| Marine Ecosystem Responses to Climate-Associated Remote Forcing from the Labrador Sea |
| Andrew J. Pershing | |
| University of Maine/ | |
| Gulf of Maine Research Institute |
| Collaborators |
| Outline |
| Project goals | |
| Results | |
| Future plans | |
| Goals |
| Characterize interannual variability in physical and biological conditions in GOM/GB | ||
| Retrospective approach | ||
| Identify drivers of variability | ||
| Focus on remote climate forcing | ||
| Compare GOM with nearby regions | ||
| Scotian Shelf, MAB | ||
| Gulf of Maine Regime Shift |
| Hallmarks | ||
| Abrupt shift in 1990, reversal in 2001 | ||
| Multiple trophic levels | ||
| Strongest in autumn | ||
| Possible Mechanism |
| Salinity and Fall Stratification |
| 1D Mixing Model | |
| Salty (1986) and Fresh (1998) initial TS-profiles | |
| 1980-1999 NCEP forcing |
| Possible Mechanism |
| Impact of Shift |
| Increase in small copepods, including Calanus copepodites | |
| Decrease in adult Calanus |
| Impact of Shift |
| Impact of Shift |
| Herring-Copepod Interactions |
| Fall-winter: larval herring | ||
| Inefficient feeding | ||
| Slide 13 |
| Slide 14 |
| Discussion |
| Importance of fall-winter period | |||
| Spring has dominated research (e.g. GLOBEC) in NW Atlantic | |||
| Spring bloom, spawning of cod and haddock | |||
| CPR data suggests that there is considerable variability in fall | |||
| Fall ecosystem changes can persist throughout the year | |||
| 1990s Freshening |
| Gulf of Maine freshening part of larger pattern extending into Labrador Sea | ||
| Non-local processes can influence Gulf of Maine | ||
| 1990s Freshening |
| Freshwater in early 1990s traced to Arctic | ||
| NAO+ winds in late 1980s pushed Arctic ice out | ||
| Increased outflow through Canadian Archipelago | ||
| Future Work |
| CAFƒ Gulf of Maine Workshop III | ||
| Theme: Arctic Influences on NW | ||
| Atlantic Shelf Ecosystems | ||
| November 7-8, GMRI, Portland, ME | ||
| Compare Gulf of Maine with Mid-Atlantic Bight | ||
| Oleander CPR data set | ||