bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence, Microscopy, and Etiology of Exoskeleton Lesions in the Tanner Crab, Chionoecetes tanneri
Authors: Baross John A. , Tester Patricia A. , Morita Richard Y.
Published: April 2011

As part of a seasonal population survey of the tanner crab, Chionoecetes tanneri Rathbun (Brachyura:Majidae), off the Oregon coast over 1400 adult and juvenile crabs were examined. A significantly high incidence of exoskeleton lesions was observed among adult females (76% infected) and to lesser extent among adult males (29%). No lesions were observed on juvenile specimens. Multiple lesions, some of which extended through the exoskeleton, were frequently observed on the carapace and appendages. Scanning electron miscroscopy of normal and diseased exoskeleton showed dense populations of bacteria associated with lesions and with the thin epicuticle of undiseased crabs. This suggests microbial degradation and/or mechanical damage to the epicuticle as a prerequisite to exoskeleton lesion formation. Chitin-digesting bacteria were isolated from all lesions examined. Sixty isolates were examined as to their phenotypic similarities to known chitin-digesting species that have been implicated as causing exoskeleton lesions in various crustaceans. Twenty-eight of the isolates were luminous and capable of digesting chitin rapidly at low temperatures. These isolates were compared with known luminous bacteria and found to be a Photobacterium sp. that did not precisely compare with known species. The possibility that multiple, luminous exoskeleton lesions might have a significant effect on some aspect of C. tanneri behavior is considered. Key words: exoskeleton lesions, crab, chitin, microbiology, crustacean, Photobacterium
Summer Phytoplankton Variability in the Lower St. Lawrence Estuary
Authors: Sinclair Michael
Published: April 2011

The study involved two data series, a weekly sampling program at a single station near Rimouski from June through September, 1974, during which semidiurnal tidal effects were considered, and a 5-d survey of the lower St. Lawrence estuary during July 1975. The biomass and species composition distributions during the survey appeared to be a function of the residual circulation and mixing characteristics of the lower estuary. Active growth in phytoplankton populations was limited to a 2-mo midsummer period. The impoverishment up to late June was probably due to high turbidity, the 1% light level being about 4 m in depth, rather than due to advective flushing. Strong temporal fluctuations in water column phytoplankton biomass and production were similar to the distribution in density stratification. The confidence limits of the derived parameters [photosynthesis at light saturation normalized by chlorophyll (θ) and by carbon (μpot), and the carbon/chlorophyll ratio] were broad with respect to their seasonal range. Due to the lack of coherence in the physiological state indices considered, and the importance of species composition differences in "explaining" the observed distributions of the indices, the utility of the derived parameters as measures of physiological state of mixed populations is questioned. Key words: phytoplankton, St. Lawrence estuary, primary production, physiological state, tidal mixing
Fecundity of Witch Flounder (Glyptocephalus cynoglossus) from St. Pierre Bank and the Grand Bank of Newfoundland
Authors: Bowering W. R.
Published: April 2011

The fecundity of witch flounder from the Grand Bank and St. Pierre Bank was correlated to length, age and weight. In all cases a log–log fit best described the relationship between fecundity and all three variables. However, variations in fecundity were best described in terms of size rather than age. Significant variations in fecundity occurred between the three areas discussed. Significant differences between samples from different years occurred for the Grand Bank areas but not for St. Pierre Bank. A comparison of witch flounder fecundity for the East and West Atlantic indicated that the rate of egg production is generally the same in both areas but the number of eggs produced at each length group in East Atlantic witch flounder is higher than those in West Atlantic. Key words: witch flounder, fecundity, length, age, weight
Zooplankton Sample Variation on the Scotian Shelf
Authors: Sameoto D. D.
Published: April 2011

