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Estuarine Studies : An Activities Text For Maine Schools, Education Division - Department Of Marine Resources

Maine Collection

Estuarine Studies : An Activities Text for Maine Schools

Fisheries Education Unit #16 - Produced by The Education Division, Department of Marine Resources, State House Station 21, Augusta, Maine 04333-0021.

Revised 1990. Printed Under Appropriation No. 3140.3260.

Fisheries Research Report No. 84 - The Marine Open Shelf Environment: Review Of Human Influences, D. A. Hancock

Fisheries Research Reports

For the purpose of this review, the marine environment has been classified into three physical zones - the littoral zone, the open-shelf environment and the coral reef. Since the boundaries are arbitrary, there will inevitably be some overlap, but for this review the subject matter will be related to the area between low water of ordinary spring tides and the edge of the continental shelf; i.e., to a depth varying to 200 metres.

Human influences may have a dual role in affecting the marine environment, firstly in a causative manner and secondly in providing a remedy, in which case the …

Fecundity Of Blue Crab, Callinectes Sapidus, In Chesapeake Bay: Biological, Statistical And Management Considerations, Michael H. Prager, John R. Mcconaugha, Cynthia M. Jones, Patrick J. Geer

OES Faculty Publications

Ovigerous blue crabs were collected from the mouth of Chesapeake Bay during the 1986 and 1987 spawning seasons. Mean carapace width was 14.7 cm; mean fecundity was 3.2×106 eggs. Fecundity was significantly related to carapace width, and did not vary significantly with developmental stage of the eggs. Mean fecundities were 2.6×106 eggs in 1986, and 4.0×106 eggs in 1987. An additive model with year and size effects described the observed fecundities reasonably well, was compact, and was easier to interpret than a multiplicative model. To fit a more general model without year effects, the authors took the mean of 1986 …

Estimates Of Spawning Stock Size Of Blue Crab, Callinectes Sapidus, In Chesapeake Bay, 1986-1987, Cynthia M. Jones, John R. Mcconaugha, Patrick J. Geer, Michael H. Prager

OES Faculty Publications

The 1986 spawning stock exhibited a single abundance peak, increasing from 1.0×105 individuals in early July to 9.3×106 in late July, maintaining high levels throughout the summer, and declining in the fall to 7.4×105 individuals. The 1987 spawning stock showed 2 peaks of abundance. The population reached the lesser peak, 1.0×106 individuals, in late July; the greater peak, 1.5×106, in late August. By late September, the population had declined to 6.5×105 individuals. The peak abundance of the 1987 female spawning stock was only 16% as great as the peak abundance in 1986; the 1987 spawning stock size in 1986. Variability …

The Temporal And Spatial Distribution Of Blue Crab Larvae On The Mid-Atlantic Bight Adjacent To The Chesapeake Bay, 1982-1983, Lyle Michael Varnell

OES Theses and Dissertations

Recruitment processes are important information for the management of commercially and recreationally exploited marine species. Recruitment processes of the Chesapeake Bay's most important commercial and recreational species, the blue crab, are unknown, due in part to the lack of knowledge of the processes directly preceeding recruitment.

The present study was undertaken to investigate and explain the movement and developmental patterns of blue crab larvae while offshore. Interannual and intraseasonal variations of these patterns were also examined.

Sampling occurred from May to November during 1982 and 1983. Larvae were collected at three depths (neuston layer (upper 10 cm), one meter and …

Growth Potential Of Young Black Sea Bass, Centropristis Striata, In Artificial Environments, Joung Won Kim

OES Theses and Dissertations

The growth potential of the commercially important marine finfish, black sea bass (Centropristis striata), was examined for aquaculture under controlled conditions. The effect of food and body weight on growth was evaluated using juveniles and young black sea bass cultured with a natural diet and a commercial diet at various feeding levels.

