bluuebunny/crossref_metadata_2025 huggingface dataset:
Two New Species of Protanypus Kieffer, with Keys to Nearctic and Palaearctic Species of the Genus (Diptera: Chironomidae)
Authors: Sæther Ole A.
Published: April 2011

Two Nearctic species of Protanypus are described: Protanypus ramosus n.sp. from imagines, pupae, and fourth-, third-, and second-instar larvae; Protanypus hamiltoni n.sp. from male imagines, pupae, and fourth-, third-, and second-instar larvae. The larvae of two other species are described. These are the first published descriptions of Nearctic imagines of the genus.Keys are given for male imagines, pupae, and known larvae of the Nearctic and Palaearctic species of the genus.Protanypus ramosus occurs in several oligotrophic and oligohumic to weakly polyhumic lakes in northwestern Ontario, in Algonquin Park, and in the Great Lakes. Protanypus hamiltoni is found in three deep and large, oligotrophic lakes in British Columbia and in Great Slave Lake. Both species are bivoltine. Protanypus sp. A occurs in Marion Lake, British Columbia, a small oligotrophic lake. Protanypus sp. B is found in George Lake, La Cloche Mountain Region, Ontario, an acidified oligotrophic lake.
Delineating Spring and Autumn Herring Populations in the Southern Gulf of St. Lawrence by Discriminant Function Analysis
Authors: Messieh S. N.
Published: April 2011

A discriminant function based on three variables, pectoral and dorsal fin rays and gill rakers, was calculated for Atlantic herring (Clupea harengus harengus) taken from spring- and autumn-spawning concentrations in the southern Gulf of St. Lawrence and tested for general applicability by classifying other herring of known origin. The function was then used to classify herring sampled from feeding concentrations. Results showed that feeding herring (pre- and postspawning) comprised a mixture of spring and autumn herring populations averaging 51.8 and 48.2%, respectively.The observed heterogeneity of feeding concentrations, in contrast to homogeneity of spawning concentrations, confirmed the hypothesis that spring and autumn herring populations mix during feeding, though they separate at the onset of spawning. Discriminant function analysis is most useful for separating herring spawning groups during their feeding season when overlap of maturation stages prevents separation by maturation stage alone.
Population Estimate of the Humpback Whale (Megaptera novaeangliae) in the West Indies by Visual and Acoustic Techniques
Authors: Winn H. E. , Edel R. K. , Taruski A. G.
Published: April 2011

Visual track census and a new method, acoustic counting, were used to estimate the humpback whale (Megaptera novaeangliae) population in the West Indies. Results produced by the two methods differed to some extent. The average or best estimate was 1018 whales with a range of 785–1157. Silver and Navidad banks, containing approximately 85% of the total population, are presently the major nursery grounds in the West Indies. The humpback whale population in the western North Atlantic has increased since the early part of the century.
Geographic Variation in Incidence of Trematode Parasites of American Plaice (Hippoglossoides platessoides) in the Northwest Atlantic
Authors: Scott J. S.
Published: April 2011

The digenetic trematodes Steringotrema ovacutum, Zoogonoides viciparus, Derogenes varicus, Lecithaster gihbosus, Fellodistomum furcigerum, and Stenakron vetustum were common in American plaice (Hippoglossoides platessoides) from the southern Gulf of St. Lawrence, Scotian Shelf, and northeast Gulf of Maine in the summers of 1971 and 1972. Levels of incidence of the trematodes in different areas within the region are compared. Steringotrema ovacutum, Z. viviparus, and F. furcigerum may be useful as biological indicators in plaice in the Northwest Atlantic.
Statistical Methods for Estimating Normal Blood Chemistry Ranges and Variance in Rainbow Trout (Salmo gairdneri), Shasta Strain
Authors: Wedemeyer Gary A. , Nelson Nancy C.
Published: April 2011

Gaussian and nonparametric (percentile estimate and tolerance interval) statistical methods were used to estimate normal ranges for blood chemistry (bicarbonate, bilirubin, calcium, hematocrit, hemoglobin, magnesium, mean cell hemoglobin concentration, osmolality, inorganic phosphorus, and pH for juvenile rainbow (Salmo gairdneri, Shasta strain) trout held under defined environmental conditions. The percentile estimate and Gaussian methods gave similar normal ranges, whereas the tolerance interval method gave consistently wider ranges for all blood variables except hemoglobin. If the underlying frequency distribution is unknown, the percentile estimate procedure would be the method of choice.
Toxaphene Effects on Growth and Development of Brook Trout (Salvelinus fontinalis)
Authors: Mehrle Paul M. , Mayer Jr. Foster L.
Published: April 2011

Twenty-two days before hatching, eyed eggs of brook trout (Salvelinus fontinalis) were placed in a flow-through system and continuously exposed to toxaphene (0, 39, 68, 139, 288, and 502 ng/liter) until they hatched and the resulting fry were exposed for a further 90 days. Hatchability was not affected by toxaphene, but all of the fry exposed to 502 and 288 ng/liter of toxaphene died by 30 and 60 days after hatch, respectively. Growth of fry was significantly depressed at the 139 and 288 ng/liter concentrations 30 days after hatch and at all concentrations after 60 and 90 days of toxaphene exposure.Whole body collagen of fry, as estimated by hydroxyproline, was significantly decreased in the four higher concentrations of toxaphene within 7–15 days after hatch. Backbone collagen was significantly decreased (P < 0.05) in 30-, 60-, and 90-day-old fry exposed to toxaphene, whereas calcium and phosphorus concentrations in the backbone were increased (P < 0.05). The mineral: collagen ratio was significantly increased by toxaphene. The whole body collagen of sac-fry was a good predictor of later growth and development of brook trout.
Meristic Differences in Spawning Populations of American Shad, Alosa sapidissima: Evidence for Homing to Tributaries in the St. John River, New Brunswick
Authors: Carscadden James E. , Leggett William C.
Published: April 2011

