A study of the efficiency of hydrodynamic cavitation and separation was carried out to evaluate an innovative, environmentally safe and acceptable system for ballast water treatment for reducing the risk of introducing non-native species worldwide. Mesocosm experiments were performed to assess the morphological changes and viability of zooplankton (copepods), Artemia salina cysts, and the growth potential of marine bacteria after the hydrodynamic cavitation treatment with a different number of cycles. Our preliminary results confirmed the significant efficiency of the treatment since more than 98% of the copepods and A. salina cysts were damaged, in comparison with the initial population. The efficiency increased with the number of the hydrodynamic cavitation cycles, or in combination with a separation technique for cysts. There was also a significant decrease in bacterial abundance and growth rate, compared to the initial number and growth potential.

Polycyclic aromatic hydrocarbons (PAHs) have been reported to absorb ultraviolet (UV) light, resulting in enhanced toxicity. Early developmental stages of bivalves may be particularly susceptible to photo-enhanced toxicity during oil spills. In the current study, toxicity tests were conducted with sperm and three larval ages of the eastern oyster (Crassostrea virginica) to evaluate the photo-enhanced toxicity of low-energy water-accommodated fractions (WAFs) of two weathered Macondo crude oils collected from the Deepwater Horizon incident. Larvae exposed to oil WAFs under UV-filtered light demonstrated consistently higher survival and normal development than larvae exposed to WAFs under UV light. The phototoxicity of weathered Macondo oil increased as a function of increasing UV light intensity and dose. Early developing oyster larvae were the most sensitive to photo-enhanced toxicity, whereas later shelled prodissoconch larvae were insensitive. Comparisons between two weathered crude oils demonstrated that toxicity was dependent on phototoxic PAH concentration and UV light intensity.

A method to integrate the environmental risk of the multiple effects from uses and activities developed in harbor areas is presented. Consequences are considered as the effects derived from all identified hazards. Vulnerability is expressed in terms of functional relations between environmental susceptibility against a disturbance and the state of protection of the receptors at risk. Consequences and vulnerability are integrated obtaining a spatial variation of risk: prioritization maps. The maps are developed by 4 main stages: (1) environmental hazard identification; (2) estimation of the consequences; (3) estimation of vulnerability and, (4) integration of environmental risks. To adapt prioritization maps to the peculiarities of the study area, three different methods for the integration of the effects are proposed: average-value, worst-case and weighted methods. The implementation to a real case (Tarragona harbor, NE Spain) confirms its usefulness as a risk analysis tool to communicate and support water quality management in harbors.

This paper discusses the combined use of tools from dynamical systems theory and remote sensing techniques and shows how they are effective instruments which may greatly contribute to the decision making protocols of the emergency services for the real-time management of oil spills. This work presents the successful interplay of these techniques for a recent situation, the sinking of the Oleg Naydenov fishing ship that took place in Spain, close to the Canary Islands, in April 2015.

Rapid assessment sampling for target species is a fast cost-effective method aimed at determining the presence, abundance and distribution of alien and native harmful aquatic organisms and pathogens that may have been introduced by shipping. In this study, the method was applied within a large tropical port expected to have a high species diversity. The port of Kaohsiung was sampled for bivalve molluscan species that attach using a byssus. Such species, due to their biological traits, are spread by ships to ports worldwide. We estimated the abundance and distribution range of one dreissenid (Mytilopsis sallei) and four mytilids (Brachidontes variabilis, Arcuatula senhousa, Mytilus galloprovincialis, Perna viridis) known to be successful invaders and identified as potential pests, or high-risk harmful native or non-native species. We conclude that a rapid assessment of their abundance and distribution within a port, and its vicinity, is efficient and can provide sufficient information for decision making by port managers where IMO port exemptions may be sought.

