bluuebunny/crossref_metadata_2025 huggingface dataset:
Crawling and Respiration as Indices of Sublethal Effects of Oil and a Dispersant on an Intertidal Snail Littorina littorea
Authors: Hargrave B. T. , Newcombe C. P.
Published: April 2011

Crawling and respiration rates of the snail Littorina littorea are increased in the presence of Bunker C oil and decreased with brief exposure to a low toxicity dispersant (Corexit 8666) in sea water at 20 C. The addition of the dispersant to an oil:seawater mixture also decreases both crawling and respiration. Behavioral traits, such as crawling, and physiological indices, such as respiration, may be sensitive measures of sublethal effects of pollutants on organisms.
Extended Analysis of Hybridization in Sunfishes (Centrarchidae) Using an Adjusted Hybrid Index Method
Authors: Keenleyside Miles H. A. , Misra R. K. , Bateson David W.
Published: April 2011

Sunfish collected from Pinehurst Lake, Ontario, were sorted into three groups: bluegill (Lepomis macrochirus), pumpkinseed (L. gibbosus), and a group possessing some of the color patterns of each of the other two. Eleven morphological characters of each fish were analyzed by a hybrid index method, and by an adjusted index which allowed: a) calculation of sampling variances of individual and mean index estimates and, b) testing of hypotheses about the position of suspected hybrids relative to the parental populations. This method, applied to single characters and to combinations of characters, showed that the anomalous group resembled bluegills in four characters, pumpkinseeds in one, and were exactly intermediate in the others. The simplest explanation of these results is that the intermediate group was a population of bluegill × pumpkinseed hybrids.This use of the hybrid index permits increased precision over earlier methods in comparing suspected hybrid individuals with their putative parent populations.
Behavioral Ecology of Chum Salmon Fry (Oncorhynchus keta) in a Small Estuary
Authors: Mason J. C.
Published: April 2011

Chum salmon fry (Oncorhynchus keta) in the estuary of a small coastal stream exploited fresh water, estuarine, and marine food chains and, by so doing, were exposed to marked, daily fluctuations in salinity that demanded active selection of fresh water on ebbing tides day and night. The resulting delay in seaward migration and associated behavioral observations are inadequately reflected in published accounts of the life history and behavior of chum fry in natural systems and laboratory situations, and the downstream displacement theory. The biological basis for delayed seaward migration of chum fry merits the attention of fishery researchers and resource managers alike.
Migration of Anadromous Dolly Varden (Salvelinus malma) in Southeastern Alaska
Authors: Armstrong Robert H.
Published: April 2011

Of anadromous Dolly Varden (Salvelinus malma) migrating from the sea into Hood Bay Creek, Admiralty Island, and two other nonlake streams nearby, 61–87% were immature. Most of the immature fish left the streams within a few days of entering. Though nearly all smolts leaving the creek for 3 yr were marked, only 16–21% of the immature fish entering the stream bore these marks. Many of the fish marked in the creek as smolt were recovered entering the two other study streams as immature fish but not as spawners.Mature immigrants remained in the streams for several weeks until they had completed spawning in October and November. Most Dolly Varden that spawned in the creek had been marked there previously as smolt or as spawners, and none were observed to spawn in a stream other than the stream of origin. Smolts transplanted during their oceanward migration returned to spawn in the receiving stream, and adults displaced to saltwater sites on returning to the study streams returned to their home streams. Most fish from the creek spawned only once or twice. Males suffered a much higher spawning mortality than did females.This study and others on fish from lake-stream systems suggest that (1) anadromous Dolly Varden from nonlake streams in southeastern Alaska migrate both between nonlake streams and between nonlake streams and lake-stream systems; (2) during their first summer in the sea, fish from nonlake streams enter several streams while searching for one with a lake; (3) mature fish from nonlake streams leave their wintering area, usually a lake, and return to their home streams to spawn; and (4) mature fish from lake-stream systems go to the ocean to feed for several weeks to a few months and return to their home system to spawn and overwinter.
Chronic Toxicity of NTA (Nitrilotriacetate) and Metal-NTA Complexes to Daphnia magna
Authors: Biesinger K. E. , Andrew R. W. , Arthur J. W.
Published: April 2011

The chronic toxicity of NTA (nitrilotriacetate) tested as the trisodium salt, to Daphnia magna in eight natural waters varied tenfold. A strong negative correlation (r = 0.95) between water hardness and NTA toxicity was found; NTA was most toxic in water with a total hardness of 22 mg/liter and was least toxic in water with a total hardness of 438 mg/liter. The 21-day LC50 in all cases closely approximated the calculated molar equivalence point of total hardness and NTA. Bioassay experiments of NTA, with copper and zinc added, confirmed earlier reports that chelates of copper and zinc with NTA are relatively nontoxic. The solutions were toxic only when the metals or NTA were present in excess. The toxicity of iron (III) was not appreciably changed by NTA chelation.
Review of Geological Research as it Relates to an Understanding of Great Lakes Limnology
Authors: Sly P. G. , Thomas R. L.
Published: April 2011

