Ecological observations on crab communities (Crustacea: Decapoda: Brachyura) on intertidal mudflats in the western Arabian Gulf and the effect of the 1991 oil spill

Michael Apel

A b s t r a c t: Between June 1992 and May 1993 four transects on muddy shores along the Saudi Arabian Gulf coast were monitored for intertidal Brachyura. Two of these sites had been heavily oiled during the 1991 oil spill, while the other two were selected as reference sites. At the oiled sites the brachyuran fauna was drastically reduced in terms of species diversity and abundance. The upper shore was still covered with tar and showed only limited resettlement in much of the affected area, whereas the mid eulittoral showed good signs of recovery and recolonisation by brachyuran decapods. Low abundance of intertidal Brachyura in the lower eulittoral of oiled transects is discussed as a possible long-term or indirect effect of the oil spill. Data on seasonality of reproductive activity and recruitment at the control sires were collected and revealed different reproductive strategies and seasonal patterns for upper and lower shore species. Recruitment at the oiled transects was observed for several species.

APEL, M. 1994. Effects of the 1991 oil spill on the crab fauna of intertidal mudflats in the Western Arabian Gulf. Courier Forschungsinstitut Senckenberg 166: 40-46.
APEL, M. & TORKAY, M. 1992. The intertidal crabs and hermit crabs (Crustacea: Decapoda: Brachyura and Paguridea) in the study area and their condition after the oil spill. In: Establishment of a Marine Habitat and Wildlife Sanctuary for the Gulf Region. Final Report for Phase I: 187-205. Jubail & Frankfurt, CEC/NCWCD.
BASSON, P.W., BURCHARD, J.E., HARDY, J.T. & PRICE, A.R.G. 1977. Biotopes of the western Arabian Gulf 284 pp. Dhahran, ARAMCO.
CEC/NCWCD, 1992. Establishment of a Marine Habitat and Wildlife Sanctuary for the Gulf Region. Interim Report for Phase 11. 96 pp. Jubail & Frankfurt.
CLAYTON, D.A. 1986. Ecology of mudflats with particular reference to those of the northern Arabian Gulf. In: Proceedings of the First Arabian Gulf Conference on Environment and Pollution, Kuwait, 7-9 February 1982. Halwagy, R., Clayton, D. & Behbehani, M. (eds): 83-96. Oxford, Alden Press.
DORJES, J., MICHAELIS, H. & RHODE, B. 1986. Long-term studies of macrozoobenthos in intertidal and shallow subtidal habitats near the island of Norderney (East Frisian coast, Germany). Hydrobiologia 142: 217-232.
HARMS, J. & ANGER, K. 1983. Seasonal, annual, and spatial variation in the development of hard bottom communities. Helgoländer Meeresuntersuchungen 36: 137-150.
HOFFMANN, L. 1994. Distribution, species composition and status of the intertidal blue-green algal mats. Courier Forschungsinsti­tut Senckenberg 166: 16-17.
JONES, D.A. 1985. The biological characteristics of the marine habitats found within the ROPME (Regional Organisation for the Protection of the Marine Environment) Sea Area (30030'N, 47"50'E; 16°39'N, 61°25'E). In: Proceedings of the Symposium on Regional Marine Pollution Monitoring and Research Programmes, AI-Ain: 71-89.
JONES, D.A. & CLAYTON, D.A. 1983. The systematics and ecology of crabs belonging to the genera Cleistostoma de Haan and Paracleistostoma de Man on Kuwait mudflats. Crustaceana 45 (2): 183-199.
JONES, D.A. & RICHMOND, M.D. 1992. Intertidal and subtidal marine habitat surveys. In: Establishment of a Marine Habitat and Wildlife Sanctuary for the Gulf Region. Final Report for Phase 1: 134-160. Jubail & Frankfurt, CEC/NCWCD.
JONES, D.A., WATT, I., WOODHOUSE, T.D. & RICHMOND, M.D. 1994. Intertidal recovery in the Dawhat ad-Dafi and Dawhat al-Musallamiya region (Saudi Arabia) after the Gulf War oil spill. Courier Forschungsinstitut Senckenberg 166: 27-33.
KFUPM/RI 1991. ARAMCO Sustaining Research Project. Environmental Studies, Vol. 1: Overview, Summary and Conclusions. The Research Institute, King Fahd University of Petroleum and Minerals, Dhahran.
MANNING, R.B. 1991. The status of Cleistostoma dotilliforme Alcock 1900 (Crustacea: Decapoda: Ocypodidae), with the description of a new genus. Raffles Bulletin of Zoology 39 (2): 299-306.
ODUM, E.P. 1971. Fundamentals of Ecology. 574 pp. Philadelphia, W.B. Saunders Co.
SNOWDEN, R.J., CLAYTON, D.A. & AL-TAHER, Y. 1991. Population biology of Ilyoplax stevensi (Brachyura: Ocypodidae) on a Kuwait mudflat. Marine Ecology Progress Series 71: 219-225.
SNOWDEN, R.J., CLAYTON, D.A. & AL-TAHER, E.Y. 1994. Aspects of the ecology of Tylodiplax indica Alcock (Brachyura: Ocypodidae) on a Kuwait mudflat. Journal of the University of Kuwait (Science) 21: 219-228.
VOUSDEN, D.H. 1987. The Bahrain Marine Habitat Survey. Vol. 1. The Technical Report. 103 pp. ROPME.