Marine debris (MD) pollution is a problem of global concern because of its impact on marine ecosystems. The current extent of this problem and its implications concerning reef conservation are unknown in Ecuador. The composition and distribution of submerged MD was assessed on two reefs using underwater surveys of geomorphological areas: crest, slope and bottom. MD items were classified according to source and use. Plastic-derived debris represents >90% of total MD found on the reefs, principally composed by plastic containers and nets. 63% of the MD was associated to fishing activities. The composition showed differences between sites and geomorphological areas, monofilament nets were found on the crests, multifilament lines on the slopes and plastic containers on the bottom. MD disposal might be a result of the influx of visitors and fishing activities. Distribution is related to bottom type, level of boating/fishing activity and benthic features.

Southeast Asia is the global centre of mangrove development but human activities have dramatically reduced mangrove area in the region. An analysis is made of the shift in carbon and nitrogen influxes into the South China Sea (SCS) resulting from three anthropogenic nutrient sources: domestic sewage discharge, fertilizer use in rice agriculture and environmental loss from mariculture, between 1997 and 2010. Anthropogenic C and N influxes were, respectively, 1.81× and 1.43× those in 1997, with coastal aquaculture contributing most to the increase. In contrast, fringing mangroves provided ~44% of the C but only ~3% of the N from anthropogenic sources in 2010. In 1997, influx from mangroves was 113% and 6% of anthropogenic influx for C and N, respectively. This dominance by relatively labile anthropogenic nutrients over mangrove sources would change nearshore trophodynamics, with negative implications for the resilience of mangroves and nutrient-intolerant systems such as corals.

The Baixada Santista, besides being an important estuarine system, is responsible for most of the international trade and economic development in the region because of the Santos Port and the Cubatão Industrial Complex. The aim of this study is to assess heavy metal contamination of the Santos São Vicente Estuary using enrichment factors (EFs) and sediment quality guidelines (SQGs). Thus, superficial sediment samples were subjected to acid digestion and analyzed (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sc, V, and Zn) by inductively coupled plasma optical emission spectrometry (ICP-OES). The results indicated an absence of contamination, with the EFs indicating moderate enrichment. As and Pb presented higher enrichment probably due to the natural processes of weathering and sedimentation, and the influence of human activity. This conjoint analysis showed that potentially polluting activities are of concern as the highest values converge near the Cubatão Industrial Complex, which correspond to intense urbanization and industrial activity.

Two methods for marine microlitter sampling were compared in the Gulf of Finland, northern Baltic Sea: manta trawl (333μm) and a submersible pump (300 or 100μm). Concentrations of microlitter (microplastics, combustion particles, non-synthetic fibres) in the samples collected with both methods and filter sizes remained <10particlesm−3. The pump with 100μm filter gave higher microlitter concentrations compared to manta trawl or pump with 300μm filter. Manta sampling covers larger areas, but is potentially subjected to contamination during sample processing and does not give precise volumetric values. Using a submerged pump allows method controls, use of different filter sizes and gives exact volumetric measures. Both devices need relatively calm weather for operation. The choice of the method in general depends on the aim of the study. For monitoring environmentally relevant size fractions of microlitter the use of 100μm or smaller mesh size is recommended for the Baltic Sea.

The European Water Framework Directive requires a good ecological potential for heavily modified water bodies. This standard has not been reached for most large estuaries by 2015. Management plans for estuaries fall short in linking implementations between restoration measures and underlying spatial analyses. The distribution of emergent macrophytes – as an indicator of habitat quality – is here used to assess the ecological potential. Emergent macrophytes are capable of settling on gentle tidal flats where hydrodynamic stress is comparatively low. Analyzing their habitats based on spatial data, we set up species distribution models with ‘elevation relative to mean high water’, ‘mean bank slope’, and ‘length of bottom friction’ from shallow water up to the vegetation belt as key predictors representing hydrodynamic stress. Effects of restoration scenarios on habitats were assessed applying these models. Our findings endorse species distribution models as crucial spatial planning tools for implementing restoration measures in modified estuaries.