A review of studies on the geology of recent sediment deposits in the Great Lakes is presented. A summary of quaternary events and a cross-correlation between each of the major basins has been attempted; in this respect it is essential to realize the control imposed upon present depositional conditions by the preceding sedimentary environments (often related to significantly different lake levels). Sediment/energy relations have been discussed, particularly in the context of large lake limnology. Geochemical topics include major and trace metal data, the formation of ferromanganese deposits, and major nutrients (C, N, and P); published material covering these topics is, however, rather limited.Throughout this review the authors have attempted to show the interrelations between such geological evidence and physical, chemical, and biological processes; further, the application of such information to human oriented problems.
Growth Stimulation and Biochemical Changes in Juvenile Coho Salmon (Oncorhynchus kisutch) Exposed to Bleached Kraft Pulpmill Effluent for 200 Days
Authors: McLeay D. J. , Brown D. A.
Published: April 2011

Juvenile coho salmon were exposed for 200 days to neutralized, filtered bleached kraft mill effluent (BKME) at concentrations of 0.1 and 0.25 of the samples' 96-h LC50 values. From 50 to 200 days, mean weights of fish exposed to 0.25 LC50 BKME were significantly higher than control values; those of fish in 0.1 LC50 BKME were consistently but not significantly higher than control weights. By 200 days, mean weight of fish receiving the higher BKME concentration was twice that of controls. Length and condition factor of this group of fish were also increased. Growth results are considered in terms of BKME-induced behavioral changes, increased nutrient supply, effluent salinity, hormetic effects, and hormonal changes.Lactate levels were elevated in the blood and muscle of coho fry exposed to the higher BKME concentration only; serum pyruvate levels were decreased in fish receiving either concentration. The serum lactic acid:pyruvic acid ratio was increased in both groups of fish continuously exposed to BKME. It was concluded that these fish had developed an oxygen debt.Plasma glucose levels were elevated in BKME-exposed fish. The liver muscle glycogen ratio was increased in fish held in 0.1 or 0.25 LC50 BKME for 200 days. Body moisture and lipid content were not altered by prolonged exposure to BKME. Body protein content was decreased in those exposed to 0.25 LC50 effluent. Total blood cell, erythrocyte, leukocyte–thrombocyte and differential leukocyte counts were not altered. Numbers of circulating neutrophils were increased by the higher effluent concentration.The chronic stress response pattern displayed was similar to a previously proposed stage of resistance to stress for mammals.
Maximum Rates of Glycolysis and Breakdown of High-Energy Phosphorus Compounds in Prerigor Cod Muscle at Specific Freezing Temperatures Between −1 and −4 C
Authors: Nowlan Sandra S. , Dyer W. J.
Published: April 2011

The rates of glycolysis and of breakdown of high-energy phosphorus compounds in prerigor muscle have been investigated at specific temperatures in the critical freezing range between −1 and −4 C to determine the temperature at which maximum degradation occurs. Glycolytic activity increased with decreasing temperature below −1 C, reaching a maximum rate with a broad peak between −2.5 and −3.2 C, then slowing down as the temperature dropped to −4 C. The maximum rate of breakdown of high-energy phosphorus compounds also occurred around −3 C. Loss of Δ7P was most rapid between −2.6 and −3 C with an average velocity of 3.5 μg atoms P/g per hour. From 25 to 41% of the initial Δ7P content was derived from creatine phosphate and this fraction was usually depleted within the first 2 h of frozen storage. Deamination of adenine nucleotides to inosine nucleotide compounds was faster at −3 C than at −2 or −4 C.
Accelerated Nucleotide Degradation and Glycolysis During Warming to and Subsequent Storage at −5 C of Prerigor, Quick-frozen Adductor Muscle of the Sea Scallop (Placopecten magellanicus)
Authors: Hiltz Doris Fraser , Bishop Lucy J. , Dyer W. J.
Published: April 2011

During slow warming of prerigor, quick-frozen scallop meats from −26 to −5 C, arginine phosphate and ATP were split rapidly between −8 and −6 C (in about 2 h), resulting in the accumulation of some ADP, and of large amounts of AMP, equivalent to 85% of the ATP originally present. Concomitant activation of glycolysis caused a substantial increase in fructose 1,6-diphosphate (FDP) concentrations, and smaller increases in the hexose monophosphates (HMP) and in octopine. The relatively low freezing point of prerigor scallop muscle, found to be −1.4 C, may be implicated in the stimulation of metabolic activity at a temperature as low as −5 C; the rates were faster than at 0 C and occurred at subfreezing temperatures considerably lower than those for most fish muscle.With continued storage at −5, FDP decreased as HMP concentrations rose sharply to maximum levels at 24 h; octopine accumulation was slower, attaining maximum concentrations at 5 wk. Rates of AMP degradation and of hypoxanthine accumulation were similar to those in unfrozen, iced scallop muscle, indicative of differential effects of temperature on the various metabolic enzymes.Because of the extensive metabolic activity in scallop muscle at temperatures near −5, the optimal quality of prerigor quick-frozen meats may be affected adversely by current commercial distribution and marketing practices where warming to temperatures just below the freezing point may be encountered.
Activity Localization in Coastal Cutthroat Trout (Salmo clarki clarki) in a Small Bog Lake
Authors: Shepherd B. G.
Published: April 2011

Skindiving observations, ultrasonic tracking, and mark–recapture techniques indicated that coastal cutthroat trout (Salmo clarki clarki) in a small coastal bog lake have, but do not defend, fixed focal points of activity.
Lobster Nutrition: The Effect on Homarus americanus of Dietary Protein Levels
Authors: Castell J. D. , Budson S. D.
Published: April 2011

