doi:10.1111/j.1095-8649.2001.tb00127.x

[19]   G. Loubens, “Biologie de Quelques Espèces de Poissons du Lagon Néo-Calédonien. III. Croissance,” Cahiers Indo- Pacific, Vol. 2, No. 2, 1980, pp. 101-153.

[20]   C. P. Mathews and M. Samuel, “Growth, Mortality and Length-Weight Parameters for Some Kuwaiti Fish and Shrimp,” Fishbyte, Vol. 9, No. 2, 1991, pp. 30-33.

[21]   R. R. C. Edwards and S. Shaher, “The Biometrics of Marine Fishes from the Gulf of Aden,” Fishbyte, Vol. 9, No. 2, 1991, pp. 27-29.

[22]   P. M. Mace, “Relationships between Common Biological Reference Points Used as Thresholds and Targets of Fisheries Management Strategies,” Canadian Journal of Fisheries and Aquatic Sciences, Vol. 51, No. 1, 1994, pp. 110-122. doi:10.1139/f94-013

[23]   R. Mahon and W. Hunte, “Trap Mesh Selectivity and the Management of Reef Fishes,” Fish and Fisheries, Vol. 2, No. 4, 2001, pp. 356-375. doi:10.1046/j.1467-2960.2001.00054.x

[24]   J. Stewart and D. J. Ferrell, “Mesh Selectivity in the NSW Demersal Trap Fishery,” Fisheries Research, Vol. 59, No. 3, 2003, pp. 379-392. doi:10.1016/S0165-7836(02)00024-3

 
 
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