Protection from fishing alters the species composition of fish assemblages in a temperate-tropical transition zone

Closure of areas to fishing is expected to result in an increase in the abundance of targeted species; however, changes to populations of species not targeted by fishermen will depend upon their role in the ecosystem and their relationship with targeted species. The effects of protection on targeted and non-targeted reef fish species at the Houtman Abrolhos Islands, Western Australia were studied using baited remote underwater stereo–video cameras. Video images were collected from shallow (8–12 m) and deep (22–26 m) reef sites inside a Marine Protected Area (MPA) at each of three island groups and from three replicate fished locations at each of these groups that span a temperate-tropical transition area. The MPAs were established in 1994 and vary in size from 13.72 km² at the Pelsaert group in the south to 22.29 km² at the Easter group to 27.44 km² at the Wallabi group in the north. The relative abundances of 137 fish species from 42 families were recorded. Large differences in fish assemblage structure existed between MPA and fished locations, and also between shallow and deep regions. Targeted fish species Plectropomus leopardus, Lethrinus miniatus, Lethrinus nebulosus, Pagrus auratus and Glaucosoma hebraicum were more abundant inside MPAs than in areas open to fishing. Their abundance inside MPAs was between 1.13 and 8 times greater than their abundance at fished locations. For non-targeted fish species many were more abundant in areas open to fishing, e.g. Coris auricularis, Thalassoma lutescens, Thalassoma lunare, Dascyllus trimaculatus, however others were conversely more abundant inside MPAs, e.g. Gymnothorax spp, Kyphosus sydneyanus, Scarus microhinos, Chromis westaustralis, Chaetodon spp. This study demonstrates that the removal of abundant targeted species from an ecosystem by fishing can indirectly impact non-fished species and alter the trophic structure of fish assemblages. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Spatial distribution of bacteria associated with the marine sponge Tethya californiana

Microbial diversity and spatial distribution of the diversity within tissue of the marine sponge Tethya californiana was analyzed based on 16S rRNA gene sequences. One candidate division and nine bacterial phyla were detected, including members of all five subdivisions of Proteobacteria. Moreover, chloroplast-derived Stramenopiles- and Rhodophyta-affiliated 16S rRNA gene sequences were found and Stramenopiles represented the most abundant clones (30%) in the clone library. On the phylum-level, the microbial fingerprint of T. californiana showed a similar pattern as its Mediterranean relative T. aurantium. An interesting difference was that Cyanobacteria that were abundantly present in T. aurantium were not found in T. californiana, but that the latter sponges harbored phototrophic Stramenopiles instead. Surprisingly, the phototrophic microorganisms were evenly distributed over the inner and outer parts of the sponge tissue, which implies that they also reside in regions without direct light exposure. The other phyla were also present in both the outer cortex and the mesohyl of the sponges. These results were confirmed by analysis on the operational taxonomic unit level. This leads to the conclusion that from a qualitative point of view, spatial distribution of microorganisms in T. californiana tissue is quite homogeneous. Thirty-two percent of the operational taxonomic units shared less than 95% similarity with any other known sequence. This indicates that marine sponges are a rich source of previously undetected microbial life.     

Australian approaches to coastal vulnerability assessment

The Australian coastline is one of the longest and most diverse of any in the world, and Australian researchers have developed preliminary models of the behaviour of major coastal systems such as beaches and reefs. The Australian population is particularly focused along the coastline, especially in metropolitan centres; however, the population of regional centres along the coast is increasing steadily in response to a phenomenon termed seachange. Coastal systems are increasingly threatened by potential impacts as a result of climate change, as indicated by the successive assessments by the Intergovernmental Panel on Climate Change (IPCC). Although Australia played a central role in applying a common methodology (CM), developed from IPCC guidelines in the 1990s, and in devising alternative approaches, which were initially trialled at nine sites on the Australian coast, there has not been a nationally co-ordinated approach to assessing the coastal vulnerability of Australia, and such an approach is only emerging now. Instead, there have been a series of different approaches adopted to look at the different parts of the Australian coast, including wetland mapping in northern Australia; geomorphic unit mapping in South Australia; storm surge vulnerability modelling in Queensland; probabilistic approaches to beach erosion in New South Wales; indicative mapping of potential coastal retreat in Tasmania. Additionally, there have been methods proposed by insurers and coastal engineers to meet their requirements. Since 2005, the Australian government has once again seen the need for a national coastal vulnerability assessment, and a series of studies are planned or under way to achieve the aims of a National Climate Change Adaptation Framework.     