Adult American lobsters (Homarus americanus) were fed artificial diets ranging between 0 and 60% protein and made isocaloric by adjusting the content of cornstarch. Those fed the highest level of protein were in the best condition; each decrease in protein resulted in a poorer condition of the lobsters. When lobsters were fed diets at the maintenance level of 0.5% of the body weight in food per day, decreasing the dietary protein content resulted in increasing weight loss and decreasing molt incidence, serum protein content, percent edible meat, heart weight, hepatopancreas and gonad weights, and increased moisture content of several tissues. Although the serum glucose level was dependent upon the cornstarch content of the diet, the glycogen content of the hepatopancreas was not affected by dietary starch levels. The glycogen content of the hepatopancreas showed a very large range of values when protein was omitted from the diet.A relationship between serum calcium level and molt cycle was demonstrated. Serum calcium values went from an average of 50 mg% after molting to over 70 mg% 1 mo before molting.
Effect of Acclimation Temperature and Heat Shock on Vulnerability of Fry of Lake Whitefish (Coregonus clupeaformis) to Predation
Authors: Yocom Thomas G. , Edsall Thomas A.
Published: April 2011

Fry of lake whitefish (Coregonus clupeaformis) acclimated to 10, 15, and 18 C were exposed to temperatures of 24.5, 25, and 28 C for 1 min and then immediately returned to water at their acclimation temperature, in test tanks containing yearling yellow perch (Perca flavescens). The number of attacks on the fry and the number captured and eaten in 30 min were recorded in separate tests of shocked and unshocked (control) whitefish.Significantly more whitefish were captured per attack (data for shocked and unshocked fry combined) at 15 and 18 C than at 10 C; and shocked fry were significantly more vulnerable to capture by the perch than were unshocked controls.
Determination of the Apparent Complexing Capacity of Lake Waters
Authors: Chau Y. K. , Gächter R. , Lum-Shue-Chan K.
Published: April 2011

A sensitive and accurate method is described for the measurement of the apparent complexing capacity of lake waters. It is based on the measurement of labile copper by differential pulse anodic stripping voltammetry after a number of ionic copper spikes have been allowed to equilibrate with the complexing materials in a water sample. Coefficients of variation for the determination of EDTA at a level of 0.50 μmole/liter in Hamilton Harbor water were 6 and 8%. Analysis of seven replicates of a Hamilton Harbor water sample gave an apparent complexing capacity of 0.52 μmole/liter Cu equivalent with a relative standard deviation of 7.7%. Analyses of a number of samples from Lake Erie and from lakes near Sudbury, Ontario gave a range from nondetectable to 0.70 μmole/liter Cu equivalent of complexing capacity.
Peptone Beef Extract Glycogen Agar, a Selective and Differential Aeromonas Medium
Authors: McCoy R. H. , Pilcher K. S.
Published: April 2011

Studies directed toward the formulation of a selective/differential pour plate medium for Aeromonas species resulted in the following composition (in grams per liter): Bacto-peptone, 10; Bacto-beef extract, 10; glycogen, 4; NaCl, 5; sodium lauryl sulfate, 0.1; bromthymol blue, 0.1; agar, 15. The pH of the medium after autoclaving was 6.9–7.1. After the agar had gelled and the surface had dried, plates were overlaid with 2% nonnutrient agar in distilled water.Aeromonas colonies were recognized by their characteristic size and yellow color in this medium. It has been used to monitor the concentrations of A. hydrophila and A. salmonicida in hatchery waters, to recover these organisms from the intestines and lesions of experimentally infected fish, to isolate A. hydrophila from fish mucus and pet turtles, and to determine aeromonad survival times in water.
Effect of Constant Temperature on Growth Rates of Pumpkinseed Sunfish (Lepomis gibbosus)
Authors: Pessah E. , Powles P. M.
Published: April 2011

Relative growth rates of fall-captured Lepomis gibbosus exposed to six constant temperature regimes (5–30 C) were clearly separable for the first 6 wk. Thereafter, growth declined, becoming uniform between 15 and 30 C, and linear and negative at 10 and 5 C, respectively. A growth model between 15 and 30 C emerged as follows: 0–4 wk, rapid; 5–10 wk, intermediate; 11–16 wk, low uniform. The initial high followed by the low uniform stanza suggests "growth acclimation" took place.
Biology of Eubothrium salvelini (Cestoda: Pseudophyllidea), a Parasite of Juvenile Sockeye Salmon (Oncorhynchus nerka) of Babine Lake, British Columbia
Authors: Boyce Norbert P. J.
Published: April 2011

Adult worms recovered from naturally infected sockeye salmon (Oncorhynchus nerka) smolts provided the eggs for regeneration of Eubothrium salvelini in the laboratory. Of several copepods tested three species of Cyclops proved to be successful intermediate hosts whereby infections were ultimately transmitted to sockeye fry. The parasite's life cycle is described. The rate of development within the intermediate host is shown to be related directly to temperature. It is also demonstrated that susceptibility of fry to infection diminishes as they exceed a certain size.
Apparent Specific Dynamic Action of Largemouth Bass, Micropterus salmoides
Authors: Beamish F. W. H.
Published: April 2011