Growth was affected by type of food, food consumption rate, and fish body weight. For fish having positive weight gain, absolute growth rate (gram/day) increased exponentially as food consumption rate (percent of body weight per day) and/or body weight increased. Instantaneous growth rate (percent of body weight per …

A Comparison Of Potential Fishing Methods Associated With Fish Aggregating Devices Off The Northeast Coast Of Puerto Rico, Alan M. Friedlander

OES Theses and Dissertations

Six fish aggregating devices (FADs) were deployed in June and monitored through December 1986. Emphasis was placed on trolling, live-bait handlining and longlining.

There was a significant difference (x2 = 7.815, pCoryphaena hippurus) which made up 64.2% of the catch.

Handlining at night around inshore buoys for one boat yielded 82.7 kg per trip. Pelagic fish comprised 83.9% of the catch, with the majority (81.4%) being kingfish (Scomberomorous cavalla). Catch rates were 50% higher and the species diversity much greater on the FADs versus control during experimental nightfishing, but the difference was not significant.

Longlining resulted in 3.4 …

Validation Of The Otolith Increment Aging Technique For Striped Bass, Morone Saxatilis, Larvae Reared Under Suboptimal Feeding Conditions, Cynthia Jones, Edward B. Brothers

OES Faculty Publications

Striped bass, Morone saxatilis, larvae were reared in the laboratory for 97 days to validate the otolith increment aging technique for this species. Otolith-increment deposition rates were determined under optimal laboratory conditions for growth and under three conditions of restricted feeding and using both light and scanning electron microscopy (SEM). Under optimal laboratory conditions. increments were deposited daily from the fourth day after hatching through the first 2 months of life and were discernible with the light microscope. For larvae reared under restricted feeding regimes and readings done with the light microscope, counts did not reflect true age. Counts …

The Spatial And Temporal Distribution Of The Larvae Of Sympatric Pagurid Hermit Crabs (Decapoda, Anomura) In Virginian Estaurine And Coastal Waters, Philip Wesley Sadler

OES Theses and Dissertations

Thirteen stations were occupied at two - week intervals from May through September 1980 within the York River, lower Chesapeake Bay depths encompassing the entire water column.

Three species of pagurids were identified: Pagurus longicarpus, P. pollicaris, and P. annulipes. The larvae of P. annulipes had not been previously identified from Virginian waters. The shapes of the antennae of P. pollicaris and P. annulipes weredistinctive, allowing rapid identification of these larvae. The shapes of the uropods were found to be useful in distinguishingthe glaucothoe· of P. longicarpus from P. annulipes. The larvae of these species …

An Intraseason Forecasting System For Commercial Marine Fisheries, Erik J. Barth

OES Theses and Dissertations

The reliability of an intraseason yield estimation technique which is commonly used by Pacific salmon harvest managers is evaluated for applicability to a variety of commercial finfish and crustacean fisheries. The estimation technique is known as the average timing or the average performance model. The method is not easily related to standard statistical models, but does show some similarity to both a single parameter linear regression model and the ratio estimator of sampling theory. A comparison of these models, a two parameter linear model, and a regression estimator is made to determine if the precision of forecasts of performance can …

An Examination Of The Variability Of Migratory Timing Statistics Estimated From Catch And Effort Observations, Arthur J. Butt

OES Theses and Dissertations

The estimate of the mean arrival time based on catch or CPUE of fishes migrating into a fixed harvest area is a function of the number of days fished. Simulation studies using chinook salmon catch and effort data from the Yukon River delta, Alaska indicate that fishing effort concentrated at the tails of the migratory distribution which would tend to erroneously weigh the estimated mean arrival time in the direction of the sample, away from the true mean, is only a significant problem when the number of days open to fishing is small, covering less than 12% of the total …

A Description And Analysis Of The Timing Of Virginia's Weakfish Fishery, Bruce William Hill

OES Theses and Dissertations

The seasonality of Virginia's weakfish fishery is quantitatively defined by providing a mean time of catch and variance of catch for the years 1960 - 1981. On the average. the central half of the population is available for harvest from mid-May through September in all of Virginia's waters and the mean date of harvest is July 20th • The 22 year average variance of catch for Virginia's waters is 3.97. In Virginia's Chesapeake Bay tributaries the mean date of harvest is July 17th and the 22 year average variance of catch is 2.50. There is evidence for an inverse relationship …

Determinants For The Timing Of Escapement From The Sockeye Salmon Fishery Of The Copper River, Alaska: A Simulation Model, Howard A. Schaller

OES Theses and Dissertations

A model to estimate determinants for migratory timing of catch and escapement in a terminal salmon fishery is presented. A method was developed to estimate average seasonal migration rates of salmon through a harvest area from catch and escapement data. The time series for the total population of Copper River sockeye salmon (Oncorhynchus nerka) was reconstructed in the reference frame of the commercial harvest area from catch and escapement data.

