This map shows the relative abundance and productivity of phytoplankton, as indicated by seasonal chlorophyll a concentrations and average rate of photosynthesis (primary production) in surface waters.

Data Considerations

This map displays seasonal chlorophyll a data from The Nature Conservancy’s Northwest Atlantic Marine Ecoregional Assessment (NAMERA), which used satellite images from the Sea Viewing Wide Field-of-View Sensor (SeaWiFS) obtained from NASA. Tim Moore (Ocean Process Analysis Laboratory, University of New Hampshire) processed the data to improve the estimation of chlorophyll in the coastal zone. Seasonally averaged chlorophyll images were created for the time period from January 1998 through December 2006.

The Northeast Fisheries Science Center (NEFSC) provided the data for mean primary production (rate of photosynthesis) between 1998 and 2007. The dataset was generated with a model that combined satellite chlorophyll (SeaWIFS sensor), sea surface temperature (AVHRR-Pathfinder, MODIS-Terra and MODIS-Aqua sensors), and photosynthetic activation radiation data. Satellite data was provided courtesy of Kimberly Hyde (NEFSC-Narragansett Laboratory).

The data cover a large geographic area from the Gulf of Maine to Cape Hatteras, North Carolina, extending out to the continental shelf-slope break. The Nature Conservancy obtained this dataset from NEFSC and prepared it for Northeast Ocean Data.


This is a final data product. We do not currently have plans to change or update the dataset.

Support for Regional Ocean Planning

For information about how data and maps are being developed with stakeholder input and used to support regional ocean planning, please visit the marine life page on the Northeast Regional Planning Body’s website.