Oxygen consumption attributable to apparent specific dynamic action (SDA) was measured in relation to feeding level and body weight in largemouth bass, Micropterus salmoides, forced to swim at 1.7 body lengths/s (BL/s). Apparent SDA rose curvilinearly with ration size, the coefficient increasing with weight of bass. For a ration of fixed percent body weight/day, apparent SDA increased curvilinearly with weight of bass, the rate being most pronounced at higher levels of food intake. Apparent SDA expressed in energy units as a percent of ration ingested did not differ significantly with weight of fish or meal size. The overall mean apparent SDA ± SD was 14.19 ± 4.19% of the energy ingested. Time required for oxygen consumption to subside to pre-feeding levels increased with ration size and weight of bass.Over the range of swimming speeds from 1.4 to 2.5 BL/s, there were no differences in apparent SDA of similar size bass fed a ration of 4% body weight/day. Similarly, time for elevated levels of oxygen consumption to return to prefeeding rates was independent of swimming speed.
A Test of a Simple Nutrient Budget Model Predicting the Phosphorus Concentration in Lake Water
Authors: Dillon P. J. , Rigler F. H.
Published: April 2011

The total phosphorus budgets for a number of lakes in the Haliburton–Kawartha region of southern Ontario were measured over a 20-mo period. These data, combined with the lakes' morphometry and water budgets, were used to test a simple nutrient budget model similar to that proposed by Vollenweider (1969) purporting to predict the total phosphorus concentration in lakes. Except in the case of two very shallow lakes [Formula: see text], the concentrations predicted by the model were very close to those measured in the lakes at spring overturn. Additional data from the literature supported the belief that this model could be used effectively for oligotrophic and mesotrophic lakes. Its value lies in the fact that quantitative changes in phosphorus loading can be interpreted in terms of changes in phosphorus concentration, which in turn, can be related to changes in parameters that reflect the lake's trophic state such as summer chlorophyll a concentration.
Theory of Size Distribution in Ecological Communities
Authors: Kerr S. R.
Published: April 2011

Observed regularities in the size composition of pelagic ecosystems are explained by a theoretical model based on trophic processes. The model assumes, in accord with available evidence, that prey and predator sizes are simply related, and that growth and metabolism satisfy similar functions of body (particle) size when averaged over entire trophic levels. The model appears suited to other community types that satisfy these conditions, and suggests that trophic processes are complementary to competitive displacement in determining that particle density is a linear function of the logarithm of particle size.
Behavior of Juvenile Coho Salmon (Oncorhynchus kisutch) Exposed to Sumithion (Fenitrothion), an Organophosphate Insecticide
Authors: Bull Christopher J. , McInerney John E.
Published: April 2011

Wild underyearling coho salmon, Oncorhynchus kisutch, in a stream aquarium were exposed to sublethal concentrations of the organophosphate insecticide Sumithion (0.10, 0.23, 0.48, and 0.75 ppm fenitrothion). After 2-h exposure at 0.48 and 0.75 ppm the pattern of behavior changes indicated physiological impairment. All behaviors involving locomotion, including some comfort behaviors, virtually ceased. Many fish, unable to maintain position, were swept downstream. Only coughing increased in frequency with insecticide concentration, providing an indicator of physiological stress. In the 0–0.23 ppm range social behaviors and feeding markedly decreased in frequency whereas comfort movements generally increased; feeding was depressed at concentrations as low as 0.1 ppm. Of the various behaviors examined, feeding probably provides the best combination of a sensitive indicator of low level contamination by an organophosphate insecticide and a behavior with important ecological implications.
Copper, Zinc, and Total Protein Levels in the Plasma of Sockeye Salmon (Oncorhynchus nerka) During their Spawning Migration
Authors: Fletcher G. L. , Watts E. G. , King M. J.
Published: April 2011

Concentrations of copper, zinc, and total protein were measured in the plasma of sockeye salmon (Oncorhynchus nerka) during their migration to the Chilko spawning grounds, British Columbia. Concentrations of both metals and total protein declined during migration. Final values for all three parameters were 20–50% of those observed in seawater animals. Concentrations of zinc and copper were positively correlated with plasma protein concentrations. An examination of the metal:protein ratios revealed that only the zinc:protein ratios declined during migration, suggesting that zinc was being removed from the plasma independent of the proteins.
Above-ground Production of Marsh Cordgrass (Spartina alterniflora) Near the Northern End of its Range
Authors: Hatcher B. G. , Mann K. H.
Published: April 2011

In Petpeswick Inlet, Nova Scotia, the above-ground portion of Spartina alterniflora lost an estimated 152 g dry weight m−2 of dead leaves during the growing season and reached an average biomass of 558 g dry weight m−2 at the end of the growing season. The total production of 710 g dry weight is higher than that recorded at many sites between Nova Scotia and North Carolina, in spite of the fact that in Nova Scotia the species is near the northern end of its range.
Metabolic Studies on the Amphipod Anisogammarus pugettensis in Relation to its Trophic Position in the Food Web of Young Salmonids
Authors: Chang B. D. , Parsons T. R.
Published: April 2011