The catchability coefficients (q), derived from the reconstructed populations were found to vary within season and between seasons. The relation between q and effort was attributed to a …

Timing Of The Blue Crab Fisheries Of Virginia And Its Application To Harvest Management, J. Dale Shively

OES Theses and Dissertations

The timing of a fishery is a quantitative expression of the composite behaviors of harvesters, markets, animals and climatic events. A quantitative description of the timing of the blue crab (Callinectes sapidus) fisheries of Virginia was established using the time density model of Mundy (1979). Blue crab catch statistics supplied by the National Marine Fisheries Service and the Virginia Marine Resource Commission were divided into two fisheries based on gear type; the summer and winter fisheries. Average performance curves were then constructed using average cumulative proportions of catch. Annual yield estimates were also made and timing in five …

The Growth And Feeding Behavior Of Juvenile Spot, Leiostomus Xanthurus Lacepede, In The Nursery Region Of The James River, Virginia, John Thomas Mccambridge Jr.

OES Theses and Dissertations

The in situ growth and feeding behavior of juvenile spot, Leiostomus xanthurus Lacepede, was investigated for populations in the nursery area of the James River, Virginia. Growth of juvenile spot was found to be fairly rapid (11.34 mm/month, standard length) during their first summer in the nursery grounds, but it levelled off in the autumn. The mean size of spot after the first year was calculated to be 195 mm total length. The weight-length relationship was log W = -5.018 + 3.246(log L), where W = wet weight in grams and L = standard length in millimeters.

Juvenile spot appeared …

The Effect Of Crowding On Growth Of The Cichlid Fish, Oreochromis Mossambicus, Bonnie A. Barrows

OES Theses and Dissertations

It has been reported that the Java tilapia, Oreochromis mossambicus, displays hypersensitivity to a substance it produces when biomass levels in a flow-through culture system exceed 20 g/1, resulting in reduced growth and high mortality. Experiments on the growth of this species in small tanks were conducted in order to determine whether O. mossambicus produces a growth-inhibiting compound under crowded conditions. This species was successfully maintained at biomass levels of 38 g/1 and 57 g/1 with a total mortality of only 4.5%.

The Java tilapia can grow rapidly in small aquaria, as indicated by the data taken during Experiment …

A Model Of The Population Dynamics Of The Blue Crab In Chesapeake Bay, Betty Springer Hester

OES Theses and Dissertations

This study has particular application to the blue crab fisheries in Chesapeake Bay, an economically important industry whose successful management has been hindered by relatively poor understanding of the population dynamics. Recent biological studies have indicated a systematic spawning behavior which seems designed for ejection of larvae seaward from the bay entrance where they spend their pre-metamorphosis stages in the neuston. A physical mechanism for retention of the larvae in sufficient proximity to the bay entrance for their return at the proper time which involves the action of wind stress in shallow waters is proposed. Since the supply of blue …

A Laboratory Study Of Nongenetic Embryonic Adaptation To Salinity And Its Subsequent Effects Upon Larval Development Of The Grass Shrimp Palaemonetes Pugio Holthius, Paul Jay Anninos

OES Theses and Dissertations

Fertilized embryos of the grass shrimp Palamonetes pugio Holthuis (Decapoda; Caridea) were exposed to two levels of salinity [5 ppt (exposed) and 20 ppt (control)] during incubation to determine the extent to which embryonic adaptation influences subsequent larval development. Larval response to embryonic exposure was measured at three salinities (5 ppt, 10 ppt, and 20 ppt) as the fraction of larvae surviving to metamorphosis and the duration (in days) of larval development. The survival rate of larvae hatched from control, or non-adapted, embryos was significantly influenced by rearing salinity. The differences in survival of pre-adapted larvae (exposed group), however, were …

