Andrew R. G. Price

The Gulf: A young sea in decline

This review examines the substantial changes that have taken place in marine habitats and resources of the Gulf over the past decade. The habitats are especially interesting because of the naturally high levels of temperature and salinity stress they experience, which is important in a changing world climate. However, the extent of all natural habitats is changing and their condition deteriorating because of the rapid development of the region and, in some cases from severe, episodic warming episodes. Major impacts come from numerous industrial, infrastructure-based, and residential and tourism development activities, which together combine, synergistically in some cases, to cause the observed deterioration in most benthic habitats. Substantial sea bottom dredging for material and its deposition in shallow water to extend land or to form a basis for huge developments, directly removes large areas of shallow, productive habitat, though in some cases the most important effect is the accompanying sedimentation or changes to water flows and conditions. The large scale of the activities compared to the relatively shallow and small size of the water body is a particularly important issue. Important from the perspective of controlling damaging effects is the limited cross-border collaboration and even intra-country collaboration among government agencies and large projects. Along with the accumulative nature of impacts that occur, even where each project receives environmental assessment or attention, each is treated more or less alone, rarely in combination. However, their combination in such a small, biologically interacting sea exacerbates the overall deterioration. Very few similar areas exist which face such a high concentration of disturbance, and the prognosis for the Gulf continuing to provide abundant natural resources is poor.

Discrete bands of petroleum hydrocarbons and molecular organic markers identified within massive coral skeletons

The tissues of corals deposit an aragonite exoskeleton beneath their outer living film at a rate dependent on growth and hence on environmental conditions. This typically results in annual (seasonal) bands being formed within colonies. By analysing molecular organic markers within these bands, our research suggests that coral skeletons record contamination from oil and potentially could be used to investigate other anthropogenic and biogenic organic inputs. Our analyses of sections from within corals (Porites lutea) sampled from the Gulf coasts of Kuwait and Saudi Arabia demonstrate discrete bands of oil contamination which, using selected terpenoid biomarkers, can be source-indexed to specific oil fields (i.e. Kuwait, Iranian or Arabian crude oils). Together with dating using microscopic and X-ray inspection, this offers the potential to investigate contamination during recent years. Further research is, however, necessary to elucidate degradation mechanisms during, and following, the occlusion process of organics within coral skeletons.

An integrated environmental assessment of the Red Sea coast of Saudi Arabia

Summary The Red Sea is a large marine ecosystem in which biological research has been considerable but integrated environmental assessment insubstantial. Approximately 1400 coastal and offshore (i.e. island) sites in the Saudi Arabian Red Sea were examined and an analysis of ordinal data on the abundance of ecosystems and magnitude of human uses/environmental impacts was conducted. Mangroves, seagrasses, other floral groups and terrestrial mammals were significantly more abundant at the coastal sites than offshore. The coastal sites were also impacted most heavily,while reefs, birds, turtles and marine mammals were significantly more abundant in offshore areas. Latitudinal trends include significantly increased abundance of mangroves and seagrasses (and other flora) towards the southern Red Sea, and a decrease in abundance of reefs. Significantly higher levels of beach oil were encountered towards the northern Red Sea, probably reflecting its greater proximity to the Gulf of Suez. Cluster analysis using all biological data revealed distinctive groupings which separated according to latitude. The biogeographic patterns are comparable to those observed in previous studies for seagrasses and other communities. Using a relational database, applications of the findings to coastal management include creation of environmental profiles for particular sites or sectors, identification of resource-use conflict areas, and selection of representative sites for protected areas. Comparison with data from a complementary investigation in the Arabian Gulf indicates that the Red Sea is less perturbed by human activities than the Arabian Gulf. However, it is also evident that the Red Sea is no longer a pristine environment.

