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At least 37 records · Page 2Linked to original sources
USGS1971

Distribution of the fiddler crab (Uca minax) in relation to marsh plants within a Virginia estuary

The distribution and abundance of the red-jointed fiddler crab, Uca minax, was related to the distribution of marsh plants within a Virginia estuary. The crab was found in association with 15 species of marsh phanerogams, occurring with five plant species more than 20 percent of the time. These plants were Spartina alterniflora, Scirpus robustus, Distichlis spicata, Spartina patens, and Spartina cynosuroides. Densities ranged from 0-76 burrows per square meter, mean densities being 7.88 within the brackish-water marsh and 14.35 within the salt-water marsh. The crab was not obtained by sampling the freshwater marsh.

Chesapeake Science↗
USGS1963

Nesting ecology and reproductive rate of the red-winged blackbird in tidal marshes of the upper Chesapeake Bay region

The nesting ecology and reproductive rate of the polygynous red-winged blackbird, Agelaius phoeniceus, were studied in the tidal marshes of Maryland during the period of 1958 through 1961. Sixteen nesting colonies were located in six major marsh communities of the Eastern Shore and were visited approximately twice a week from late April to mid-August. The average clutch size for 537 clutches was 3.3 eggs, with a range of 2 to 5 eggs. The ratio of territorial males to nesting females was 1:1.9. There was direct evidence of double broods by four females. The average number of young produced was 4.2 per breeding female or 8.1 per breeding male. Nesting success for the total of 675 active nests was 57%, with a range from 38% to 69% in the colonies. Robust plants that held constant form throughout the nesting season supported 95% of the nests, and the success of these nests was 58%; in contrast, non-robust plants supported only 5% of the nests, and success of this group of nests was only 26%. Nesting success varied with height from ground: 45% for nests less than 2 feet from the ground, 55% for those 2 to 4 feet, and 62% for those more than 4 feet. Histories of 749 nests were summarized by stages: 749 newly built, 675 with eggs, 424 with nestlings, and 388 with fledging young.

Chesapeake Bay region↗
USGS1971

Reproductive success of Potomac River ospreys--1970

Osprey reproductive success on the Potomac River during 1970 is described. Thirty-five percent of the accessible active nests fledged young and only 0.70 young were fledged per active nest. Egg failure was the major cause of poor success. Reproduction was below that considered normal for a stable population.

Chesapeake Science↗
USGS1974

The 1973 distribution and abundance of breeding ospreys in the Chesapeake Bay

An aerial survey in association with several intensive ground surveys yielded the first estimate of the size of the osprey ( Pandion haliaetus carolinensis ) nesting population in Chesapeake Bay. The 1973 population was estimated at 1,450 ± 30 pairs, of which 713 were on the western shore and 737 on the eastern shore. A small percentage of nonbreeders (possibly 2-5 percent) may be included in this estimate. Only 31.7 percent of the population was nesting in trees; the remaining birds utilized duck blinds (28.7 percent), channel markers (21.8 percent), and miscellaneous man-made structures (17.8 percent). The geographical distribution of nesting ospreys has quite likely changed during the last several decades as suitable artificial nesting sites have become more available. Furthermore, limited evidence suggests that birds nesting on the man-made sites were more successful than those nesting in trees. This study provides a basis for monitoring future changes in numbers and distribution.

Maryland, Virginia↗
USGS1970

Temperature and water-quality conditions of the Patuxent River estuary, Maryland, January 1966 through December 1967

