Fish Cognition and Consciousness

Questions about fish consciousness and cognition are receiving increasing attention. In this paper, I explain why one must be careful to avoid drawing conclusions too hastily about this hugely diverse set of species.     

Aggregation and ecotoxicity of CeO₂ nanoparticles in synthetic and natural waters with variable pH, organic matter concentration and ionic strength

The influence of pH (6.0-9.0), natural organic matter (NOM) (0-10 mg C/L) and ionic strength (IS) (1.7-40 mM) on 14 nm CeO₂ NP aggregation and ecotoxicity towards the alga Pseudokirchneriella subcapitata was assessed following a central composite design. Mean NP aggregate sizes ranged between 200 and 10000 nm. Increasing pH and IS enhanced aggregation, while increasing NOM decreased mean aggregate sizes. The 48 h-E_rC20s ranged between 4.7 and 395.8 mg CeO₂/L. An equation for predicting the 48 h-E_rC20 (48 h-E_rC20 = −1626.4 × (pH) + 109.45 × (pH)² + 116.49 × ([NOM]) − 14.317 × (pH) × ([NOM]) + 6007.2) was developed. In a validation study with natural waters the predicted 48 h-E_rC20 was a factor 1.08-2.57 lower compared to the experimental values.     

Radiocesium in caribou and reindeer in northern Canada, Alaska and Greenland from 1958 to 2000

This study summarizes the spatial and temporal trends of fallout (137)Cs concentrations in caribou and reindeer (Rangifer tarandus ssp.), reported in various programs in Canada, Alaska and Greenland, over a 40-y period. During the 1960s, the highest (137)Cs concentrations (2000-3000Bqkg(-1) wet weight in muscle) were found in the large caribou herds of central northern Canada, with levels about 50% lower in Alaska and Greenland. Concentrations varied by up to a factor of 6 between spring and fall. Concentrations in reindeer were comparable to those in caribou from the same regions. The highest (137)Cs concentrations (750Bqkg(-1)) in the late 1980s were found in the Caniapiscau herd of central Québec. The contribution from the Chernobyl accident in 1986 was estimated from (134)Cs measurements to be 10-40% of the total (137)Cs. Present concentrations have declined to 200-300Bqkg(-1). The effective half-life (T(eff)) of (137)Cs in Canadian caribou herds was estimated to be about 6 y. The potential impact on the health of northern residents is discussed.     

The problem of estimating recent genetic connectivity in a changing world

Accurate understanding of population connectivity is important to conservation because dispersal can play an important role in population dynamics, microevolution, and assessments of extirpation risk and population rescue. Genetic methods are increasingly used to infer population connectivity because advances in technology have made them more advantageous (e.g., cost effective) relative to ecological methods. Given the reductions in wildlife population connectivity since the Industrial Revolution and more recent drastic reductions from habitat loss, it is important to know the accuracy of and biases in genetic connectivity estimators when connectivity has declined recently. Using simulated data, we investigated the accuracy and bias of 2 common estimators of migration (movement of individuals among populations) rate. We focused on the timing of the connectivity change and the magnitude of that change on the estimates of migration by using a coalescent‐based method (Migrate‐n) and a disequilibrium‐based method (BayesAss). Contrary to expectations, when historically high connectivity had declined recently: (i) both methods over‐estimated recent migration rates; (ii) the coalescent‐based method (Migrate‐n) provided better estimates of recent migration rate than the disequilibrium‐based method (BayesAss); (iii) the coalescent‐based method did not accurately reflect long‐term genetic connectivity. Overall, our results highlight the problems with comparing coalescent and disequilibrium estimates to make inferences about the effects of recent landscape change on genetic connectivity among populations. We found that contrasting these 2 estimates to make inferences about genetic‐connectivity changes over time could lead to inaccurate conclusions.     

