Metabolism and organ distribution of nonylphenol in Atlantic salmon (Salmo salar)

Nonylphenol (NP) is a breakdown product of alkylphenol polyethoxylates (APEs), an important class of non-ionic surfactants that are widely used in many detergent formulations and plastic products for industrial and domestic use. A complex microbial degradation pattern, characterized by the formation of several metabolic products that are more toxic than the parent compound, has been established for APEs. We have studied the in vivo metabolism and organ distribution of NP in juvenile salmon. Fish were exposed to a single oral dose of [³H]-4-n-NP (1295 KBq, 25 μg) and sampled at 24, 48 and 72 h after exposure. Metabolites were separated by radio-high-performance liquid chromatography and tentatively identified by co-chromatography with standards characterized by mass spectrometry. Our results show that 4-n-NP was mainly metabolized in vivo to its corresponding glucuronide conjugate and to a lesser extent to various hydroxylated and oxidated compounds. Biliary excretion at 72 h after dosing amounted to 2.83±0.75% of the administered radioactivity. Kinetic analysis shows that NP-glucuronide accounted for 83, 95 and 81% of total radioactivity in the HPLC-injected bile sample at 24, 48 and 72 h, respectively, after exposure. The half-life of residues in carcass and muscle was between 24 and 48 h after exposure.     

Improving market access for salmon through free trade agreements: The role of interests and institutional frameworks

This article compares the strategies of Chile and Norway toward free trade agreements (FTAs) and the market access results achieved for salmon, showing that Chile has been more successful than Norway. Hence, the article addresses whether Norway will be able to compete with Chile with regard to better market access for salmon through FTAs. The second part of the article analyses the trade interests and the institutional frameworks chosen to pursue FTAs, emphasizing how these two countries operate under different conditions for market access improvement, which in turn can make it difficult for Norway to take the market access lead from Chile.     

Introducing run-size driven fisheries management for the coastal fishery of Atlantic salmon: Preseason forecasts for policy makers

The Finnish coastal fishery of Atlantic salmon (Salmo salar) in the northern Baltic Sea is regulated using multi-annual, pre-fixed, opening dates of harvests that aim to enhance spawning escapement of early migrating wild salmon. Such an inflexible management regime does not set regulations that track varying run sizes of salmon. We introduce an array of computational intelligence techniques to estimate and forecast coastal run size and escapement of salmon into three spawning rivers in the northern Baltic Sea. Our results indicated that the present management pattern, driven largely by regional fisheries policy, contrasts greatly with a “run-size driven” (i.e. abundance-based) management approach. Introducing run-size driven management, i.e. setting regulations annually by tracking preseason forecasts, would better ensure adequate escapement and at the same time allow the maintenance of coastal catch at sustainable level. Setting regulations annually would allow effective harvesting in years when the run is high, and would effectively restrict harvests when the run is low.     

Searching for sustainability in aquaculture: An investigation into the economic prospects for an integrated salmon–mussel production system

The pollution effects of cage aquaculture represent an external cost to society, and the challenge for environmental economists has been to estimate the magnitude of these costs and to suggest ways in which they can be mitigated or ‘internalised’. One possible mitigation strategy involves the development of integrated production systems based on polyculture, and this paper examines the financial viability of such a system that integrates the farming of salmon and mussels. The results demonstrate the commercial potential of an integrated salmon–mussel production system under present market conditions, but highlight the critical role played by future price trends.