Saudi Journal of Biological Sciences (2012) 19, 311–315
King Saud University Saudi Journal of Biological Sciences
www.ksu.edu.sa www.sciencedirect.com
ORIGINAL ARTICLE Integrating spatial data and shorebird nesting locations to predict the potential future impact of global warming on coastal habitats: A case study on Farasan Islands, Saudi Arabia
Monif AlRashidi a,*, Mohammed Shobrak b, Mohammed S. Al-Eissa a, Tama´s Sze´kely c a Department of Biology, College of Science, University of Hail, P.O. Box 2440, Hail, Saudi Arabia b Department of Biology, College of Science, Taif University, P.O. Box 888, Taif, Saudi Arabia c Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK
Received 22 September 2011; revised 29 December 2011; accepted 29 February 2012 Available online 7 March 2012
KEYWORDS Abstract One of the expected effects of the global warming is changing coastal habitats by accel- Remote sensing; erating the rate of sea level rise. Coastal habitats support large number of marine and wetland spe- Climate change; cies including shorebirds (plovers, sandpipers and allies). In this study, we investigate how coastal Sea level rise; habitats may be impacted by sea level rise in the Farasan Islands, Kingdom of Saudi Arabia. We use Intertidal habitats; Kentish plover Charadrius alexandrinus – a common coastal breeding shorebird – as an ecological Kentish plover; model species to predict the influence of sea level rise. We found that any rise of sea level is likely to Charadrius alexandrinus; inundate 11% of Kentish plover nests. In addition, 5% of the coastal areas of Farasan Islands, Red Sea which support 26% of Kentish plover nests, will be flooded, if sea level rises by one metre. Our results are constrained by the availability of data on both elevation and bird populations. There- fore, we recommend follow-up studies to model the impacts of sea level rise using different elevation
* Corresponding author. Present Address: Harvard University, Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, 26 Oxford Street, Cambridge, MA 02138, United States. Tel.: +966 5047111300. E-mail address: [email protected] (M. AlRashidi).
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Peer review under responsibility of King Saud University. http://dx.doi.org/10.1016/j.sjbs.2012.02.001
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scenarios, and the establishment of a monitoring programme for breeding shorebirds and seabirds in Farasan Islands to assess the impact of climate change on their populations. ª 2012 King Saud University. Production and hosting by Elsevier B.V. All rights reserved.
1. Introduction 2.2. Topographic analysis
During the 21st century, climate change will be one of the ma- A digital elevation model (DEM) data acquired from the Shut- jor impacts of humans in natural ecosystems (Dawson et al., tle Radar Topography Mission (SRTM) onboard the Space 2011). Although the magnitude, spatial distribution and im- Shuttle Endeavour (launched in December 2000) were down- pacts of climate change are still being quantified, climatologists loaded from the Global Landcover Facility (http://www.land- agree that one of the major impacts will be sea level rise due to cover.org), and were used to investigate the topographic the melting of currently frozen water mainly in the Antarctic variations of the study area. This seamless DEM image has and the Arctic regions (Meehl et al., 2005). Sea level rise due 90 m spatial resolution and 1 m vertical resolution, and uses to climate changes predicted to be between 0.18 m and 1.2 m a Universal Transverse Mercator (UTM) projection (Zone by 2100 (IPCC, 2007; Rahmstorf et al., 2007). This will poten- 38). Arc-Map Software was used to classify elevation of the tially pose a major threat to coastal areas, disrupt coastal eco- studied islands on the bases of 1 m elevation interval. The systems, and induce changes in breeding and feeding areas of number of pixels representing the elevation of 0–1 m height shoreline dependent organisms including shorebirds that feed was counted to assess potential areas of inundation by a rising and breed on coastal and intertidal habitats (Hughes, 2004; sea level, assuming 1 m increase in mean high tide values. Baker et al., 2006; Finlayson et al., 2006; Fujii and Raffaelli, 2008; Nicholls et al., 2009; Chu-Agor et al., 2011). 