Zooplankton sampling experiments on the Scotian Shelf during September 1973 and August 1974 using vertical tows demonstrated that numbers of many zooplankton species had a periodic fluctuation over 26 h. The fluctuations appeared related to the tide during 1974 but not in 1973. The periodic fluctuations accounted for a major portion of the sample variation in many species during both years. The mean numbers of small forms of zooplankton (copepods) obtained from the 26-h time series on a single station were very similar to means obtained during the same cruise over a wide area of the shelf. This suggested that a single station sampled over a period of two tidal cycles may be representative of the sample variation encountered over a wide geographic area of many hundreds of kilometres. Only Calanus and Pseudocalanus were correlated during all the experiments and from year to year. The abundance and distribution of the other species of zooplankton compared from one year to the next were not significantly correlated. This suggested the species populations were independent of one another. Key words: zooplankton, sample variation, time series, Scotian Shelf, fish larvae, Copepoda, tide
Revision of the Turbellarian Genus Ectocotyla (Seriata, Monocelididae) Associated with the Crabs Chionoecetes opilio and Hyas araneus
Authors: Fleming Lesley C. , Burt Michael D. B.
Published: April 2011

Ectocotyla hirudo (Levinsen, 1879) is redescribed and recorded for the first time from the gills and branchial chambers of Chionoecetes opilio and Hyas araneus. Problems arising from previous descriptions are resolved through comparison of freshly collected material, at different times of the year, with type material of Coleophora sp. and the type material of E. paguri Hyman, 1944, both of which are shown to be identical to the present material. Accordingly, E. paguri Hyman, 1944 is regarded as a junior synonym of E. hirudo (Levinsen, 1879). A new species, E. multitesticulata, is described and recorded also from C. opilio and H. araneus. Ectocotyla multitesticulata differs from E. hirudo primarily in the larger size of the worm, the greater number and size of the testes, the size of the egg capsule, and in the differences of the karyotype. The genus Ectocotyla is discussed in relation to closely related genera (Peraclistus, Minona, and Preminona) in the family Monocelididae. Key words: turbellarian systematics, Proseriata, Monocelididae, Ectocotyla, crab commensal
Effect of Extended Galvanonarcosis on Behavior of Rainbow Trout, Salmo gairdneri, and Channel Catfish, Ictalurus punctatus
Authors: Curry Kevin D. , Kynard Boyd
Published: April 2011

Yearling rainbow trout, Salmo gairdneri, and channel catfish, Ictalurus punctatus, were subjected to 0.5- and 3-h periods of narcosis using continuous direct current. Galvanonarcosis treatments decreased the immediate individual and group activity in both species of fish. Twenty-four hours after treatment, all fish except trout narcotized for 3 h recovered to levels of individual and group activity equivalent to those of untreated fish. Photonegative response was strong in both fish species and was not influenced by galvanonarcosis treatments. Trout narcotized with direct current were more vulnerable to predation than untreated fish; susceptability increased with increasing treatment periods. The potential of extended galvanonarcosis as a fish immobilization technique is strong. Key words: galvanonarcosis, behavior, extended narcosis, direct current, rainbow trout, channel catfish, photonegative, activity, prey vulnerability, immobilization
Parasitic Mastitis in the Atlantic White-Sided Dolphin, Lagenorhynchus acutus, as a Probable Factor in Herd Productivity
Authors: Geraci J. R. , Dailey M. D. , Aubin D. J. St.
Published: April 2011

In a survey of 30 female Atlantic white-sided dolphins, Lagenorhynchus acutus, taken from a mass stranded herd of approximately 150 animals, 47% were found to be infected with Crassicauda grampicola (Nematoda: Spiruridae) in the mammary glands. Associated lesions included verminous cysts, fibrosis, necrosis and inflammation, and destruction or replacement of normal parenchyma by nonsecretory tissue. The high incidence and severity of these lesions are viewed as potentially compromising the reproductive success of the herd. The life cycle of C. grampicola is discussed in relation to its presence in the mammary gland. Key words: cetacean, Atlantic white-sided dolphin, pathology, nematodes, mastitis, population, nutrition
Toxicological Comparison of Natural and Cultured Populations of Acartia tonsa to Cadmium, Copper, and Mercury
Authors: Sosnowski S. L. , Gentile J. H.
Published: April 2011

Cultured Acartia tonsa manifested a reproducible toxicological response through six generations. There were no statistically significant differences in the responses of F1 and F6 generations to cadmium, copper, and mercury. Cultured and field populations (parental) exposed to cadmium did not manifest statistically different response patterns. The response variability of cultured populations was less than that of field populations. The 96-h LC50 concentrations for cultured (F1) populations were 90 μg Cd/L, 31 μgCu/L, and 10 μg Hg/L. The presence and abundance of ova and unicellular glands in the circumesophogeal region were used as criteria for evaluating the nutritional condition of test populations. Key words: marine, metals, bioassay, culture, calanoid copepods, toxicity, histology, filial generations
A von Bertalanffy Growth Model with a Seasonally Varying Coefficient
Authors: Cloern James E. , Nichols Frederic H.
Published: April 2011

