Gulf of Salwa IMMA
Size in Square Kilometres
10 676 km2
Qualifying Species and Criteria
Dugong – Dugong dugon
Criterion A; B (2), C (1,2)
Marine Mammal Diversity
Balaenoptera edeni, Delphinus delphis tropicalis, Dugong dugon, Neophocaena phocaenoides, Orcinus orca, Sousa plumbea, Tursiops aduncus
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Summary
The Gulf of Salwa covers the territorial waters of both Bahrain and Qatar. The area is characterised by shallow water habitats with extensive seagrass meadows, and is recognised as a globally important area for the world’s second largest population of Vulnerable dugongs (Dugong dugon) outside of Australian waters. Dugongs have been documented feeding in this unique habitat. The Gulf of Salwa is partially constricted at its northern end by a reef complex that stretches from Bahrain towards Qatar. Depths within the gulf are generally <10m, with tidal ranges varying from 1.2 m to the north of Bahrain to only 0.5 m in the south of the Gulf of Salwa. Indo-Pacific bottlenose dolphins (Tursiops aduncus) and Endangered Indian Ocean humpback dolphins (Sousa plumbea) are also reported from the area, while Vulnerable finless porpoises (Neophocaena phocaenoides) are only rarely sighted.
Description of Qualifying Criteria
Criterion A – Species or Population Vulnerability
The dugong (Dugong dugong) is listed as threatened according to the IUCN Red List (Marsh and Sobtzick, 2015) with a decreasing population trend. The status assessment is based on global review of the population although within this review information from the Arabian Gulf is considered as ‘Data Deficient’. However studies in Bahrain in 2006 (Hodgson, 2009), produced population estimates of Dugongs within these waters equivalent to those encountered 20 years previously by Preen (2004).
Criterion B: Distribution and Abundance
Sub-criterion B2: Aggregations
During Preen’s (1989) summer survey, dugongs were mainly sighted as single individuals. By contrast, during winter months, two large groups in close proximity composed of 577 and 97 dugongs were sighted between Bahrain and Qatar, (Preen, 2004). Very few dugongs were recorded outside of these two groups. The survey results corresponded with information obtained from interviews with fishers who also reported that dugongs tened to aggregate in large herds in winter. Large aggregations of >50 animals have also been reported in 2005 from the same area (Hodgson, 2009), and marine mammal surveys off the west coast of Qatar in the January to March and December of 2015 came across a large aggregations of Dugongs (n=508) (Marshall et al. 2018) equivalent to the large aggregation (n=674) observed by Preen in March of 1986 (Preen, 2004).
Criterion C: Key Life Cycle Activities
Sub-criterion C1: Reproductive Areas
The presence of cow-calf pairs have been reported in both Preen (2004) and Marshall et al. (2018) surveys. Preen (2004) reports calves making up 15.7% (SE 0.5%) of a single large herd of 674 animals taken from a series of 5 close-up photos close to the maritime boundary between Bahrain and Qatar in March 1986. Marshall et al. (2018) documents a count of 508 animals within an area of <1 km2 from vessels surveys assisted using UAV to produce aerial imagery of the herd. Analysis of the imagery revealed that cow-calf pairs comprised 9.9% of the group. Sub-criterion C2: Feeding Areas
Large aggregations of foraging dugongs of up to 508 animals have been reported (Marshall, 2018). Underwater observations confirmed animals feeding in seagrass meadows (comprised of Halodule univernis and Halophila ovalis) during vessel surveys conducted in off northwest Qatar (Marshall et al. 2018). Two seperate herds (n=226 and n=166) of foraging dugongs were also observed during two separate helicopter surveys of northwest Qatari waters in early December 2015. Foraging behaviour was interpreted from surface intervals of animals and plumes of sediment trails. This confirms the food preference reported by Preen (1995, 2004) based on observations of dugongs from Australia.
Supporting Information
Al-Abdulrazzak, D. and Pauly, D., 2017. Reconstructing historical baselines for the Persian/Arabian Gulf Dugong, Dugong dugon (Mammalia: Sirena). Zoology in the Middle East, 63(2), pp.95-102.