Univariate and multivariate analyses were performed on five meristic characters of American shad, Alosa sapidissima, spawning in the Miramichi, St. John, Connecticut, and Hudson rivers. In 71% of the comparisons, significant differences in mean numbers of meristic characters existed between river populations and between tributaries within the St. John River system. Comparisons of populations using multivariate techniques revealed that percentage of overlap of meristic characters was low (< 1% in most comparisons). It is suggested that shad not only home to their natal river but also to their natal tributary. The results suggest that in shad, meristic counts are strongly influenced by a genetic component.
Effects of Acute Exposure to Bleached Kraft Pulpmill Effluent on Carbohydrate Metabolism of Juvenile Coho Salmon (Oncorhynchus kisutch) During Rest and Exercise
Authors: McLeay D. J. , Brown D. A.
Published: April 2011

In the static study (no exercise), liver glycogen stores were unchanged during 12-h exposure to 0.8 of the 96-h LC50; longer exposures caused a progressive decrease to levels one fifth those of controls at 72 h. Plasma glucose levels in fish held in 0.8 LC50 effluent for 3–96 h were elevated; at 96 h, glucose had increased threefold. Mean values for plasma lactate were elevated significantly at 3, 6, 24, 72, and 96 h.In the exercise (swimming one body length per second)–rest study, muscle glycogen levels decreased 53–78% during exercise in water or effluent (0.7 LC50) for 4–12 h, and did not recover during 12-h rest in water. Muscle glycogen for fish exercised for 12 h in effluent and then rested for 4 or 12 h in effluent was lower compared to values for fish exercised in effluent and then rested in water. There was no difference in liver glycogen levels offish exercised in effluent or water for 4–12 h. Values of liver glycogen for fish exercised in effluent for 12 h and then rested for 4, 8, or 12 h in effluent decreased 60–70% compared to fish exercised in water for 12 h and then rested in water and by 55–65% from fish exercised in effluent for 12 h and rested in water for 4–12 h. Plasma glucose levels were elevated one- to fourfold during exercise in water or effluent. Fish resting in water for 4, 8, or 12 h following exercise in water had relatively stable glucose levels; whereas for fish exercised and then rested in effluent the glucose levels increased twofold during resting. Plasma lactate levels were elevated five- to sixfold during exercise in water or effluent for 4–12 h, declining to values 1–2 times those of stock fish within 4-h rest. Plasma lactate levels for fish exercised in effluent and then rested in effluent or water were continually higher than those for fish exercised and rested in water.It was concluded that measurement of carbohydrate metabolites, particularly blood sugar levels, in unexercised fish could prove useful as a rapid method for measuring toxicity of pulpmill effluents and other pollutants.
Swimming Performance of Juvenile Coho Salmon (Oncorhynchus kisutch) Exposed to Bleached Kraft Pulpmill Effluent
Authors: Howard T. E.
Published: April 2011

Maximum critical swimming speeds were not achieved by fingerling coho salmon (Oncorhynchus kisutch) in concentrations of bleached kraft pulpmill effluent above a threshold concentration between 10–20% of the 96-h LC50. Reduction of swimming performance was related to effluent concentration but not to exposure time after the initial 18 h. Swimming performance returned to control levels for fish tested in water after 6–12 h recovery from exposure to effluent concentrations up to 0.7 LC50. Effluent was rendered nontoxic by aerobic microbiological fermentation but some reduction in swimming performance was measured which was attributed, in part, to the effects of color and lignin materials remaining after treatment.The results are discussed in relation to the mode of toxic action of bleached kraft pulpmill effluents and their possible impact on aquatic ecosystems.
Dolphin and Small Whale Fisheries of the Caribbean and West Indies: Occurrence, History, and Catch Statistics — with Special Reference to the Lesser Antillean Island of St. Vincent
Authors: Caldwell David K. , Caldwell Melba C.
Published: April 2011

Humpback whaling, and fishing for smaller cetaceans in the West Indies and Caribbean is on the decline, mainly due to economic factors. These factors are summarized. Catch statistics are tabulated for pilot, killer, false killer, and sperm whales, along with landed weight for mixed catches of dolphins. The pilot whale fishery of St. Vincent has taken 2912 blackfish (Globicephala macrorhynchus) in the period 1962–74 (mean 224 per annum). Catches occur in all months, but are lowest in December and January. Ten other species of smaller cetaceans known to be taken in the waters of St. Vincent are listed.
Review of Japanese small-type whaling
Authors: Ohsumi Seiji
Published: April 2011

A review is given of Japanese whaling operations taking small whales with catcher boats of approximately 40 tons and mounting cannons of 50-mm bore and under. Main species caught are minke, Baird’s beaked, pilot, and killer whales. The catch of minke whales peaked at 532 in 1956, and has ranged between 220 and 365 annually since 1959. Decreases have been seen in catches of Baird’s, pilot, and killer whales. Catcher efficiency may have changed.
Summerkill Risk in Prairie Ponds and Possibilities of its Prediction
Authors: Barica Jan
Published: April 2011