The marine amphipod Anisogammarus pugettensis has been studied as part of the natural food of young salmon and as a potential organism for aquaculture projects. It has been shown to be an omnivore capable of eating seaweed, diatoms, fish pellets, and fish. It survived well under eurythermal and euryhaline conditions but grew best (14% of body weight per day) at a salinity of 28‰ and 20 C. Growth efficiency (K1) was between 19 and 34%, depending on the size of animal and temperature.
Use of Sodium Pentachlorophenate and Dehydroabietic Acid as Reference Toxicants for Salmonid Bioassays
Authors: Davis John C. , Hoos Richard A. W.
Published: April 2011

Results of an interlaboratory bioassay standardization exercise involving seven independent fish bioassay laboratories in British Columbia are presented. Toxicity of standard solutions of sodium pentachlorophenate and dehydroabietic acid was determined in freshwater static bioassays with underyearling rainbow trout (Salmo gairdneri), coho salmon (Oncorhynchus kisutch), and sockeye (Oncorhynchus nerka) salmon. Reported LC50s for the three species ranged from 37 to 130 ppb for sodium pentachlorophenate and 1.03–2.14 ppm for dehydroabietic acid. In general, test results for individual species and toxicants were fairly consistent and major disparities could be explained in some instances by variations in physical and chemical characteristics of the bioassay such as water temperature, hardness, or pH. Fish size and condition factor appeared to have little effect on apparent toxicity over the ranges tested.The usefulness of reference toxicants for standardizing bioassays is emphasized and suggestions are made for improved test procedures and increasing accuracy of results. Guidelines for toxicity tests should include the use of reference toxicants as a means of standardizing bioassay results.
Frequency of Detection and Survival of Infectious Pancreatic Necrosis Virus in a Carrier Population of Brook Trout (Salvelinus fontinalis) in a Lake
Authors: Yamamoto T.
Published: April 2011

Brook trout (Salvelinus fontinalis) distributed from a hatchery into a small enclosed lake were examined for IPN virus carriers over a period of 21/2 yr. The carrier rate of 90% at the time of distribution decreased to 69%, but organ analysis showed differing trends in carrier rate. There was a decrease of virus in the pancreas–caeca (82–32%) and an increase in the feces (2–39%) whereas virus was detected to be present at a constant level in the kidneys (53–57%) and the spleen (8–14%). Virus was not detected in the gonads except for a few which yielded virus later in the sampling period.These data indicate that brook trout IPN carriers distributed from a hatchery into lakes do not readily lose their virus over a period of several years, and that both caeca and kidneys are organs of choice for the detection of virus.Neutralizing antibody levels were very low or nondetectable in the carrier population and could not be correlated with yield of virus.
Toxaphene Effects on Growth and Bone Composition of Fathead Minnows, Pimephales promelas
Authors: Mehrle Paul M. , Mayer Jr. Foster L.
Published: April 2011

Fathead minnows (Pimephales promelas) were exposed to toxaphene (55–1230 ng/liter) in a flow-through diluter system for 150 days. Growth was not affected by toxaphene for up to 90 days of exposure, but within 150 days it was significantly reduced at all concentrations. Collagen content of the backbone was decreased (P < 0.05), amino acid composition was changed, and calcium concentration was increased. Results from this study suggest that toxaphene altered the development and quality of the backbone, and induced biochemical manifestations of the "broken-back" syndrome. Radiographic analyses of the fish support our hypothesis that toxaphene induced a weakened, fragile backbone.
Adenosine Triphosphate Measurements in Soil and Marine Sediments
Authors: Karl David M. , Larock Paul A.
Published: April 2011

A sulfuric acid–EDTA method for extracting ATP from soil and marine sediments was devised. The efficacy of this method is compared to the boiling Tris extraction procedure. Efficiency of ATP recovery from solid substrates typically ranged between 81–94% for the sulfuric acid–EDTA procedure in comparison to a recovery of 3–6% using boiling Tris buffer. The presence of various ions in the acid extract, however, inhibited light emission in the luciferin–luciferase measurement of ATP. Addition of EDTA to the extract reduced but did not eliminate the ionic interference. An internal ATP standard was thus used to determine the magnitude of the residual interference.
Red Crab (Geryon quinquedens) and Snow Crab (Chionoecetes opilio) Resistance to Infection by the Lobster Pathogen Aerococcus viridans (var.) homari
Authors: Cornick John W. , Stewart James E.
Published: April 2011

Red crabs (Geryon quinquedens) were acclimated to water temperatures up to 14 C without excessive mortality. The lobster pathogen Aerococcus viridans (var.) homari was nonpathogenic for the red crab at 5, 10, and 15 C and for the snow crab (Chionoecetes opilio) at 5 C, but could be recultured from each species after 60 and 100 days, respectively, with no loss of virulence for the lobster. The lack of virulence was not due to the inadequacy of the hemolymph as a growth medium. Although the serum of each species contained natural bactericidal and agglutinating principles, only the snow crab agglutinin was active against A. viridans (var.) homari. The resistance of these crab species is discussed in relation to their potential as reservoirs of infection.
Nonselective Feeding of Pseudocalanus minutus
Authors: Poulet S. A. , Chanut J. P.
Published: April 2011

