Fishing gear dominates marine litter in the Wetlands Reserve in Al Wusta Governorate, Oman.

The Wetlands Reserve in Al Wusta Governorate on the Arabian Sea is important for internationally migrating birds and local wildlife, but data on marine litter in the reserve, and wider region, are rare. Seven beaches around the reserve were surveyed for litter in February 2020. Abundance and weight of litter were categorised along 100 m transects. Abundance ranged from 0.1 to 1.4 items m-2 and weight ranged from 3.2 to 170.4 g m-2. Plastic was the dominant material in abundance (84.4-97.7%) and weight (71.3-99.3%). Top categories in abundance and weight were fisheries-related, water bottles and caps, and food packaging. Fisheries-related litter comprised 19.6-36.7% of all in abundance, but 41.4-94.4% in weight. The high proportion of fisheries-related litter (by weight) indicates that providing practical disposal facilities for unwanted and broken fishing gear would substantially reduce the impact of litter on this vital wetlands reserve.

A standardised approach to the environmental risk assessment of potentially polluting wrecks.

The potential risk to the marine environment of oil release from potentially polluting wrecks (PPW) is increasingly being acknowledged, and in some instances remediation actions have been required. However, where a PPW has been identified, there remains a great deal of uncertainty around the environmental risk it may pose. Estimating the likelihood of a wreck to release oil and the threat to marine receptors remains a challenge. In addition, removing oil from wrecks is not always cost effective, so a proactive approach is recommended to identify PPW that pose the greatest risk to sensitive marine ecosystems and local economies and communities. This paper presents a desk-based assessment approach which addresses PPW, and the risk they pose to environmental and socio-economic marine receptors, using modelled scenarios and a framework and scoring system. This approach can be used to inform proactive management options for PPW and can be applied worldwide.

Connectivity of larval stages of sedentary marine communities between hard substrates and offshore structures in the North Sea.

Man-made structures including rigs, pipelines, cables, renewable energy devices, and ship wrecks, offer hard substrate in the largely soft-sediment environment of the North Sea. These structures become colonised by sedentary organisms and non-migratory reef fish, and form local ecosystems that attract larger predators including seals, birds, and fish. It is possible that these structures form a system of interconnected reef environments through the planktonic dispersal of the pelagic stages of organisms by ocean currents. Changes to the overall arrangement of hard substrate areas through removal or addition of individual man-made structures will affect the interconnectivity and could impact on the ecosystem. Here, we assessed the connectivity of sectors with oil and gas structures, wind farms, wrecks, and natural hard substrate, using a model that simulates the drift of planktonic stages of seven organisms with sedentary adult stages associated with hard substrate, applied to the period 2001-2010. Connectivity was assessed using a classification system designed to address the function of sectors in the network. Results showed a relatively stable overall spatial distribution of sector function but with distinct variations between species and years. The results are discussed in the context of decommissioning of oil and gas infrastructure in the North Sea.

Polycyclic aromatic hydrocarbons in fish from St Helena, South Atlantic, in relation to an historic wreck.

Concentrations of polycyclic aromatic hydrocarbons were determined in edible tissues of fish species consumed by the islanders of St Helena to assess any risk to human health posed by oil leaking from an historic wreck. Samples were collected from the vicinity of the wreck site and at two reference locations at which fishing activity occurs. Summed PAH concentrations ranged from 2.2 to 20 µg kg(-1) wet weight, and no PAHs with more than 4 fused rings were detected. All concentrations of the four PAH used as a basis for assessment in relation to health risks to human consumers of foods within the EU (benz[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene and chrysene) were<0.1 µg kg(-1) wet weight and raised no concerns. Additionally, concentrations were calculated as the benzo[a]pyrene toxic equivalency quotient and found to be well below the level of concern (0 to 0.05 µg kg(-1) wet weight benzo[a]pyrene equivalents).

Macrofaunal recolonisation following the intertidal placement of fine-grained dredged material.

Dredged material is increasingly being regarded as a potential resource, and one of its many uses is to create and/or improve intertidal habitats (i.e. beneficial use). However, uncertainties over the longer-term environmental consequences of such schemes have, to date, limited the practice to small-scale applications in UK waters. This paper studies the macrofaunal recolonisation of fine-grained dredged material recharged concurrently at four adjacent recharge areas along the south-east coast of the UK in order to facilitate predictions regarding the recolonisation of comparable schemes and, thereby, to promote effective environmental management. During the 2-year study period, the four recharge areas were distinctly different in terms of their environmental characteristics, primarily wave exposure and bed level. These conditions resulted in different macrofaunal recolonisation rates and community structures. While the low-level, wave-sheltered area experienced rapid recolonisation, the process was delayed until 12 months post-recharge at the relatively wave-exposed areas. Bed level differences resulted in distinctly different communities in wave-sheltered areas but not under wave-exposed conditions. While we are unable to separate the effects of individual environmental variables on recolonisation, these results provide general conclusions as to the importance of environmental conditions on resulting macrofaunal communities.