Description: The ability of management strategies to achieve the fishery management goals are impacted by environmental variation and, therefore, also by global climate change. Management strategies can be modified to use environmental data using the "dynamic B 0 " concept, and changing the set of years used to define biomass reference points. Two approaches have been developed to apply management strategy evaluation to evaluate the impact of environmental variation on the performance of management strategies. The "mechanistic approach" estimates the relationship between the environment and elements of the population dynamics of the fished species and makes predictions for population trends using the outputs from global climate models. In contrast, the "empirical approach" examines possible broad scenarios without explicitly identifying mechanisms. Many reviewed studies have found that modifying management strategies to include environmental factors does not improve the ability to achieve management goals much, if at all, and only if the manner in which these factors drive the system is well known. As such, until the skill of stock projection models improves, it seems more appropriate to consider the implications of plausible broad forecasts related to how biological parameters may change in the future as a way to assess the robustness of management strategies, rather than attempting specific predictions per se .

Description: Welcomme, R. L. 2011. An overview of global catch statistics for inland fish. – ICES Journal of Marine Science, 68: 1751–1756. The reported global inland fish catch passed 10 million tonnes in 2008, after almost linear growth from the early 1950s. The rise coincides with an increasing number of reports of falling catches resulting from environmental degradation. It is thought that catches from inland waters were underreported in the past because of constraints on collecting the relevant data. National approaches to data collection are not generally comparable and their accuracy not usually assessed. National data processing and reporting should be audited, and training undertaken to harmonize these activities. The apparently bigger catches probably result from better reporting of actual catches rather than any increase in the amount of fish landed. Current data are sufficient only for a general overview of global inland catches of fish, rather than for the detailed analysis needed for management, policy formulation, and the valuation of inland fisheries. There is a need for improved approaches to data collection and for historical catches to be corrected to account for changes in methodologies and reporting procedures.

Description:    Nitrous oxide (N 2 O) emissions from grazed grasslands are estimated to be approximately 28% of global anthropogenic N 2 O emissions. Estimating the N 2 O flux from grassland soils is difficult because of its episodic nature. This study aimed to quantify the N 2 O emissions, the annual N 2 O flux and the emission factor (EF), and also to investigate the influence of environmental and soil variables controlling N 2 O emissions from grazed grassland. Nitrous oxide emissions were measured using static chambers at eight different grasslands in the South of Ireland from September 2007 to August 2009. The instantaneous N 2 O flux values ranged from -186 to 885.6 μg N 2 O-N m −2  h −1 and the annual sum ranged from 2 ± 3.51 to 12.55 ± 2.83 kg N 2 O-N ha −1  y −1 for managed sites. The emission factor ranged from 1.3 to 3.4%. The overall EF of 1.81% is about 69% higher than the Intergovernmental Panel on Climate Change (IPCC) default EF value of 1.25% which is currently used by the Irish Environmental Protection Agency (EPA) to estimate N 2 O emission in Ireland. At an N applied of approximately 300 kg ha −1  y −1 , the N 2 O emissions are approximately 5.0 kg N 2 O-N ha −1 y −1 , whereas the N 2 O emissions double to approximately 10 kg N ha −1 for an N applied of 400 kg N ha −1  y −1 . The sites with higher fluxes were associated with intensive N-input and frequent cattle grazing. The N 2 O flux at 17°C was five times greater than that at 5°C. Similarly, the N 2 O emissions increased with increasing water filled pore space (WFPS) with maximum N 2 O emissions occurring at 60–80% WFPS. We conclude that N application below 300 kg ha −1  y −1 and restricted grazing on seasonally wet soils will reduce N 2 O emissions. Content Type Journal Article Pages 1-20 DOI 10.1007/s10021-011-9434-x Authors Rashad Rafique, Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland Deirdre Hennessy, Department of Animals &, Grassland Science Research, Teagasc-Moorpark, Fermoy, Ireland Gerard Kiely, Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland Journal Ecosystems Online ISSN 1435-0629 Print ISSN 1432-9840

Description:    Agricultural drainage is thought to alter greenhouse gas emissions from temperate peatlands, with CH 4 emissions reduced in favor of greater CO 2 losses. Attention has largely focussed on C trace gases, and less is known about the impacts of agricultural conversion on N 2 O or global warming potential. We report greenhouse gas fluxes (CH 4 , CO 2 , N 2 O) from a drained peatland in the Sacramento-San Joaquin River Delta, California, USA currently managed as a rangeland (that is, pasture). This ecosystem was a net source of CH 4 (25.8 ± 1.4 mg CH 4 -C m −2  d −1 ) and N 2 O (6.4 ± 0.4 mg N 2 O-N m −2  d −1 ). Methane fluxes were comparable to those of other managed temperate peatlands, whereas N 2 O fluxes were very high; equivalent to fluxes from heavily fertilized agroecosystems and tropical forests. Ecosystem scale CH 4 fluxes were driven by “hotspots” (drainage ditches) that accounted for less than 5% of the land area but more than 84% of emissions. Methane fluxes were unresponsive to seasonal fluctuations in climate and showed minimal temporal variability. Nitrous oxide fluxes were more homogeneously distributed throughout the landscape and responded to fluctuations in environmental variables, especially soil moisture. Elevated CH 4 and N 2 O fluxes contributed to a high overall ecosystem global warming potential (531 g CO 2 -C equivalents m −2  y −1 ), with non-CO 2 trace gas fluxes offsetting the atmospheric “cooling” effects of photoassimilation. These data suggest that managed Delta peatlands are potentially large regional sources of greenhouse gases, with spatial heterogeneity in soil moisture modulating the relative importance of each gas for ecosystem global warming potential. Content Type Journal Article Pages 1-15 DOI 10.1007/s10021-011-9411-4 Authors Yit Arn Teh, Environmental Change Research Group, School of Geography & Geosciences, University of St Andrews, St Andrews, KY16 9 AL Scotland, UK Whendee L. Silver, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Oliver Sonnentag, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Matteo Detto, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Maggi Kelly, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Dennis D. Baldocchi, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Journal Ecosystems Online ISSN 1435-0629 Print ISSN 1432-9840

Description: Wigand, L. A., Klinger, T., and Logsdon, M. G. 2013. Patterns in groundfish abundance along the Eastern Bering Sea outer continental margin. – ICES Journal of Marine Science, 70: 1181–1197. Place-based management approaches require understanding the spatial arrangement and interaction of elements. To address this need, we explored the utility of spatial-pattern analysis to understand the distribution of groundfish in the Eastern Bering Sea outer continental margin. We divided this region into discrete geomorphological units to explore spatial pattern on a range of scales. We used groundfish catch per unit effort (cpue) trawl survey data collected in four years to quantify spatial autocorrelation. Global statistics indicated that groundfish cpue was dominated by clusters of low values in all years. Local statistics showed that clusters of low values in groundfish cpue were confined to the southern portion of the study area, while clusters of high values varied across the study area. Outliers were most commonly found in close proximity to the shelf–slope break. Our results reveal the existence of spatial dependency in groundfish abundance and demonstrate that spatial analysis can be used to better understand spatial arrangements of these and other living marine resources, and to quantify and validate the local ecological knowledge of resource users. Our results indicate the feasibility of using spatially explicit tools to improve integration and visualization of marine environmental data for purposes of management and conservation.