Summer fish kills in shallow, landlocked ponds of the Erickson–Elphinstone area, southwestern Manitoba, were caused by collapses of heavy algal blooms, mostly Alphanizomenon flos-aquae, and subsequent oxygen depletion. Kills occurred only in ponds that were in the specific conductance range of 800–2000 μmho/cm and where chlorophyll a concentrations exceeded 100 μg/liter. A practical rating system for assessment of summerkill risk was suggested. Correlations between various parameters from 51 ponds were computed; the best correlation (r = 0.866; P = >0.99) was found between the late-winter concentration of ammonia nitrogen and the maximum concentration of chlorophyll a in the following summer. Two summerkill prediction systems were proposed, based on ammonia, dissolved oxygen, and Secchi disc transparency, enabling the prediction of summerkill risk 9 or 3 mo prior to stocking of the fish.
A Revised Interpretation of the History of the Skeena River Sockeye Salmon (Oncorhynchus nerka)
Authors: Ricker W. E. , Smith H. D.
Published: April 2011

Three factors are examined as an aid to interpreting the historical sequence of Skeena sockeye catches. One of these (Exploitation Mechanism 1) affects the catch directly, the other two affect catch by way of increasing or decreasing the recruitment produced by a given number of spawners. "Exploitation Mechanism 1" of Ricker (1973) makes the catch taken from any given brood during a time of increasing rate of exploitation greater than when exploitation is steady or decreasing; this is the main reason for excellent catches from 1905 to 1925. "Exploitation Mechanism 2" makes the progeny of any given number of spawners less numerous under conditions of maximum sustainable yield than during the period when rate of utilization is increasing; as a result recruitments observed prior to 1930 overestimate the potential productivity of the system and hence the sustainable yield. Mechanisms 1 and 2 are both operative even if the best rate of exploitation is never exceeded. In fact, however, the rate of exploitation began to exceed the optimum level of 50–55% about 1908, continued to increase until 1928, and then slowly decreased until the optimum level was reached about 1945; during the latter period, and for about 15 yr subsequently, catches were further depressed as spawning stocks were slowly rebuilt. Another factor affecting recruitment is the apparent existence of interaction between neighboring year-classes in respect to survival rate. Although the exact mechanism of this interaction is not yet known, it has produced three sequences of moderately "dominant" year-classes, the most recent being 1959–63–67–71, in spite of the complication of having two important ages of maturity for Skeena sockeye. More important is the fact that during the recent period large spawnings (0.75–1 million) have produced poor returns while moderately small spawnings (0.25–0.5 million) have produced larger year-classes than they did at any earlier period — in spite of the handicap of Mechanism 2. This apparent interaction between broods implies that one or more small spawnings are a necessary prerequisite for unusually successful reproduction by a later large one, and that successful large spawnings depress the reproduction of subsequent smaller ones. When all these factors are considered together, the observed trend of the Skeena catches can be reproduced. Maximum natural sustainable yield from the system would have been achieved about 1960 except for 2 yr of much reduced reproduction caused by the Babine River rock slide of 1951. Currently, the increased numbers of fry produced in artificial spawning channels at Babine Lake have contributed to large smolt runs that are now beginning to appear in the adult catches.
Relation of Water Temperature to Ceratomyxosis in Rainbow Trout (Salmo gairdneri) and Coho Salmon (Oncorhynchus kisutch)
Authors: Udey L. R. , Fryer J. L. , Pilcher K. S.
Published: April 2011

Juvenile rainbow trout (Salmo gairdneri) were exposed to infection with Ceratomyxa shasta transferred in groups of 25 to aquaria, and tempered to various temperature levels increasing from 3.9 to 23.3 C (39 to 74 F) by 2.8 degree C (5 degree F) increments. During a 237-day observation period mortality in the experimental groups averaged about 80%, and was independent of water temperature between 6.3 and 23.3 C (44 and 74 F). No deaths occurred at 3.9 C (39 F). The geometric-mean time from exposure to death, however, was definitely a function of temperature, increasing from 14 days at 23.3 C (74 F) to 155 days at 6.7 C (44 F).A similar experiment with juvenile coho salmon (Oncorhynchus kisutch) gave quite different results. In this species, percent mortality due to C. shasta increased progressively from 2% at 9.4 C (49 F) to 22% at 15.0 C (59 F) and 84% at 20.5 C (69 F). No deaths occurred at 3.9 or 6.7 C (39 or 44 F) during the 201-day experimental period. As with the rainbow trout, the geometric-mean time from exposure to death was temperature dependent, increasing from 12.5 days at 23.3 C (74 F) to 146 days at 9.4 C (49 F). The data indicate that ceratomyxosis in coho can be suppressed by water temperatures of 6.7 C (44 F) or below.
Significance of Detritus or Detritus-Associated Invertebrates to Fish Production in a New Impoundment
Authors: Cherry Donald S. , Guthrie Rufus K.
Published: April 2011

During early stages of succession in a new impoundment, fish species that could assimilate the readily available food resources, i.e. carp (Cyprinus carpio) and flat bullhead (Ictalurus platycephalus) were initially favored in numbers and weight. Detrital feeders or omnivores represented by carp and the flat bullhead comprised a majority of the numbers (56%) and weight (65%) of the 25 species captured during a 2-yr period. Numbers of the major fish groups captured decreased from 1971 to 1972, while the weight per species increased.On a volumetric basis, detritus and detritus-associated invertebrates (coleopterans and dipterans), were the major food items consumed by carp and catfish. Relative abundance of animal food items, in terms of frequency of occurrence and percentage of stomach contents, was greater at warmer water temperatures. In comparison to other species, catfish contained the greatest diversity of food items during warmer months and consumed larger quantities of detritus in the winter. Fish groups that constituted a smaller biomass, such as centrarchids, were generally insectivorous or fed upon cladocerans and copepods, while adult basses (Micropterus salmoides and M. coosae) and chain pickerel (Esox niger) were piscivorous.
Prolonged Oral Administration of Methyl Mercury Chloride to Rainbow Trout (Salmo gairdneri) Fingerlings
Authors: Wobeser G.
Published: April 2011