The von Bertalanffy model of body growth is inappropriate for organisms whose growth is restricted to a seasonal period because it assumes that growth rate is invariant with time. Incorporation of a time-varying coefficient significantly improves the capability of the von Bertalanffy equation to describe changing body size of both the bivalve mollusc Macoma balthica in San Francisco Bay and the flathead sole, Hippoglossoides elassodon, in Washington state. This simple modification of the von Bertalanffy model should offer improved predictions of body growth for a variety of other aquatic animals. Key words: Bertalanffy, growth model, growth rate, Macoma balthica
Effect of Capture Stress on Plasma Enzyme Activities in Rainbow Trout (Salmo gairdneri)
Authors: Bouck G. R. , Cairns M. A. , Christian A. R.
Published: April 2011

Four capture methods were used to collect domesticated rainbow trout (Salmo gairdneri): angling, electroshocking, seining, and direct netting (control). Blood was sampled rapidly upon capture, usually within 2 min. No significant differences were noted within the time frame of the experiment between the four capture groups for plasma protein concentration, lactate dehydrogenase activity, or leucine aminonaphthylamidase activity. Creatine phosphokinase activity was elevated among electroshocked fish. Acid phosphatase activity was too low for accurate measurement. Hematocrits were significantly elevated by capture struggles. These results indicate that these capture methods do not preclude the use of plasma enzyme levels for investigating the health of wild fish. Key words: plasma enzyme, capture stress, physiology, plasma protein, rainbow trout, lactate dehydrogenase, leucine aminonaphthylamidase, creatine phosphokinase
The Hemolymph Bactericidin of American Lobster (Homarus americanus): Adsorption and Activation
Authors: Mori Katsuyoshi , Stewart James E.
Published: April 2011

The bactericidin of American lobster (Homarus americanus) hemolymph was adsorbed readily by representatives of two bacterial genera: a nonpathogen, Pseudomonas perolens, and the lobster pathogen Aerococcus viridans (var.) homari. Activation of the bactericidin by factor(s) secreted by the hemocytes can occur before adsorption and also after adsorption by bacteria. Although the lobster pathogen A. viridans (var.) homari is unaffected by the activated bactericidin, this lack of effect is not related to adsorption since this bacterium adsorbs the bactericidin as readily and completely as does the susceptible nonpathogen. Key words: lobster, Homarus americanus, plasma bactericidin, adsorption and activation, hemocytic activator, Pseudomonas perolens, Aerococcus viridans (var.) homari
The Coastline.
Authors: Boalch G. T.
Published: April 2011

not available
Impact of the Introduction of Kokanee (Oncorhynchus nerka) and Opossum Shrimp (Mysis relicta) on a Subalpine Lake
Authors: Morgan Mark D. , Threlkeld Stephen T. , Goldman Charles R.
Published: April 2011

Introductions of opossum shrimp (Mysis relicta) and kokanee salmon (Oncorhynchus nerka) are common management tools for improvement of local sport fisheries. This paper summarizes published information from varied sources and presents supplemental data on the impact of these introductions on the Lake Tahoe zooplankton and fish communities. Concomitant with peak spawning runs of kokanee and the establishment and high densities of Mysis was the disappearance of the three pelagic cladoceran species in the lake. Population dynamics analysis of the cladoceran populations indicate that their elimination was due to increasing death rates (related to Mysis and kokanee predation) and decreasing birth rates (possibly related to cultural eutrophication). Changes have also been observed in the fish populations. Lake trout have altered their food habits to include large quantities of Mysis, but this has been done to the exclusion of other prey types. Thus, improvement in lake trout condition has been indicated only in years when Mysis is abundant. Recent evidence of a sustained decline in the mysid population suggests that unless lake trout shift back to more traditional food sources, their condition could deteriorate to below pre-mysid levels. Finally, mean weight and abundance of kokanee spawners have declined since the cladoceran disappearance, suggesting a negative impact on the whole population which fed heavily on cladocerans. Key words: opossum shrimp, kokanee salmon, population dynamics, cladoceran decline, introductions, subalpine lake
Daily Ration of Yellow Perch (Perca flavescens) from Lake Memphremagog, Quebec–Vermont, with a Comparison of Methods for In Situ Determinations
Authors: Nakashima Brian S. , Leggett William C.
Published: April 2011

