Kenneth Drinkwater (Institute of Marine Research, Norway)
Shoshiro Minobe (Graduate School of Science, Hokkaido University, Japan)
Ocean upwelling regions contain the most productive fisheries in the world accounting for around 25% of the global catch. This fish production results from upwelled nutrients that lead to high primary and secondary production. Characteristically, fisheries in upwelling areas are dominated by small and medium sized schooling pelagic fish, especially sardine and anchovy that contribute significantly to the annual global fish production. Bakun (1990) proposed increased winds in eastern boundary currents (EBCs) under climate change will result in increased upwelling. While evidence for recent increased upwelling has been found in some EBCs, other EBCs and upwelling regions have shown decreased upwelling intensity or had no trend at all. As such it has recently been suggested that Bakun’s hypothesis was over simplified and it is not clear that there will be increased upwelling in EBCs, at least the Pacific, in the future. Clearly more work is needed to determine the future state of upwelling, not only in EBCs, but in other upwelling types. Upwelling systems typically have been poorly represented in global models owing to the small spatial scales of the upwelling relative to the horizontal resolution of the global models. Indeed, EBCs are often associated with warm temperature biases in the model results that strongly limit the prediction of future evolution. Also, it is not simply local winds that affect upwelling but basin-scale physics needs to be considered to understand and simulation regional upwelling variability. For these reasons the most recent high resolution global model results, as well as available regional models of upwelling regions, are needed to meet some of the challenges in developing upwelling scenarios under future climate change. Also, any attempt to predict future fisheries yields in upwelling areas in relation to global warming needs to consider retrospective studies of the impact of climate variability of anchovies and sardines.
The main objective of the workshop is to investigate the potential effects of climate change on upwelling systems. The most recent available global and regional models will be used to determine future scenarios in the upwelling regions of the world’s oceans. These, together with information on the present trends in upwelling, will be used to determine the likely impacts on the primary and secondary production and further on fish and fisheries. This will be undertaken using a combination of retrospective analyses and ecosystem modeling. Examination of several of the major upwelling areas around the globe, e.g. within eastern and western boundary currents, along the equator, in the Indian Ocean, in Polar Regions, etc. will allow comparisons between regions. The workshop will also cover physical, biogeochemical, biological, fish and fisheries dynamics. The workshop will consist of invited and contributed talks that will focus upon (1) future climate scenarios in upwelling regions around the globe and (2) recent observed trends in these regions. Breakout groups will discuss the likely impacts of the future upwelling scenarios on the physics and biogeochemistry, as well as the biology, including fish and fisheries and will identify what additional research is needed. Plenary presentations and discussions from the breakout groups will allow interactions between disciplines and trophic levels.
Several outputs will produced from this workshop. The workshop stems from a CLIVAR/IMBER/SOLAS working group and a workshop report will be presented to these global change projects. A journal paper on the recent upwelling trends in as many of the world’s upwelling regions and on their physical and biogeochemical (e.g. oxygen) scenarios under future climate change is also planned. The expected impact of future change on anchovies and sardines will either be highlighted in the workshop report or in a separate paper focused only upon this topic, a decision that will be made during the workshop. The results of the work on anchovies and sardines will be presented at the planned joint 2016 PICES/ICES Symposium on Drivers of Dynamics of Small Pelagic Neritic Fish Resources.”