Aspects of seagrass ecology along the western Arabian Gulf coast

Results of semi-quantitative observations and quantitative sampling of seagrasses at coastal and offshore sites along the western Arabian Gulf are presented. Overall seagrass cover (all species together) shows significant positive correlation with latitude, but not with salinity, temperature or depth. The same pattern is shown by Halodule uninervis (Forsk.) Aschers., the dominant species. Mean seagrass biomass ranged from 53–235 g m-2 (dry weight). These values are comparable with biomass estimates from regions in which environmental conditions are generally less extreme than in the Gulf. Seagrass biomass is significantly negatively correlated with depth and sediment grain size. No significant correlation is apparent between seagrass biomass and factors such as season, salinity, or concentrations of nutrients and heavy metals measured. It is pointed out that any correlations observed are not necessarily taken to imply causality.

TOXICITY AND PERSISTENCE OF NEARSHORE SEDIMENT CONTAMINATION FOLLOWING THE 1991 GULF WAR

Abstract In January 1991, the worlds largest oil spill inundated extensive coastal areas of the Gulf with massive quantities of crude oil. In August 1993, the authors collected sediment samples from eleven beach sites at four tidal elevations in Kuwait and Saudi Arabia. Ten-day static sediment toxicity tests with the marine amphipod Rhepoxynius abronius revealed significant sediment toxicity (reduced survival) at five sites. Infrared spectrometry indicated that the highest concentrations of petroleum hydrocarbons occurred at these same five sites. Other variables such as ammonia concentration, silt and clay content, and total organic matter in the sediment had no affect on amphipod survival. Concentrations of petroleum hydrocarbons greater than about 1 mg g −1 dry sediment caused significant amphipod mortality. Such toxic sediment concentrations occurred at Al Khiran, Kuwait, and along an extensive coastal area of Saudi Arabia from Ras Tanajib to Abu Ali (a distance of over 100 km). The overall area of sediment toxicity corresponds closely to the spill trajectory and presence of sea surface petroleum as recorded on airborne radar soon after the spill (9 March 1991). These results indicate that sediment toxicity from the worlds largest oil spill persisted for at least 30 months. Additionally, petroleum hydrocarbon concentrations in the sediments of contaminated sites were sufficiently high to cause continued leaching of oil to the sea-surface.

Environmental Concerns for the Future of Gulf Coral Reefs

The Gulf is located in a subtropical, hyper-arid region. It is shallow, and bordered by several wealthy states (Fig. 16.1) undergoing rapid economic growth involving substantial construction along shores and offshore regions, underpinned by its oil and gas industry, and by wealth derived from financial centres. Thriving economic activity has, over the past few decades, begun to exert significant pressure on the Gulf’s marine environment. It is changing rapidly, by developments which include construction, substantial coastline alterations, habitat loss, creation of beds of shifting or suspended sediments, and temperature and salinity changes in restricted water flows along the coast, as well as by climate warming. The Gulf suffers from a “shifting baseline syndrome” (Pauly 1995; Sheppard 1995) and it is difficult to find any meaningful baselines, not only because of ongoing, intensive constructions that cause large-scale alterations of the environment, but also because of several recent episodes of marine mortality from seawater warming.

The Marine Food Chain in Relation to Biodiversity

Biodiversity provides “raw materials” for the food chain and seafood production, and also influences the capacity of ecosystems to perform these and other services. Harvested marine seafood species now exceed 100 million t y -1 and provide about 6% of all protein and 17% of animal protein consumed by humans. These resources include representatives from about nine biologically diverse groups of plants and animals. Fish account for most of the world’s marine catches, of which only 40 species are taken in abundance. Highest primary productivity and the richest fisheries are found within Exclusive Economic Zones (EEZ). This narrow strip (200 nautical mile/370 km wide) is not only the site of coastal “food factories” but also the area associated with heaviest perturbation to the marine environment. Structural redundancy is evident in marine ecosystems, in that many species are interchangeable in the way they characterise assemblage composition. While there is probably functional redundancy within groups, the effects of species loss on ecosystem performance cannot be easily predicted. In particular, the degree to which biodiversity per se is needed for ecosystem services, including seafood/fishery production, is poorly understood. Many human activities, including unsustainable fishing and mariculture, lead to erosion of marine biodiversity. This can undermine the biophysical cornerstones of fisheries and have other undesirable environmental side effects. Of direct concern are “species effects”, in particular the removal of target and non-target fishery species, as well as conservationally important fauna. Equally disrupting but less immediate are “ecosystem effects”, such as fishing down the food web, following a shift from harvested species of high to low trophic level. Physical and biological disturbances from trawl nets and dynamite fishing on coral reefs can also severely impact ecosystem structure and function. “Broadscale” biological and social effects brought about by fishing carry even more far-reaching consequences. For example, fishing itself can change the age at which sexual maturity is reached, thus affecting the reproductive status of the stock. Hence, fishing may be regarded as a mediator of evolution. Social impacts include conflicts over fish prices and policies arising from heavy fishing and inadequate institutional structures. Measures to increase the sustainability of catches and of biodiversity need to be much more tightly coupled. Promising approaches include use of bio-economic indicators and fully protected marine areas. High- and local-level governance options are also examined. Use of expert systems incorporating “fuzzy logic” are providing useful environmental insights in the ASEAN countries and other parts of the world, and have applications in fishery management and biodiversity conservation.

