Structural time series methods are applied to modeling endogenous fishing effort in the German North Sea shrimp fishery. The effects on fishing effort of shrimp price, catch per unit effort and environmental variation are examined. Preliminary results suggest that fishing firms do not respond much to price changes but they...
The fish markets in Finland were formerly protected from international competition. The markets were gradually
opened to free competition in the 1990s due to the EEA agreement and EU membership. As a consequence, the importation of fresh salmon from Norway rapidly increased, and imported salmon captured the markets from domestic...
The optimal harvesting time in a fish farm is analyzed in the paper. Fish population is assumed to be heterogeneous with respect to weight, so a distributed parameter dynamic model is considered. Theoretical and numerical results are obtained and compared with the ones concerning homogeneous fish cultures only. The results...
For the probabilistic model of shuffling by random transpositions we provide a coupling construction
with the expected coupling time of order C*n*log(n), where C is a moderate constant. We enlarge the
methodology of coupling by including intuitive non-Markovian coupling rules. We discuss why a typical
Markovian coupling is not always...
When dealing with time, a fishery manager faces a major difficulty. On an N-period time horizon, should he follow
several short-run objectives for every n sub-period, or should he consider only the long-run objective? If a European
manager trying to implement a stock recovery plan prefers to achieve the long-run...
ICES – the International Council for the Exploration of the Sea – was founded more than a century ago out of
concern for overfishing. However, today’s global marine ecosystems are for the most part in a degraded state, many
alarmingly so. Why is the science used so little to make...