Showing papers in "Chesapeake Science in 1969"
TL;DR: The upper limits of thermal tolerance for two species of copepods from Chesapeake Bay were found to be near the normal temperature of the habitat during the summer, and acclimation temperature had little effect on the upper limitsof thermal tolerance.
Abstract: All metabolic rates of zooplankton are dependent on temperature. Rates generally rise in a linear fashion, with inflection points when plotted on a semi-log scale, and fall at higher temperatures. The upper limits of thermal tolerance for two species of copepods from Chesapeake Bay were found to be near the normal temperature of the habitat during the summer. Acclimation temperature had little effect on the upper limits of thermal tolerance.
149 citations
TL;DR: Findings confirm the contention of Crisp (1967) that gregarious setting occurs in Crassostrea virginica and suggest that a water-borne pheromone may be the stimulating agent.
Abstract: In laboratory cultures of setting oyster larvae,Crassostrea virginica, it was noted that few of many exposed cultch shells collected most of the set. Also, setting, was very sporadic with respect to time. Several hypotheses were tested to explain such observations. Individual cultch shells were not differentially attractive to setting larvae. However, cultch shells containing 24-hour-old spat or 2-month-old spat attracted more set than unspatted control shells in the same culture and stimulated more set than that received in separate control cultures. Undersides of bottom-most layers of shells attracted more set than the higher layers of shells in laboratory cultures. Two-month-old spat, inside larval-proof plankton mesh bags, stimulated set on shells outside the bags indicating that a water-borne pheromone may be the stimulating agent. These findings confirm the contention of Crisp (1967) that gregarious setting occurs inC. virginica.
92 citations
TL;DR: In this article, rates of photosynthesis were used to evaluate the response of phytoplankton when passed through the cooling system of a power generating facility, where photosynthesis was measured as the uptake of carbon.
Abstract: Rates of photosynthesis were used to evaluate the response of phytoplankton when passed through the cooling system of a power generating facility. Photosynthesis was measured as the uptake of carbon. A factorial design permitted evaluation of heat input, total effect of passage, and degree of recovery. Six experiments measured response at a fixed time of day and at various times in a daily cycle.
77 citations
TL;DR: Indications in the Patuxent point to a relationship between oyster copper uptake and power plant operation, since green color and copper concentration were closely correlated.
Abstract: The effects of heated effluent on oysters in the Patuxent River were investigated. Oyster meats near the outfall of a steam electric generating station started to display green color shortly after initiation of plant operation. In time, the affliction increased in intensity and spread to oyster stations farther removed from the outfall. The greening of Patuxent oysters was probably caused by copper uptake, since green color and copper concentration (mg of copper per g dried meat weight) were closely correlated. Copper content of oysters decreased with distance from the outfall. There was an inverse relationship between oyster condition and copper concentration. This was most evident at stations near the outfall where oysters had high copper content. Amounts of copper per oyster, based on mg of copper per liter shell cavity volume, did not display great seasonal fluctuation. Oysters at special stations, established to investigate a possible copper source upstream from the plant, showed a reduction in mg of copper per g dried meat, while oysters at stations inside and near the outfall increased sharply in mg of copper per g dried meat. Indications in the Patuxent point to a relationship between oyster copper uptake and power plant operation.
66 citations
TL;DR: The sandy-beach community, as composed of a homogeneous group of organisms, was identified through the use of an index of faunal affinity and community structure is described in terms of abundance, frequency diversity, and feeding types.
Abstract: A series of 452 samples collected from November 1964 through February 1966 from a North Carolina sandy beach contained 27,219 invertebrates representing 41 species. The sandy-beach community, as composed of a homogeneous group of organisms, was identified through the use of an index of faunal affinity. Community structure is described in terms of abundance, frequency diversity, and feeding types. Six species,Neohaustorius schmitzi, Acanthohaustorius millsi, Donax variabilis, Scolelepis squamata, Exosphaeroma diminutum, andHaploscoloplos fragilis comprise 97% of the fauna by number. Niche differences among these species are discussed.
40 citations
TL;DR: A broad study of temperature effects on respiration and photosynthesis of aquatic plants was begun in relation to the disappearance of aRuppia maritima population near the effuent of an electrical generating station on the Patuxent River, Maryland.
Abstract: In relation to the disappearance of aRuppia maritima population near the effuent of an electrical generating station on the Patuxent River, Maryland, a broad study of temperature effects on respiration and photosynthesis of aquatic plants was begun.
