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Sound decisions on control actions for established invasive alien species (IAS) require information on ecological as well as socio-economic impact of the species and of its management. Cost-benefit analysis provides part of this information, yet has received relatively little attention in the scientific literature on IAS. We apply a bio-economic model in a cost-benefit analysis framework to greater Canada goose , an IAS with documented social, economic and ecological impacts in Flanders (northern Belgium). We compared a business as usual (BAU) scenario which involved non-coordinated hunting and egg destruction with an enhanced scenario based on a continuation of these activities but supplemented with coordinated capture of moulting birds. To assess population growth under the BAU scenario we fitted a logistic growth model to the observed pre-moult capture population. Projected damage costs included water eutrophication and damage to cultivated grasslands and were calculated for all scenarios. Management costs of the moult captures were based on a representative average of the actual cost of planning and executing moult captures. Comparing the scenarios with different capture rates, different costs for eutrophication and various discount rates, showed avoided damage costs were in the range of 21.15 M€ to 45.82 M€ under the moult capture scenario. The lowest value for the avoided costs applied to the scenario where we lowered the capture rate by 10%. The highest value occurred in the scenario where we lowered the real discount rate from 4% to 2.5%. The reduction in damage costs always outweighed the additional management costs of moult captures. Therefore, additional coordinated moult captures could be applied to limit the negative economic impact of greater Canada goose at a regional scale. We further discuss the strengths and weaknesses of our approach and its potential application to other IAS.

Rat superior cervical sympathetic ganglion was used to begin studying the regulation of molecular components of the synapse. Ganglionic postsynaptic densities (PSDs) exhibited a thin, disc-shaped profile electron microscopically, comparable to that described for brain. Moreover, the presumptive ganglionic PSD protein (PSDp) was phosphorylated in the presence of Ca2+ and calmodulin, bound 125I-labeled calmodulin, and exhibited a Mr of 51,000, all characteristic of the major PSD protein of brain. These initial studies indicated that ganglionic PSDp and the major PSD protein of brain are comparable, allowing us to study synaptic regulation in the well-defined superior cervical sympathetic ganglion. To obtain enough quantities of ganglionic PSDp, we used synaptic membrane fractions. During postnatal development, calmodulin binding to the ganglionic PSDp increased 411-fold per ganglion from birth to 60 days, whereas synaptic membrane protein increased only 4.5-fold. Consequently, different synaptic components apparently develop differently. Moreover, denervation of the superior cervical sympathetic ganglion in adult rats caused an 85% decrease in ganglionic PSDp-calmodulin binding, but denervation caused no change in synaptic membrane protein 2 weeks postoperatively. Our observations suggest that presynaptic innervation selectively regulates specific molecular components of the postsynaptic membrane structure.