Occurrence and source of PAHs in Miankaleh International Wetland in Iran.

We examined the occurrence and sources of 16 priority PAHs in the water and sediment samples of the Miankaleh Wetland (Coastal Biosphere Reserve), famous for harbouring huge flocks of migrating birds. The water and sediment samples collected from various locations were visualized and processed using a self-organizing map, positive matrix factorization and GIS. All the sediment samples, and >90% of the water samples, showed some degree of PAHs contamination. Higher PAH levels occur near the Chopoghi Channel, powerplants, sewage outfalls, and near fishing operations. Compared with previous study in this area, the PAHs concentration in the sediments of aquatic ecosystem of Miankaleh Wetland is increasing. The levels of PAH contamination seem too low to account for the mass deaths of migratory birds, and botulinus contamination seems the likely cause. Fugacity calculations show that the sediments act as a sink for PAHs. According to PMF and SOM analyses, three origins of PAHs were recognized: (i) fossil fuel and vehicular emissions with high-molecular weight PAHs (4-5 ring); (ii) municipal and industrial sewages characterized by low-molecular weight PAHs (2-3 ring) typical of petrogenic sources; and (iii) port activity characterized by prevalence of petrogenic influence and petroleum-related activities (combustion PAHs and low-molecular weight PAHs) consistent with port activity. This wetland needs serious attention because of continuous input of pollutants. The results and the methods used in this study may assist in improving coastal wetlands management.

Oxybenzone contamination from sunscreen pollution and its ecological threat to Hanauma Bay, Oahu, Hawaii, U.S.A.

Hanauma Bay is a 101-acre bay created by the partial collapse of a volcanic cone and once supported a vibrant coral reef system. It is the most popular swimming area in the Hawaiian Islands and has been reported to have averaged between 2.8 and 3.5 million visitors a year between the 1980s and the 2010s, with visitors averaging between 3000-4000 a day and peaking around 10,000-13,000 per day. Concentrations of oxybenzone and other common UV filters were measured in subsurface water samples and in sands from the beach-shower areas in Hanauma Bay. Results demonstrate that beach showers also can be a source of sunscreen environmental contamination. Hydrodynamic modeling indicates that oxybenzone contamination within Hanauma Bay's waters could be retained between 14 and 50 h from a single release event period. Focusing on only oxybenzone, two different Hazard and Risk Assessment analyses were conducted to determine the danger of oxybenzone to Hanauma Bay's coral reef system. Results indicate that oxybenzone contamination poses a significant threat to the wildlife of Hanauma Bay. To recover Hanauma Bay's natural resources to a healthy condition and to satisfactorily conserve its coral reef and sea grass habitats, effective tourism management policies need to be implemented that mitigate the threat of sunscreen pollution.

A benthic survey of Aliwal Shoal and assessment of the effects of a wood pulp effluent on the reef.

Aliwal Shoal lies south of Durban in South Africa and has been the subject of recent bathymetric, seafloor and benthic surveys. ANOVA of the biological data revealed that the biota were uniformly distributed on the reef with the exception of encrusting sponges and algae on rock. The variations in distribution of these biota were significant and, in the case of the encrusting sponges, appeared to be related to the discharge of a wood pulp effluent. Further evidence of this was suggested by stable isotope analyses of representative organisms. The encrusting sponges were recommended as good candidates for further monitoring of the effects of the wood pulp effluent on Aliwal Shoal as the effluent pipeline has been extended.

Clionid sponge surveys on the Florida Reef Tract suggest land-based nutrient inputs.

Bioerosion by Cliona delitrix and Cliona lampa was assessed at 43 sites along the Florida Reef Tract, USA, in the summer of 2001. Sponge abundances were estimated using rapid visual assessment. Tissue samples of sponges were taken for analysis of delta15N. Comparison samples were taken from Belize. Annual trends in sponge abundance were estimated from archived videos covering the period from 1996 to 2001. Sites with the greatest boring sponge size and cover were in the Backcountry and Lower Keys, where total nitrogen, ammonium, and delta15N levels were highest. The sites with the largest relative increase of C. delitrix and C. lampa over the 5 year period were in the Upper Keys, where the greatest relative decline in stony coral cover has occurred. Florida sponge delta15N values were 5.2(+/-0.1)%, suggesting the influence of human waste; in comparison, offshore Belize samples were 2.1(+/-0.1)%. These results suggest sewage contamination of the Florida Reef Tract, shifting the carbonate balance from construction to destruction.

