Energy consumption in the Norwegian fisheries

Energy use is of great concern within fisheries, due to both associated environmental effects and the cost of fuel to fishermen. This article explores the scale of energy consumed by most segments of the Norwegian fishing fleet for gadoid fish and for parts of the pelagic fleet for the period 1980–2005. Fuel use is assigned to the different species caught and different fishing gears using economic and mass-based allocation, where data permit. Correlations between variations in energy use and changing catch rates, quotas and oil prices are found. Inverse correlations are found between fuel consumption per kilogram of fish and catch rates on a yearly basis and between fuel consumption and oil prices on a longer term basis. A long term trend towards increased fuel consumption and reduced real prices is observed from the mid 1980s until 2000. This may indicate that low fuel prices do not motivate the development of energy efficient technology in the long run. Increased fuel use may further be used as an indication of over fishing as the correlation between low catch rates and increased fuel consumption is rather strong. Possible means of reducing energy use and emissions are discussed including changing operational strategies, hull forms and the use of alternative energy carriers. A comparison with measures taken in connection with the previous oil crisis around 1980 is done.     

Temperate reefs in a changing ocean: skeletal carbonate mineralogy of serpulids

We present a review of the published data about serpulid skeletal carbonate geochemistry, augmented with new data from the Southern Hemisphere. We know something about skeletal carbonate mineralogy of 15 % of extant species (n = 52); and about half of extant genera (n = 25). Serpulid worm tubes vary in their skeletal mineralogy from entirely aragonitic (about 24 % of species) to entirely high-Mg calcite (40 %) to mixtures of the two. Mg in calcite ranges from 7 to 15 wt% MgCO₃, with a mean of 11 wt% MgCO₃. Little mineralogical variation within individuals or species can be found in aragonitic specimens, whereas high-Mg calcitic species show somewhat more variability in both calcite and Mg content, and those with mixed mineralogies are highly variable. These three groups correspond broadly with currently accepted clades. Given this strong phylogenetic signal, we analysed the data using phylogenetically independent contrasts, a statistical approach that separates genotypic from phenotypic variability; we found that variations which might be ascribed to environment were generally weak. The mineralogy of serpulid tubes makes them particularly vulnerable to ocean chemistry changes. While some serpulids appear to be able to adjust their tube mineralogy in order to adapt to sea-water chemistry, overall strength and elasticity may be sacrificed when they do. The biodiverse reef habitat provided by serpulids in some temperate regions may be the only complex solid habitat available, and loss or compromise of these temperate reefs will most likely have deleterious flow-on effects on temperate benthic communities.     

Impacts of golf courses on macroinvertebrate community structure in Precambrian shield streams

The influence of golf course operation on benthic macroinvertebrate communities in Precambrian Shield streams was evaluated using rapid bioassessment and the reference condition approach. Streams were sampled for water chemistry and invertebrates in 1999 and 2000, six on operational golf courses, and seven in forested reference locations. Correspondence analysis (CA) was used to determine the major patterns in the macroinvertebrate taxa, and canonical correspondence analysis (CCA) was used to evaluate relationships with environmental variables. The reference streams were used to define the normal range of variation for a variety of summary indices to evaluate the golf course streams. In all cases, golf course streams were higher in nutrients and dissolved ions and more alkaline than the forested reference streams. There was considerable variability in the macroinvertebrate fauna from the golf course streams, which was related to differences in golf course land management practices and to the potential influence of highway runoff. Of the management practices evaluated, fertilizer application rates in particular were important, as was the presence of ponds upstream on the course. Invertebrate taxa with higher abundances in golf course streams included Turbellaria, Isopoda, Amphipoda, Zygoptera, and Trombidiformes. Taxa more common in the reference streams included Ephemeroptera, Megaloptera, Culicidae, and Plecoptera. There were marked differences in the overall benthic macroinvertebrate community in three of the six golf course streams studied relative to the forested reference streams, suggesting that golf course land management on the Precambrian Shield can be associated with significant differences in macroinvertebrate community structure.     

Delineation and evaluation of hydrologic-landscape regions in the United States using geographic information system tools and multivariate statistical analyses

Hydrologic-landscape regions in the United States were delineated by using geographic information system (GIS) tools combined with principal components and cluster analyses. The GIS and statistical analyses were applied to land-surface form, geologic texture (permeability of the soil and bedrock), and climate variables that describe the physical and climatic setting of 43,931 small (approximately 200 km2) watersheds in the United States. (The term "watersheds" is defined in this paper as the drainage areas of tributary streams, headwater streams, and stream segments lying between two confluences.) The analyses grouped the watersheds into 20 noncontiguous regions based on similarities in land-surface form, geologic texture, and climate characteristics. The percentage of explained variance (R-squared value) in an analysis of variance was used to compare the hydrologic-landscape regions to 19 square geometric regions and the 21 U.S. Environmental Protection Agency level-II ecoregions. Hydrologic-landscape regions generally were better than ecoregions at delineating regions of distinct land-surface form and geologic texture. Hydrologic-landscape regions and ecoregions were equally effective at defining regions in terms of climate, land cover, and water-quality characteristics. For about half of the landscape, climate, and water-quality characteristics, the R-squared values of square geometric regions were as high as hydrologic-landscape regions or ecoregions.