Preliminary Investigations for Causes of the Disappearance of \u3ci\u3eDiporeia\u3c/i\u3e spp. from Lake Ontario

The amphipod Diporeia spp. comprised 60-80% of the benthos in offshore Lake Ontario and was an important food for fish. In eastern Lake Ontario, Diporeia spp. began disappearing in 1993 just after the arrival of dreissenid mussels. We compared survival of Diporeia spp. and Hyalella azteca in sediments from areas where Diporeia spp. populations had vanished with survival in sediments still inhabited. Survival was also examined in the presence of zebra mussel (Dreissena polymorpha) pseudofeces, filtered water from mussel cultures, and added bacteria. The Microtox® test indicated that sediment pore water was not toxic. Sediments from sites with large Dreissena spp. populations (Lake Erie and western Lake Ontario) lowered Diporeia spp. survival. Diporeia spp. and H. azteca responded differently to test sediments and zebra mussel pseudofeces. Pseudofeces added to Lake Superior sediment greatly reduced H. azteca survival but had less effect on Diporeia spp. survival. Added bacteria had little effect on the survival of either species. Sediments exposed to dying Diporeia spp. caused significant mortality suggesting the presence of a pathogen. Diporeia spp. remained common in two inland lakes containing dreissenids indicating that the amphipod can co-exist with the mussels

Workshop on nitrogen deposition, critical loads and biodiversity: scientific synthesis and summary for policy makers

It is clear that nitrogen (N) deposition impacts on the biodiversity and ecosystem services provided by natural and semi-natural ecosystems have been experienced in Europe, North America and Asia over the last 50 years. Impacts are also estimated to increase in line with increasing rates of N deposition in coming decades across the globe, especially in Asia. To improve the assessment of impacts progress is required in the following key areas: the extent of monitoring networks and the measurement of dry and organic deposition; the modelling of N deposition in areas with complex topography; the assessment of impacts on fauna generally and impacts on flora in areas outside the relatively well studied temperate ecosystems; the application of critical load (CL) and level approaches outside of Europe; and the linkage between impacts on biodiversity and important ecosystem services. New indicators are required, in addition to N deposition and critical loads, to demonstrate the wider impacts and to help integrate the biodiversity, air pollution and climate change policy communities

From Monodisciplinary via Multidisciplinary to an Interdisciplinary Approach Investigating Air-Sea Interactions – a SOLAS Initiative

Understanding the physical and biogeochemical interactions and feedbacks between the ocean and atmosphere is a vital component of environmental and Earth system research. The ability to predict and respond to future environmental change relies on a detailed understanding of these processes. The Surface Ocean-Lower Atmosphere Study (SOLAS) is an international research platform that focuses on the study of ocean-atmosphere interactions, for which Future Earth is a sponsor. SOLAS instigated a collaborative initiative process to connect efforts in the natural and social sciences related to these processes, as a contribution to the emerging Future Earth Ocean Knowledge-Action Network (Ocean KAN). This is imperative because many of the recent changes in the Earth system are anthropogenic. An understanding of adaptation and counteracting measures requires an alliance of scientists from both domains to bridge the gap between science and policy. To this end, three SOLAS research areas were targeted for a case study to determine a more effective method of interdisciplinary research: valuing carbon and the ocean’s role; air-sea interactions, policy and stewardship; and, air-sea interactions and the shipping industry

From Monodisciplinary via Multidisciplinary to an Interdisciplinary Approach Investigating Air-Sea Interactions – a SOLAS Initiative