A Quantitative Description Of Migratory Behavior Of The Brown Shrimp (Penaeus Aztecus) With Applications In Fisheries Management, Anne Madolyn Babcock

OES Theses and Dissertations

A quantitative description of the migratory behavior of the brown shrimp, Penaeus aztecus, was established using the density approach. A theoretical time density was estimated by the proportion of catch and catch per boat hour NOAA-NMFS fisheries statistics collected in Pamlico Sound, the Neuse River, and Core Sound. A clear quantitative description of brown shrimp migratory timing is found in the time densities. The impact of various physical tactors on the progress of the fishery in time and space can be objectively evaluated by using the time density statistics as dependent variables in modeling efforts. The distributions also enable …

Growth And Recruitment Of Two Penaeids In The Bay Of St. Louis, Mississippi During 1979, Teresa C. Heaton

OES Theses and Dissertations

Juvenile brown (Penaeus aztecus, Ives) and white (Penaeus setiferus, Linnaeus) shrimp were collected from two stations of a nursery area in St. Louis Bay Mississippi, during May to October, 1979. Periods of shrimp recruitment and growth were determined to discern whether the concurrent environmental variables of salinity and temperature had an influence on shrimp abundance and yield. Growth estimates were obtained from length frequency measurements of trawl samples taken over a 24-h period per month from each station. An analysis of variance of length versus the variables of sex, month, station, time of day, salinity and …

Filtration Ingestion And Assimilation Rates Of The Mysid Shrimp Neomysis Americana Smith, Fed Three Food Sources, Robert W. Grabb

OES Theses and Dissertations

Laboratory grazing and assimilation experiments were conducted on the mysid shrimp Neomysis americana in an attempt to assess the suitability of three potential food sources. It was hypothesized that the smaller size classes were primarily herbivores, not becoming omnivorous until attaining lengths of approximately 5-6 mm. Four size classes of mysids from the summer generation, juveniles, immature, adult males, and adult ovigerous females were each fed three concentrations of Artemia salina nauplii, the rotifer Brachionus plicatilis, and the diatom Coscinodiscus lineatus. The mean lengths of the size classes utilized, plus or minus one standard deviation, were 2.5 …

Mercury, Copper, And Zinc In Selected Ichthyofauna Of Lower Chesapeake Bay And Hampton Roads, Virginia, W. Bruce Aitenhead

OES Theses and Dissertations

Anchovys, croaker, spat, summer flounder and hogchokers were collected monthly to seasonally from November 1972 to October 1973 at three locations in the southern Chesapeake Bay region of Virginia.

The concentrations of mercury, copper and zinc were determined by atomic absorption spectrophotometry in whole fishes. Metal concentration varied with species and location. Anchovys had the highest mean concentrations of mercury and zinc while hog- chokers had the highest mean copper concentration. Mercury levels exceeding O.5 ppm were observed in species from all three loca- tions, but maximum heavy metal concentrations per species were highest in Craney Island fishes.

Temporal variations …

Experiments In Attempted Interspecific And Interpopulational Hybridzation Of Grass Shrimp Of The Genus Palaemonetes (Caridea Palaemonidae), Mark Andrew Boston

OES Theses and Dissertations

The present study investigates the interfertility of Palaemonetes populations, Interspecific crosses were attempted between representatives of sympatric :populations of P. pugio, P. vulgaris, and P. intermedius, Intraspecific crosses were undertaken between geographically separated :populations of P. pugio. Laboratory conditions of 25°c, 25°/oo, and 14.5 hour photoperiod per day were maintained for all breeding attempts, Under these conditions interspecific hybridization of Palaemonetes pugio and P. vulgaris was not feasible. P. intermedius could not be hybridized with P. pugio and P. vulgaris. At 40 days of age P. pugio juveniles were significantly larger than P. vulgaris juveniles of …

Description Of The Larval Development Of Squilla Empusa Say (Crustacea Stomatopoda) With Aspects Of Larval Ecology In Chesapeake Bay, Steven Gaines Morgan

OES Theses and Dissertations

Larvae of Sguilla empusa were collected from the plankton and were reared in the laboratory to describe the pelagic larval development and the postlarval stage. Nine pelagic stages are passed through before the postlarval stage is attained.

