Quantitation of persistent organic pollutants adsorbed on plastic debris from the Northern Pacific Gyre's "eastern garbage patch"

Floating marine plastic debris was found to function as solid-phase extraction media, adsorbing and concentrating pollutants out of the water column. Plastic debris was collected in the North Pacific Gyre, extracted, and analyzed for 36 individual PCB congeners, 17 organochlorine pesticides, and 16 EPA priority PAHs. Over 50% contained PCBs, 40% contained pesticides, and nearly 80% contained PAHs. The PAHs included 2, 3 and 4 ring congeners. The PCBs were primarily CB-11, 28, 44, 52, 66, and 101. The pesticides detected were primarily p,p-DDTs and its metabolite, o,p-DDD, as well as BHC (a,b,g and d). The concentrations of pollutants found ranged from a few ppb to thousands of ppb. The types of PCBs and PAHs found were similar to those found in marine sediments. However, these plastic particles were mostly polyethylene which is resistant to degradation and although functioning similarly to sediments in accumulating pollutants, these had remained on or near the ocean surface. Particles collected included intact plastic items as well as many pieces less than 5 mm in size.     

Changes in persistent contaminant concentration and CYP1A1 protein expression in biopsy samples from northern bottlenose whales, Hyperoodon ampullatus, following the onset of nearby oil and gas development

A small population of endangered northern bottlenose whales (Hyperoodon ampullatus) inhabits "The Gully" a Marine Protected Area on the Scotian Shelf, eastern Canada. Amid concerns regarding nearby oil and gas development, we took 36 skin and blubber biopsy samples in 1996-1997 (prior to major development) and 2002-2003 (five years after development began), and three samples from a population in the Davis Strait, Labrador in 2003. These were analysed for cytochrome P4501A1 (CYP1A1) protein expression (n=36), and for persistent contaminants (n=23). CYP1A1 showed generally low expression in whales from The Gully, but higher levels during 2003, potentially coincident with recorded oil spills, and higher levels in Davis Strait whales. A range of PCB congeners and organochlorine compounds were detected, with concentrations similar to other North Atlantic odontocetes. Concentrations were higher in whales from The Gully than from the Davis Strait, with significant increases in 4,4'-DDE and trans-nonachlor in 2002-2003 relative to 1996-1997.     

Arctic marine mammal population status,sea ice habitat loss,and conservation recommendations for the 21st century

Arctic marine mammals (AMMs) are icons of climate change, largely because of their close association with sea ice. However, neither a circumpolar assessment of AMM status nor a standardized metric of sea ice habitat change is available. We summarized available data on abundance and trend for each AMM species and recognized subpopulation. We also examined species diversity, the extent of human use, and temporal trends in sea ice habitat for 12 regions of the Arctic by calculating the dates of spring sea ice retreat and fall sea ice advance from satellite data (1979–2013). Estimates of AMM abundance varied greatly in quality, and few studies were long enough for trend analysis. Of the AMM subpopulations, 78% (61 of 78) are legally harvested for subsistence purposes. Changes in sea ice phenology have been profound. In all regions except the Bering Sea, the duration of the summer (i.e., reduced ice) period increased by 5–10 weeks and by >20 weeks in the Barents Sea between 1979 and 2013. In light of generally poor data, the importance of human use, and forecasted environmental changes in the 21st century, we recommend the following for effective AMM conservation: maintain and improve comanagement by local, federal, and international partners; recognize spatial and temporal variability in AMM subpopulation response to climate change; implement monitoring programs with clear goals; mitigate cumulative impacts of increased human activity; and recognize the limits of current protected species legislation.     

Microplastic pollution in deposited urban dust,Tehran metropolis,Iran

Environmental pollutants such as microplastics have become a major concern over the last few decades. We investigated the presence, characteristics, and potential health risks of microplastic dust ingestion. The plastic load of 88 to 605 microplastics per 30 g dry dust with a dominance of black and yellow granule microplastics ranging in size from 250 to 500 μm was determined in 10 street dust samples using a binocular microscope. Fluorescence microscopy was found to be ineffective for detecting and counting plastic debris. Scanning electron microscopy, however, was useful for accurate detection of microplastic particles of different sizes, colors, and shapes (e.g., fiber, spherule, hexagonal, irregular polyhedron). Trace amounts of Al, Na, Ca, Mg, and Si, detected using energy dispersive X-ray spectroscopy, revealed additives of plastic polymers or adsorbed debris on microplastic surfaces. As a first step to estimate the adverse health effects of microplastics in street dust, the frequency of microplastic ingestion per day/year via ingestion of street dust was calculated. Considering exposure during outdoor activities and workspaces with high abundant microplastics as acute exposure, a mean of 3223 and 1063 microplastic particles per year is ingested by children and adults, respectively. Consequently, street dust is a potentially important source of microplastic contamination in the urban environment and control measures are required.     

