Geology Reports⌕ Search

Geology topics

L. W. Hall

Publications and source records attributed to L. W. Hall.

5 recordsLinked to original sources
USGS1989

Studies of contaminant and water quality effects on striped bass prolarvae and yearlings in the Potomac River and upper Chesapeake Bay in 1988

Simultaneous on‐site and in situ studies of survival of prolarval and yearling striped bass Morone saxatilis were conducted in the Potomac River during the 1988 spawning season. Various water quality and contaminant conditions were monitored during these experiments. In situ experiments on yearlings and monitoring of water quality and contaminants were also conducted in the Susquehanna, Elk, and Sassafras rivers of the upper Chesapeake Bay. Survival of striped bass prolarvae ranged from 1 to 20% in the Potomac River during three concurrent 96‐h on‐site and in situ experiments; survival of control fish was 78% or greater. Survival of striped bass yearlings was 15% or less during 28‐d in situ tests at two Potomac River field locations; survival of control fish was 100%. Mortality of prolarvae in the Potomac River was likely caused by a combination of cadmium, lead, chlordane, and sudden drops in temperature. Mortality of yearlings was possibly caused by a combination of cadmium, lead, zinc, chlordane, and ammonia. Survivals of striped bass yearlings tested in 28‐d tests in the Susquehanna, Elk, and Sassafras rivers were 57, 100, and 100%, respectively; survival of control fish was 100%. Mortality of striped bass in the Susquehanna River may have been partly caused by copper and lead concentrations; however, other nonidentified factors were likely more important. Water quality problems were not detected in the Elk or Sassafras rivers.

Maryland↗
USGS1988

Concurrent mobile on-site and in situ striped bass contaminant and water quality studies in the Choptank River and upper Chesapeake Bay

In situ and mobile on-site striped bass prolarval and yearling survival studies were conducted in the Choptank River and in the Chesapeake and Delaware (C & D) Canal area of the Upper Chesapeake Bay. Extensive chemical analyses of both organic and inorganic contaminants in the habitat water were performed and water quality parameters were monitored during these experiments. Surviving yearling striped bass were subjected to histological examination. Prolarval survival data from both the in situ and mobile on-site studies were similar for each spawning area. Prolarval survival ranged from 30 to 45% after 96 h of exposure to Choptank River water in four separate experiments (two in situ , two on-site); control survival was greater than 74%. Based on a comparison of laboratory toxicity data and reported field concentrations in the Choptank River for various water quality and contaminant conditions, the following combination of conditions was potentially stressful to striped bass prolarvae: low hardness (36 to 48 mg/L CaCO 3 ), monomeric aluminum (0.150 mg/L), cadmium (0.003 mg/L) and copper (0.040 mg/L). Yearling survival in both in situ and on-site tests ranged from 93 to 100% in both the control and Choptank River water after 9 d of exposure. Survival of striped bass prolarvae in C & D Canal water ranged from 52.5 to 70% after 96 h of exposure in four separate experiments. Control survival of prolarvae was not significantly different. Survival of yearling striped bass in on-site and in situ tests was 95% or greater in C & D Canal water and control water. Acute contaminant effects were not verified in the C & D Canal area.

Environmental Toxicology and Chemistry↗
USGS1987

Survival of striped bass larvae and yearlings in relation to contaminants and water quality in the upper Chesapeake Bay

This study was designed to evaluate survival of striped bass yolk-sac larvae and yearlings at three locations in their natural spawning habitat in the upper Chesapeake Bay (Chesapeake and Delaware Canal) using “in-situ” chambers; correlate larval and yearling survival with the presence of 11 water quality parameters, 10 inorganic contaminants and 21 organic contaminants and assess histological effects on yearlings after exposure to habitat water. The cumulative percent survival ranged from 42–59.5% for striped bass larvae after 96 hr of exposure to habitat water during two experiments. Survival in control conditions during these two experiments was 77.5 and 80.5%. Data from previous studies have shown that mortality rates for wild yolk-sac larvae ranged from 7–19% per day. Daily mortality of larvae in the present study was 13–16%; therefore, suspected acutely harmful water quality or contaminant conditions affecting survival were not substantiated. All yearling striped bass survived 10 days of exposure to habitat water. Although habitat water was not acutely toxic, histological examination of surviving yearling striped bass indicated sublethal effects. Telangiectases (lamellar dilations) of the gills was reported for yearlings exposed to habitat water. This pathological change was not found in the controls.

Delaware, Maryland↗
USGS1987

In situ striped bass (Morone saxatilis) contaminant and water quality studies in the Potomac River

The objectives of this study were to evaluate survival of striped bass ( Morone saxatilis ) prolarvae and yearlings in the Potomac River by using in situ test chambers; correlate survival of both striped bass life stages with the presence of water quality conditions, inorganic contaminants, and organic contaminants and conduct histological examinations of surviving yearling striped bass. Survival of striped bass prolarvae ranged from 4.5–22.5% at three field locations during three 96-h experiments; control survival was ≥81%. Yearling survival ranged from 0–77.5% at three river stations during two 7-d experiments; highest mortality occurred at the upriver station. Control survival was 100%. Poor survival of striped bass prolarvae was likely related to the presence of inorganic contaminants (monomeric aluminum, cadmium, and copper) acting singly or synergistically and sudden decreases in water temperature (< 11°C). Yearling mortality at the upriver station was likely correlated with high pH conditions from a point source discharge and perhaps inorganic contaminants. Histological examinations of yearlings suggested that test organisms exposed to Potomac River water exhibited adverse changes in the kidney.

Maryland, Virginia↗