WATER RESOURCE POLITICS AND INTEREST GROUP TACTICS1

ABSTRACT: The traditional strong role of interest groups in water resources policy making has been modified recently by the introduction of many environmental groups. The new groups differ from traditional groups in their relatively modest resources and their relative lack of access to traditional decision points. This paper examines the extent to which the new groups differ in their perceptions of the effectiveness of tactics and in their use of tactics, taking into account group resources and group access to decision makers.     

LOCATION OF MUNICIPAL WELL FIELDS IN AN ENVIRONMENTALLY SENSITIVE REGION1

ABSTRACT: A visual selection technique can be utilized to locate potential well field sites prior to on-site testing. The technique is based upon an understanding of the regional hydrology and an appreciation for development goals such as the identification of high-yield and low-impact locations. Although the uniqueness of Pasco, Pinellas, and Hillsborough Counties in Western Florida has been incorporated into the current application, the methodology, with modifications, is transferable to other geographic regions. Overlays of each criterion used in site selection are combined to form a regional composite showing favorable site locations and further serve a useful communications role as visual aids during public presentation. Implications of direct and indirect cost savings to the public are obtained when the methodology is applied to the location of municipal well fields.     

Accumulation, release, and solubility of arsenic, molybdenum, and vanadium in wetland sediments

This study was undertaken to determine the fate of As, Mo, and V (trace elements, TEs) in the sediments of a constructed wetland in use for the remediation of potentially toxic trace element-contaminated agricultural drainwater. After three years of wetland operation, sediment cores were collected to determine changes in TE concentrations as a function of depth and the effects of varying water column depth. All TE concentrations were highest in the top 2 to 4 cm and decreased with depth. Molybdenum accumulated in the wetland sediments, up to levels of 32.5 +/- 4.6, 30.2 +/- 8.9, and 59.3 +/- 26.1 mg kg(-1) in the top 1 cm of sediment at water depths of 15, 30, and 60 cm, respectively. In the top 2 cm of sediment, As accumulated (28.2 +/- 3.0 mg kg(-1)) only at the 60-cm water depth. Below 2 cm, as much as 10 mg kg(-1) of As was lost from the sediment at all water depths. In most cases, V concentrations decreased in the sediment. In this wetland system, the lowest redox potentials were found near the sediment surface and increased with depth. Thus, in general As, Mo, and V concentrations in the sediment were highest under more reducing conditions and lowest under more oxidizing conditions. Most of the accumulated Mo (73%) became water soluble on drying of samples. This has important implications for systems undergoing changes in redox status; for instance, if these wetland sediments are dried, potentially large amounts of Mo may be solubilized.     

The jurisdictional framework for municipal action to reduce greenhouse gas emissions: Case studies from Canada, the USA and Germany

This paper addresses two questions: (1) Given a commitment at the national level to reduce greenhouse gas (GHG) emissions, what tools are available to national-level governments to induce complimentary actions required at subnational levels? (2) In the absence of a serious commitment at national and regional levels to reduce GHG emissions, what is the scope for, and jurisdictional rights of, cities to undertake actions? In this context, federal, regional and municipal legislation relevant for GHG emissions is examined in Canada, the USA and Germany. Regarding the first question, different national governments find themselves in considerably different positions to implement climate initiatives at subnational levels, with the German government in the strongest position and the Canadian government in the weakest. The implications of this for a nation's willingness to adopt emission reduction targets could be serious. Regarding the second question, there are few significant differences among Canadian, US and German municipalities' jurisdictional capabilities (and limitations) to reduce GHG emissions. Though limited in their legal capacity, these municipalities demonstrate that through their own, often informal, initiatives they can reinforce and compliment the more formal, regulatory actions by senior-level governments, thereby paving the way for senior-level governments to deliver meaningful domestic emission reductions.     

Slip and fall accident prevention: A review of research, practice, and regulations

This paper summarizes current research, practices, and regulations regarding walking/working surface slipperiness and coefficient of friction (COF) measurements. The literature and data are reviewed from three aspects:

1. (a) the biomechanics of walking and psychophysiological factors involved in slips and falls studied by the scientific community,

2. (b) various measuring devices and methods developed in an attempt to quantify the “slipperiness” of walking/working surfaces, and

3. (c) an acceptable quantitative standard for the “slipperiness” of surfaces and the impact of the Americans with Disabilities Act (ADA) on such a standard.

Unresolved issues related to slip-resistance are identified. A multifaceted approach and synergy from researchers, the building industries, standards organizations, and government are needed to obtain concensus on such issues.