Baldwin, R.M., Gallagher, M.D. and Van Waerebeek, K. 1999. A review of cetaceans from waters off the Arabian Peninsula. In: Oman’s Natural History, eds. Fisher, M., Spalton, A. and Gazanfar, S., Backhuys Publishers, Leiden. Pp. 161-189.
Baldwin, R. M. 2003. Whales and Dolphin of Arabia. Mazoon Printing Press, Muscat, Sultanate of Oman. Pp 111
Baldwin R.M. 2005. Marine Life of Arabian Seas. Seawords Publishing, Noordhoek, South Africa. Pp 210
Bell, I. 2001. A preliminary assessment of the turtle and dugong population of Bahrain and Hawar Islands. Manama, Bahrain: Unpublished internal report for the Ministry of Housing.
Braulik, G.T., Ranjbar, S., Owfi, F., Aminrad, T., Dakhteh, S.M.H., Kamrani, E. and Mohsenizadeh, F., 2010. Marine mammal records from Iran. Journal of Cetacean Research and Management, 11(1), pp.49-63.
Braulik, G.T., Findlay, K., Cerchio, S., Baldwin, R. & Perrin, W. 2017. Sousa plumbea. The IUCN Red List of Threatened Species 2017: e.T82031633A82031644. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T82031633A82031644.en. Downloaded on 31 August 2019.
Collins, T., Preen, A., Willson, A., Braulik, G., Baldwin, R.M. 2005. Finless Porpoise (Neophocaena phocaenoides) in the waters of Arabia, Iran and Pakistan. Submitted paper to the International Whaling Commission Scientific Committee 2005. SC/57/SM6.
Cope, R.C., Pollett, P.K., Lanyon, J.M. and Seddon, J.M. 2015. Indirect detection of genetic dispersal (movement and breeding events) through pedigree analysis of dugong populations in southern Queensland, Australia. Biological Conservation 181: 91-101.
Gallagher, M. D. 1991. Collection of skulls of cetacea: Odondoceti from Bahrain, United Arab Emirates and Oman, 1969 – 1990 Pages 89-97 in S. Leatherwood, and G. P. Donovan, editors.
Cetaceans and Cetacean Research in the Indian Ocean Sanctuary: Marine Mammal Technical Report Number 3. UNEP, Nairobi, Kenya.
Hodgson, A. J. 2009. ‘Marine Mammals’. In Marine Atlas of Bahrain. Ed R. Loughland pp233 – 261. GEOMATEC Bahrain Centre for Studies and Research.
Keijl, G.O. and Have, T.M.V.D., 2002. Observations on marine mammals in southern Iran, January 2000. Zoology in the Middle East, 26(1), pp.37-40.
Marsh, H. and Sobtzick, S. 2015. Dugong dugon. The IUCN Red List of Threatened Species 2015: e.T6909A43792211. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T6909A43792211.en. Downloaded on 31 August 2019.
Marshall, C.D., Al Ansi, M., Dupont, J., Warren, C., Al Shaikh, I. and Cullen, J., 2018. Large dugong (Dugong dugon) aggregations persist in coastal Qatar. Marine Mammal Science, 34(4), pp.1154-1163.
Nithyanandan, M., 2010. Opportunistic sightings of Indo-Pacific humpback dolphin, Sousa chinensis from Kuwait waters with notes on their behaviour. J. of the Marine Biological Association of India, 52(1), pp.19-23.
Preen, A., 1995. Impacts of dugong foraging on seagrass habitats: observational and experimental evidence for cultivation grazing. Marine Ecology Progress Series, 124, pp.201-213.
Preen, A. 2004. Distribution, abundance and conservation status of dugongs and dolphins in the southern and western Arabian Gulf. Biological Conservation 118 (2004) 205-218.
Sheppard, C.R., 1993. Physical environment of the Gulf relevant to marine pollution: an overview. Marine Pollution Bulletin, 27, pp.3-8.
Sheppard, J., Preen, A.R., Marsh, H., Lawler, I.R., Whiting, S. and Jones, R.E. 2006. Movement heterogeneity of dugongs, Dugong dugon (Müller) over large spatial scales. Journal of Experimental Marine Biology & Ecology 334: 64–83.