Rainbow trout (Salmo gairdneri) fingerlings were fed rations containing 4, 8, 16, and 24 ppm mercury as methyl mercury chloride over a 105-day period. Fish receiving the 16- and 24-ppm rations had significantly higher blood packed cell volumes than did controls. Hyperplasia of the gill epithelium was the only morphologic alteration detected in these fish. Individual fish accumulated up to 30 ppm mercury in muscle tissue, but no mortality that could be attributed to mercury occurred.The results suggest that trout can tolerate a large body burden of mercury, if this mercury is acquired over a period of time.
Seasonal Changes of Fat Content in the Yellow Perch (Perca flavescens) of Two Laurentian Lakes
Authors: Newsome George E. , Leduc Gérard
Published: April 2011

Different body fat reserves in male and female yellow perch (Perca flavescens) may determine a marked differential mortality during the winter. This was revealed by a study in two Laurentian lakes of the Province of Quebec harboring stunted yellow perch with a marked predominance of males. The proportion of females in each year-class is markedly smaller, thus suggesting a higher mortality among immature and mature females than among males.In an attempt to explain the differential mortality, the seasonal variation of body fat content in males and females was measured; also the fat level at time of death caused by starvation under laboratory conditions was determined. The results showed that in the females the body fat content falls to a critical level of about 2% at least 4 mo before spawning, whereas the males maintain a fat level of almost 5% throughout winter.
Fluorescent Antibody Identification and Detection of the Corynebacterium Causing Kidney Disease of Salmonids
Authors: Bullock G. L. , Stuckey H. M.
Published: April 2011

An indirect fluorescent antibody technique (FAT) has been developed for serological identification, diagnosis of kidney disease (KD), and detection of subclinical infections of KD. Rabbit or goat antikidney disease serum and appropriately labeled immunoglobulin was found to be specific for the KD bacterium. The technique was superior to examination of gram-stained smears for detection of small numbers of KD bacteria. The test requires approximately 2 h.
Seaward Movement of Juvenile Fishes, Including Lunar Periodicity in the Movement of Coho Salmon (Oncorhynchus kisutch) Fry
Authors: Mason John C.
Published: April 2011

Following emergence, more than 51,000 coho salmon (Oncorhynchus kisutch) fry moved seaward from Lymn Creek. Peaks in movement occurred coincident with the new moon and progressively declined through four lunar cycles although 75% of the outmovement took place between early April and the middle of June. Coho smolt migration occurred simultaneously, the run peaking in late May during a period of maximum low tides between sunrise and sunset when the moon was full. Sticklebacks (Gasterosteus) moved seaward sporadically throughout the trapping period from April to September but their numbers increased markedly in August due to the appearance of underyearlings. The seaward movement of coho fry and smolts and of sticklebacks showed no apparent relationship to either stream discharge or temperature.Lunar rhythmicity in movement of coho fry and probable fate of fry are discussed within a framework of behavioral and ecologic concepts pertinent to the species’ life history in the juvenile stage and relevant to concern for enhancing coho salmon production.
Analysis of Threshold-Induced Bias Inherent in Acoustic Scattering Cross-Section Estimates of Individual Fish
Authors: Weimer R. T. , Ehrenberg J. E.
Published: April 2011

During acoustic fish stock assessment surveys, it is often desirable to measure the distribution of the acoustic scattering cross-section of single fish. One of the problems in such measurements is that a threshold in the electronic circuitry discriminates against small fish. This effect is analyzed in detail, and an expression is derived for the threshold-induced bias in the mean scattering cross-section estimate. Results are plotted for a typical set of operating conditions.
Ration, Growth, and Measures of Somatic and Organ Condition in Relation to Meal Frequency in Winter Flounder, Pseudopleuronectes americanus, with Hypotheses Regarding Population Homeostasis
Authors: Tyler A. V. , Dunn R. S.
Published: April 2011

Six ration levels were established among 120 large, adult winter flounder (Pseudopleuronectes americanus) by setting different feeding frequencies, but with unlimited feeding at each meal. All fish were maintained at 7 C. With decrease in feeding frequency, fish ate less food per month but more food per meal — i.e. ration compensation was attempted. At the lowest frequency, two meals per month, fish did not compensate. At any one feeding frequency, fish ate progressively more per meal from the first to the fourth (final) month of the experiment.Maintenance ration was 7.9 gcal/g per day. Weight loss on starvation was equivalent to 2.14–2.35 gcal/g per day. Gross conversion efficiency ranged from 1 to 16%, and was positively correlated with ration. Net conversion efficiency averages 24.3% and was not related to ration.Positive correlations were found between mean calories consumed per day and condition, liver weight, percent fat in the liver, percent of fish with yolk-bearing ovaries, ovary weight, and percent of ovarian follicles with yolk. The decrease in proportion of yolked oocytes with decrease in ration was not due to increased follicular atresia, but to a decrease in number of oocytes starting vitellogenesis.Comparisons with flounders sampled directly from Passamaquoddy Bay, N.B. showed that the negative correlation between condition index and percentage of oocytes not in vitellogenesis was the same for Bay and laboratory fish, the range of response being greater in the laboratory fish. The existence of this relationship was interpreted as evidence that some flounders within the Bay were not getting all the food they could use. In the face of food scarcity, the winter flounder’s adaptive reproductive strategy seems to be to sacrifice egg production and maintain body weight, and so when a good year comes its body will be large and able to carry a larger ovary.
Coastal Circulation and Physical Oceanography of the Scotian Shelf and the Gulf of Maine
Authors: Sutcliffe Jr. W. H. , Loucks R. H. , Drinkwater K. F.
Published: April 2011

