Assessment of seagrass communities in the northern Gulf of Aqaba: Mapping their distribution

Within the Gulf of Aqaba, coral reefs have been considered the dominating ecosystem, attracting not only scientific attention, but also restoration efforts, aquarium exhibits and outreach educational programs. Seagrasses, which are known worldwide as a highly important ecosystem, have not received much attention by the public, scientists or authorities involved in conservation and management in this region. This is surprising considering the value of ecosystem services associated with seagarsses and the fact that many of these services are important to adjacent coral reefs. The absence of comprehensive seagrass maps for this region, prohibits other downstream activities such as evaluations of the associated ecosystem services and implementation of potential conservation and management tools. Here we present efforts to map seagrass meadows along the Israeli coast of the northern Gulf of Aqaba. Mapping was done by snorkeling with a GPS and a handheld echo-sounder. Transects perpendicular to the shore were conducted with measurements taken every 10-20 m that included water depth, GPS position and percent of seagrass cover estimated visually up to 13-23 m depending on visibility. In addition to these transects, we also tracked the shallow boundary of the meadows parallel to shore, usually at 3-5 m depth. Both data sets were then fed into Arc-GIS to create an interpolated GIS layer. Out of 11 km available shoreline, we swam along 9.7 km and collected a total of 2830 data points. Seagrasses were found growing along 7.5 km of these shores, with seagrass meadows covering 707,000 sqm².estimated to be worth = US$ 2,000,000 year^-1 in associated ecosystem services. In addition to mapping the seagrass meadows themselvs, we also mapped the potential dangers to seagrasses in the region. Disturbances were ranked as low, medium or high according to severity and frequency. We expect that these maps (GIS layers) will allow us to not only understand the current distribution of seagrasses in the area, but also to develop a GIS-based tool that will improve our understanding of how changes in the Gulf could affect the cover and state of seagrasses, and thus improve conservation efforts in the region.