The larvae reared for descriptive purposes were subjected to sixteen combinations of temperature and salinity to determine their tolerance to the two parameters. Larvae survived longer and molted more frequently when reared at 25°/oo and 20°C or 25°C, which corresponds to the natural conditions of the Chesapeake Bay when the larvae were collected.

A three year planktonic survey conducted in the lower region …

Temperature And Salinity Tolerance Of The Larvae Of The Sand Shrimp, Crangon Septemspinosa (Say), Karen Lyttle Hinsman

OES Theses and Dissertations

The effects of temperature and salinity on the larval development of the sand shrimp, Crangon septemspinosa, were investigated in the laboratory using 30 combinations of temperature and salinity in a five by six factorial experiment. The five temperatures were 5°c, 10°c, 15°c, 20°c, and 25°c and the six salinities were 10°/oo, 15°/oo, 20°/oo, 25°/oo, 30°/oo and 35°/oo. Thirty-six larvae were used for each temperature-salinity combination. Temperature and salinity produced significant differences (1% level) in survival and the duration of larval development. Highest survival occurred at 15°c and 20°/oo. At optimum temperatures (15°c to 20°c) larvae exhibited the broadest tolerance …

A Comparative Study Of A Salt Water Impoundment With Its Adjacent Tidal Creek Pertinent To Culture Of Crassostrea Virginica (Gmelin), William D. Anderson Iii

OES Theses and Dissertations

Certain physical, chemical and biological characteristics associated with the culture of subtidal Crassostrea virginica were assessed in a salt water impoundment and its adjacent tidal feeder creek. Large seed oysters (initial y = 57.3 mm) were transferred from a somewhat polluted estuary of Charleston Harbor to floating, mid-water, and bottom hardware cloth trays (200/tray) in a four hectare pond. Identical trays at comparable depths were placed in the tidal creek and each location was sampled monthly for growth and survival. Surface and bottom water samples were collected weekly throughout the study and hourly during four seasonal 25 hour stations. Standard …

Feeding And Food Preferences By Three Sympatric Species Of Cyprinodontid Fishes, Lawrence J. Baer

OES Theses and Dissertations

The feeding and food utilization by three sympatric species of cyprinodontid fishes was examined using a modified Ivlev Electivity Co-efficient. Results indicated that although Fundulus heteroalitus and Fundulus majalis are sympatric in the area examined,their usage of the available food source varied noticeably. The third investigated species, Cyprinodon variegatus, fed mainly upon a vegetal detritus food source varied by the consumption of invertebrate and vertebrate food items. Slight intra-specific variances of diet between crespuscular periods was also discussed.

Food And Feeding Of Fishes From Magothy Bay, Virginia, Joseph J. Kimmel

OES Theses and Dissertations

No abstract provided.

Morphologic Time Series From A Submarine Sand Ridge On The South Virginia Coast, John F. Mchone Jr.

OES Theses and Dissertations

Submarine sand ridges several km long locally merge southward into the U. S. Atlantic coastline. Shallow (< 8m) observations of -such a ridge at False Cape, Virginia, favor a modern hydraulic origin. Time series maps show the ridge to be paralleled by a landward trough of approximately equal volume. Ridge flanks are usually steeper on the trough side.

Northeasterly winds and waves generate a coast-parallel current which funnels southward into the trough scouring it out and providing sediments for ridge aggradation. The current may be organized as a helical flow cell or cells. Bottom currents converge southward along the ridge crest causing landward transport of traction load along the crest. The trough current eventually breaches the confining ridge at the head of the trough, cutting saddles with steeper seaward slopes and producing outlying sediment fans.

The ridge and trough rest obliquely …