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Observed gravity values, station locations, terrain corrections, and Bouguer gravity data are provided as computer printout tabulations for the San Francisco Bay area, California.
Observed gravity values, station locations, terrain corrections, and Bouguer gravity data are provided as computer printout tabulations for the La Sal Mountains area, Utah-Colorado.
Observed gravity values, station locations, elevations, theoretical gravity, and free-air anomaly values are provided in tabular form for 554 gravity locations in northeastern Oklahoma-southeastern Kansas.
This publication is concerned mainly with alkylbenzenesulfonate (ABS), the anionic surface-active agent most frequently found in water supplies.
The application of contrast stretch and haze removal techniques to Landsat/MSS imagery for shallow seas bathymetry is discussed. The application of these techniques is based upon procedures inherent in the EDIPS system processing. Application of both MSS band 4 and band 5 data are discussed in lx and 3x gain mode. Both quantitative and qualitative (imagery) data are used to demonstrate the existence of bathymetric information after EDIPS processing.
The Columbian white-tailed deer ( Odocoileus virginianus leucurus) was designated an endangered species in 1968. At that time the estimated population along the lower Columbia River of Washington and Oregon was 300 to 400 deer (Gavin, 1984). The Julia Butler Hansen Refuge for the Columbian White-tailed Deer was established in 1972 to protect Columbian white-tailed deer and associated habitat Currently, an estimated 600 deer are present in several separate populations. The total refuge population is estimated at 200 animals. Of those, the mainland population consists of approximately 60 animals while the largest refuge island (Tenasillahe.Island) supports about 120 animals. The remaining 420 deer are present on private lands near the refuge (AI Clark, pers. com.). Higher than expected deer mortality on Tenasillahe Island in the spring of 1996 prompted refuge personnel to request assistance from the National Wildlife Health Center (NWHC) for diagnostic evaluation to determine the cause of the mortalities. The mortality event occurred in the wake of extraordinary .flooding that reduced the availability and quality of forage on the island. It is estimated that 50% of the deer population on the refuge died during this time period. The basic finding of emaciation attributable to probable starvation raised concerns regarding the health status of the deer herd, available food resources, and current population levels. A health evaluation was conducted on free-ranging deer from the refuge in February, 1998. This evaluation was an analysis of physiologic parameters obtained from live deer in an attempt to determine the health of individual animals and, with adequate sampling, the health of the population. This study was conducted during February to examine individual animal health during the seasonal period when the deer are in their poorest physical condition. The late winter period prior to spring green-up is a time when the effects ofbreeding and winter stress are most evident (Venne and Ozoga, 1971). The objectives of this study were to: (1) gather baseline physiologic data on a subset of the population, (2) evaluate the data to determine the health of the animals sampled, (3) if possible, identify causes of poor health and, ( 4) provide refuge personnel with information that will aid them in managing the population.
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Records are presented of Na+, K+, Ca++, SiO2, pH, alkalinity, O2, and specific conductance at 106 stations in Lake Ontario. These data are compared for east-west and surface-subsurface variations. Water quality in Lake Ontario is similar to that in Lake Erie with the exception of dissolved oxygen. The open waters of Lake Ontario had no areas of serious oxygen depletions.
The recent discovery of a group of chemical compounds that are significantly more toxic to sea lampreys than to other aquatic organisms offers promise of an early and effective control of this pest. The sea lamprey has all but destroyed the lake trout populations of Lakes Huron and Michigan. In Lake Superior, production of the lake trout fishery has declined to record low levels. Only a rapid and drastic reduction in sea lamprey predation can save the lake trout population there. Other species of food and game fishes have suffered severe decreases from persistent attack by the lamprey. The sea lamprey spends only a small portion of its life as a parasite in the Great Lakes. The fully grown and sexually mature adults migrate into streams to spawn and thereafter die. The eggs hatch in a week to 10 days and the larvae remain in the stream bottom for 5 years or longer before metamorphosis into the adult form. Following this transformation the young lampreys migrate downstream to the lakes to begin their parasitic existence. The life cycle of the sea lamprey has been described in detail elsewhere (Applegate 1950; Applegate and Moffett 1955). Control of the adult lampreys distributed throughout a body of open water as large as one of the Great Lakes, by known and available techniques, is not feasible. Fortunately, this pest can be attacked effectively at those stages in its life cycle when it is concentrated in restricted areas. Various devices have been developed which prevent spawning by blocking the streams below the spawning grounds. Electrical weirs, that repel or destroy the lampreys, have been used (Applegate, Smith, and Nielsen 1952; Erkkila, Smith, and McLain 1956). A serious shortcoming of this control method is the time required to achieve the desired effect. Even though the adults have been destroyed before spawning, 5 or more generations of larval lampreys are already in the stream-enough to provide an annual supply of parasitic adults for an equal period of time. Almost all the larvae of the sea lamprey live in the spawning streams. Treatment of these streams with selectively toxic chemicals that kill the larvae provides immediate reduction of all generations in the population before they become parasites. Control of the species can thus be achieved without a delay of several years.
