The Dubai Palms: Can Large-Scale Coastal Development Provide Shelter for Overfished Species?

The coastline of Dubai (United Arab Emirates) has been substantially transformed during the last decade through the development of large, offshore artificial islands.  This development has resulted in an expansion of the coastline from 50 km to 1600 km  by the addition of rocky breakwater structures that have substantially altered the topological structure of the surrounding coastal habitats. Such change in the availability of suitable habitat may be important in structuring the abundance and diversity of the commercially important and heavily overfished Orange Spot grouper, locally known as hamour.  We hypothesized that the increase in rocky habitat within Dubai waters, due to breakwaters, has led to changes in both the biomass and size structure of hamour communities through either (1) increased production within the breakwater habitat (resulting in high abundances of new recruits) or (2) immigration of individuals (resulting in higher abundances of adults in breakwaters).  Using underwater visual surveys we compared the abundance and size class structure of hamour populations within 4 natural reefs and 3 artificial breakwaters (Palm Jumeirah, Palm Jebel Ali and The World breakwaters).  Our results found no significant difference in the average biomass of E. coioides between natural reefs and breakwaters (F_1,8 = 1 .57, p = 0.47).  Suggesting no clear pattern of hamour choosing natural reefs over breakwaters.  Similarly, there was no significant difference in size class distribution (F_2,38 = 1 .92, p = 0.15) between natural reefs and breakwaters.  However, larger individuals (>60 cm TL) where found predominantly on natural reefs, and smaller individuals (<10 cm TL) where found exclusively on natural reefs.  The results of this work suggest that while the breakwater habitat may provide shelter for mid sized individuals, natural reefs form an important habitat for both larger and smaller sized individuals, and may be an essential nursery habitat for hamour.  As Dubai’s natural coral reef habitat is rapidly becoming degraded with increasing coastal development, the results of this work argue for an increase in the protection of these vital marine habitats.