Correlations between annual catch of coastal commercial species of fish and the environmental factors of sea temperatures and St. Lawrence River discharge have led to an investigation of the relationship between the latter. Examining year-to-year variability of monthly means, effects of the St. Lawrence River discharge can be traced by correlation analysis with sea temperatures to propagate from the Gulf of St. Lawrence onto the Scotian Shelf and through the Gulf of Maine at known coastal current drift speeds. Seasonal salinity and transport data support such a flow at least to a section off Halifax on the Scotian Shelf. Within the Gulf of Maine seasonal salinities do not support continuity of flow; however, possible reasons and mechanisms for this are discussed. Other factors such as local river runoff in the Gulf of Maine, Labrador Current, and large-scale weather systems are briefly considered and discussed. It is proposed that the Gulf of St. Lawrence to the Gulf of Maine inclusive be considered as an oceanographic system and events occurring in the southern part on time scales of a month or more are not independent of more northerly events. It is not interpreted that the river discharge is the driving force of such an oceanographic system but rather influences the water properties within the source region of the flow, i.e. the Gulf of St. Lawrence. Some biological implications of the Gulf of St. Lawrence to Gulf of Maine pathway are pointed out.
Computations of Physical Transport and Regeneration of Phosphorus in Lake Erie, Fall 1970
Authors: Lam D. C. L. , Jaquet J.-M.
Published: April 2011

A one-layer, two-dimensional computer model for the time-dependent, lakewide advective and diffusive transports as well as physical regeneration of total phosphorus in Lake Erie has been developed. It has 60 × 16 square grid cells of 6.67-km mesh size and uses a time step of 12 h. The model has been verified and found to be in reasonably good agreement with the Canada Centre for Inland Waters (CCIW) monitor cruise data for October, November, and December during which period there were high winds with high phosphorus concentrations being observed. Computed, daily averaged currents from a hydrodynamic model developed at CCIW are used for the transport terms and actual data for the lake boundary conditions. The physical regeneration is attributed to wave motions induced by wind. A formula is proposed which expresses the regenerated amount of total phosphorus in terms of wave orbital velocity and sediment mean grain size. A discussion is presented on the choice of the settling rate and the regeneration coefficient which produce satisfactory model results.
Assessment of the United States Lake Whitefish (Coregonus clupeaformis) Fisheries of Lake Superior, Lake Michigan, and Lake Huron
Authors: Jensen A. L.
Published: April 2011

The logistic surplus production model is applied to lake whitefish (Coregonus clupeaformis) yield and effort data from Lake Superior, Lake Michigan, and Lake Huron. The fitted models indicate that the whitefish populations in most areas of the lakes have been overexploited, and that in these areas yield was below the maximum sustainable yield before sea lamprey (Petromyzon marinus) predation took its toll. In some areas of Lake Superior the whitefish populations are not overexploited. The sea lamprey is the apparent cause of the drastic decrease in the whitefish population that occurred in northern Lake Michigan during the 1950’s.
Current Status and Future Prospects for Harvesting and Resource Management of the Agarophyte in Japan
Authors: Yamada Nobuo
Published: April 2011

Agar-agar manufacturing was Japan’s monopoly for about 300 yr from 1644 until about 1920, when its production was initiated in the USA by introducing techniques from Japan, and then was begun in South Korea, Indonesia, and many other countries. Today the average annual output of agar-agar of over 20 countries amounts to 6000 tons, half of which is produced in Japan.Agarophytes are harvested in many countries and traded among them. In Japan, nearly 14,000 tons are consumed in a year, two thirds of which are imported from about 20 countries.Under these circumstances, there is a worldwide demand for appropriate measures for resource conservation, effective harvesting, and utilization of agarophytes.This paper presents the results of basic and applied investigations on the agarophytes and the existing state of harvesting and resource-conservation management in Japan.
Effects of Environmental Disturbance on the Distribution and Primary Production of Benthic Algae on a British Columbia Estuary
Authors: Pomeroy W. M. , Stockner J. G.
Published: April 2011

Construction of a river training dyke at Squamish, B.C., has resulted in strong salinity, water transparency, and sedimentation gradients across the estuary face which have significantly affected the distribution and primary production of benthic algae. The estuary west of the dyke is now a very unstable habitat for algal colonization and growth. During river freshet, heavy sedimentation and salinities less than 3‰ make algal survival difficult. At other times of the year, a salinity range of up to 25‰ is common over a tidal cycle. Algae in this area are generally strongly euryhaline, the dominant species being Enteromorpha minima, Rhizoclonium riparium, and Vaucheria dichotoma; mean production is 0.6 g Cm−2 day−1. The eastern portion of the estuary has a more stable benthic environment; lower sedimentation and higher salinity result in greater species diversity, biomass, and primary production. Dominant species are E. minima, Ulva lactuca, Pylaiella littoralis, and a variety of diatom communities. These algae tend to be weakly euryhaline, with optimum salinities between 15 and 30‰. Mean production is 2.2 g C m−2 day−1. Recent intrusion of Fucus vesiculosus strongly indicates that the eastern estuary is developing into a more marine habitat.Primary production of benthic algae is maintained by the wax and wane of low light and high light favoring species. Annual production estimates of 215 g C m−2 approximate those for estuaries at similar latitudes.
Chemical Characteristics and Acute Toxicity of Foam on Two Aerated Lagoons
Authors: Servizi J. A. , Gordon R. W. , Rogers I. H. , Mahood H. W.
Published: April 2011

