Problems to be solved
Marine fish resources are in a crisis world wide today, probably mainly due to overexploitation of fish stocks. Simultaneously, it is well-known that fish stocks, especially in regions with harsh natural conditions, e.g., the polar oceans, experience large natural variations depending on natural environmental parameters, such as feeding conditions, sea water temperature, ice coverage and radiation conditions. In today's fishery management, only few of these parameters are considered for fish stock size estimation, which is the basis for determining fishing quota. A more comprehensive understanding of the causal chains of natural impact parameters is essential for a more sustainable exploitation of wild fish stocks in the future. This will be even more relevant, if global change (enhanced greenhouse effect, ozone depletion) and its impact on marine ecosystems will come true as expected by the scientific community.
Scientific objectives and approach
The main objective of UVAC is to investigate the impact of solar ultra-violet radiation (UVR) on the Northeast Arctic cod stock. This relation will be investigated as part of a more comprehensive impact system, including both other geophysical factors such as climate, and biological species which are important for the cod stock (zooplankton, phytoplankton). The UVR impact will be investigated both statistically using long-term biological and geophysical data records, and in-depth in dedicated field and laboratory experiments. A second major objective is to develop modelling tools, which will be used to estimate cod stock size based on geophysical information available from remote-sensing and ground-based monitoring, thus providing a more reliable basis for a sustainable management of marine resources. The project will be performed using three sets of biological and geophysical data, covering different time scales and having different levels of information. Data over a 100-year period, consisting of annual cod landing records and C. finmarchicus annual biomass estimates on the biological side, and records of local climate conditions, regional climate indices and total ozone/UVR records on the geophysical side, will be used to determine long-term correlations, and, if possible, to separate the impact of climate from that of UVR. Data with a significantly enhanced degree of detail over a 14-year period (1985-1998) will then be used to investigate the impact of UVR on the species involved in more detail. To this purpose, high-resolution maps of relevant UVR parameters, based on remote-sensing data of total ozone and cloud coverage and calculated with state-of-the art radiative transfer models, will be constructed for the cod spawning area. These investigations will be supported by field and laboratory experiments/studies, which will cover the whole scope of biological and geophysical parameters assumed to play a role in the UVR - cod interaction. The combined results of the above work will be used to develop modelling tools (short-term process modelling and long-term modelling) which can reproduce past (observed) cod stock variations and predict variability in the future.
The project will hopefully enlighten the influence of a potentially very important natural parameter on marine ecosystems. Integration of UVR impact processes into fish stock size modelling tools have the potential to improve these tools considerably, both in terms of uncertainty reduction and long-term applicability of such tools, which is of great importance for a future sustainable fishery management.
Funding SchemeCSC - Cost-sharing contracts
20008 San Sebastian