34 citations
TL;DR: In contrast to amphi-AtlanticGammarus faunas of northern glaciated coastlines, the Gammarus species of the Middle Atlantic States are North American endemic.
Abstract: Gammarus daiberi n. sp. andGammarus palustris n. sp. are newly described from estuaries of the Chesapeake and Delaware Bay regions, and further tide-water records ofGammarus tigrinus Sexton,G. fasciatus Say, andG. mucronatus Say are given. A key to American Atlantic species ofGammarus (sens. lat.) is included. In contrast to amphi-AtlanticGammarus faunas of northern glaciated coastlines, theGammarus species of the Middle Atlantic States are North American endemic.
31 citations
TL;DR: In this paper, the abundance, distribution and seasonality of hogchoker life history stages in the Patuxent River Estuary are discussed. And the importance of various segments of the estuary for completion of life history cycle is emphasized.
Abstract: Information is presented on the abundance, distribution and seasonality of hogchoker life history stages in the Patuxent River Estuary. Egg collections indicate that the spawning area is located in the lower river in salinities greater than 9.0 ppt. Following hatching, during July and August, the larvae move upstream and congregate in a low salinity nursery area close to the salt-freshwater interface where they remain during winter. As spring approaches the juveniles move toward the spawning area. These two distinct movements, upstream toward the nursery area in fall and downstream toward the spwaning area in spring, apparently continue at least through the fourth year. As the fish mature they progressively increase their range of travel away from the nursery ground toward higher salinities. Life history activities were determined by monitoring an abundant 1963 year-class using three sampling techniques; meter nets, shallow and deep water trawls. The importance of various segments of the estuary for completion of life history cycle is emphasized.
31 citations
TL;DR: Research being conducted on salmonid fishes at the Hanford nuclear complex on the Columbia River is discussed, including studies of thermal effects on reproduction and behavior.
Abstract: Some current research being conducted on salmonid fishes at the Hanford nuclear complex on the Columbia River is discussed. Studies of thermal effects on reproduction and behavior include a 20-year annual census of spawning chinook salmon near reactor discharges, laboratory experiments on incubation and rearing success at elevated temperatures, studies of equilibrium loss prior to thermal death at lethal temperatures, tests of relative predation rates upon thermally shocked and normal young salmonids, and tracking sonic tagged adults to determine migration behavior near thermal outfalls.
30 citations
TL;DR: In this article, the fluorometric method was used to obtain a continuousin vivo record of chlorophylla distribution in surface waters of the mid-Chesapeake Bay, and measurements were made just previous to and during a fall dinoflagellate bloom.
Abstract: The fluorometric method was used to obtain a continuousin vivo record of chlorophylla distribution in surface waters of the mid-Chesapeake Bay. Measurements were made just previous to and during a fall dinoflagellate bloom. Chlorophylla values computed from calibration curves ranged from 10 to 56 mg m−3. Off-scale values as high as 167 mg m−3 were noted during the dinoflagellate bloom. It should be possible, with care, to monitor chlorophyll in many estuaries that have very high standing crops of phytoplankton.
29 citations
TL;DR: In this paper, an intensive investigation was made of the seston population of the upper Chesapeake Bay from 1 November 1965 through 30 March 1967, and the concentrations of seston were determined primarily by resuspension and by the net non-tidal estuarine circulation.
Abstract: An intensive investigation was made of the seston population of the upper Chesapeake Bay from 1 November 1965 through 30 March 1967. During the period of high spring runoff the seston population of the upper Bay was closely linked to the major source of new sediment, the Susquehanna River. Throughout the remainder of the year however, the concentrations of seston were greater within the Bay north of 39° 12′ N (Tolchester) than in the mouth of the Susquehanna River or farther seaward in the estuary, and the concentrations of seston were determined primarily by resuspension and by the net non-tidal estuarine circulation which traps much of the seston within this segment of the Bay. Seaward of 39° 12′ N the concentrations of seston decreased quite sharply throughout the year.
[...]
TL;DR: While the monofactorial approach will continue to provide physiological insight, the introduction of multivariable factorial experiments, including multivariate responses, holds greater promise for revealing the respective roles of environmental factors.