Foam collected from two aerated lagoons treating kraft pulp effluents was highly toxic to juvenile sockeye salmon (Oncorhynchus nerka). Chemical fractionation of one foam revealed large amounts of toxic resin acids and neutral diterpenes. In the other foam, toxicity was related to a pitch dispersant and unidentified material. Neither foam was readily detoxified by biological treatment in the laboratory.
Field Testing of Injected Vibrio anguillarum Bacterins in Pen-Reared Pacific Salmon
Authors: Antipa Ross
Published: April 2011

Intraperitoneal injection of three types of Vibrio anguillarum bacterin (heat-killed, formalin-killed, and a combination of heat and formalin-killed) was tested in Chinook (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) to assess the feasibility of preventing vibriosis by immunization in commercial aquaculture. A single injection of V. anguillarum bacterin gave substantial protection to chinook salmon for 6 mo postinoculation (32% mean mortality in all injected groups) in comparison to the control group (85% mortality). Chinook salmon showed the highest survival when treated with the heat-killed V. anguillarum bacterin. All groups of coho salmon had less than 7.0% mortality, and immunization was not beneficial to survival. Serum antibody titer of V. anguillarum agglutinins was increased by intraperitoneal injection. Vibrio anguillarum was the pathogen most frequently isolated from moribund chinook salmon; Aeromonas salmonicida was the predominant organism isolated from moribund coho salmon.
Buoyancy Compensation by Atlantic Salmon (Salmo salar) Smolts Tagged Internally with Dummy Telemetry Transmitters
Authors: Fried Stephen M. , McCleave James D. , Stred Kristin A.
Published: April 2011

Negative buoyancy was induced in Atlantic salmon (Salmo salar) smolts by insertion of dummy telemetry tags (4.0 g in water) into the stomach. Buoyancy adjustment by means of swimbladder volume change was determined in tagged and untagged (control) smolts either allowed or denied access to the water surface. Regression of percent recovery of initial buoyancy on recovery time showed that tagged fish with access to the surface gradually increased their buoyancy over a 6-h test period. Only 1 of 28 fish held 0.5–2.0 h recovered its initial buoyancy, while 7 of 26 held 2.5–4.0 h recovered, and 7 of 24 held 4.5–6.0 h recovered. Tagged fish without access to the surface never regained buoyancy and became slightly heavier with time. Two tagged fish without access to air were unable to compensate for negative buoyancy after 24 h, but exhibited total or partial recovery when examined 6 h after being allowed access. Control fish did not alter buoyancy with handling or over time.
Distribution, Age and Growth, and Sexual Maturity of Witch Flounder (Glyptocephalus cynoglossus) in Newfoundland Waters
Authors: Bowering W. R.
Published: April 2011

Witch flounder (Glyptocephalus cynoglossus) were caught from the Hawke Channel to the southern edge of the Grand Bank and west to the Scotian Shelf and the Gulf of St. Lawrence. Although the largest catches were taken at 2–6 C and 185–370 m, witch flounder were found at temperatures ranging from −1 to 10 C and depths of 20–870 m. Witch flounder of the Northeast Newfoundland Shelf were largest and those of the Gulf of St. Lawrence smallest at comparable ages, with growth rates for the east coast of Newfoundland being faster than most other areas. Age and length at 50% sexual maturity ranged from 4.20 to 5.59 yr and 25 to 30 cm for males, and from 8.42 to 10.21 yr and 40 to 50 cm for females.
Acute and Chronic Toxicity of Copper to Four Species of Daphnia
Authors: Winner Robert W. , Farrell Michael P.
Published: April 2011

The sensitivity of Daphnia magna, D. pulex, D. parvula, and D. ambigua to acute and chronic copper stresses was evaluated under laboratory conditions. Using 72-h LC50 values as the index, the two larger species were significantly less sensitive to an acute copper stress than were the two smaller species. All four species exhibited reductions in survival at Cu concentrations > 40 μg/liter. Daphnia magna exhibited a decrease in the instantaneous rate of population growth (r) at Cu concentrations > 60 μg/liter; r decreased in the other three species at concentrations > 40 μg/liter. Daphnia ambigua produced significantly smaller broods at Cu concentrations > 40 μg/liter, whereas mean bood sizes did not decrease in D. pulex and D. parvula until the Cu concentration exceeded 60 μg/liter. Daphnia magna did not exhibit any reduction in mean brood size related to copper concentration; reproduction in this latter species was inhibited only as a consequence of females dying before they reached reproductive maturity at concentrations > 80 μg/liter. Application factors, based on the highest concentration that did not reduce survival and 72-h LC50 values, ranged from 0.47 to 0.59 and were not significantly different for the four species. We concluded that the four species do not differ in their susceptibility to a chronic copper stress.
Proliferative Branchiitis due to Tetraonchus rauschi (Trematoda: Monogenea) in Captive Arctic Grayling (Thymallus arcticus)
Authors: Wobeser G. , Kratt L. F. , Smith R. J. F. , Acompanado G.
Published: April 2011