Is the Arabian Gulf really such a lowspot of biodiversity?: Scaling effects and management implications

Analysis of echinoderm datasets for the Arabian Gulf and Red Sea region reveals lower species richness in the Gulf at 4 different spatial scales: Point, Sample, Large area and Biogeographical province. Species richness correlates positively with spatial scale in both regions, as does endemism, although levels of the latter are comparable for both regions. Values of taxonomic distinctness (Δ*), a relatedness measure based on average properties, are very similar for the Gulf and the Red Sea over all spatial scales. This might seem surprising, given that (i) the Gulfs environment is highly stressful, and (ii) the Red Sea is one the worlds top 10 coral reef high diversity areas, and the habitat associated with most echinoderm records for this region, but not for the Gulf. These findings may partly reflect the behaviour of Δ* to ‘saturate’ (reach maximal values as sampling/spatial scale increases) much sooner than species richness, endemism and other ‘species’ measures. Our results suggest the Gulf may not be the lowspot of biodiversity generally acclaimed, especially if a broad set of measures is utilised. Biodiversity is an important constituent of ecosystem health and criterion for determining where conservation attention should be targeted. Until the functional/ecological significance of Δ* is better understood, management implications of our studys findings remain unclear. Further attention should also be given to β-diversity, the change in species composition along a gradient. We also stress that any conclusions drawn from the study are tentative, pending compilation and analysis of datasets for other groups.

Shifting environmental baselines in the Red Sea

The Red Sea is among the worlds top marine biodiversity hotspots. We re-examined coastal ecosystems at sites surveyed during the 1980s using the same methodology. Coral cover increased significantly towards the north, mirroring the reverse pattern for mangroves and other sedimentary ecosystems. Latitudinal patterns are broadly consistent across both surveys and with results from independent studies. Coral cover showed greatest change, declining significantly from a median score of 4 (1000-9999 m(2)) to 2 (10-99m(2)) per quadrat in 2010/11. This may partly reflect impact from coastal construction, which was evident at 40% of sites and has significantly increased in magnitude over 30 years. Beach oil has significantly declined, but shore debris has increased significantly. Although substantial, levels are lower than at some remote ocean atolls. While earlier reports have suggested that the Red Sea is generally healthy, shifting environmental baselines are evident from the current study.

Observations on surface pollution in the Indian Ocean and South China Sea during the Sindbad Voyage (1980–1981)

Abstract Analysis of 159 visual observations on tar balls, oil slicks and other surface pollutants in the Indian Ocean and South China Sea form the basis of this study. Observations were made between November 1980 and June 1981 aboard a replica of an ancient Arab sailing vessel, Sohar, during the ‘Sindbad Voyage’. The vessel, being both small and slow-moving, provided an almost ideal platform from which to make visual observations on surface pollution. Tar balls were encountered in more than 20% of the observations, and show a progressive increase in occurrence from Malaysia/Indonesia ( 60%). In contrast, oil slicks and other forms of surface pollution were encountered less frequently. The results are discussed in the light of observations made during the Marine Pollution [Petroleum] Monitoring Pilot Project (MAPMOPP).