Feeding by adult females of Pseudocalanus minutus on naturally occurring particles was determined by comparing particle size spectra in the water and that removed from it as the ration. Mean diameters and variances computed for the overall particle spectra were similar in both water and ration. Cumulative frequencies of particle numbers and volumes computed for both water and ration were not significantly different in two thirds of the experiments. In one third of the experiments significant values were found, mainly due to addition of particles in the small size ranges, as a result of feeding. The hypothesis of nonselectivity by Pseudocalanus minutus was not rejected by the Kolmogorov-Smirnov’s test. It is suggested that when particle peaks occur copepods obtain a part of their ration from the most productive cells of the phytoplankton population.
Distribution of Hyperiid Amphipods off the Oregon Coast
Authors: Lorz H. (Van Arsdale) , Pearcy W. G.
Published: April 2011

A total of 19 species of hyperiid amphipods was collected from 1963 to 1967 off Oregon. Parathemisto pacifica, Paraphronima gracilis, Streetsia challengeri, Tryphana malmi, Hyperia medusarum, Hyperoche medusarum, and Primno macropa were common. New distributional records are reported for Scina crassicornis bermudensis and Lanceola loveni. Abundance and occurrence of common species are lower inshore than offshore suggesting centers of abundance are in offshore-oceanic waters. Yearly changes in occurrence and abundance of hyperiid amphipods inshore may be related to coastal upwelling. There was no evidence for vertical migrations or diel differences at depth intervals of 0–150 m and 150–450 m.
Phoma herbarum, a Fungal Plant Saprophyte, as a Fish Pathogen
Authors: Ross A. J. , Yasutake W. T. , Leek Steve
Published: April 2011

Phoma herbarum, a fungal plant saprophyte, was isolated from diseased hatchery-reared coho salmon (Oncorhynchus kisutch), chinook salmon (O. tshawytscha), and rainbow trout (Salmo gairdneri). The disease was observed at 10 national fish hatcheries in Washington and Oregon, but the low incidence of experimental infections indicate that it is only weakly contagious. Histopathological examination suggests that the air bladder is one of the primary organs infected. The visceral organs are also affected in both natural and experimental infections.
Distribution of Fish Species in Great Bear Lake, Northwest Territories, with Reference to Zooplankton, Benthic Invertebrates, and Environmental Conditions
Authors: Johnson Lionel
Published: April 2011

Benthic invertebrates in Great Bear Lake are most highly concentrated in the upper 20 m. Densities between 20 and 100 m are low; below 100 m only Mysis relicta and Myoxocephalus quadricornis exist at measurable densities. All benthic organisms exhibit a high degree of patchiness.Lake trout, Salvelinus namaycush, and M. quadricornis are two species that inhabit the lake at all depths (3–400 m) and temperatures (13.2 C for M. quadricornis and 15 C for S. namaycush).Whitefish, Coregonus clupeaformis, inhabit only the bays, seldom being caught in water over 20 m deep. The distribution of whitefish is considered to be restricted mainly by the density of benthic organisms.Three species are confined to the periphery of the lake, Stizostedion vitreum, Lota lota, and Catostomus catostomus. Two species, Couesius plumbeus and Percopsis omiscomaycus, are present in the headwaters and Great Bear River but have not been able to establish themselves in Great Bear Lake. Extreme oligotrophy is considered to have had the effect of reducing species diversity.
Growth in a Population of the Crayfish Pacifastacus leniusculus from a Subalpine Lacustrine Environment
Authors: Flint R. Warren
Published: April 2011

Observations on growth increments at each molt in a population of Pacifastacus leniusculus from a subalpine lake were made from periodically recaptured marked crayfish, as well as from molts recorded in the laboratory. After the first growing season the growth increment at molt remained relatively constant. Throughout the life of this crustacean no differences were observed between sexes. Analysis of size distributions in samples taken at different times of the year revealed that between 8 and 12 year-classes were normally present in the population of Lake Tahoe. Growth of these age-classes could be followed through consecutive samples. The number of molts completed by each year-class was found by relating data on growth increment per molt to growth shown in consecutive quantitative samples. Mean carapace length at recruitment for juvenile crayfish was 3.75 mm with 11 molts occurring during the first growing season, and juveniles reached 13.0 mm by the end of their first year. Molt frequency decreased in successive year-classes, and crayfish surviving past their fourth growth season molted only once a year. Length–weight relationships were similar for both sexes of the population even though their external anatomy differed. Growth comparison between this population and that of a coastal stream population showed that the stream population had a slightly faster overall growth rate due to higher water temperatures and a longer growing season.
Response of Two Arctic Amphipods, Gammarus zaddachi and Boeckosimus (Onisimus) affinis, to Variations in Temperature and Salinity
Authors: Busdosh M. , Atlas Ronald M.
Published: April 2011

Two arctic amphipods were found to be capable of tolerating a wide range of temperatures and salinities. They were tolerant to both abrupt changes, as would occur in crossing a thermocline, and to gradual changes, as would occur seasonally.Gammarus zaddachi could survive lower salinities and higher temperatures than Boeckosimus (Onisimus) affinis. Salinity had a statistically significant effect on rates of respiration for both organisms, but only Gammarus zaddachi showed significant changes in respiration rate in response to temperature changes. The ecological distribution of these amphipods appears to be in part determined by their ability to tolerate fluctuations in salinity and temperature.
Fathead Minnows (Pimephales promelas) and Goldfish (Carassius auratus) as Standard Fish in Bioassays and Their Reaction to Potential Reference Toxicants
Authors: Adelman Ira R. , Smith Jr. Lloyd L.
Published: April 2011

