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Boston Harbor Ecosystems

Ecosystem Zones


closeup of estuary zone Graphic diagram of the Ecosystem zones

Figure based on Knebel & CircÚ, 1995, Seafloor Environments within the Boston Harbor - Massachusetts Bay Sedimentary System: A Regional Synthesis; Journal of Coastal Research; vol. 11, no. 1

Ecosystem zones:

Watershed:
area drained by rivers and streams discharging to an estuary
  • rivers have been used for transportation, water supply, and waste discharge
  • rivers are a source of fine-grained sediments
Estuary:
a coastal embayment or the mouth of a river
  • characterized by mixtures of fresh and salty waters
  • influenced by the ebb and flow of ocean tides
  • protected from large waves
  • tends to receive large amounts of nutrients and have high organic productivity
  • tends to be sink for fine-grained sediments
Inner Shelf:
an area affected by tidal and storm waves and currents
  • sediment erosion and redistribution by sub-aerial process during past sea-level changes
  • sediment resuspension and winnowing by modern waves and currents
  • supply of fine-grained sediments is small
Basin:
deeper-water offshore area extending below normal regions of tidal- and storm-induced currents
  • natural settling area, having weak bottom currents
  • significant suply of fine-grained sediments, with much lower organic matter than in estuaries

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