Abstract: It has been a prime assumption of those working in the laboratory that physiological experiments would have direct ecological significance. Further, it was assumed that by studying static, limited cases (monofactorial) on intact animals it would be possible to unravel some of the more important interrelations of stimulus and response which characterize the dynamic, unlimited natural environment. In theory, given enough time, this should prove correct. But to date there are only suggestions of cause and effect regarding the ecological role of temperature, and time is pressing. While the monofactorial approach will continue to provide physiological insight, the introduction of multivariable factorial experiments, including multivariate responses, holds greater promise for revealing the respective roles of environmental factors. Two areas of biological inquiry are likely to provide greatest insight: 1)development, involving growth and differentiation, and 2)energetics, involving metabolism, performance and efficiency of energy transformation. Unless these functional capacities can be maintained at a high level, abundance and well-being cannot prevail. They constitute key responses of the whole organism to sublethal effects, particularly in the case of an environmental entity like temperature which acts as a “controlling” factor,without threshold levels within the tolerance zone. In those exceptional cases where fish have been found living close to their lethal limit the above functions have been maintained at a relatively high level. The inclusion of a biotic factor (e.g., food, yolk, activity, age, weight) in multifactorial experiments has considerably improved their predictive power for assessing the ecological consequences of changed environments.
TL;DR: The distribution, quantitative abundance, and period of maximum set of the polyp stage of the sea nettle Chrysaora quinquecirrha DeSor were investigated in the York River, Virginia, from September 1966 to November 1967.
Abstract: Distribution, quantitative abundance, and period of maximum set of the polyp stage of the sea nettleChrysaora quinquecirrha DeSor were investigated in the York River, Virginia, from September 1966 to November 1967. The distribution and abundance of the medusoid stage were also determined. Effects of varying salinity and temperature on the polyp were investigated in the laboratory. The polyp stage occurred on oysters and shells dredged in a 12-mile segment of the river. Medusae appeared in tributary creeks in June, 15 to 30 days carlier than in the river. In the river, medusae were observed between 12 June and 2 October; peak abundance was reached during the week of 17–21 July.
TL;DR: In this paper, the densities of postlarval Penaeus species, Trachypeneus constrictus, Acetes americanus carolinae, and Lucifer faxoni are discussed for surface plankton samples taken at a series of estuarial stations maintained for up to 10 years.
Abstract: Densities of postlarvalPenaeus species,Trachypeneus constrictus, Acetes americanus carolinae, andLucifer faxoni are discussed for surface plankton samples taken at a series of estuarial stations maintained for up to 10 years. Semiquantitative data forPenaeus show frequency distributions of log-normal type. Densities vary among years, within years in accord with predictable recruitment seasons, and among localities in expected relationship to habitat. In general, samples with highest densities were from areas near the sea. Some inland areas with presumably suitable salinity-temperature regimes may lie beyond the zone of effective tidal transport for these shrimps. Species not belonging toPenaeus are warm-weather transients penetrating the estuarial system as conditions permit.
TL;DR: In this article, an analytical method of chlorophyll analysis, field sampling, and standing crop estimates, and interpretation of the relationship of photosynthesis to chlorophilophyll is presented.
Abstract: of plant production and the standing crop in the aquatic environment (Goldman, 1965). The measurement of plant pigments, especially chlorophyll a, is the only current rapid chemical method available to estimate the amount of living particulate plant matter. Attention in this paper will be given mainly to analytical methods of chlorophyll analysis, field sampling, chlorophyll-standing crop estimates, and interpretation of the relationship of photosynthesis to chlorophyll.
TL;DR: To evaluate the probable metabolic success of an organism in a region of thermal additions, a number of factors need to be considered, including body size, stage in the life cycle of an organisms, cyclic changes, and the habitat of the animal.
Abstract: Most invertebrates cannot maintain a body temperature independent of their environment. However, various physiological and ecological strategies have evolved that enable poikilotherms to metabolically compensate for thermal changes. To evaluate the probable metabolic success of an organism in a region of thermal additions, a number of factors need to be considered. These include body size, stage in the life cycle of an organism, cyclic changes, and the habitat of the animal.
TL;DR: In this article, the Barnegat Bay investigation was multiplied by 0.375 to obtain a first order approximation of fixation of carbon into organic compounds, and the results are thus translatable.
Abstract: The estimation of primary productivity using dissolved oxygen data is predicated upon the relationship between oxygen evolution and carbon fixation. Ultimately our conclusions depend on the validity of this conversion. Whatever parameter is measured, it should be cited in conjunction with the other. The results are thus translatable. In the current Barnegat Bay investigation, the change in mg 02/1 was multiplied by 0.375 to obtain a first order approximation of fixation of carbon into organic compounds. Oxygen techniques, contrasted with the somewhat more sensitive 14C method, provide estimates of the disparity between gross and net photosynthesis. The often pronounced or even overriding effects of of a zooplankton as a component in the dynamics of a plankton community however cannot be ignored.