The length, age and sex compositions of dead and dying alewives collected in June 1967 at six locations in southern, central, and northern Lake Michigan are compared with those of fish taken in experimental trawls at five locations in April and June 1967. Behavior at the time of death, condition of the body and gonads, stomach contents, and the incidence of Saprolegnia and subcutaneous hemorrhages also are described for alewives in the dieoff. The length distributions of alewives in the dieoff and trawl collections were similar and bimodal. Yearlings made up 25 and 42 percent of the respective collections. The average age of adults (age-group II and older) were nearly identical in the dieoff and trawl collections (3.5 and 3.6 years, respectively). Both collections were dominated by age-groups III and IV. The average lengths of adult alewives in age-groups II to V in the dieoff were smaller than or identical to those in the trawl collections. In all collections females were consistently older (0.4 year) than the males and larger at the greater ages. The sexes were almost equally represented among age-II and older fish in the dieoff. Despite the presence of Saprolegnia and hemorrhages on some fish, alewives in the dieoff appeared robust. Spawning attrition could not have been a major cause of the dieoff because many immature yearlings died and 80 percent of the dead adults were unspawned. The presence of rapidly digestible zooplankton in the stomachs of dead alewives indicated that many fish were feeding just before death. About 20 percent of the alewives in the selected samples of fish from the dieoff were infected by Saprolegnia; twice as many females were infected as males. The fungus was randomly distributed among the size groups. Hemorrhages may have been a symptom or physiological response to the cause of the dieoff because they affected a much higher percentage of the dying alewives (47 percent) than did fungus. Occurrence of the hemorrhages did not differ significantly between the sexes or among the size groups.
This paper examines the population dynamics of the bloater (Coregonus hoyi) in Lake Michigan during a progressive decline in abundance from about the mid1960s through the mid1970s, and during a subsequent recovery that is still underway. The study focused on developing a data base and methodology for projecting fishable surpluses, in cooperation with a chub technical committee sponsored by the Great Lakes Fishery Commission. The Technical Committee was formed in 1974 because of depletion of bloaters and other deepwater ciscoes or 'chubs,' as they are known by Great Lakes fishermen. Subsequently the Technical Committee recommended a lakewide ban on chub fishing that was fully enacted by the states of Illinois, Michigan, and Wisconsin in 1976. With the Committee's help, commercial fishery statistics and stock assessment data were obtained from state and federal research files and used with various indirect analytical techniques to estimate relevant population parameters. The lakewide fishable stock in fall 1973, before the fishery was affected by several incomplete closures and then by the lakewide ban, was estimated as 48 to 73 million bloaters weighing 20 to 29 million pounds. Exploitation of the estimated stock varied considerably among 11 statistical districts in the several jurisdictions. Yield to the fishery exceeded production by the stock in some districts. Theoretical yields of bloaters totaling 3.59 to 3.72 million pounds were projected from 1979 for all waters combined. These projected yields were intended as guidelines for experimental quotas that the states might establish, because the population had stabilized and the potential for recruitment had improved in most areas.
The presence and relative abundance of bottom macrofauna in Lake Ontario are documented. Bottom samples were collected at 24 stations in September 1964. The quantity of organisms and the distribution of some species were affected by depth of water. Samples from the shallower stations (47.5 m or less) yielded an average of 41,631 organisms per mA? whereas the deeper stations (91.5 m or more) yielded an average of only 7,938. The Oligochaeta, the most abundant group of macroinvertebrates, was represented by four families - Enchytraeidae, Lumbriculidae, Naididae, and Tubificidae. The lumbriculid worm, Stylodrilus heringianus, and the burrowing amphipod, Pontoporeia affinis, were rare or absent in areas affected by pollution. In kinds and abundance of organisms, the bottom fauna in Lake Ontario was generally similar to that in Lake Michigan.