Bioerosion of corals and the influence of damselfish territoriality: A preliminary study.

Samples of the staghorn coral Acropora were taken from within territories defende by damselfish (Pisces: Pomacentridae) and from undefended areas. The fish utilized in this experiment were Hemiglyphidodon plagiometopon Bleeker and Pomacentrus bankanensis Bleeker. The extent of bioerosion was determined by randomly selecting pieces of coral substrate from treatment and control areas, cutting transverse sections, and determining total eroded area with the aid of enlarged photographs. Boreholes within the photos were traced with a digitizing sensor and area was integrated with the aid of a computer.Corals inside territoties were significantly more bioeroded (p<0.001) than corals outside areas. Most of the destruction was caused by boring sponges (Cliona sp.) and sipunculids (Cleosiphon). It is suggested that bioerosion is accelerated within territories as a result of reduction in grazing by fish.

Health of the coral reefs at the US Navy Base, Guantánamo Bay, Cuba: a preliminary report based on isotopic records from gorgonians.

Specimens of the gorgonian Plexaura homomalla were sampled from several areas along the fringing reefs fronting the United States Naval Base at Guantánamo Bay, Cuba. Sample coverage extended from apparently healthy reefs in oceanic waters to declining reefs located in the plume of the drainage from upper parts of Guantánamo Bay. Tentacle tips were excised, and trunk sections were cut and polished. Stable isotope ratios of nitrogen (δ(15)N) and carbon indicate a strong correlation of reef health with proximity to the plume of the river. Of all the worldwide cases in which land-based sources of pollution have impacted reefs, this one may well be the most intractable. The US Navy has jurisdiction over the reefs, with the obligation to protect them, yet the threat comes down the river from Cuba.

Nitrogen isotopic records of terrestrial pollution encoded in Floridian and Bahamian gorgonian corals.

Stable nitrogen isotope (delta(15)N) analysis has proven an effective "fingerprint" of sewage contamination in coral reef environments; however, short-term variability in nitrogen cycling and isotopic fractionation may obscure long-term trends. Here, we examine delta(15)N signatures in the organic endoskeletons of long-lived (20-40 years) gorgonian corals. Specimens were collected from relatively pristine reefs off Green Turtle Cay, Bahamas, and from reefs off southeast Florida heavily impacted by multiple sources of anthropogenic nitrogen. The delta(15)N of the most recently grown skeleton (branch tips) ranged from +2 to +3 per thousand at Green Turtle Cay, and +4.5 to +10 per thousand off Florida. These values closely match the delta(15)N of macroalgae collected from the same locations, indicating that gorgonian corals are isotopically similar to primary producers, and therefore suitable for assessing sources of dissolved inorganic nitrogen. Differences in the delta(15)N between younger and older skeleton indicated an overall decline of -0.34 +/- 0.06 per thousand (1 s.e) over the last 20 - 40 years at Green Turtle Cay, reflecting a possible increase in nitrogen fixation and/or atmospheric deposition of anthropogenic nitrogen. Off southeast Florida, there was an overall increase in delta(15)N over the same time period, reflecting increasing wastewater discharges from the rapidly growing population. These results highlight the usefulness of delta(15)N recorded in gorgonians and other long-lived organisms in assessing spatiotemporal patterns of nitrogen sources to coastal marine environments.

The use of delta(15)N in assessing sewage stress on coral reefs.

While coral reefs decline, scientists argue, and effective strategies to manage land-based pollution lag behind the extent of the problem. There is need for objective, cost-effective, assessment methods. The measurement of stable nitrogen isotope ratios, delta(15)N, in tissues of reef organisms shows promise as an indicator of sewage stress. The choice of target organism will depend upon study purpose, availability, and other considerations such as conservation. Algae are usually plentiful and have been shown faithfully to track sewage input. The organic matrix of bivalve shells can provide time series spanning, perhaps, decades. Gorgonians have been shown to track sewage, and can provide records potentially centuries-long. In areas where baseline data are lacking, which is almost everywhere, delta(15)N in gorgonians can provide information on status and trends. In coral tissue, delta(15)N combined with insoluble residue determination can provide information on both sewage and sediment stress in areas lacking baseline data. In the developed world, delta(15)N provides objective assessment in a field complicated by conflicting opinions. Sample handling and processing are simple and analysis costs are low. This is a method deserving widespread application.