On Friday, July 23rd, Page Valentine, a Research Geologist with the USGS Woods Hole Coastal and Marine Science Center, collected his 5,000th sample in the Stellwagen Bank National Marine Sanctuary of Massachusetts Bay!
5000th Sample Collected!
Before Page began studying the Stellwagen Bank National Marine Sanctuary (SBNMS), little was known of the seafloor environments in this heavily utilized area offshore of Cape Cod, MA. In collaboration with NOAA and the Canadian Hydrographic Service, USGS conducted a multibeam topographic and backscatter survey of the SBNMS region that in it’s time (around 1993) was the among the largest seafloor mapping efforts in history. Page has now collected 5,000 sediment samples to verify the remotely-sensed bottom types covering 3,800 square kilometers of the continental shelf. The mapping methodology developed by Page is the first successful attempt to integrate surficial geology, sediment stability and movement, and seabed features to fully characterize substrate conditions of this topographically rugged and diverse region. Glacial ice left its indelible imprint in the form of moraines, eskers, hanging valleys, banks, basins, ice fall deposits, iceberg gouges, and other features that are the foundation for highly productive marine ecosystems. In water depths of less than 50 meters, Stellwagen Bank has long been heavily impacted by major winter storms, which generate large sand waves, and also by mobile bottom fishing gear which has re-shaped large areas of the ocean floor.
This series of interpretive maps (18 contiguous quadrangles) provides a framework for scientific research in the region and for managing fishery resources and infrastructure. For example, extensive boulder ridges (remnants of glacial eskers and moraines) are commonly utilized by juvenile and adult commercial fish species; thus GIS-based maps of boulder ridges allow fisheries managers to locate and calculate the areas of these critical habitats. The dynamics of seabed sediments determine the distribution of many species, such as juvenile cod which are now known to require a stable pebble gravel habitat. Juvenile sea scallops are adapted to gravel and immobile sand and cannot survive on mobile sand. The distribution of highly invasive tunicates (commonly called sea squirts) also can be predicted from the mapping results because it can only survive on hard substrates and requires a specific temperature range for reproduction.