Evidence of food-based competition among passerine migrants during stopover

Summary Local concentrations of migrating, fat-depleted birds with similar diets can lead to increased competition for food at a time when energy demand is high. Results of a predator-exclosure experiment indicate that intercontinental passerine migrants depress food abundance during stopover following migration across the Gulf of Mexico. Moreover, migrants that stop when a high number of potential competitors are present replenish energy reserves more slowly than migrants that stop under low density conditions. Competition increase the rate of food depletion and may decrease the probability that a migrant will meet its energetic requirements and complete a successful migration.     

Heavy metals in seaducks and mussels from misty fjords national monument in Southeast Alaska

Quartz Hill, in Misty Fjords National Monument near Ketchikan, Alaska, is the site of a proposed molybdenum-producing mine. To provide baseline data for use in post-development comparisons, we analyzed tissues of Barrow's goldeneyes (Bucephala islandica), common mergansers (Mergus merganser), and blue mussels (Mytilus edulis) for seven heavy metals that could potentially be released into the environment as a result of mining operations. Specimens were collected in 1980, 1981, and 1982 from two fjords likely to be used for discharge of tailings from the proposed mine and from two control fjords. Concentrations of arsenic, cadmium, copper, chromium, molybdenum, lead, and zinc were measured in soft tissues of mussels and in kidney, liver, and muscle of birds. The highest mean concentrations of metals found in bird tissues were 55.7 ppm dry weight cadmium in kidneys and 154 ppm dry weight zinc in livers of Barrow's goldeneyes. Concentrations of several metals in blue mussels differed among seasons and locations, but the most significant finding in mussels was a maximum mean cadmium concentration of 9.6 ppm dry weight, a level higher than normally found in undisturbed areas. With the exception of 104 ppm dry weight cadmium in the kidney of one common merganser and 12.7 ppm dry weight lead in the kidney of another, concentrations of other metals in seaduck and mussel tissues were low, consistent with what would be expected for a pre-development environment. Molybdenum was found in low concentrations (<10 ppm dry weight) in all avian kidney samples and most liver samples, but was not detected in blue mussels.THE U.S. GOVERNMENT RIGHT TO RETAIN A NON-EXCLUSIVE, ROYALTY FREE LICENCE IN AND TO ANY COPYRIGHT IS ACKNOWLEDGED.     

A management strategy to reduce bacterial pollution in shellfish areas: A case study

The problem of bacterial pollution in shellfishing areas is not uncommon in the coastal regions of the United States. Bacterial contamination from man's activities can effectively reduce our natural shellfish resource areas by forcing their closure because of high potential risk of diseases being spread by shellfish harvested in these areas. Tillamook Bay, a relatively small, enclosed drainage basin of nonurban character, presents an excellent study area for observing this problem. The high population density of animals, raised on a relatively small floodplain area, represents one of the major sources of pollution in the bay. This paper summarizes the history of the agencies involved with the problem and presents the current approach to alleviate bacterial pollution in the bay without unduly penalizing other industries in the Tillamook basin. The paper also presents some of the legal aspects of reducing water pollution in shellfish harvesting areas and the jurisdiction of federal agencies in these matters. Finally, recommendations are given to reduce bacterial output by the major source categories in the basin, and criteria for bay closure to shellfish harvest are developed to protect the public from bacterially contaminated shellfish.     

Measuring differences between overlapping but unpaired spatial surveys using a geographic information system

To compare the results from two overlapping but unpaired synoptic surveys, a method using a geographic information system is proposed. The new method uses a GIS to create (i) minimum convex polygons (MCP) enclosing each set of survey data and (ii) Voronoi tesselations assigning area weights to each datum. The pairs of MCP and Voronoi maps are overlaid to produce a mosaic of polygons each with one datum assigned from each survey. The differences between the pairs weighted by the polygon areas provides the basis for statistical testing. Area-weighted means and variances of paired differences are computed and a z-statistic measures the significance of differences for the whole intersection area. A cross-product autocorrelation statistic provides an assessment of the spatial distribution of differences. Alternate, conventional methods are compared with the new method: analysis of variance (ANOVA), analysis of covariance (ANCOVA), and contour overlays. The four methods were applied to the comparison of two macrobenthic surveys conducted in Lake Erie. Measures for five different taxa were examined. The ANOVA and ANCOVA methods found many significant differences between surveys. Both methods were judged inappropriate as sampling data are not expected to be drawn from normally-distributed populations in spatial surveys. Differences between surveys were detected but were difficult to assess using contour overlays. The new method only found a significant difference in one taxon, an expected difference as members of that taxon were absent from most sites in one survey.