Fathead minnows (Pimephales promelas) and goldfish (Carassius auratus) were compared for their suitability as standard bioassay fish. Both species showed the same variability of bioassay results when tested with four toxicants. Fathead minnows are recommended on the basis of their small size and on their capability for use in complete life cycle tests.On the basis of minimum variability of bioassay results, sodium chloride was superior for use as a reference toxicant. Both sodium chloride and pentachlorophenol seemed capable of detecting abnormal fish. On the basis of seven listed criteria either sodium chloride or pentachlorophenol would be acceptable as a reference toxicant.
δ-Amino Levulinic Acid Dehydratase Activity of Fish Blood as an Indicator of a Harmful Exposure to Lead
Authors: Hodson Peter V.
Published: April 2011

The activity of red cell δ-amino levulinic acid dehydratase of rainbow trout (Salmo gairdneri) was depressed after exposure of the fish to lead. Concentrations of lead in water as low as 13 μg/liter caused a significant inhibition of activity after only 4-wk exposure. Assays of this enzyme’s activity may provide a short-term indication of long-term harmful effects of lead.
Predation, Yield, and Ecological Efficiency in Aquatic Food Chains
Authors: Dickie L. M.
Published: April 2011

Given constancy of biomasses and sizes of predators and prey, the basic ecological equations are used to show that relative predation rates must increase rapidly as trophic level in aquatic food-chains drops towards primary production. The implications of this conclusion for exploitation at different food-chain levels is discussed.
Continuous Dynamical Computations of Water Transports in Lake Erie for 1970
Authors: Simons T. J.
Published: April 2011

A numerical model of Lake Erie has been used to compute water transports throughout the 1970 shipping season on the basis of continuous wind observations from six shore stations. A vertically integrated model was used for quasi-homogeneous conditions, and a two-layer model was employed to simulate summer stratification. The computed water circulations were retained for a study of the horizontal distribution of various chemical parameters measured by regular ship cruises on the lake during this period. Computed surface elevations were compared with observed water level data to verify the model calculations and to adjust the windstress coefficient from month to month. The coefficient of correlation between observed and computed Buffalo-minus-Toledo water setup averages out to.95 for the complete integration period. In addition, a comparison was made of model results and available data from current meters maintained in the lake during this period. The results show the feasibility of quasi-operational applications of a model of the present type for computing the necessary water transport information for ecosystems modeling and water resources planning.
Forms of Phosphorus in the Surficial Sediments of Lake Erie
Authors: Williams J. D. H. , Jaquet J-M. , Thomas R. L.
Published: April 2011

The phosphorus in 48 surficial Lake Erie sediment samples was present in three major forms: phosphorus associated with apatite, nonapatite inorganic phosphorus (NAIP), and organic phosphorus. The apatite was of natural, detrital origin. It existed as particles ranging from fine sand to clay in size but mostly as silt-sized particles and was concentrated in nearshore sediments. Both NAIP and organic phosphorus was concentrated in fine-grained sediments accumulating in offshore depositional areas. NAIP was associated with amorphous hydrated ferric oxide in the oxidized microzone but was present as vivianite (Fe3(PO4)2∙8H2O) and possibly other forms also in the reduced zone. The organic phosphorus content of the sediment was closely related to organic carbon content. The phyllosilicate, organic matter, and reactive iron and manganese components of the sediments existed in intimate association.
Cultural Impact on the Geochemistry of Sediments in Lake Erie
Authors: Kemp A. L. W. , Thomas R. L. , Dell C. I. , Jaquet J.-M.
Published: April 2011

The chemical and physical characteristics of six cores from Lake Erie are described. The concentrations of Si, Al, K, Na, and Mg, which represent the major mineral species in the sediment, were uniform in each core. Surface enrichments of Hg, Pb, Zn, Cd, Cu, Organic-C, N, and P were observed at each location, due mainly to the increasing anthropogenic loading of these elements to the sediments since 1850. Concentration profiles for Mn, Fe, and S were related to sediment Eh and are due to mobilization of these elements in the pore waters.Natural and anthropogenic inputs of nutrients and heavy metals were calculated. About 60% of the total loading of these elements is being deposited in the Eastern basin. It is calculated that 30 million metric tons of fine-grained sediment accumulates in the offshore basins of the lake, each year. The major source of the sediment input is erosion of the shoreline bluffs, with the north shore between Erieau and Long Point contributing 21 million metric tons annually. A sediment mass balance suggests that a large part of this bluff material is transported up to 150 km and is deposited in the Eastern basin.
Temperature, Oxygen, and Nutrient Distribution Patterns in Lake Erie, 1970
Authors: Burns N. M.
Published: April 2011

Ten major surveys of biological and chemical variables in Lake Erie were carried out during the 1970 shipping season. The observed distributions of temperature, turbidity, oxygen, soluble and particulate phosphorus, nitrate plus nitrite, ammonia, and soluble reactive silica are presented. Comment on the probable causes of the observed distribution patterns has been included where appropriate. Ammonia quantities in the lake remained almost unchanged throughout the year while nitrate plus nitrite quantities varied considerably. The ratio of particulate to total phosphorus showed very little seasonal change.
Aspects of the Biology and Morphology of the Snake Eel, Pisodonophis cruentifer (Pisces, Ophichthidae)
Authors: Wenner Charles A.
Published: April 2011

