Feeding ecology and niche segregation in oceanic top predators off eastern Australia

We examined the feeding ecology and niche segregation of the ten most abundant fish species caught by longline operations off eastern Australia between 1992 and 2006. Diets of 3,562 individuals were examined. Hook timer data were collected from a further 328 fish to examine feeding behaviour in relation to depth and time of day. Prey biomass was significantly related to predator species, predator length and year and latitude of capture. Although the fish examined fed on a mix of fish, squid and crustacea, fish dominated the diet of all species except small albacore (Thunnus alalunga) which fed mainly on crustacea and large swordfish (Xiphias gladius) and albacore which fed mainly on squid. Cannibalism was observed in lancetfish (Alepisaurus spp.). Multidimensional scaling identified three species groups based on their diet composition. One group consisted of yellowfin tuna (T. albacares), striped marlin (Tetrapturus audax) and dolphinfish (Coryphaena hippurus); a second group consisted of bigeye tuna (T. obesus), swordfish and albacore; and a third consisted of southern bluefin tuna (T. maccoyii) and blue shark (Prionace glauca). Of note was the separation of mako shark (Isurus oxyrhynchus) and lancetfish from all other predators. Prey length generally increased with increasing predator length although even large predators fed on a wide range of prey lengths including very small prey. Overall, differences in prey type and size, feeding times and depths were noted across the range of species examined to the extent that predators with overlapping prey, either in type or size, fed at different times of the diel period or at different depths. Taken together these data provide evidence for feeding niche segregation across the range of oceanic top predators examined.     

Occupational stressors identified by small-scale,independent commercial crab pot fishermen

IntroductionWe interviewed fishermen to identify jobs and/or tasks of concern in order to guide and inform current ergonomic interventions.MethodsWe administered surveys to two groups of southeastern US commercial crab fishermen: a cohort contacted by telephone and fishermen recruited at 11 local fish houses. Fishermen were asked to rate physical stress of selected work tasks and conditions on a scale from 0 (no problem) to 10 (major problem). Fishermen were also asked open-ended questions about other work-issues of concern.ResultsFishermen who completed the survey (n = 91) were predominantly male (90%), white (96%), and over 40 years of age (71%). The five most physically strenuous tasks and conditions as rated by fishermen were pulling pots by hand (mean 6.4), rough weather (6.1) or rough water (6.2), unloading without mechanical assistance (5.8), and long work days (5.3). Task stress ratings with the most variability measured by the inter-quartile range (IQR) included: pulling pots by hand (IQR = 5), unloading without mechanical assistance (IQR = 5), gear maintenance (IQR = 4.5), and moving boxes and baskets on board (IQR = 4.5). Other situations that fishermen identified as a problem included: economic, off-shore work, declining industry, mental stress, environment, regulation, conflict with other commercial or recreational fishermen, issues with crew, sun (glare or burn), and breaking up frozen bait.ConclusionsIn general, stressful tasks identified from previous research were rated similarly by the fishermen surveyed. Development and testing of ergonomic interventions is ongoing.     

Measurement and Interpretation of Concentrations of Urban Atmospheric Organic Compounds

The presence of volatile organic compounds (VOCs) from traffic and other sources in urban areas is a cause for concern about public health. Canister, chemical derivatisation, particulate sampling and adsorption sampling techniques were used to measure VOC concentrations of a wide range of compounds (C6-C40) during a four day campaign in south London with subsequent laboratory analysis of the samples. Compounds quantified included alkanes, mono- and poly-nuclear aromatic hydrocarbons. Also the first sequential measurements of carbonyl compounds (C1-C8) in a UK urban area are presented. Results from canister and adsorption sampling methods are compared. A comparison of the results with other urban data is presented and the temporal variations in VOC concentrations were interpreted with reference to the prevalent wind speeds and directions. The CALINE4 line source dispersion model was generally successful in reproducing the daytime 12 hour average concentrations of selected VOCs.     

More than good intentions: the role of conditions in personal transportation behaviour

Engaging individuals in pro-environmental behaviours is critical to addressing today’s environmental challenges. This study examines how conditions – or an individual’s context – influence action. Through semi-structured narrative interviews and document analysis, we examined the influence of conditions in five individual cases involving attempted change in personal transportation behaviour. The cases, studied over the course of one year, are derived from participants in a sustainability institute, representing a range of attempted behaviours, and highlight numerous potential barriers to desired pro-environmental behaviours. We found that the degree of engagement with sustainable transportation primarily was influenced by the amount and intensity of supportive conditions relative to barriers. Participants who successfully engaged in their desired transportation-related pro-environmental behaviours experienced physical, social, and learning conditions that promoted competence and satisfaction. We discuss the implications for designing interventions that encourage pro-environmental behaviours.     

Control of Particulate Emissions from Turbine Engine Test Cells by Cooling Water Injection

Abstract

This paper presents an experimental study of calcium bisulfite oxidation, a key step in the wet limestone-gypsum flue gas desulfurization (FGD) process, in the presence of catalysts (e.g., cobalt ions and a mixture of ferrous and cobalt ions). A fundamental approach is followed, by reproducing a simplified synthetic FGD liquor in which both catalyst ions, alone or mixed together, are present. A laboratory-scale apparatus is used, in which sulfurous solution is contacted with a gas phase at a fixed oxygen partial pressure (21.3 kPa) and at different temperature levels (25, 45, and 55 °C). The experimental results are analyzed using the theory of gas-liquid mass transfer with chemical reaction, showing that the slow reaction regime is explored and the transition from the kinetic to the diffusional subregime is identified. The experimental results are compared with those obtained in the presence of other catalytic species (manganese and ferrous ions), showing that cobalt is effective in catalyzing the oxidation of calcium bisulfite to sulfate, but to a minor extent with respect to iron and manganese.     

