Human-induced changes in life-history traits have been observed for many harvested populations, with a component of those changes being attributed to an evolutionary (i.e., genetic) response. Most notably, fish stocks that experience high fishing mortality show a tendency to mature earlier and at a smaller size. Some have suggested that...
The central objective of fishery management is to ensure the sustainability and profitability of the resource base. The
importance of the fish stock's age-structure is increasingly recognized in economics and ecology. Still, current
policies predominately rely on the aggregate biomass. We carefully calibrate a detailed model on the North-East
Arctic...
This paper shows that the importance of fish habitat depends in part on the management of the fishery. Two cases of cold water coral - fisheries interactions are studied in a bioeconomic model setting: Norwegian and Icelandic redfish fisheries. The two countries have applied different types of management; Norway’s management...
We introduce a modified version of the standard Gordon-Schaefer fishery model. Standard theoretical models usually treat fishing effort as an aggregate measure encompassing all different types of inputs. Consequently, these models do not enable us to examine the problem of fleet redundancy and capital stuffing separately, i.e. two ways in...
The objectives pursued by governments managing fisheries may include harvesting the fish stocks to maximize profits, to minimize the impact of harvesting on the marine ecosystem, or to secure jobs in the fishing industry. These objectives all depend on the composition of the fishing fleet as the various vessel types...
The sustainable management of small-scale fisheries in coral reef ecosystems constitutes a difficult objective especially because these fisheries usually face several stringent pressures including demographic growth and climate changes. The implications are crucial in term of food security as fish represents the major protein source for local populations in those...
Over the past 30 years, fisheries management on the west coast of the United States has undergone a rapid evolution. Starting with very limited management and stock assessment techniques, the complexity of fishery models and size and breadth of fishery data sets have gradually increased, which has coincided with increasingly...
Globally, alterations of marine food webs due to overfishing of species at high trophic levels are leading to unpredictable changes in coastal ecosystems. In parts of the Western Indian Ocean, increasing abundances of sea urchins (particularly Tripneustes gratilla) have been observed. Sea urchins’ grazing intensity on seagrass beds is generally...
Fishery scientists distinguish between recruitment overfishing (i.e. suboptimally low reproduction because the spawning stock is fished down) and growth overfishing (i.e. catching fish at an inefficiently young age). We use an age-structured bio-economic model to study how important the (endogenous) recruitment is compared to the growth of individual fish under...
This paper reviews New Zealand‚ orange roughly fishery management and applies a bioeconomic model to explain the seamount depletion externality by bottom trawling. The model shows that despite an upper limit on annual harvest, the potential gains in economic rent from trawling on pristine habitat, where catch rates are high,...