Plântulas de soja 'Tracajá' expostas ao ozônio sob condições controladas

The objective of this work was to assess initial growth, biomass production, gas exchange and antioxidative defenses of soybean 'Tracajá' seedlings, cultivated in the Amazonian region, exposed to ozone under controlled conditions. Seeds germinated in pots were placed in two chambers, one with filtered air (AF) and other with filtered air plus 30 ppb of ozone (AF + O 3). At 10 and 20 days after sowing, gas exchange, growth and biomass were measured; at 20 days after sowing, antioxidative defenses (ascorbic acid and superoxide dismutase) were analyzed. Net photosynthesis, stomatal conductance, transpiration rate, height, leaf area and biomass were 16, 27, 11, 22, 29 and 18% smaller, respectively, in AF + O3 at 10 days after sowing. At 20 days after sowing, besides this parameters, root length, stem diameter and root:shoot ratio were 10, 15 and 12% smaller, respectively, although ascorbic acid concentrations and superoxide dismutase activity increased. Soybean 'Tracajá' seedlings have low tolerance to concentration of 30 ppb of ozone

Profile of the illegal abalone (<i>Haliotis midae</i>) fishery in the Eastern Cape, South Africa: organised pillage and management failure

Since 1997 the Eastern Cape of South Africa has become a major source of supply for the illicit abalone trade as illegal fishers have located a substantial abalone (Haliotis midae) resource. We determined illegal fishing effort and yield in the Port Elizabeth-based abalone fishery, and used biological indices to determine the impact of fishing on the abalone stock. The failure of the state to issue fishing rights and conduct effective sea-based compliance, combined with the incentives to fish abalone (high price, low cost, ease of access) created the conditions for a full scale illegal fishery to emerge very rapidly. By 2005, the scale of the fishery was remarkable: a fleet of 30 purpose built vessels existed, harvesting 1000–2000 tons of abalone with an export value of 35–70 million USD per year. The uncontrolled fishing effort had a dramatic effect on the stock: the average size of abalone decreased significantly, densities declined in the sampling areas, but recruitment of young abalone was still observed at the heavily fished Cape Recife site. It is concluded that the illegal fishing operations and the resultant ecological effects on the abalone resource, reflect deficiencies in South Africa's current abalone fisheries management and compliance paradigm