The impact of marine ecotourism on reef predators is poorly understood and there is growing concern that overcrowding in Marine Protected Areas (MPAs) may disturb the species that these areas were established to protect. To improve our understanding of this issue, we used acoustic telemetry to examine the relationship between human activity at the Molokini Marine Life Conservation District (MLCD) and the habitat use of five reef-associated predators (Caranx melampygus, Caranx ignobilis, Triaenodon obesus, Carcharhinus amblyrhynchos, and Aprion virscens). During peak hours of human use, there was a negative relationship (R2=0.77, P<0.001) between the presence of bluefin trevally (Caranx melampygus) and vessels in subzone A. No other species showed strong evidence of this relationship. However, our results suggest that during this time, the natural ecosystem function that the reserve was established to protect may be compromised and overcrowding should be considered when managing MPAs.

This study investigated the spatial variability of a common faecal indicator organism, Escherichia coli, in an urban salt-wedge estuary in Melbourne, Australia. Data were collected through comprehensive depth profiling in the water column at four sites and included measurements of temperature, salinity, pH, dissolved oxygen, turbidity, and E. coli concentrations. Vertical variability of E. coli was closely related to the salt-wedge dynamics; in the presence of a salt-wedge, there was a significant decrease in E. coli concentrations with depth. Transverse variability was low and was most likely dwarfed by the analytical uncertainties of E. coli measurements. Longitudinal variability was also low, potentially reflecting minimal die-off, settling, and additional inputs entering along the estuary. These results were supported by a simple mixing model that predicted E. coli concentrations based on salinity measurements. Additionally, an assessment of a sentinel monitoring station suggested routine monitoring locations may produce conservative estimates of E. coli concentrations in stratified estuaries.

Coastal hypoxia affects the survival, behavior, and reproduction of individual local marine organisms, and the abundance, biomass, and biodiversity of coastal ecosystems. In this study, we investigated the chronic effects of hypoxia on the metabolomics in the gills of Ruditapes (R.) philippinarum. The results indicated significant alterations in the metabolite profiles in the gills of the hypoxia-treated clams, in comparison with those maintained under normoxia. The levels of betaine, taurine, glycine, isoleucine, and alanine were significantly reduced, suggesting a disturbance of osmotic balance associated with hypoxia. Meanwhile, metabolites involved in energy metabolism, such as alanine and succinate, were also affected. Dramatic histopathological changes were observed in the gills and hepatopancreases of R. philippinarum grown in hypoxic waters, demonstrating tissue damages apparently caused by long-term exposure to hypoxia. Our findings suggest that hypoxia significantly affects the physiology of R. philippinarum, even at a sub-lethal level, and impedes health of the clams.

This study aimed to identify new biomarkers for metal exposure in two bivalve species. Suppressive Subtractive Hybridization (SSH) was employed to evaluate the transcriptomic response of Cerastoderma edule and Ruditapes philippinarum to metal pollution. Protein synthesis and catalytic activity were the most affected metabolic processes in C. edule and R. philippinarum, respectively. Also, different genes responded to the effect of contamination in each species. The different response observed in both species reinforces the importance of including more than one bioindicator species in risk assessment studies. These results provide the basis for new studies, which are necessary for further validation of the use of the identified genes as molecular biomarkers for metal exposure.

The Columbus crab Planes minutus and Arch-fronted swimming crab Liocarcinus navigator, within their distribution ranges in the Mediterranean, were found rafted on plastic macro-litter floating on the open south Adriatic. While P. minutus was recorded from inanimate flotsam outside of the Mediterranean, L. navigator is herein reported for the first time on floating marine litter. The role of floating litter as habitat or as a dispersal agent for marine invertebrates has received quite attention however, records of decapod crabs drifting on litter has been relatively sparse. Our results suggests that vast quantities of floating debris, comprised primarily of non-biodegradable plastic polymers, probably will augment natural floating substrates in the marine environment, potentially facilitating the spread of invasive species. The dispersion of rafting crabs through floating debris should be investigated given the high potential ecological risk of invasion by exotic species due to the increase in waste production (ecological risk assessment).

