Response of juvenile lemon sharks, Negaprion brevirostris, to a magnetic barrier simulating a beach net

Beach nets are preventative devices used to minimize interactions between potentially harmful sharks and unsuspecting swimmers. Quantitative studies demonstrated that beach nets drastically reduced local elasmobranch populations, as well as caused considerable bycatch mortality. For this experiment, a beach net-like device was constructed and the behaviors of six juvenile lemon sharks (Negaprion brevirostris) were analyzed. Induced by olfactory and gustatory cues, sharks were given the choice to swim through a magnetic or control opening in the net. In the first trial, all six sharks avoided the magnetic region and significantly preferred to swim through the control region of the fence. The magnetic stimulus no longer affected the swimming behavior of three sharks retested after resting 24 h. Results from the retested sharks were correlated with those from repeated tonic immobility trials, which demonstrated a linear decrease in sensitivity to repeated magnetic stimulation. This study serves as a baseline experiment demonstrating that permanent magnets may substantially decrease elasmobranch mortality within beach nets.     

Food,Morality and Identity: mobility,remittances and the translocal community in Paama,Vanuatu

Migration and remittances characterise many small Pacific islands, where local livelihoods are limited, and the need for money has increased. A majority of Paamese have left the island of Paama, in the central island chain of Vanuatu, and more now live in the capital city, Port Vila, than on Paama. Remittances are bidirectional, between the island and Vila, a duality that has rarely been discussed in Melanesia. Almost every household on Paama and in Vila is involved in sending and receiving remittances. Remittances usually involve food: ‘modern’ foods (such as rice) flowing from Vila, and island foods (yams and laplap) travelling to Vila. While such transfers make little formal economic sense, they emphasise a constant process of negotiating and manipulating social relationships. Food, as an expression of identity and locality, is a powerful and repetitive reminder of moral obligations and rural–urban kinship connections. The material significance of exchange is thus less than its affective significance, within the field of reciprocity that structures kin relationships. Food and remittances have become metaphors for defining the experience of migration, as their meaning and function are more than to merely provide a source of nutrition. They have also become the means of structuring a translocal moral economy.     

Impact of early prehistoric farming on chironomid communities in northwest Ireland

This study explored the utility and performance of chironomid (Diptera: Chironomidae) autecology in the investigation of prehistoric farming impacts on freshwater lake systems. Chironomid subfossils, lake sediment geochemistry (δ¹³C, δ¹⁵N and C:N), pollen and macroscopic charcoal analyses were used in a comparative limnological assessment of three archaeologically rich study sites in northwest Ireland. At all three study sites, pastoral farming and its associated nutrient inputs, as represented by non-arboreal pollen indicative of grassland/pasture (NAPp) and lake sediment geochemistry, are concomitant with increases in eutrophic chironomid taxa. Redundancy analysis (RDA) and partial RDAs established that δ¹⁵N and NAPp were controlling factors of chironomid community compositional change during the Neolithic (4000–2500 BC) and Bronze Age (2500–600 BC). Bronze Age farming had a considerably greater impact on the lake systems than Neolithic farming, as indicated by a higher proportion of eutrophic taxa and increases in δ¹⁵N, C:N and δ¹³C values, consistent with increased erosion and agricultural inputs. Findings emphasise the importance of identifying the natural, pre-impacted state of a lake system to determine the extent of agricultural impact accurately. The timing and magnitude of change show that Neolithic and Bronze Age farming exhibited a strong control over chironomid communities at all three sites.     

Airflow patterns in a small subalpine basin

Summary A study of mean wind speeds and directions has been completed in the Snowy Range of Southern Wyoming, U.S.A. It was conducted in a subalpine ecosystem at an altitude of 3 200 m to 3 400 m above sea level during the summers of 1988 and 1989. Indexes of deformation and axes of asymmetry due to wind shaping of Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) are related to wind speeds and directions on a 100 m × 100 m grid spacing over the 300 ha research site. Isotach and airflow patterns are drawn to represent climatological near-ground-level winds.A statistical analysis of the wind data and deformation indexes indicates that the indexes estimated independently by three of the authors were not significantly different at the F_0.025 level. Two methods of calculating wind speeds were applied. At lower mean wind speeds in Engelmann spruce, results from the Wade-Hewson method were not significantly different from the Griggs-Putnam method at the F_0.025 level. In slightly higher wind speeds in subalpine fir, the Wade-Hewson method produced significantly lower wind speeds than the Griggs-Putnam method.With 3 Figures     

Green Watershed in Yunnan: a multi-scalar analysis of environmental non-governmental organisation (eNGO) relationships in China

Responding to China's major environmental challenges, researchers are increasingly exploring dynamics between international non-governmental organisations, the nation-state, and local communities. Much less understood are domestic environmental non-governmental organisations (eNGOs) and their interactions with actors across scales. This paper responds by exploring domestic eNGOs and interactions with institutional actors, including international donors, and with levels of Chinese government. The practices of eNGOs in China are influenced by interactions at various scales. Rather than being directly influenced by international partners and simply constrained by state regulations, Chinese eNGOs are embedded in more complex power relations. These interrelationships are exemplified in the operations of Green Watershed, a domestic eNGO working in Yunnan Province. Green Watershed has extensive interactions with international donors and various levels of government as a result of its national campaign and long-term local projects. Relationships between eNGOs’ international donors and the Chinese government are significant in influencing eNGO practice. NGO–government relations in China are inconsistent and constantly changing owing to the diverse interests and priorities of the various levels of government. The impacts of the local practice of Chinese eNGOs are deeply informed by their relationships both at and beyond the local level. Complex interrelationships make it difficult to achieve bottom-up, participatory resource management in China.