171 B.M. Riegl and S.J. Purkis (eds.), Coral Reefs of the Gulf: Adaptation to Climatic Extremes, Coral Reefs of the World 3, DOI 10.1007/978-94-007-3008-3_10, © Springer Science+Business Media B.V. 2012 10.1 Introduction Over 70% of the largest cities on earth are associated with seashores (Duarte et al. 2008), and two thirds of the human population lives within 100 km of a coast (UNEP 2002). The Gulf is no exception, with most major urban centers directly adjacent to coasts, with its people both culturally and economically tied to marine resources. Coastal develop- ment has rapidly expanded in the Gulf since the 1950s, lead- ing to an increase in the exploitation of coastal marine resources and the degradation of coastal habitats (Al-Madani et al. 1991; Mohammed and Al-Sadh 1996). Coastal fisher- ies throughout the Gulf are being increasingly exploited, with demersal reef fisheries stocks declining by over four- fifths in the past three decades (see Chap. 8), while dredg- ing, reclamation, and associated coastal development activities have contributed to the permanent loss or long- term degradation of important intertidal, sea-grass, man- grove, and coral reef habitats throughout the Gulf (Price 1993; Al-Jamali et al. 2005; Khan 2007; Burt et al. 2008, 2009b; Maghsoudlou et al. 2008; Sheppard et al. 2010, chapter 16). It is likely that such impacts will accelerate in the coming decades as population continues to grow and become progressively more urbanized along the Gulf’s coastlines (GRWv3 2005). Purpose-built artificial reefs are increasingly being promoted as a means to mitigate impacts to coastal resources and habitats in the Gulf (Erftemeijer et al. 2004). Proponents of artificial reefs in the Gulf suggest that such structures can increase commercial fisheries yield by aggregating tar- get species (Downing et al. 1985; IFRO 2005; Hopkins 2007; Azhdari and Azhdari 2008; EAD 2008), or that arti- ficial reefs can potentially increase demersal reef fisheries yields in areas where reef habitat is limited (Polovina and Sakai 1989; Bohnsack et al. 1997). Indeed, purpose-built artificial reefs to enhance fish catch have been in use for centuries in the Gulf, with these structures (called shad in Arabic, pl. shadood) being inherited through family lines and their use regulated by the Senat Al-Bahar – the ‘code of the sea’ (Al-Oufi et al. 2000; Azhdari 2003; EAD 2008). Unfortunately, such artificial reefs may often attract com- mercial fish species which are already over-exploited, mak- ing them easier to target and further exacerbating stock declines (Grossman et al. 1997). There is evidence that purpose-built artificial reefs in the Gulf may be effective in attracting commercially valuable species. Within a year of deployment in Kuwait, three 25 m 2 artificial reefs constructed of tires held over 50 species of fish from 33 families, with sports fish making up 86% of all fish observed and the commercially important grouper Epinephelus tauvina and the barracuda Sphyraena jello contributing over 50% of the biomass (Downing et al. 1985). These same reefs were also rapidly colonized by epifauna, with serpulid tubeworms, ectoprocts, and oysters dominating the benthos (Downing et al. 1985). Small artifi- cial reefs deployed in the waters of the United Arab Emirates attracted a range of commercially important species, includ- ing grouper (Family Serranidae), snapper (Lutjanidae) and sweetlip (Haemulidae) species (Hopkins 2007; Al-Cibahy et al. 2009). Harris and Schroder (2001) described 17 ship- wrecks, or groups of wrecks, and 1 artificial reef in the waters of the United Arab Emirates. Of these wrecks, at least eight were purposefully sunk to create artificial reefs, Man-Made Structures as Artificial Reefs in the Gulf John A. Burt, Aaron Bartholomew, and David A. Feary 10 J.A. Burt (*) Division of Science and Mathematics, New York University-Abu Dhabi, P.O. Box 129–188, Abu Dhabi, United Arab Emirates e-mail: John.Burt@nyu.edu A. Bartholomew Department of Biology, Chemistry and Environmental Sciences American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates e-mail: abartholomew@aus.edu D.A. Feary School of the Environment, University of Technology, Sydney, Australia e-mail: David.Feary@uts.edu.au