Stakeholder perspectives on the value proposition of enterprise-level natural capital accounting for three primary industries

Environment Systems and Decisions - Globally we are experiencing a decline in aggregate natural capital. Many primary industries and enterprises are highly dependent on renewable and non-renewable...     

Stable isotopic evidence for trophic groupings and bio-regionalization of predators and their prey in oceanic waters off eastern Australia

Muscle tissue was collected for stable isotope analysis (SIA) from the main fish predators and their fish and cephalopod prey from oceanic waters off eastern Australia between 2004 and 2006. SIA of δ¹⁵N and δ¹³C revealed that the species examined could be divided into three main trophic groups. A “top predator” group consisted mainly of large billfish (Xiphias gladius and Tetrapturus audax), yellowfin (Thunnus albacares), bigeye (T. obesus) and southern bluefin (T. maccoyii) tunas and sharks; with mako (Isurus oxyrinchus) the highest. Below this tier was a second group composed of mid-trophic level fishes including albacore tuna (Thunnus alalunga), lancet fish (Alepisaurus ferox), mahi mahi (Coryphaena hippuris) and ommastrephid squid. Underlying both groups was a grouping of small fishes including myctophids, small scombrids and nomeids as well as surface fishes including macrorhamphosids. These groupings were based largely on mean animal size which showed a positive linear relation to δ¹⁵N (r ² = 0.58). Some species showed significant ontogenetic variation in either δ¹⁵N (swordfish, lancet fish, yellowfin and albacore tuna) or δ¹³C (mako shark). We also noted a consistent latitudinal change in δ¹⁵N and δ¹³C at ~28°S for the top predator species, particularly albacore and yellowfin tuna. The differences were consistent with a change from oligotrophic Coral Sea to nutrient rich Tasman Sea waters. These differences suggest that predatory fishes may have extended residence time in distinct regions off eastern Australia.     

Realizing an effectiveness revolution in environmental management

The environmental movement of the 20(th) century has evolved into a large, diverse and well-financed global community that is increasingly required to prove its worth. Though the environmental sector collects and uses data to determine the status of ecological and social systems, the effectiveness of the programs and policies it uses to affect this status remains largely untested. As governments and donor institutions insist on greater transparency, accountability and evidence of what works and what does not, much is being learned from other fields (e.g. health services, education, international development) and increasingly sophisticated approaches are emerging to manage effectiveness. For example, program evaluation, adaptive management, and systematic review provide frameworks and methods to collect and use information to measure and improve performance. However, the critical data and collaborations necessary for an effectiveness revolution are marginalized by technical, cultural and political obstacles. Learning from other fields, the environmental sector must exploit key leverage points, such as flows of information and self-organization, to overcome impediments and create incentives to initiate and realize an era of effectiveness in environmental management.     

Sustainable local land use policy: rhetoric and reality

Abstract

This study examined trends in population redistribution and residential land use changes in northeast Scotland during 1988 to 2003. We utilised a geographical information system (GIS) tool to bring together data from interrelated sources and to analyse population settlement and land use changes at detailed spatial scale. This analysis revealed that substantial land conversion had taken place in the region; particularly conversion of agricultural lands to built-up and residential areas. It also drew attention to policy conflicts, discrepancies between policy rhetoric and policy implementations. More specifically, it was shown that substantial farm land conversion had taken place in suburban areas and rural Aberdeenshire with little change in the size of derelict land in Aberdeen City. The reason given for this was that it was costly to rehabilitate and reuse derelict lands and this conflicted with the objective of providing affordable housing in the City region. The implication of this study is that if the declared policy objectives of integrated and sustainable land use and transport policies are to be achieved, then local authorities may need to cooperate to minimise conflicts between economic and environmental objectives.     

Relationships between water quality, habitat quality, and macroinvertebrate assemblages in Illinois streams

The influence of specific stressors, such as nutrient enrichment and physical habitat degradation, on biotic integrity requires further attention in Midwestern streams. We sampled 53 streams throughout Illinois and examined relationships between macroinvertebrate community structure and numerous physicochemical parameters. Streams were clustered into four major groups based on taxa dissimilarity. Habitat quality and dissolved nutrients were responsible for separating the major groups in a nonmetric multidimensional scaling ordination. Furthermore, the alignment of environmental factors in the ordination suggested there was a habitat quality-nutrient concentration gradient such that streams with high-quality habitats usually had low concentrations of nutrients. Discrimination by community measures further validated the major stream groups and indicated that forested streams had generally higher biological integrity than agricultural streams, which in turn had greater integrity than urban streams. Our results demonstrate that physical habitat degradation and nutrient pollution are important and often confounded determinants of biotic integrity in Illinois streams. In addition, we suggest that management of Midwestern streams could benefit from further implementation of multivariate data exploration and stream classification techniques.