Assessing the toxicity of organophosphorous pesticides to indigenous algae with implication for their ecotoxicological impact to aquatic ecosystems

This study aimed to determine the toxicity of three organophosphorous pesticides, chlorpyrifos, terbufos and methamidophos, to three indigenous algal species isolated from local rivers and algal mixtures. The diatom Nitzschia sp. (0.30–1.68 mg L^?1 of EC₅₀ -the estimated concentration related to a 50% growth reduction) and the cyanobacteria Oscillatoria sp. (EC₅₀ of 0.33–7.99 mg L^?1) were sensitive to single pesticide treatment and the chlorophyta Chlorella sp. was the most tolerant (EC₅₀ of 1.29–41.16 mg L^?1). In treatment with the mixture of three pesticides, Chlorella sp. became the most sensitive alga. The antagonistic joint toxic effects on three indigenous algae and algal mixtures were found for most of the two pesticide mixtures. The results suggested that mixture of pesticides might induce the detoxification mechanisms more easily than the single pesticide. The synergistic interactions between terbufos and methamidophos to algal mixtures and between methamidophos and chlorpyrifos to Nitzschia sp. indicated methamidophos might act as a potential synergist. Differential sensitivity of three families of algae to these pesticides might result in changes in the algal community structures after river water has been contaminated with different pesticides, posing great ecological risk on the structure and functioning of the aquatic ecosystem.     

The survey of living conditions in the Arctic (SLiCA): A comparative sustainable livelihoods assessment

The Arctic is a region of the world experiencing extremely rapid climatic and social change. Indigenous communities have faced similar challenges for millennia and have historically demonstrated remarkable resilience to socioecological perturbations. In contemporary contexts, however, it appears that the pace and extent of change is overwhelming the adaptive capacities of many indigenous communities. Scholars recently completed a survey of living conditions spanning the circumpolar Arctic to quantitatively document the impacts of social and ecological stress across regions. The database they created is called the Survey of Living Conditions in the Arctic or SLiCA. This article explores the utility of using this dataset to compare livelihood systems across three sub-regions of Alaska and four sub-regions within the Chukotka Autonomous Okrug of the Russian Federation. The results point out that livelihood systems in Chukotka have a substantially lower level of sustainability than in Northwest Alaska due to the high prevalence of vulnerable households.     

A comparative assessment of waste incinerators in the UK

The uptake in Europe of Energy from Waste (EfW) incinerator plants has increased rapidly in recent years. In the UK, 25 municipal waste incinerators with energy recovery are now in operation; however, their waste supply chains and business practices vary significantly. With over a hundred more plant developments being considered it is important to establish best business practices for ensuring efficient environmental and operational performance. By reviewing the 25 plants we identify four suitable case study plants to compare technologies (moving grate, fluidised bed and rotary kiln), plant economics and operations. Using data collected from annual reports and through interviews and site visits we provide recommendations for improving the supply chain for waste incinerators and highlight the current issues and challenges faced by the industry. We find that plants using moving grate have a high availability of 87–92%. However, compared to the fluidised bed and rotary kiln, quantities of bottom ash and emissions of hydrogen chloride and carbon monoxide are high. The uptake of integrated recycling practices, combined heat and power, and post incineration non-ferrous metal collections needs to be increased among EfW incinerators in the UK. We conclude that one of the major difficulties encountered by waste facilities is the appropriate selection of technology, capacity, site, waste suppliers and heat consumers. This study will be of particular value to EfW plant developers, government authorities and researchers working within the sector of waste management.     

A free-enzyme catalyst for the bioremediation of environmental atrazine contamination

Herbicide contamination from agriculture is a major issue worldwide, and has been identified as a threat to freshwater and marine environments in the Great Barrier Reef World Heritage Area in Australia. The triazine herbicides are of particular concern because of potential adverse effects, both on photosynthetic organisms and upon vertebrate development. To date a number of bioremediation strategies have been proposed for triazine herbicides, but are unlikely to be implemented due to their reliance upon the release of genetically modified organisms. We propose an alternative strategy using a free-enzyme bioremediant, which is unconstrained by the issues surrounding the use of live organisms. Here we report an initial field trial with an enzyme-based product, demonstrating that the technology is technically capable of remediating water bodies contaminated with the most common triazine herbicide, atrazine.