Award: OCE-1459216

The key outcome is that our original, overarching hypothesis, the Coastal Amplification of Supply and Transport (CAST) hypothesis, explaining the persistence of very high abundance of C. finmarchicus in the western Gulf of Maine despite recent warming, has been supported by our observations and modeling investigations to date. We have also come to recognize that the dynamics controlling population abundance in the eastern Gulf of Maine are different, in that source of advective supply of Calanus to in the eastern Gulf of Maine Basin in summer is likely to have a more important role in determining summer abundance in this region. Our NSF funded research has enabled us to provide insight into the temporal and spatial dynamics of C. finmarchicus, the key food source for northern right whales in the Gulf of Maine, in relation to the decline of sightings and reduced fecundity of northern right whales in the Gulf of Maine since 2010. We find significant reductions of C. finmarchicus in summer and fall but significant increases in C. finmarchicus in the western Gulf of Maine in spring (due to earlier timing of phytoplankton production) that are consistent with recent observations of northern right whale distribution. These findings are of great interest to NOAA managers, fishermen and conservations, and our results have been cited in several recent media reports on the decline and migration shifts of northern right whales. We note that another key outcome of our project is contribution to a baseline of time series information on the abundance of C. finmarchicus in the Gulf of Maine. The overwhelming dominance of this species in the biomass of mesozooplankton in the Gulf of Maine and the uniqueness of its life history and large, energy-rich developmental stages place this species at the foundation of the Gulf of Maine?s pelagic ecosystem. Continued environmental change due to atmospheric greenhouse gas increases will continue to place pressures on this species to sustain its historic abundance and maintain the present structure of the Gulf of Maine ecosystem. Our achievements to date, in which we report on the details of these key outcomes, are represented by: Presentations at conferences and seminars During the review period, we presented the results supported at least in part by project funds at 18 conferences or seminars. See the list of presentations in the final report. Preparation of manuscripts. Six manuscripts citing support from this NSF award have been published or submitted during the review period. See the list of publications in the final report. Last Modified: 04/30/2018 Submitted by: Joseph E Salisbury