International management of Atlantic salmon, Salmo salar L., by the North Atlantic Salmon Conservation Organization, 1984–1994

Abstract  The development of distant water fisheries at West Greenland and in the Northern Norwegian Sea during the 1960s and, more recently, in the Faroese zone, led to the establishment, in 1984, of the North Atlantic Salmon Conservation Organization (NASCO). This paper summarizes the progress made in the 10 years since this Organization was established towards achieving its goals of conservation, restoration, enhancement and rational management of salmon, Salmo salar L., stocks. Agreements on regulatory measures have reduced the proportion of the total catch taken by the distant water fisheries and, in the case of the West Greenland fishery, management is now firmly based on scientific advice. The stability created by these regulations has allowed NASCO to address the broader areas of conservation called for under the Convention and international action has been taken to address a number of threats to the resource, including the impacts of aquaculture, introductions and transfers, and fishing in international waters by non-contracting parties. These actions are described and the paper concludes that NASCO has a significant role to play in the future, both through continued regulation of the fisheries and by promoting international cooperation to address these broader threats to the resource.     

Clinical and pathological findings of Babesia infection in dogs

The clinical and pathological findings of Babesia infection in 32 dogs in northern Australia are presented. Eleven different breed types were represented from 6 localities in north Queensland and one locality in northern Western Australia. Twenty three (72%) were males. Babesia-infected dogs were grouped by the degree of haematological disturbance and clinical severity: Acute babesiosis (25/32), all pups with severe haemolytic anaemia; subclinical carriers (5/32) with non-specific malaise, characterised haematologically by a normal erythrogram but marked leucopenia; chronic anaemia, observed in 2 adult dogs. Pups were azotaemic (serum urea greater than 6.6 mmol/l) and had elevated serum bilirubin levels (20.8 to 48.5 mmol/l). Total serum protein was usually within the normal range. Pups that died were also hypoglycaemic and severely hyperkalaemic (K+ greater than 10 mmol/l). Low parasitaemias in routine blood smears complicated diagnosis but smears made from ear or toe capillaries, or after haematocrit concentration, greatly enhanced finding parasitised cells. At necropsy, pallor and jaundice were the most consistent observations. Haemoglobinuric nephrosis, an active reticulo-endothelial system and capillaries packed with large numbers of infected erythrocytes were the main histopathological findings. A combination of imidocarb dipropionate at 5 mg/kg body weight, given intramuscularly, with fluid therapy and blood transfusion was the most successful treatment.     

RELATIONSHIP BETWEEN SUGAR MAPLE DECLINE AND CORRESPONDING CHEMICAL CHANGES IN THE STEM TISSUE

Wood cores were taken at breast height of mature sugar maple (Acer Saccharum Marsh.) trees of approximately the same age from four sites in Ontario, Canada differing in soil characteristics and general tree health. The soils of two of the sites were acidic (podzols), while the soils of the other two sites were calcareous (brunisols). Selected elemental analyses using Neutron Activation Analysis were conducted on the soils and the xylem wood of the sugar maple trees, and the results were compared relative to tree health. Aluminum in stem xylem was found to be significantly higher in declining trees (mean 7.7 ppm) relative to the healthy trees (mean 4.0) from the acidic sites, where aluminum was freely available in the soil. Soil extractable aluminum was also significantly higher in the soil adjacent to the declining trees (mean 5.10) compared to the healthy trees (mean 3.20). These results show that xylem aluminum contents reflect the increased availability of aluminum in acidifying soils and provide additional evidence that dendrochemistry may be used as a proxy environmental monitoring tool.     

Clinical pathology of experimental stephanuriasis in pigs

SUMMARY Haematology and serum aspartate aminotransferase and alanine aminotransferase activities were studied during the migration phase of Stephanurus dentatus in the livers of experimentally infected pigs. There was no evidence of anaemia but total leucocyte counts were raised and peripheral eosinophilia began 2 to 3 weeks after infection. Peak eosinophilia occurred 6 to 7 weeks after infection and levels were still elevated at 20 weeks. Lymphocyte and neutrophil numbers remained constant. Reinfection did not stimulate a secondary eosinophil response. Only aspartate aminotransferase was temporarily elevated. The gross pathology resulting from the infections is described. Several clinicopathological differences in the response of pigs to invasion of the liver by S. dentatus were noted compared to those produced by Ascaris suum but none are pathognomonic.     

The Determination of Risk Adjusted Discount Rates for Private Sector Forestry Investment

In forestry economics a great deal of attention has been givento the choice of discount rate when this activity has been constitutedas part of the public sector investment portfolio. In contrast,little attention has been paid to the discount rate that shouldbe used when afforestation is considered as part of a portfolioof investments in the private sector. There are major difficulties,both practical and methodological, in determining the discountrate that should be applied to private as opposed to publicsector afforestation projects. The central purpose of this paperis thus to derive the appropriate discount rate for privatesector forestry with attention focused primarily on risk adjusteddiscount rates of the type applied in commercial capital budgeting.The relevant risk adjusted rates are then employed to assessthe viability of a 28.5 ha private sector afforestation standbased on Oceanic forestry technology. The afforestation projectis assessed under the differing tax and grant anangements introducedin 1988, available within the Farm Woodland Scheme and the WoodlandGrant Scheme. The analysis finally concludes that the use ofa risk adjusted discount rate leads to forestry, under bothschemes, being characterized as a profitable venture.     

A difference between biological effects of gamma rays and heavy ions

When irradiated with gamma rays, Arteinia eggs show the typical sigmoidal survival curve of a multicellular organism, with little change at low doses and an abrupt decrease in survival above a threshold dose. On irradiation with 160-Mev oxygen ions, the threshold disappears and viability can be destroyed by passage of a single energetic ion.