In situ estimates of daily ration for yellow perch (Perca flavescens) range from a high of 5.5–6.7% body weight in July to a low of 2.2–2.4% body weight in October. The seasonal pattern corresponds well to known patterns of growth. Comparison of three methods for in situ determination of daily ration levels indicated the method outlined here and the more complex method of Thorpe yield similar results. The method of Keast and Welsh and derivatives of this method which correct for digestion between sampling periods give unreliable values that are 50% below the other two and, in general, are below maintenance ration levels. Diet composition and feeding activity varied seasonally and with body size. Key words: body size relationships, diet composition, seasonality
Numerical Model of the Circulation in an Open Bay
Authors: Petrie Brian , Drinkwater Ken
Published: April 2011

An external alongshore current setting to the east and across the mouth is proposed as the driving mechanism for the measured clockwise circulation in St. Georges Bay, Nova Scotia. A barotropic numerical model of an open bay forced by an alongshore current was able to produce a clockwise gyre in the bay. The model current velocities were in good agreement with the data. The generation, size, and intensity of the gyre required low values of vertical viscosity relative to horizontal viscosity. Key words: numerical model, bay, gyre, circulation, barotropic, current, coastal
Biological Availability of Low Versus High Molecular Weight Reactive Phosphorus
Authors: Paerl Hans W. , Downes Malcolm T.
Published: April 2011

When equivalent concentrations of reactive high molecular weight phosphorus (RHMW-P > 5000) and free orthophosphate (PO4-P) from Lake Tutaeinanga, New Zealand, were added to P-starved Chlorella cultures, free PO4 showed a faster growth response within 48 h than RHMW-P. Algal preference for PO4 over RHMW-P could also be shown by (32P)PO4 turnover experiments. After 96 h both fractions showed good growth yields. Analyses on culture filtrates indicated that all forms of reactive P had been removed. This demonstrates that RHMW-P, which reacts with "reactive P" reagents, can eventually be utilized. Key words: reactive phosphorus, orthophosphate, algae, Chlorella, growth, bioassay
Modification of the Rheotropic Behavior of Male Rainbow Trout (Salmo gairdneri) by Ovarian Fluid
Authors: Emanuel Mary E. , Dodson Julian J.
Published: April 2011

The upstream orientation and frequency of upstream movement of ripe male rainbow trout (Salmo gairdneri) in the presence of ovarian fluid obtained from spawning females of the same species were observed and quantified. In a stream tank, male trout moved upstream in the ovarian fluid odor plume. In an optomotor tank, male trout exhibited an increase in the frequency of upstream orientation and movement in the presence of diffuse, nondirectional ovarian fluid. It is concluded that water currents provide directional cues and olfactory stimuli regulate the orientational and kinetic components of the rheotropic response. The significance of this mechanism of orientation in fish migration is discussed. Key words: rheotropism, behavior, olfaction, orientation, migration, ovarian fluid
Marine Pollutant Transfer.
Authors: Giles M. A.
Published: April 2011

not available
Distribution of Nutrients in the Gulf of St. Lawrence
Authors: Coote A. R. , Yeats P. A.
Published: April 2011

The general pattern of nutrient distribution in the Gulf of St. Lawrence results from regeneration processes being superimposed on the physical processes of estuarine circulation within the Gulf. This leads to a general increase in nutrient concentration with depth and with distance into the Gulf from Cabot Strait. Nutrient concentrations in the Laurentian Channel are higher inside the Gulf than at equal or even greater depths in the Atlantic Ocean some distance outside Cabot Strait. Summer nutrient concentrations in the surface layer are generally low. However, during the winter when biological activity is low, quite high concentrations of the nutrients are found in the surface waters of the Gulf. A balance exists between inward and outward fluxes of all three nutrients through Cabot Strait in the winter. However, in the summer the influxes of both nitrate and silicate at Cabot Strait greatly exceed the outgoing fluxes. Losses of biogenic silica to the sediments may account for the silicate imbalance. Excess nitrate may be accounted for if ammonia or nitrogen bound with dissolved organics had been measured. Key words: nutrients, silicate, phosphate, nitrate, distribution, regeneration, transport, Gulf of St. Lawrence, Cabot Strait, Laurentian Channel
Estimated Escapement of Atlantic Salmon (Salmo salar) for Maximum Smolt Production in Rivers of Different Productivity
Authors: Symons Philip E. K.
Published: April 2011