Assimilation of 210Po by the mussel Mytilus edulis from the alga Isochrysis galbana

Marine invertebrates are thought to accumulate ²¹⁰Po primarily from their food. In this study, a pulse-chase methodology was used to examine the assimilation and depuration of ²¹⁰Po by Mytilus edulis from the common marine alga Isochrysis galbana. The digestion of ²¹⁰Po from I. galbana occurred via a biphasic process, characteristic of a rapid (extracellular) and slow (intracellular) digestion typical of marine bivalves. The mantle/gill and foot have no known digestive role, yet their ²¹⁰Po specific activities increased after 24 h. It is proposed that this increase in ²¹⁰Po specific activity was related to ²¹⁰Po being incorporated into these tissues from ²¹⁰Po assimilated from I. galbana during extracellular digestion. It is proposed that the linear loss of ²¹⁰Po previously accumulated by control mussels was related to the continual state of renewal and replacement of cellular proteins, with ²¹⁰Po turnover and metabolism governed by protein turnover and metabolism. M. edulis' assimilation efficiency of ²¹⁰Po from the ²¹⁰Po-labelled alga was calculated to be 17.2 ± 2.1%, and thus similar to that of Ag, Cd, Co, Se and Zn by bivalves from other marine algae species. It is proposed that the assimilation efficiency of ²¹⁰Po is a function of protein assimilation. Received: 27 August 1998 / Accepted: 3 September 1999     

Community air monitoring for pesticides—part 2: multiresidue determination of pesticides in air by gas chromatography,gas chromatography–mass spectrometry,and liquid chromatography–mass spectrometry

Two multiresidue methods were developed to determine pesticides in air collected in California. Pesticides were trapped using XAD-4 resin and extracted with ethyl acetate. Based on an analytical method from the University of California Davis Trace Analytical Laboratory, pesticides were detected by analyzing the extract by gas chromatography–mass spectrometry (GC-MS) to determine chlorothalonil, chlorthal-dimethyl, cycloate, dicloran, dicofol, EPTC, ethalfluralin, iprodione, mefenoxam, metolachlor, PCNB, permethrin, pronamide, simazine, trifluralin, and vinclozolin. A GC with a flame photometric detector was used to determine chlorpyrifos, chlorpyrifos oxon, diazinon, diazinon oxon, dimethoate, dimethoate oxon, fonophos, fonophos oxon, malathion, malathion oxon, naled, and oxydemeton. Trapping efficiencies ranged from 78 to 92 % for low level (0.5 μg) and 37–104 % for high level (50 and 100 μg) recoveries. Little to no degradation of compounds occurred over 31 days; recoveries ranged from 78 to 113 %. In the California Department of Food and Agriculture (CDFA) method, pesticides were detected by analyzing the extract by GC-MS to determine chlorothalonil, chlorpyrifos, cypermethrin, dichlorvos, dicofol, endosulfan 1, endosulfan sulfate, oxyfluorfen, permethrin, propargite, and trifluralin. A liquid chromatograph coupled to a MS was used to determine azinphos-methyl, chloropyrifos oxon, DEF, diazinon, diazinon oxon, dimethoate, dimethoate oxon, diuron, EPTC, malathion, malathion oxon, metolachlor, molinate, norflurazon, oryzalin, phosmet, propanil, simazine and thiobencarb. Trapping efficiencies for compounds determined by the CDFA method ranged from 10 to 113, 22 to 114, and 56 to 132 % for 10, 5, and 2 μg spikes, respectively. Storage tests yielded 70–170 % recovery for up to 28 days. These multiresidue methods represent flexible, sensitive, accurate, and cost-effective ways to determine residues of various pesticides in ambient air.     

EMAP Overview: Objectives, Approaches, and Achievements

This paper summarizes the recommendations from the Intergovernmental Panel on Climate Change (IPCC) Workshop on Adaptation to Climate Variability and Change convened in Costa Rica in 1998. Specifically, this paper also summarizes the adaptive management science issues and, in many cases, sectoral options. The Workshop, organized by Canada and Costa Rica, involved more than 200 experts and focused on adaptation science, adaptive management and adaptation options for climate variability and change.     

Drain-blocking techniques on blanket peat: A framework for best practice

In recent years there has been a dramatic increase in artificial drain-blocking in world peatlands. The UK blanket peatlands have been severely drained over the past few decades but now drains are being blocked in an attempt to improve peatland environments. The drain-blocking has been a disparate process with limited knowledge transfer between organisations and within organisations operating in different geographic areas. Consequently, there has been no compilation of techniques used and their effectiveness. During this study thirty-two drain-blocked sites were surveyed and all the key stakeholders interviewed. Drain-blocking using peat turf was preferred by practitioners and was also the most cost-effective method. Peat turves were successful except on steep slopes, in areas of severe erosion, in very wet or very dry locations, or if the mineral substrate was exposed. A drain-blocking best practice guide is offered by this paper, providing information on the most suitable methods for blocking peatland drains under different circumstances. Additional considerations are provided for practitioners to ensure peatland drain-blocking is as successful as possible.