. Ecology of Buzzards Bay : an estuarine profile . Unfertilized er Inflorescence with mature seeds Root cluster on rhizome node Fig. The general morphology of the eelgrass Zostera marina. From Costa (1988a) Buzzards Bay populations of Zostera appear to have generally recovered (Costa 1988b) from the catastrophic decline because of a lasting" dis- ease (Tabarynthula), which decimated eelgrass beds throughout New England from 1931 to 1933 (Cottam 1933). Costa (1988b), using aerial pho- tographs, determined that several years after the decline, eelgrass beds in Buzzards Bay covered less
. Ecology of Buzzards Bay : an estuarine profile . Unfertilized er Inflorescence with mature seeds Root cluster on rhizome node Fig. The general morphology of the eelgrass Zostera marina. From Costa (1988a) Buzzards Bay populations of Zostera appear to have generally recovered (Costa 1988b) from the catastrophic decline because of a lasting" dis- ease (Tabarynthula), which decimated eelgrass beds throughout New England from 1931 to 1933 (Cottam 1933). Costa (1988b), using aerial pho- tographs, determined that several years after the decline, eelgrass beds in Buzzards Bay covered less than 10% of the present area. Although epidemics of "wasting" disease have not reoccurred since the 1930's in Buzzards Bay, smaller outbreaks have been found in New England (Short et al. 1986). Zostera appears to colonize sandy and mud bottoms of the open bay and its embayments. The major factor determining the upper limits of this subtidal species appears related to desiccation in summer and ice scour in winter (Davis 1913; Costa 1988b). While the lower limit is set by light pen- etration (Dennison and Alberte 1985, 1986), the level of light intensity is less important in determin- ing depth than the daily duration of intensity above a physiologically set level. Light penetration in simplest terms is a function of depth and the concentration of particles within the water column. The particles can be living (phy- toplankton) or inert (sediments). Because Buzzards Bay has no large river discharging into it and rela- tively coarse-grained sediments resulting from its formation, the major source of particles attenuating light is generally phytoplankton within the water column (and epiphytes on the eelgrass leaves). As a result, light attenuation relative to eelgrass growth in Buzzards Bay may be more directly related to factors controlling phytoplankton and epiphyte den- sity (, nutrients) than in other systems with a higher inorganic load. Shallow protected embayme
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Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