Smolt production at different egg deposition densities is estimated from data on survival rates and space requirements of juvenile Atlantic salmon (Salmo salar) reported in the literature. Average maximum production of smolts is estimated to be approximately 5/100 m2 for 2+ smolts, 2/100 m2 for 3+ smolts, and 1/100 m2 for 4+ smolts. Minimum egg depositions recommended for production of these numbers of smolts are 220/100 m2, 165–220/100 m2, and 80/100 m2 for each age of smolts, respectively. The escapement of adults required to produce these depositions must be estimated from observed average weights of returning females and a reported fecundity of Atlantic salmon between 1650 and 1760 eggs/kg of female. With the exception of Ungava rivers, average smolt age in any particular river can be estimated from the number of days per year on which water temperature reaches or exceeds 7 °C. Key words: fishery resources, fishery management, production (biological), escapement, survival, game fish, freshwater fish, rivers
Tissue Sources and Diagnostic Value of Circulating Enzymes in Cetaceans
Authors: Geraci J. R. , St. Aubin D. J.
Published: April 2011

Tissue activities of alanine aminotransferase (AlAT), aspartate aminotransferase (AspAT), sorbitol dehydrogenase (SDH), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), and creatine kinase (CK) were determined in three cetacean species: the bottlenosed dolphin, Tursiops truncatus, beluga whale, Delphinapterus leucas, and harbor porpoise, Phocoena phocoena. Liver was the principal source of AlAT and SDH activity; GGT and ALP were concentrated in kidney. Muscle tissues showed the highest CK and AspAT activity, although most other tissues had appreciable AspAT activity. Based on tissue specificity, plasma AlAT and SDH are recommended for use in diagnosing hepatic disorders. Plasma GGT may have potential value in assessing the type of hepatobiliary damage caused by trematodes in cetaceans; ALP has no obvious advantage over GGT. Creatine kinase elevations in plasma would indicate muscle damage or exercise stress, while plasma AspAT may reflect either muscle or liver release and must be used in conjunction with other more tissue-specific enzymes. Reference plasma enzyme activities determined in healthy captive T. truncatus showed significant procedure-related differences that must be considered when circulating enzymes are used in research or diagnosis. Key words: enzymes, tissues, plasma, Cetacea, stress
Summer Plankton Distributions Associated with the Physical and Nutrient Properties of the Northwestern Gulf of St. Lawrence
Authors: Sevigny J.-M. , Sinclair M. , El-Sabh M. I. , Poulet Serge , Coote A.
Published: April 2011

Two transects, north–south and east–west, through the Anticosti gyre and the Gaspé current were sampled for physical properties, nutrient and plankton concentrations over a 5-d period during July 1976. Temperature, salinity, σt and nutrient isolines formed a dome characteristic of cyclonic circulation with the apex within the Anticosti gyre, but a strong shallow thermocline prevented nutrient enrichment of the surface mixed layer. Surface nitrate and silicate concentrations were very low, except for two anomalies, throughout the region sampled, with phosphate concentrations higher. Phytoplankton biomass was uniformly low and dominated by nannoplankton (< 15 μm) at all stations except that in the Gaspé current at which netplankton (15–202 μm) was important and the total biomass considerably higher. The higher biomass and importance of larger celled species suggest higher nutrient turnover in the Gaspé current. Nitzschia delicatissima dominated the species composition in the Gaspé current, dinoflagellates and microflagellates being of more importance within the gyre and along the north shore. Zooplankton biomass was distributed fairly uniformly over the entire region but species composition at the shallower stations was characterized by small copepod species (Pseudocalanus sp., Acartia sp.) and fish larvae, the gyre stations being characterized by larger copepod species (Calanus sp.), euphausids, and decapod larvae. Physical properties, nutrients, and plankton were distributed quite uniformly except for the marked variability in the measurements made in the strongly advective Gaspé current station. Distributions of derived parameters that were estimated at 5 m depth suggest nutrient limitation at most stations within the gyre, with the exception of the two stations at which surface nutrient anomalies were detected, while at the nearshore stations, in the Gaspé current and along the north shore, better physiological state and lack of nutrient limitation were observed. Short-term variability in these parameters complicate geographic interpretation, but trends were discernable. Estimated daily primary production was an order of magnitude less than that reported previously. Key words: Anticosti gyre, Gaspé current, primary production, nutrient limited growth
Expressing the Phosphorus Loading Concept in Probabilistic Terms
Authors: Chapra Steven C. , Reckhow Kenneth H.
Published: April 2011