TL;DR: Odum's method has been used to determine metabolism and gaseous diffusion in intertidal bay and marine waters, as well as in laboratory microcosms (McConell, 1962; Abbott, 1966, 1967).
Abstract: Changes in dissolved oxygen (DO) which occur in an aquatic system over a period of time are normally the result of: 1. Photosynthetic production by aquatic plants within the water mass, 2. Respiration of aquatic plants, animals and bacteria, 3. Diffusion of oxygen into or out of the water, depending on the saturation gradient and certain physical factors, and/or 4. Advective gains or losses due to displacement of a water mass. Estimates of oxygen gained from photosynthesis and lost to respiration are often based on the incubation of enclosed samples which may or may not be representative of the community. Estimates of oxygen interchange between the water and the atmosphere are usually based on engineering formulae (Eckenfelder and O'Connor, 1961) or upon some form of direct measurement (Copeland and Duffer, 1964; Gameson and Truesdale, 1959). Advective gains or losses, if any, can often be evaluated from knowledge of the hydrology or by means of dye-tracer or radio-isotope time-of-travel studies. Correlating these essentially independent estimates with observed DO concentrations, however, may be formidable. Over a decade ago (1956), H. T. Odum formulated a procedure to evaluate DO diurnal changes to obtain simultaneous estimates of community metabolism and gaseous transfer. By means of graphical analysis, values of gross community production (P), community respiration (R) and an atmospheric diffusion coefficient (k) were determined. Since its introduction, Odum's method has been used to determine metabolism and gaseous diffusion in intertidal bay and marine waters (Odum and Hoskin, 1958: McFarland and Prescott, 1959; Odum and Wilson, 1962), coral reefs (Kohn and Helfrich, 1957), estuaries (Bailey, 1967; Chadwick et al., 1967), rivers (Hoskin, 1959), springs (Odum, 1957 a,b), stabilization ponds (Copeland and Dorris, 1962) as well as in laboratory microcosms (McConell, 1962; Abbott, 1966, 1967). Diurnal curve analyses similar to that of Odum have also been employed in English rivers (Edwards and Owens, 1962; Owens and Edwards, 1963; and Edwards, 1964) and in a western mountain stream (O'Connell and Thomas, 1965). Two principal approaches of the procedure are available to the investigator, the "single-station" method and the "upstreamdownstream" method. The choice of either
TL;DR: During the summer when high surface-water temperatures prevailed, there seemed to be a reduced number and/or disappearance of flatworms and colonial hydroids, along with increased barnacle growth.
Abstract: Two sets of test panels, one in the intake and the other in the effluent canal of a steam-generating station, were submerged at montly intervals in 1967. The panels were analyzed for epifaunal species composition, abundance, seasonal attachment, and total biomass production. The average surface-water temperature rose 6.3 C above ambient on the effluent side, and the biomass production of the epifaunal organisms found there increased nearly three times that of the intake. An earlier and larger set of some attached organisms occurred in the effluent, but there was little change in species composition between the intake and effluent canals. During the summer when high surface-water temperatures prevailed, there seemed to be a reduced number and/or disappearance of flatworms and colonial hydroids, along with increased barnacle growth. *** DIRECT SUPPORT *** A00BY035 00006
TL;DR: In the upper Patuxent Estuary environmental changes in temperature, salinity, and turbidity over a 5-year period are linked to changes in epifaunal production and species distribution.
Abstract: In the upper Patuxent Estuary environmental changes in temperature, salinity, and turbidity over a 5-year period are linked to changes in epifaunal production and species distribution. During 1967 a series of monthly panels showed dry weight production averaged 2.8 times greater in a steam electric station heated effluent than in the intake. A downriver shift in epifanual production in 1967 and changes in species abundance was noted and attributed to natural changes in salinity and turbidity and man-induced changes in temperature.
TL;DR: In this article, a study was conducted concerning the possible effects of thermal additions on the finfish and benthic mussel communities found in the Cape Cod Canal, based on laboratory experimentation and field observations.
Abstract: Based on laboratory experimentation and field observations a study was conducted concerning the possible effects of thermal additions on the finfish and benthic mussel communities found in Cape Cod Canal.
TL;DR: A study was made of the intertidal zone of aged wooden pilings Iocated in the lower York River estuary at Gloucester Point, Virginia from February to June 1967, where six species were found that have not previously been reported from Virginia.
