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Millicent L. Quammen

Publications and source records attributed to Millicent L. Quammen.

7 recordsLinked to original sources
USGS1993

Laguna madre: Seagrass changes continue decades after salinity reduction

Vegetation maps of the lower Laguna Madre prepared from surveys conducted in 1965–1967, 1974–1976, and 1988 document a >330 km 2 decrease in cover by Halodule wrightii , an increase of almost 190 km 2 in other seagrass species, and an increase of 140 km 2 in bare bottom. Loss in seagrass cover is confined to deeper parts of the laguna; turbidity caused by maintenance dredging is the suspected cause. The species shifts are consistent with observed reductions in salinity maxima. Although the hydrological alterations and climatic shift responsible for moderating the salinity regime occurred between 1948 and 1965, the biological changes continue. Establishment of patches away from source meadows appears to be the process for displacing species that limits their rate of expansion into suitable habitat in this elongate embayment.

Texas↗
USGS1985

Development of a computerized wetlands mapping data base for use in section 404 jurisdictional determinatins in San Francisco Bay

Development and habitat alteration in the San Francisco Bay-Delta system have placed the remaining wetlands in jeopardy. The Bay-Delta wetlands will be mapped in a joint project of the U. S. Environmental Protection Agency (EPA) and the U. S. Fish and Wildlife Service (FWS). Maps at a 1:24,000 scale will be produced for the entire study area. High altitude color infrared photography from 1985 and historical photographs from 1976-77 and the mid-1950's for selected areas of the Bay-Delta will be used. A wetland change analysis of the Bay-Delta area will be used to define current habitat boundaries for planning a mitigation strategy to manage the system.

California↗