The effect of power plant cooling water in raising natural water temperatures at a location near the power plant on the Patuxent River estuary is clearly evident from thermograph records. Surface temperature at a station 333 m (1,000 ft) downstream from the discharge canal was raised an average of about 4 C, and at times by as much as 8 C. Temperature rises were greatest during the winter. Infrared imagery showed that elevated surface temperatures could be detected about 5.5 km (3 nautical miles) upstream at flood tide. Temperature profiles obtained from airborne radiation equipment revealed a complicated surface temperature pattern and also showed the effects of density differences and wind action on the steam-electric station (S.E.S.) effluent plume. Mean annual salinity for a 5-year period (1963–1967) was highest in 1966, about 12.3 ‰, and lowest in 1967, about 9.9‰. Dissolved oxygen values for 1966–1967 ranged from 3.2 to 15.6 mg/l, and saturation ranged from 55 to 152%. Turbidity levels were inversely related to salinity, with the highest annual, mean of 28 JCU (Jackson Candle Units) occurring in 1967, the lowest salinity year. The extreme tide range was 2.1 m (6.7 ft); mean water levels at the Patuxent Bridge were highest in summer and lowest in winter. Water stages are more affected by wind speed and direction than by flow in the river.

Maryl↗
USGS1967

Epifauna of the Patuxent River Estuary, Maryland, for 1963 and 1964

Methods of collection and analysis of epifaunal communities from six stations in the Patuxent estuary are described. The stations were distributed from Solomons near the mouth of the estuary , upstream to Lower Marlboro, near the limit of salt water intrusion. Species composition and abundance, seasons of attachment, and production of the epifaunal community were determined on material collected from panels submerged for 1, 3, and 12 month periods covering the years 1963 and 1964 . Salinity was highest downstream, as was the number of species. Salinity decreased rapidly between the Patuxent River Bridge station and Lower Marlboro, where the number of species was reduced to half. Seasons of attachment corresponded with seasonal temperature changes, with the greatest attachment taking place during the summer months. Over 40 species were identified with 7 of them comprising the bulk of the biomass produced. For the 7 most productive species, seasons of attachment and total numbers collected from areas of one square decimeter from monthly and quarterly panels from each station are shown. The seven species were the barnacle Balanus improvisus; the tunicate, Molgula manhattensis; the hydroids, Cordylophora lacustris and Bimeria franciscana; the amphipod, Corophium lacustre; the anemone Sagartia leucolena; the tubeworm, Polydora ligni. Their respective importance varied with seasons of attachment and location. Comments on the distribution and abundance of the less significant forms are included. Dry and ash-free dry weight (organic carbon) production of the epifaunal community varied from month to month depending on the seasons of attachment of the various species. The highest production for a single month was observed at the upriver station, Lower Marlboro, where barnacles and amphipods produced 2,754 g/m 2 /30 days dry weight and 351 g c /m 2 /30 days organic weight during August 1963 . At the same station, barnacles, amphipods, and hydroids produced, on quarterly panels, the highest yearly average weight of about 1150 g c /m 2 /yr organic carbon and on monthly panels, about 6,500 g/m 2 /yr dry weight or about 3.5 times the least organic weight and 8 times the least dry weight produced at the downriver Station, Queentree Landing.

Maryland↗
USGS1966

Some blood chemistry values for five Chesapeake Bay area fishes

Blood samples from gizzard shad,largemouth bass, white perch, pumpkinseed, and toadfish were analyzed for hemoglobin, total plasma protein, total plasma cholesterol, and ion concentrations of plasma sodium, potassium, and chloride. The hemoglobin concentration and total plasma cholesterol found in a given species seem to have positive correlation with the customary activity level of that species. The plasma ionic concentrations in general agree with those found by other authors.

Chesapeake Bay area↗
USGS1974

Changes in oxygen and primary production of the Patuxent estuary, Maryland, 1963 through 1969