The monogenetic trematode Tetraonchus rauschi was diagnosed as the cause of severe proliferative and inflammatory gill disease among captive Arctic grayling (Thymallus arcticus). Grayling captured from the wild had few flukes and very limited pathologic lesions when compared to captive fish.
Strait of Georgia Oscillations: Low-Frequency Currents and Topographic Planetary Waves
Authors: Helbig J. A. , Mysak L. A.
Published: April 2011

Chang recently showed that up to 46% of the horizontal kinetic energy in the Strait of Georgia (GS), British Columbia, is contained in current oscillations possessing periods exceeding 4 days. In an attempt to explain these findings we study here a class of low-frequency oscillations in a model channel of GS. The Strait is modeled by an infinitely long, rectangular channel with a bottom that slopes upwards to the east; the stratification is idealized by a two-layer system. This model admits northward-traveling, topographic planetary waves with frequencies that lie in the observed range for reasonable values of the wavelength. However, the model does not accurately predict the observed vertical distribution of the horizontal kinetic energy.
Movements of Mountain Whitefish (Prosopium williamsoni) in the Sheep River Watershed, Alberta
Authors: Davies Ronald W. , Thompson Gerald W.
Published: April 2011

Movements of mountain whitefish (Prosopium williamsoni) in the Sheep River were studied during 1972 and 1973. Movement patterns of young-of-the-year and immature whitefish are ill-defined. Although some adult mountain whitefish are nonmigratory, the majority are migratory and show complex movement patterns including spring feeding, summer feeding, prespawning, spawning, and postspawning-overwintering movements. Environmental factors affecting and/or controlling these movements are discussed.
Parasites of Fishes of Aishihik and Stevens Lakes, Yukon Territory, and Potential Consequences of Their Interlake Transfer Through a Proposed Water Diversion for Hydroelectrical Purposes
Authors: Arthur J. R. , Margolis L. , Arai H. P.
Published: April 2011

Forty-six species of parasites (14 Protozoa, 7 Monogenea, 7 Digenea, 8 Cestoda, 2 Acanthocephala, 4 Nematoda, 3 Copepoda, and 1 Hirudinoidea) were recovered from 383 specimens of 8 species of fishes collected from Aishihik and Stevens lakes, Yukon Territory, during the summer of 1973. Four species, Chloromyxum dubium Auerbach, 1908, C. esocinum Dogiel, 1934, Sphaerospora cristata Shulman, 1962 (all Protozoa), and Crepidostomum metoecus Braun, 1900 (Digenea) are reported for the first time from North America.Aspects of the systematics and distribution of several species are discussed and the following new synonymies recognized: Tetraonchus rauschi Mizelle and Webb, 1953 with T. borealis (Olsson, 1893) (Monogenea);Cystidicola stigmatura (Leidy, 1886) with C. farionis Fischer, 1798; and Raphidascaris canadensis Smedley, 1933 with R. acus (Bloch, 1779) (both Nematoda).Substantial differences in the parasite fauna of Aishihik and Stevens lakes are noted; the possible consequences of the introduction of species of potential economic and pathogenic importance e.g. Henneguya zschokkei (Gurley, 1893), Hexamita salmonis (Moore, 1923) (both Protozoa), Discocotyle sagittata (Leuckart, 1842) (Monogenea), Neoechinorhynchus rutili (O. F. Müller, 1780) (Acanthocephala), and Triaenophorus nodulosus (Pallas, 1781) (Cestoda) into new areas as a result of the proposed diversion of Stevens Lake (Yukon River system) into Aishihik Lake (Alsek River system) are discussed.
High Seas Oil Pollution: Particulate Petroleum Residues in the North Atlantic
Authors: Levy E. M. , Walton A.
Published: April 2011

The results of a continuing investigation into the occurrence and distribution of particulate petroleum residues on the surface of the North Atlantic are presented. From 1971 to 1974 more than 850 samples were collected from the North Atlantic on transects between the east coast of Canada and South America, the Caribbean, Baffin Bay and surrounding waters, the Labrador Sea, and the Azores. Repeated sampling was carried out in the Gulf of St. Lawrence and the region between Nova Scotia and Bermuda. The results indicate that the waters north of the Gulf Stream–North Atlantic Current system were virtually free from floating petroleum residues, while the waters of the Gulf Stream, Sargasso Sea, and Caribbean Sea were much more heavily polluted. Although concentrations as high as 91.8 mg/m2 were encountered, the general level of pollution was much less with tar contents in southern waters following a lognormal distribution with a geometric mean of 0.16 mg/m2. The geographical distribution of tar is interpreted in terms of inputs from shipping and tanker traffic, and surface circulation patterns.
Inert Particle Agglutination Tests for Detection of Antibody to Enteric Redmouth Bacterium
Authors: Hansen C. B. , Lingg A. J.
Published: April 2011

Carriers (charcoal particles and latex balls) were sensitized with antigen extracts of enteric redmouth (ERM) bacterium and reacted with serum samples from immunized rabbits and hatchery trout populations. Specificity of the test was evaluated using rabbit antisera prepared against several bacterial fish pathogens. The sensitivity of the test was compared with passive hemagglutination, tube agglutination, and slide agglutination procedures. Preliminary hatchery trials determined the practicality of using these tests under field conditions. The tests were shown to be rapid, reliable, sensitive, and specific serological tools. They would be suitable as supplements to recommended isolation methods in large-scale fish disease inspection and certification programs.
Uptake from Sea Water and Clearance of 14C-p,p′-DDT by the Marine Copepod Calanus finmarchicus
Authors: Harding Gareth C. H. , Vass W. Peter
Published: April 2011