Understanding the physical and biogeochemical interactions and feedbacks between the ocean and atmosphere is a vital component of environmental and Earth system research. The ability to predict and respond to future environmental change relies on a detailed understanding of these processes. The Surface Ocean-Lower Atmosphere Study (SOLAS) is an international research platform that focuses on the study of ocean-atmosphere interactions, for which Future Earth is a sponsor. SOLAS instigated a collaborative initiative process to connect efforts in the natural and social sciences related to these processes, as a contribution to the emerging Future Earth Ocean Knowledge-Action Network (Ocean KAN). This is imperative because many of the recent changes in the Earth system are anthropogenic. An understanding of adaptation and counteracting measures requires an alliance of scientists from both domains to bridge the gap between science and policy. To this end, three SOLAS research areas were targeted for a case study to determine a more effective method of interdisciplinary research: valuing carbon and the ocean’s role; air-sea interactions, policy and stewardship; and, air-sea interactions and the shipping industry

A global assessment of precipitation chemistry and deposition of sulfur, nitrogen, sea salt, base cations, organic acids, acidity and pH, and phosphorus

A global assessment of precipitation chemistry and deposition has been carried out under the direction of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) Scientific Advisory Group for Precipitation Chemistry (SAG-PC). The assessment addressed three questions: (1) what do measurements and model estimates of precipitation chemistry and wet, dry and total deposition of sulfur, nitrogen, sea salt, base cations, organic acids, acidity, and phosphorus show globally and regionally? (2) has the wet deposition of major ions changed since 2000 (and, where information and data are available, since 1990) and (3) what are the major gaps and uncertainties in our knowledge? To that end, regionally- representative measurements for two 3-year-averaging periods, 2000-2002 and 2005-2007, were compiled worldwide. Data from the 2000-2002 averaging period were combined with 2001 ensemble-mean modeling results from 21 global chemical transport models produced in Phase 1 of the Coordinated Model Studies Activities of the Task Force on Hemispheric Transport of Air Pollution (TF HTAP). The measurement data and modeling results were used to generate global and regional maps of concentrations in precipitation and deposition. A major product of the assessment is a database of quality assured ion concentration and wet deposition data gathered from regional and national monitoring networks. The database is available for download from the World Data Centre for Precipitation Chemisty http://wdcpc.org/). The assessment concludes that global concentrations and deposition of sulfur and nitrogen are reasonably well characterized with levels generally highest near emission sources and more than an order of magnitude lower in areas largely free of anthropogenic influences. In many parts of the world, wet deposition of reduced nitrogen exceeds that of oxidized nitrogen and is increasing. Sulfur and nitrogen concentrations and deposition in North America and Europe have declined significantly in line with emission reduction policies. Major regions of the world, including South America, the more remote areas of North America, much of Asia, Africa, Oceania, polar regions, and all of the oceans, are inadequately sampled for all of the major ions found in wet and dry deposition, and particularly so for phosphorus, organic forms of nitrogen, and weak acids including carbonates and organic acids. Measurement-based inferential estimates of dry deposition are limited to sulfur and some nitrogen in only a few regions of the world and methods are highly uncertain. The assessment concludes with recommendations to address major gaps and uncertainties in global ion concentration and deposition measurements.JRC.H.4-Monitoring Agricultural Resource

Progress in nitrogen deposition monitoring and modelling

The chapter reviews progress in monitoring and modelling of atmospheric nitrogen (N) deposition at regional and global scales. The Working Group expressed confidence in the inorganic N wet deposition estimates in U.S., eastern Canada, Europe and parts of East Asia. But, long-term wet or dry N deposition information in large parts of Asia, South America, parts of Africa, Australia/Oceania, and oceans and coastal areas is lacking. Presently, robust estimates are only available for inorganic N as existing monitoring generally does not measure the complete suite of N species, impeding the closing of the atmospheric N budget. The most important species not routinely measured are nitrogen dioxide (NO2), ammonia (NH3), organic N and nitric acid (HNO3). Uncertainty is much higher in dry deposition than in wet deposition estimates. Inferential modelling (combining air concentrations with exchange rates) and direct flux measurements are good tools to estimate dry deposition; however, they are not widely applied. There is a lack of appropriate parameterizations for different land uses and compounds for input into inferential models. There is also a lack of direct dry deposition flux measurements to test inferential models and atmospheric model estimates