Federal, provincial, state, and university organizations participated in cooperative limnological surveys of Lake Erie in September 1959 and August 1960 to determine the extent and severity of the low dissolved-oxygen content of the hypolimnetic waters. Observations were restricted to the central basin in 1959, but were lake-wide in 1960. Approximately 70 percent of the bottom waters of the central basin had a serious oxygen deficiency during both years. Data were obtained also on the distribution of temperature, transparency, specific conductance, pH, and phenolphthalein and total alkalinity. The distributions of the chemical values are discussed in terms of their relationships to each other, and to thermal stratification, river outflow, lake morphometry, and lake currents.
Water temperature and the distribution of various chemicals measured during surveys from June 7 to October 30, 1956, reflect a highly variable and rapidly changing circulation in Saginaw Bay, Lake Huron. The circulation is influenced strongly by local winds and by the stronger circulation of Lake Huron which frequently causes injections of lake water to the inner extremity of the bay. The circulation patterns determined at six times during 1956 reflect the general characteristics of a marine estuary of the northern hemisphere. The prevailing circulation was counterclockwise; the higher concentrations of solutes from the Saginaw River tended to flow and enter Lake Huron along the south shore; water from Lake Huron entered the northeast section of the bay and had a dominant influence on the water along the north shore of the bay. The concentrations of major ions varied little with depth, but a decrease from the inner bay toward Lake Huron reflected the dilution of Saginaw River water as it moved out of the bay. Concentrations in the outer bay were not much greater than in Lake Huron proper. The proportions of various cations and anions were similar to the average proportions for the freshwaters of the world. The average flushing time was 186 days, but was 113 days during the period of peak river discharge. The lakeward transport of Saginaw River water ranged from 619 to 2,294 feet per day in the inner bay to 1,410 to 3,000 feet per day in the outer bay on June 7 and October 30, respectively.
The selective lampricide, 3-trifluoromethyl-4-nitrophenol (TFM), and its synergist, 5,2'-dichloro-4'-nitrosalicylanilide (DCN), are separable from natural waters by anion exchange. The adsorbed compounds can then be recovered from the resin as concentrates by elution with selective solvent mixtures. Measurements of the amounts of lampricides in the final concentrates can be made colorimetrically at 395 mI? for TFM and at 530 mI? for the safranin complex of DCN. TFM has also been separated for quantitative determination from homogenates of whole fish. The fish is first macerated in a blender and then hydrolyzed in hot, 3 N hydrochloric acid. The amount of background color, due to certain components of the fish in the hydrolysate, is reduced by one or a combination of three methods: (1) a series of three extractions with ether, methylene chloride, and benzene; (2) cation exchange followed by methylene chloride extraction; or (3) ether extraction followed by anion exchange and subsequent desorption with amyl acetate-acetic acid.
The chemical, P,P-bis(1-aziridinyl)-N-methylphosphinothioic amide (bisazir), was found in laboratory studies to be an effective sterilant for both sexes of adult sea lampreys (Petromyzon marinus) when given intraperitoneally at a dosage of 100 mg per kilogram of body weight. A total of 300 normal spawning-run sea lampreys and 300 injected with bisazir were released into the Big Garlic River, Marquette County, Michigan, (a small stream divided into five sections by natural barriers), to determine the effect of bisazir on the nesting and spawning behavior of the adults and on the production of larvae. The lampreys constructed and spawned in 95 nests. Sterile adults showed no abnormal nest building or spawning behavior. Sterile males competed effectively with normal males for females. Egg samples taken from nests indicated that eggs in nests where sterile males spawned with sterile or normal females did not hatch, although some embryonic development occurred. Extensive surveys with electric shockers produced no larvae in stream sections where sterile males spawned, but yielded numerous larvae in sections where normal males spawned with normal females. These findings suggest that the release of sterile males may be an effective tool in an integrated approach to control of sea lampreys in the Great Lakes.
A dye detector, based on a modified photoelectric amplifier, has been planned, built, and tested. It was designed to record automatically the time of arrival of fluorescein dye at predetermined points in a stream system. Laboratory tests and stream trials proved the instrument to be efficient. Small changes in color can be detected in turbid or clear water. The unit has been used successfully for timing intervals of more than 17 hours; significant savings of time and manpower have resulted. Replacement of the clock, included in the original device, with a recording milliammeter increases the efficiency of the unit by contin,!ously recording changes in turbidity. The addition of this component would increase the cost from $75 to approximately $105.