It is impossible to measure the uptake rate of p,p′-DDT by copepods from sea water directly since uptake and depuration occur simultaneously. Copepods were found to lose p,p′-DDT exponentially in flowing sea water with a rate constant of kj = 0.048/day; [Formula: see text]. Five experiments were performed to obtain uptake rates with DDT concentrations ranging from 32.5 to 1337 pptr in sea water. Copepod uptake of p,p′-DDT from sea water is amply described by a single-compartment model, [Formula: see text], which accounts for influx and efflux of DDT. Calculated influx rate constants, ki, varied between 1.5 and 2.7 × 103/day. These results enable prediction of DDT levels in nonfeeding copepods if the concentration of DDT in sea water is known.
Flathead Sole (Hippoglossoides) in the North Pacific
Authors: Forrester C. R. , Tsuyuki H. , Fuke S. , Smith J. E. , Schnute J.
Published: April 2011

Morphometric and electrophoretic examinations were made of 314 specimens comprising 16 samples of flathead sole (Hippoglossoides) from various locations in the North Pacific. On the basis of muscle and hemoglobin analysis no distinction could be made among samples from different locations. However, with the aid of discriminant function analyses on the morphometrics three groups were distinguishable which can be equated to H. elassodon (Jordon and Gilbert), H. robustus (Gill and Townsend), and H. dubius (Schmidt).
A Colorimetric Method for Determination of Saxitoxin
Authors: Gershey R. M. , Nevé R. A. , Musgrave D. L. , Reichardt P. B.
Published: April 2011

Saxitoxin, the paralytic shellfish poison, can be conveniently determined by colorimetry after hydrogen peroxide oxidation and reaction of the resultant guanidine with biacetyl. This colorimetric method has been used to assay saxitoxin quantitatively at concentrations down to 0.5 μg/ml. Saxitoxin levels in the Alaskan butter clam (Saxidomus gigantea) have also been determined by this test coupled with a preliminary chromatographic cleanup procedure. Key words: saxitoxin, paralytic shellfish poison, colorimetry, Alaskan butter clam (Saxidomus gigantea)
Characterization of Suspended Particles in Some Pulp and Paper Mill Effluent Plumes
Authors: Leslie J. K.
Published: April 2011

Some physical characteristics of the suspended particles from seven pulp mill effluent plumes were analyzed electronically. An effluent flow rate of 1.2 m3∙s−1 contained a mean of 75.9 × 109 μm3∙ℓ−1 particulate volume in a size range of 3.2–84.0 μm "diameter." The visible particle surface area was 334.8 cm2∙ℓ−1, and there were 1045 × 103 particles∙ml−1. A slight increase in size was detected as the particles aged in the plume. The transported particulates were reduced by dispersion and sedimentation to approximately 5% by a transit of less than 1 km, but effluent was still detectable 2 km from the point source.
Susceptibility of Salmonid Species and Hatchery Strains of Chinook Salmon (Oncorhynchus tshawytscha) to Infections by Ceratomyxa shasta
Authors: Zinn J. L. , Johnson K. A. , Sanders J. E. , Fryer J. L.
Published: April 2011

Nine salmonid species and nine hatchery strains of chinook salmon (Oncorhynchus tshawytscha) were examined for susceptibility to infection by Ceratomyxa shasta. All salmonid species tested were susceptible to infection by this myxosporidan, although no deaths occurred in the Atlantic salmon (Salmo salar). The level of resistance varied widely among the different species. A low prevalence of ceratomyxosis occurred in hatchery strains of chinook salmon from the Columbia River basin, while those chinook strains derived from outside this drainage system were highly susceptible to the parasite. Key words: Oncorhynchus tshawytscha, salmonidae, ceratomyxosis, Ceratomyxa shasta, resistance, susceptibility
Establishment of White Perch, Morone americana, in Lake Erie
Authors: Busch Wolf-Dieter N. , Davies David H. , Nepszy Stephen J.
Published: April 2011

White perch, Morone americana, was first reported in Lake Erie in 1953. No further reports of capture were recorded until 1973, when one fish was taken. Three other captures were confirmed in 1974, and 34 in 1975. All but 3 of the 38 specimens were taken in the warm, shallow western basin and the extreme eastern end of the central basin. The widespread distribution and the sizable numbers of specimens collected in 1975 strongly indicate that this nonendemic species has become established in Lake Erie. Key words: white perch, range, Lake Erie
Diseases of Marine Aquarium Fishes.
Authors: Bell G. R.
Published: April 2011

not available
Distribution, Abundance, and Resource Utilization of Littoral Zone Fishes in Response to a Nutrient/Production Gradient in Lake Memphremagog
Authors: Gascon Dominique , Leggett William C.
Published: April 2011

The abundance and distribution of six littoral zone fish species (Notropis volucellus, Hybognathus nuchalls, Notemigonus crysoleucas, Pimephales notatus, Fundulus diaphanus, and Etheostoma nigrum) in Lake Memphremagog were influenced directly by a nutrient-driven production gradient existing along the long axis of the lake. The biomass of the six littoral zone fish species was approximately 3 times greater in the more productive southern areas than in the less productive northern areas. Interspecific competition for food was more intense in the less productive northern areas than in the more productive southern areas, and strongly influenced the patterns of food utilization. However, interspecific competition did not appear to play the major role in determining the distribution of the species on the gradient. Distribution of individual species was principally governed by the relative abundance of preferred food resources. The distribution of only one species, Fundulus diaphanus, appeared to be determined primarily by direct competition. Key words: littoral zone, Lake Memphremagog, nutrients, production, resource utilization, fish, food availability