Keith Brander IMBER-GODAE 12 June 2007 Variability and shifts in marine ecosytems Keith Brander ICES/GLOBEC Coordinator

Keith Brander IMBER-GODAE 12 June 2007 People are interested in climate change and in changes in marine ecosystems.

Keith Brander IMBER-GODAE 12 June 2007

Rapid spread of tropical species along the continental slope Is the rate of biological shift commensurate with the rate of ocean climate shift? Should we say: “the ecosystem is changing” or “the ecosystem is moving”? What about the conservation of ecosystem functions? Is that allowed to move too? Is fish production affected? Should we be managing differently?

Keith Brander IMBER-GODAE 12 June Biogeographic shifts of ~ 50km y -1 in NE Atlantic 2Increases in number of warm water species Attributed to (i) advection and (ii) change in local properties i.e transport of both biota and heat, salt etc. (Issue of Eulerian vs Lagrangian observation)

Keith Brander IMBER-GODAE 12 June 2007 Southern shelf edge species Psuedo-oceanic temperate species Changes in range of copepod species - Beaugrand et al Science Based on 176,778 CPR samples. Euchaeta gracilis, Euchaeta hebes, Ctenocalanus vanus, Calanoides carinatus Rhincalanus nasutus, Eucalanus crassus, Centropages typicus, Candacia armata, C. helgolandicus Other taxa have also shifted at similar rates

Keith Brander IMBER-GODAE 12 June 2007 Northward spread of cod at West Greenland from Other areas have shown similar rates

Keith Brander IMBER-GODAE 12 June 2007 The cod stock at Greenland is recovering as conditions there get warmer. A positive effect which poses some management questions: How should it be managed? What about the shrimp fishery? What about sharing with Iceland? Could Greenland help recovery of Canadian stocks? IPCC predicts slow warming at Greenland

Keith Brander IMBER-GODAE 12 June 2007

Cod recruitment at Greenland

Keith Brander IMBER-GODAE 12 June 2007 Decline of the Baltic cod stock will this continue? Less inflow of Atlantic water Falling salinity

Keith Brander IMBER-GODAE 12 June 2007 Recovery of Gulf of St Lawrence cod stock – has begun now the environment has improved 2004 year class is biggest since 1980 Survival is higher Seal predation is lower Recent rise in temperature

Keith Brander IMBER-GODAE 12 June 2007 Figure 2: Monthly temperatures by depth for the Northern Gulf with recaptures of tagged cod (yellow box-plots).

Keith Brander IMBER-GODAE 12 June 2007 Regime shifts in N Pacific – are the (physical and biological) processes non-linear? Note use of regional synoptic indices

Keith Brander IMBER-GODAE 12 June 2007 Data sources, current trends, attribution of causes Sources Time series of commercial fish species for many areas Time series (near-surface mesozooplankton) from CPR for some areas Trends Northward distribution shifts (fish, plankton) in NE Atlantic Decline in abundance of many fish species Attribution Physical forcing is both local and via large scale advection Biological forcing could be top-down or bottom-up Very strong direct human impact through fishing

Keith Brander IMBER-GODAE 12 June 2007 Data and analyses needed Improved availability and presentation of trends and changes in ocean properties (at many scales) Climate scenarios which include ocean properties (temperature, salinity, advection, upwelling, stratification) Compilation and interpretation of comparative regional data to test the attribution of change

Keith Brander IMBER-GODAE 12 June 2007 Gaps Few time series of marine biota are suitable for detecting and attributing effects of climate change (whether in distribution, abundance or phenology) (mention Perkinsus – oyster parasite, as a good example which combines observation and modelling to determine causes) The geographic and biotic coverage of this presentation is itself limited

Keith Brander IMBER-GODAE 12 June 2007 Sensitivity/vulnerability Some marine ecosystems are topographically bounded, but others (e.g. planktonic systems) are not, therefore they can shift distributions quickly. Shallow areas are more vulnerable to changes in temperature and salinity (the communities there are also more adapted to extremes) Coastal areas are vulnerable (and relatively well studied), but are usually impacted by many anthropogenic factors other than climate change