From 1963 through 1969, the U.S. Geological Survey operated a water-quality monitor system in the upper-middle Patuxent estuary, near Benedict, Maryland. Over the period of record, a pronounced change occurred in the diel (24 hr.) oxygen measurement, particularly during the months of July, August, and September. Annual variations of dissolved oxygen ranged from 3.6 to 15.0 mg liter −1 in 1964 and from 2.3 to 16.5 mg liter −1 in 1969 with percentage saturation varying from 60 to 130 percent in 1964 and from 30 to 184 percent in 1969. The magnitude of diel summer oxygen variation changed from about 3 to 7 mg liter −1 day −1 over the same period. From hourly values of temperature, oxygen, and conductivity, gross primary production (GP) and respiration (R) were estimated. Data representing greatest daily change for spring, summer, and autumn of each year and “average” values for each month of years 1964 and 1969 were analyzed for GP and R. From the seasonal data, GP ranged from about 3 to 25 g O 2 m −2 day −1 , and R ranged from about 4 to 32 g O 2 m −2 day −1 . From the “average” days, GP ranged from 2 to 10 g O 2 m −2 day −1 in 1964 and from 1 to 16 in 1969. In 1964, daily average GP was 5.2 g O 2 m −2 day −1 as compared to 6.1 in 1969, and respiration was 6.1 g O 2 m −2 day −1 in 1964 versus 10.2 g O 2 m −2 day −1 in 1969, increases of 20 and 16 percent, respectively. Ratios of GP/R averaged 0.84 in 1964 versus 0.60 in 1969, reflecting a larger respiration in 1969 and suggesting a trend towards community instability. Productivity estimates by other investigators showed a two-to threefold increase in production over the same period of time. The increases in production were attributed to upstream domestic waste loading. If the present trend increases, metabolic imbalance and anaerobic conditions may develop.

Maryland↗
USGS1967

Haemoproteus, a blood parasite, in domestic pigeons and mourning doves in Maryland

The occurrence of Haemoproteus in pigeons throughout the world and in mourning doves in the United States is reviewed. Haemoproteus has previously been reported only once from pigeons in Maryland. During this study it was found in all of 18 pigeons from one area but in none of 12 from an adjacent area. No infections were found in 90 Maryland mourning doves. All of the 10 mourning doves from Florida were infected whereas 60 nestlings from Texas and Mississippi had no parasites. None was found in 358 nestling white-winged doves from Texas.

Chesapeake Science↗
USGS2017

U.S. Geological Survey Science—Improving the value of the Chesapeake Bay watershed

Introduction Congress directed the Federal Government to work with States to restore the Nation’s largest estuary. Chesapeake Bay restoration provides important economic and ecological benefits: 18 million people live and work in the Bay watershed and enjoy its benefits. 3,600 types of fish, wildlife, and plants underpin the economic value of the Bay ecosystem. Poor water quality and habitat loss threaten restoration and negatively impact the economy. 10 Goals to meet by 2025 through the Chesapeake Bay Program, a voluntary partnership.

Delaware, Maryland, New York, Pennsylvania, Virgin↗
USGS2020

Sediment dynamics and implications for management: State of the science from long‐term research in the Chesapeake Bay watershed, USA

This review aims to synthesize the current knowledge of sediment dynamics using insights from long‐term research conducted in the watershed draining to the Chesapeake Bay, the largest estuary in the U.S., to inform management actions to restore the estuary and its watershed. The sediment dynamics of the Chesapeake are typical of many impaired watersheds and estuaries around the world, and this synthesis is intended to be relevant and transferable to other sediment‐impaired systems. The watershed's sediment sources, transport, delivery, and impacts are discussed with implications for effectively implementing best management practices (BMPs) to mitigate sediment issues. This synthesis revealed three key issues to consider when planning actions to reduce sediment loading: Scale, time, and land use. Geology and historical land use generated a template that current land use and climate, in addition to management, are acting upon to control sediment delivery. Important sediment sources in the Chesapeake include the Piedmont physiographic region, urban, and agricultural land use, and streambank erosion of headwater streams, whereas floodplain trapping is important along larger streams and rivers. Implementation of BMPs is widespread and is predicted to lead to decreased sediment loading; however, reworking of legacy sediment stored in stream valleys, with potentially long residence times in storage, can delay and complicate detection of the effects of BMPs on sediment loads. In conclusion, the improved understanding of sediment sources, storage areas, and transport lag times reviewed here can help target choices of BMP types and locations to better manage sediment problems—for both local streams and receiving waters.

New York, Pennsylvania, Maryland, Delaware, Virgin↗