3. Results and discussion Here we investigate an aspect of the potential future impact of sea level rise on coastal-breeding shorebirds using Kentish Twenty three out of 207 Kentish plover were located at/or be- plover Charadrius alexandrinus as an ecological model species low sea level; therefore any rise of sea level is predicted to inun- (AlRashidi et al., 2011a). Shorebirds (sandpipers, plovers, gulls date 11% of these nests (Table 1). In addition, Farasan Islands and allies; about 350 species) are an excellent group to investi- are estimated around 700* km2 and the total coastal area that gate the coastal impacts of climate change (Piersma and Lind- located below 1 m and is subjected to the possibility of inunda- stro¨ m, 2004). They are distributed globally (Monroe and tion if the sea level rise by one metre is 35 km2, which is Sibley, 1993; del Hoyo et al., 1996), and they indicate global approximately 5% of the islands’ area (Fig. 1). The 35 km2 environmental changes such as ecosystem health and climate area holds 26% of Kentish plover nests, i.e. 54 out of 207 nests change (Piersma and Lindstro¨ m, 2004; Thomas et al., 2006). (Fig. 2). In addition, they exhibit exceptional diversity in their life his- Sea level rise due to thermal expansion and the melting of tory and behaviour including breeding systems, foraging land based ice is likely to have a major impact on island coastal behaviour and migratory habits (Sze´ kely et al., 2006; Thomas and intertidal habitats, leading to increase their loss and ero- et al., 2006; Garcı´ a-Pen˜a et al., 2009). sion, with the heaviest impact predicted for salt marshes and Here we focus on the Farasan Islands, an archipelago in the sandy beaches (Bo¨ hning-Gaese and Lemoine, 2004; Hughes, Red Sea about 50 km from the city of Jizan, Kingdom of Saudi 2004; Baker et al., 2006; BirdLife International, 2008). Our re- Arabia. It was established as a protected area in 1996 by the sults reflect concerns raised by the study of Austin and Re- Saudi Wildlife Authority (SWA). It is one of the most impor- hfisch (2003) that suggests sea level rise will affect both the tant breeding sites for seabirds and shorebirds in the Red Sea extent and quality of coastal habitats in the UK. Galbraith including the endemic White-eyed gulls Larus leucophthalmus et al. (2002) modelled the potential impacts of sea level rise and Crab plover Dromas ardeola (PERSGA/GEF, 2003). and climate change on shorebird tidal foraging habitat at five These islands comprise a variety of habitat types including important migration sites in the US, and reported major inter- mangrove, wet and dry salt marshes, sand dunes, sand plains tidal habitat losses at four of the sites. In addition, Durell et al. and rocky habitats (El-Demerdash, 1996). (2006) found that a reduction of just 10 cm of intertidal habi- tats in Poole Harbour, UK removed sufficient area in the har- 2. Methods bour to reduce survival rates in all shorebird species. A
2.1. Fieldwork and breeding data collection
Fieldwork was carried out in 3 years (between 8th and 19th of Table 1 Number of Kentish plover nests and their percentage July in 2007, between 17th of April and 4th of July in 2008, in relation to elevation data. and between the 15th of May and 4th of July in 2009) in the Elevation Nest numbers (%) Farasan Islands. The Kentish plover is a common shorebird on the Farasan Islands, nesting on salt marshes and sand More than 1 m 153 (73.91) dunes up to 1 km away from the shore. We used a four- More than zero and less than or equal to 1 m 31 (14.97) wheel-drive car to search for nests, and once a nest was found, Zero or less 23 (11.11) its location was recorded using a hand held GPS unit, Garmin Total 207 nests e-Trex (see details in AlRashidi et al., 2011a,b). Integrating spatial data and shorebird nesting locations 313
Figure 1 Map showing the coastal areas with elevation less than 1 m (red colour areas), and all nests of Kentish plover included in the study (n = 207 nests, black dots).
Figure 2 Map showing the coastal areas with elevation less than 1 m (red colour areas), and Kentish plover nesting locations which will be flooded if the sea level rise by one metre (black dots).
reduction of 40 cm meant that no birds survived during the temperatures of the Red Sea over the last 10 years have been winter. on average 1.46 C higher than the historical mean of temper- Our results are in line with the recent study on closely re- atures from 1950 to 1997, and the increased sea temperature lated species, Aiello-Lammens et al. (2011) assessed the effect has lead to reduced coral growth. of sea level rise on the viability of the Snowy plover population The major objective of our study is to undertake some pre- along the Gulf Coast in Florida, US. Their results indicated liminary work to highlight two important issues. First, there are that sea level rise will cause a decline in suitable habitat and coastal areas in the Farasan Islands where sea level rise could carrying capacity for Snowy plover leading to an increase in result in the loss of ecologically important habitats. Second, the risk of its extinction and decline. our work highlights a considerable need for ongoing research Global warming is already taking place, and a recent work and monitoring shorebirds and other animals at the study site, by Cantin et al. (2010) found strong evidence in Red Sea re- and indeed in the whole Red Sea region. Future works should gion. Cantin et al. (2010) found that the summer sea surface expand the scope of our study at least in three respects. 314 M. AlRashidi et al.
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