Failure of the Bay Park Sewage Treatment Plant (STP) during Superstorm Sandy led to adverse effects in the waters of Hempstead Bay, Long Island, NY. These appear to be related to large discharges of partially treated sewage through its primary and auxiliary outfalls. Modeled dilution discharges indicate that sewage infiltrated the bay, remaining up to 10days. Water column impacts included salinity and dissolved oxygen declines, and biological oxygen demand and nitrogen concentration increases. While the STP does not appear to have released fecal coliform, there were elevated levels of enterococci within the bay for a considerable period following the storm, probably from multiple sources.The STP's reduced functioning and associated environmental impacts, even with resilience upgrades, are not conducive to removing the bay from the list of Impaired Water Bodies. The results reinforce the need to transfer the discharge from the existing outfall to the ocean.

A high concentration of hydrocarbons in the environment is indicative of pollution. To evaluate the effect of hydrocarbons transported by urban runoff, the present study analyzed total petroleum hydrocarbons (TPHs), aliphatic hydrocarbons (AHs), unresolved complex mixture (UCM), and n-alkanes of the sediments of the canal that cross the urban area of Pelotas, Rio Grande do Sul, Brazil. The carbon preference index (CPI), terrigenous/aquatic ratio (TAR), and pristane/phytane ratio were determined. The TPH content ranged from 177,043.7μg·kg−1±13.4% to 5,892,667.0μg·kg−1±5.9%. The total aliphatic content ranged from 116,268.8μg·kg−1±11.1% to 2,393,592.6μg·kg−1±7.7%, indicating chronic contamination of n-alkanes petrogenic and biogenic sources. The levels of hydrocarbons (TPH, AHs, and n-alkanes) were considered relatively high, confirming the effect of urban runoff on the drainage system of cities and their consequent effect on the estuarine region of Patos Lagoon and other water resources.

In the present work we compared the type and frequency of gonadal abnormalities among Mytilus trossulus populations from the Gulf of Gdańsk, Baltic Sea. Observed histopathologies were grouped as regressive changes (RC, gonadal atresia (GA) and regression (GR)), progressive changes (PC, gonadal tumors) and intersex. Sex-based and spatial differences in frequency of RC were found, with the highest frequency of RC and PC found in mussels from polluted station B followed by mussels from station A located near a purification plant outlet. Bivalves from the reference area had the lowest frequency of RC.In order to confirm biomarker applicability of RC, an exposure experiment with model xenoestrogen 17α-ethinylestradiol (EE2) was performed. The exposure of M. trossulus to 50 and 500ngdL−1 of EE2 resulted in an increased frequency of gonadal regression and atresia, including melanized hemocytes infiltration in seminiferous tubules. We thus suggest that these changes can serve as biomarkers of endocrine disrupting compounds in biomonitoring studies.

Bioelectrochemical systems (BESs) convert the energy present in wastewater to recover resources like bioelectricity, hydrogen, nutrients, heavy metals, minerals, and industrial chemicals. Various aspects of BES have been discussed here along with their applications and other advantages towards bioenergy recovery. More scientifically organized cross-discipline research efforts are required to scale-up these systems and to get benefit of recovering useful energy from waste materials. Full-scale implementation of bioelectrochemical wastewater treatment is complicated because certain microbiological, technological, and economic challenges need to be resolved that have not previously been encountered in any other wastewater treatment system. BES has higher prospects for in situ remediation of polluted water body or marshy soils and sediments. This technology is likely to evolve as a way of treating sewage, industrial, or agricultural wastewater, not only by lowering the amount of energy required, but at the same time producing electricity, hydrogen, or other chemicals of high value. Thus, after improving the performance of the BES, widening the scope for products recovery by developing better understanding of the process and with efforts to reduce its production cost, it can become a sustainable technology for treatment of wastewater with added advantage of recovery of resources and bioenergy.

The United Nations Sustainable Development Goals (SDG), adopted in September 2015, are accompanied by targets which have to be met individually and collectively by the signatory states. SDG14 Life Below Water aims to lay the foundation for the integrated and sustainable management of the oceans. However, any environmental management has to be based around targets which are SMART – specific, measurable, achievable, realistic and time bounded – otherwise it is not possible to determine whether management actions are successful and achieve the desired aims. The discussion here shows that many of the targets adopted for SDG14, and especially a detailed analysis of Target 1, are aspirational rather than fully quantified. In order to move towards making the targets operational, we advocate merging the language of environmental management with that used by industry for linking risks to the environment, management performance and ensuing controls. By adopting an approach which uses Key Performance Indicators (‘KPIs’), Key Risk Indicators (‘KRIs’) and Key Control Indicators (‘KCIs’), we advocate that a degree of rigour leading to defendable actions can be brought to marine management.