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D. H. Peterson

Publications and source records attributed to D. H. Peterson.

34 records · Page 2Linked to original sources
USGS1986

The modification of an estuary

The San Francisco Bay estuary has been rapidly modified by human activity. Diking and filling of most of its wetlands have eliminated habitats for fish and waterfowl; the introduction of exotic species has transformed the composition of its aquatic communities; reduction of freshwater inflow by more than half has changed the dynamics of its plant and animal communities; and wastes have contaminated its sediments and organisms. Continued disposal of toxic wastes, the probable further reduction in freshwater inflow, and the possible synergy between the two provide the potential for further alteration of the estuary's water quality and biotic communities.

California↗
USGS1985

Interannual variability in dissolved inorganic nutrients in northern San Francisco Bay estuary

Nearly two decades of seasonal dissolved inorganic nutrient-salinity distributions in northern San Francisco Bay estuary (1960-1980) illustrate interannual variations in effects of river flow (a nutrient source) and phytoplankton productivity (a nutrient sink). During winter, nutrient sources dominate the nutrient-salinity distribution patterns (nutrients are at or exceed conservative mixing concentrations). During summer, however, the sources and sinks are in close competition. In summers of wet years, the effects of increased river flow often dominate the nutrient distributions (nutrients are at or less than conservative mixing concentrations), whereas in summers of dry years, phytoplankton productivity dominates (the very dry years 1976-1977 were an exception for reasons not yet clearly known). Such source/sink effects also vary with chemical species. During summer the control of phytoplankton on nutrient distributions is apparently strongest for ammonium, less so for nitrate and silica, and is the least for phosphate. Furthermore, the strength of the silica sink (diatom productivity) is at a maximum at intermediate river flows. This relation, which is in agreement with other studies based on phytoplankton abundance and enumeration, is significant to the extent that diatoms are an important food source for herbivores. The balance or lack of balance between nutrient sources and sinks varies from one estuary to another just as it can from one year to another within the same estuary. At one extreme, in some estuaries river flow dominates the estuarine dissolved inorganic nutrient distributions throughout most of the year. At the other extreme, phytoplankton productivity dominates. In northern San Francisco Bay, for example, the phytoplankton nutrient sink is not as strong as in less turbid estuaries. In this estuary, however, river effects, which produce or are associated with near-conservative nutrient distributions, are strong even at flows less than mean-annual flow. Thus, northern San Francisco Bay appears to be an estuary in between the two extremes and is shifted closer to one extreme or the other depending on interannual variations in river flow. ?? 1985 Dr W. Junk Publishers.

Hydrobiologia↗
USGS1984

Numerical simulation of phytoplankton productivity in partially mixed estuaries

A two-dimensional steady-state model of light-driven phytoplankton productivity and biomass in partially mixed estuaries has been developed. Effects of variations in river flow, suspended sediment concentration, phytoplankton sinking, self-shading and growth rates on distributions of phytoplankton biomass and productivity are investigated. Numerical simulation experiments show that biomass and productivity are particularly sensitive to variations in suspended sediment concentrations typical of natural river sources and to variations in loss rates assumed to be realistic but poorly known for real systems. Changes in the loss rate term within the range of empirical error (such as from dark bottle incubation experiments) cause phytoplankton biomass to change by a factor of two. In estuaries with adequate light penetration in the water column, it could be an advantage for phytoplankton to sink. Species that sink increase their concentration and form a phytoplankton maximum in a way similar to the formation of the estuarine turbidity maximum. When attenuation is severe, however, sinking species have more difficulty in maintaining their population.

Estuarine, Coastal and Shelf Science↗
USGS1977

Suspended particle transport and circulation in San Francisco Bay - an overview

Differences in the relative magnitude and timing of wind stress and river inflow in the northern and southern reaches of San Francisco Bay create different sedimentary conditions. The northern reach is a partially to well mixed estuary receiving most of the total annual fresh-water input (840 m 3 sec −1 ) and suspended sediment input (4 × 10 6 metric tons) into the bay; more than 80% of the sediment is received during winter. Density-driven nontidal estuarine circulation (~5 cm sec −1 ) maintains a turbidity maximum which changes seasonally in particle concentration (40 to 80 mg litre −1 ). Strong tidal currents (≤225 cm sec −1 ) and wind-generated waves resuspend sediment from the shallow bay floor: some of the riverborne sediment deposited during winter is resuspended during summer and transported landward to the turbidity maximum. Long-term sediment data (extrapolated from bathymetrie charts) indicate that the northern reach is an effective sediment trap. In contrast, long-term sediment data suggest that the southern reach is experiencing net erosion. The southern reach receives little river inflow or riverborne suspended sediment, and the average nontidal circulation is weak (≤2 cm sec −1 ). The principal source of suspended sediment (25 mg litre −1 ) in the southern reach is the shallow bay floor (average depth 6 m).

Book chapter↗
USGS1972

Drift of surface and near-bottom waters of the San Francisco Bay system, California: March 1970 through April 1971

The San Francisco Bay system is a complex estuary in which there is an interplay between natural chemical and physical processes, and changes resulting from the works of man. The bay is used for recreation, water-borne commerce, fishing, domestic and industrial waste disposal, and esthetic pleasure. Because some of these uses are competitive, it is desirable to adequately predict the impact of man's activities on this natural system. The reliability of such predictions will be strengthened by long-term observations directed toward understanding the natural processes occurring in the bay. This study is a compilation of one aspect of the U.S. Geological Survey's continuing investigations of the San Francisco Bay system.

California↗