What the Macrofaunal Associations Tell Us.

    The macrofaunal associations, and microfaunal assemblages can tell us a great deal about climate, hydrology, and salinities of the past.  Without the use of these assemblages it would be very difficult to piece together the history of any given region.  In our case they indicate a cold (subarctic)  high salinity water occupied the deeper parts of the basin, which was overlain by cold lower salinity water at shallower depths.  They also clearly show the sequence from a freshwater to marine.  There are 69 foraminifera taxa identified in the region which indicate diluted waters from their low abundance, and diversity.
    The most familiar, and useful Champlain Sea fauna are listed below, with a brief interpretation of their importance.
Hiatella arctica
        - most common species
        - tolerant to low salinities
        - adapted to diluted waters
Mytilus edulis
        - a mussel abundant in cold water
        - adapted to low salinity
Macoma calcarea
        - develop in waters close to 0 degrees Celsius
        - found in waters 10 to 35m deep
Portlandia arctica
        - silty clay environments
        - common along glacier fronts
        - adapted to varying salinities
Mya arenaria
        - found in shallow water shoreline deposits
        - occupied inter-tidal zone
        - reduced size from low salinity
Macoma calcarea
        - found in deeper waters

(Hillaire-Marcel, 1988)

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