Variability in meristic and morphometric characters and dentition of the snake eel, Pisodonophis cruentifer, is presented. Pisodonophis cruentifer is distributed from the Laurentian Channel in the north to just north of Cape Hatteras in the south and is most abundant between 150 and 400 m in the Norfolk Canyon area. Males collected in June 1973 possessed mature spermatozoa in testicular tissue while females had yolk-laden eggs 0.6–1.0 mm in diameter. The total length−fecundity relation is log10 y = 4.28696 (log10 x) − 7.33402, where y = total fecundity and x = total length in millimeters. Gross and microscopic morphology of the gonads is presented. Morphological adaptations of P. cruentifer for burrowing into the substrate are contrasted with the benthopelagic eel, Synaphobranchus qffinis, and actual burrowing into the substrate is documented.
Engineering and the Economics of Aquaculture
Authors: Milne P. H.
Published: April 2011

The engineering developments of the last decade into the design and construction of facilities for aquaculture have considerably improved the economic prospects.This review of engineering techniques for aquaculture discusses the problems of site selection and analysis with special reference to the requirement of pollution-free water and its abstraction rate. The design and construction of facilities used for aquaculture are described for land-based farms, sea enclosures, and cages. The various types of ponds and tanks and their advantages of adaptability are emphasized. Examples are given of sea enclosures, both intertidal and sublittoral, the latter being either rigid or flexible frameworks. The diversification throughout the world of materials and techniques for fish cage construction, using rigid and flexible frameworks, are considered with their advantages and disadvantages.The need for careful monitoring of the surrounding environment in marine aquaculture is most important since the sea enclosures or cages may affect the hydrography of the area, and marine fouling will alter the water currents.It is felt that the most important future developments in aquaculture are first the utilization of the present underexploited resource of heated waste water from power station outfalls, and secondly the ability to produce really reliable filtration units for commercial closed cycle circulation systems.The advances made in the last decade indicate hopeful signs that the FAO projected requirement of 40 million tons of fish and shellfish will be met from aquaculture by the year 2000.
Progress of Laminaria Cultivation in Japan
Authors: Hasegawa Yoshio
Published: April 2011

To increase the output of Laminaria in Japan, considerable importance has been attached to the propagation of Laminaria that grow on natural reefs. Various methods of propagation have been used, namely, planting of stones and blasting of reefs. In spite of these efforts, the productivity of Laminaria of good quality has fluctuated remarkably, and further, it has been decreasing gradually. A method of cultivation was then tried. At first, however, production of Laminaria of good quality did not increase readily, because this plant usually requires two winters to attain its commercial size.As a result, the improvement of techniques for cultivating Laminaria has become an important subject for research workers. During the study of the cultivative process, we have succeeded in developing techniques for rearing 2-yr-old plants in 1 yr without debasing their quality. This method is called the "Forced Cultivation Technique."Since 1969 the yield of cultivated plants using this technique has increased remarkably in various districts from the south of Hokkaido to the northern part of the mainland of Japan.
Application of 24-Hour Postexposure Observation to Acute Toxicity Studies with Invertebrates
Authors: Hansen Jr. Carl R. , Kawatski Joseph A.
Published: April 2011

Experimentation with carbaryl, dieldrin, endothal, malathion, and TFM (3-trifluoromethyl-4-nitrophenol) on the ostracod Cypretta kawatai and the midge Chironomus tentons demonstrated that the method of routine toxicity tests with invertebrates can be substantially improved by including a posttreatment (toxicant-free water) observation period. This improvement enables confirmation of death and thereby reveals latent toxicity or recovery.
Destructive Grazing of Kelp by Sea Urchins in Eastern Canada
Authors: Breen P. A. , Mann K. H.
Published: April 2011

Destruction of kelp beds by sea urchins has been documented in St. Margaret’s Bay, Nova Scotia, and also appears to be taking place in other parts of eastern Canada. Continued sea urchin settlement onto grazed areas prevents the return of kelp and other algae for long periods. Because of the large contribution of kelp beds to coastal productivity, the disappearance of kelp from large areas is alarming. Dynamics of sea urchin grazing are discussed.
An Inexpensive Tag for Short-Term Visual Tracking Studies
Authors: Leaman Bruce M.
Published: April 2011

The construction of an inexpensive tag for visual tracking studies is described. The results of field evaluation of the tag are presented and discussed in relation to previous tags and other tracking methods. Advantages of the tag are listed.
Feeding Modes and Prey Size Selection in the Alewife (Alosa pseudoharengus)
Authors: Janssen John
Published: April 2011

Alewives (Alosa pseudoharengus) feed on zooplankton in three modes: 1) particulate feeding on individual prey; 2) filtering with the mouth held agape, accompanied by strong swimming; and 3) gulping, in which the mouth opens and closes more slowly than a particulate feeder and more rapidly than a filterer, and swimming is slower than in a filterer. Individuals that feed by filtering are not size selective; gulpers are size selective; and particulate feeders are more size selective than gulpers. Gulpers and filterers take more than 1 prey per mouth opening and closing; particulate feeders take only 1.