Nutrient pathways and their susceptibility to past and future change in the Eurasian Arctic Ocean

Climate change is altering nutrient cycling within the Arctic Ocean, having knock-on effects to Arctic ecosystems. Primary production in the Arctic is principally nitrogen-limited, particularly in the western Pacific-dominated regions where denitrification exacerbates nitrogen loss. The nutrient status of the eastern Eurasian Arctic remains under debate. In the Barents Sea, primary production has increased by 88% since 1998. To support this rapid increase in productivity, either the standing stock of nutrients has been depleted, or the external nutrient supply has increased. Atlantic water inflow, enhanced mixing, benthic nitrogen cycling, and land–ocean interaction have the potential to alter the nutrient supply through addition, dilution or removal. Here we use new datasets from the Changing Arctic Ocean program alongside historical datasets to assess how nitrate and phosphate concentrations may be changing in response to these processes. We highlight how nutrient dynamics may continue to change, why this is important for regional and international policy-making and suggest relevant research priorities for the future.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01673-0.     

Source apportionment of fine particulate matter in the southeastern United States

Particulate matter (PM) less than 2.5 microm in size (PM2.5) source apportionment by chemical mass balance receptor modeling was performed to enhance regional characterization of source impacts in the southeastern United States. Secondary particles, such as NH4HSO4, (NH4)2SO4, NH4NO3, and secondary organic carbon (OC) (SOC), formed by atmospheric photochemical reactions, contribute the majority (>50%) of ambient PM2.5 with strong seasonality. Source apportionment results indicate that motor vehicle and biomass burning are the two main primary sources in the southeast, showing relatively more motor vehicle source impacts rather than biomass burning source impacts in populated urban areas and vice versa in less urbanized areas. Spatial distributions of primary source impacts show that each primary source has distinctively different spatial source impacts. Results also find impacts from shipping activities along the coast. Spatiotemporal correlations indicate that secondary particles are more regionally distributed, as are biomass burning and dust, whereas impacts of other primary sources are more local.     

Design standards and technology adoption: welfare effects of increasing environmental fines when the number of firms is endogenous

Environmental Economics and Policy Studies - This paper examines the consequences of an increase in the expected fine for non-compliance with an environmental design standard for an industry with...     

ASSEMBLY OF MAP‐BASED STREAM NARRATIVES TO FACILITATE STAKEHOLDER INVOLVEMENT IN WATERSHED MANAGEMENT1

ABSTRACT: Watershed stewardship activities throughout North America have evolved into a process that requires more involvement in planning and decision making by community stakeholders. Active involvement of all stakeholders in the process of watershed stewardship is dependent on effective exchange of information among participants, and active involvement of a wide range of stakeholders from “communities of place” as well as those from “communities of interest.” We developed a map‐based stream narrative tool as a means to: (a) assemble a wealth of incompletely documented, “traditional” ecological or natural history observations for rivers or streams; and (b) promote a higher level of active involvement by community stakeholders in contributing to information‐based, watershed management. Creation of stream narratives is intended for use as a tool to actively engage local stakeholders in the development of a more comprehensive information system to improve management for multiple stewardship objectives in watersheds. Completion of map‐based stream narrative atlases provides a valuable supplement to other independent efforts to assemble observations and knowledge about land‐based natural resources covering entire watersheds. We are confident that completion of stream narrative projects will make a valuable addition to the information and decision making tools that are currently available to the public and resource agencies interested in advancing the cause of community‐based approaches to watershed and ecosystem management.     

UV-Filtersubstanzen in Wasser und Fischen

A method was developed for the analysis of fish samples to detect sunscreen agents (SSA) together with organochlorides (PCB, DDT) in different fish tissues. Detection limits of the compounds analyzed are in the range of ng/kg and vary between 40 and 90 ng/kg fillet. Recovery rates range from 78 to 104%. The contamination of water and fish with SSA in Meerfelder Maar lake, the Eifel, Germany was investigated in 1991 and 1993 and allowed the identification and quantification of six different SSA in the fish. The sum of SSA concentrations in perch taken in the summer of 1991 was 2.0 mg/kg lipid and 0.50 mg/kg lipid was found in roach sampled during the summer of 1993. Both species were contaminated with SSA and organochlorides to the same ranges as PCB and DDT. Even in the fillet of roach taken from three other lakes in Germany, methylbenzylidene camphor, a lipophilic SSA, was detected. These results indicate that SSA are wide-spread in German lakes. Therefore, they can be seen as a new group of relevant environmental chemicals. In the investigated lakes, the concentrations of the SSA in water were mostly below the detection limits. Thus, fish can be used as a biomonitor for these lipophilic compounds. Due to the lack of toxicological data for aquatic organisms, an ecotoxicological assessment is impossible at the moment.