Abstract: A study was made of the intertidal zone of aged wooden pilings Iocated in the lower York River estuary at Gloucester Point, Virginia, from February to June 1967. The upper vertical limit was determined for the 26 benthic algal species (7 Cyanophyta, 8 Rhodophyta, 1 Phaeophyta and 10 Chlorophyta) found at this Iocation. More than 30% of the species were limited to below mean low water and half of the species had ranges extending from mean low water or below to various intertidal heights. Six species were found that have not previously been reported from Virginia.
TL;DR: Three natural combinations of cyprinid hybrids were found in the Little Patuxent River, Maryland in the vicinity of the Fall Line; they resulted from the spawning ofNotropis cornutus, Notropis rubellus and Clinostomus funduloides over the nests of Nocomis micropogon.
Abstract: Three natural combinations of cyprinid hybrids were found in the Little Patuxent River, Maryland in the vicinity of the Fall Line. They resulted from the spawning ofNotropis cornutus, Notropis rubellus andClinostomus funduloides over the nests ofNocomis micropogon. The hybridN. rubellus ×C. funduloides was an unreported hybrid combination. It was rare; its characteristics were intermediate between the parental species. The hybridN. cornutus ×N. rubellus was common whileN. cornutus ×C. funduloides occurred rarely. The particular ecology, including the high stream gradient and generally sandy bottom with boulders and bedrock, appeared to contribute to the hybridization. The rarity of hybrids involvingC. funduloides is attributed to the greater genetic isolation. There appeared to be no relationship between the frequency of hybridization and the distance between the precise positions of the parental species as they spawned over theNocomis nest.
TL;DR: In this paper, the occurrence of thermal anomalies in various properties of (aqueous) physico-chemical, biochemical, and biologically interesting systems is discussed, and it is proposed that certain temperature ranges (especially 30 −33 C and 44 −46 C) may exert a profound and sometimes dominating effect on biological activity through changes in the structure of water.
Abstract: The occurrence of thermal anomalies in various properties of (aqueous) physico-chemical, biochemical, and biologically interesting systems is discussed. Thermal anomalies are frequently encountered and on this basis, it is proposed that certain temperature ranges (especially 30–33 C and 44–46 C) may exert a profound and sometimes dominating effect on biological activity through changes in the structure of water. The “site” of these structure-sensitive effects in living organisms may be the water associated with various membranes or other interfacial regions, or the water of hydration of different macromolecules (for instance, enzymes). On this basis, general limits on thermal pollution may possibly be derived on a purely physico-chemical basis.
TL;DR: In this article, a typical cooling water system for a steam plant is described, along with possible variations in intake and discharge designs, and predictions of the impact of the plant on the ecosystem are made by ecological studies combined with temperature predictions.
Abstract: A typical cooling water system for a steam plant is described, along with possible variations in intake and discharge designs. Biological implications are discussed in view of known physical parameters at operating power plants. Some studies at thermal power plants operated by Pacific Gas and Electric Company in California are reviewed. The P G and E approach to nuclear thermal plant siting in California consists of consultation and agreements with state regulatory and resource agencies, and with conservation groups, before a site is developed. Predictions of the impact of the plant on the ecosystem are made by ecological studies combined with temperature predictions.
TL;DR: There is evidence that competitive exclusion of algal species by other more tolerant algaI species may cause qualitative shifts in the community structure which may be undesirable and it is probable that similar shifts occur in protozoan communities—a factor which should be considered in future studies.
Abstract: The response of fresh-water protozoan communities exposed to both severe acute temperature shocks as well as small gradual long-term increases are discussed. The former experiments were carried out in plastic troughs with a constant flow of unfiltered lake water. Severe acute shocks (some to nearly 50 C) resulted in a marked reduction in number of species present. However, recovery was quite rapid (a matter of a few days) once the temperature stress ceased. Observations of the effects of small gradual long-term increases were made on the protozoan communities of the Savannah and Potomac rivers each of which received heated waste water discharges. Each of these studies covered a period in excess of nine years and observations are still being made. At the time the paper was prepared there was no evidence that indicated the protozoan communities of these rivers had been degraded by the small gradual temperature increases resulting from the discharge of heated waste waters. However, there is evidence that competitive exclusion of algal species by other more tolerant algaI species may cause qualitative shifts in the community structure which may be undesirable. It is probable that similar shifts occur in protozoan communities—a factor which should be considered in future studies.