Data from North Temperate lakes were used to estimate the uncertainty of a phosphorus loading model. A number of graphical representations of the uncertainty were developed to demonstrate the importance of including probabilistic information in phosphorus loading calculations. Key words: limnology, lake management, phosphorus, eutrophication, models, statistics, probability, loading, lakes, prediction
Multilingual Dictionary of Fish and Fish Products/Dictionnaire multilingue des poissons et produits de la pêche
Authors: Lingeman B.
Published: April 2011

not available
Journal of Fish Diseases, Vol. 1, No. 1.
Authors: Kelly Russell K.
Published: April 2011

not available
Lightweight Corer Designed for Sampling Very Soft Sediments
Authors: Williams J. D. H. , Pashley A. E.
Published: April 2011

An underwater corer has been developed capable of taking 10-cm diam cores up to 1 m long from unconsolidated, fine-grained fluvial and lacustrine sediments including organic-rich (gyttja-like) deposits. The corer is lightweight and compact for transport and hand operation from float planes and small boats. It is of the piston type and has a sphincter valve for core retention. A miniature optical sensor triggers the corer when the sediment–water interface is penetrated. The corer is compatible with a system to subdivide the cores by vertical extrusion. Key words: corer, sediment, piston, sampling
A Reason for Pleomerism
Authors: Spouge John L. , Larkin P. A.
Published: April 2011

Pleomerism, the increase in vertebral number with maximum recorded length for species within a family, may be explained for fish by hydrodynamic considerations. A model is developed that suggests that the upper limits of the slope of the relation between log vertebral number and log length should be 0.43 in laminar flow and 0.35 in turbulent flow. These slopes are compared with those of previous studies only with difficulty because (1) those values were for predictive rather than functional regressions, (2) the slope will depend on the range in length of various species across temperature zones, and (3) no distinction was made between structural and locomotor vertebrae. Variations in shape also complicate the relation between vertebral count and length, there are latitudinal factors involved, and maximum length is probably only a weak correlate of the length at which natural selection may be concentrated. When these factors are considered, it is to be expected that observations would provide only a rough approximation to theory.The theory underlying the model is also used to derive a formula for the stride length of fish motion that is then compared with empirical results. Key words: vertebrae counts, body size, locomotion, hydrodynamic equations, mathematical model, stride length
Concentrations of Cd, Cu, Mn, Pb, and Zn in Fishes in a Highly Organic Softwater Pond
Authors: Wiener James G. , Giesy Jr. John P.
Published: April 2011

Concentrations of Cd, Pb, and three essential metals (Cu, Mn, and Zn) in stocked bluegill (Lepomis macrochirus) and eight resident species of fish were studied in an acidic, highly organic pond on the southeastern U.S. coastal plain. Concentrations of Cu, Mn, and Zn in stocked and resident fish were apparently homeostatically controlled in liver tissue, axial musculature, and whole body. Concentrations of all metals studied in axial muscle tissue and whole body of stocked bluegill remained relatively constant after 200 d of residence in the pond. Analysis of concentration factors from pond water to whole stocked bluegill indicated that Pb in this system was less available to fish than in hardwater lakes. In contrast, Cd in the pond was as available to fish as in harder waters. Differences in relative availabilities of Cd and Pb were explained by the tendency of Pb to form complexes with naturally occurring organics. The need for metal-specific analysis of biological availability of metals in highly organic softwater systems is stressed. Key words: trace metal, availability, fish, soft water, concentration factor, organic water
Analysis of the British Columbia Salmon Purse-Seine Fleet: Dynamics of Movement
Authors: Hilborn Ray , Ledbetter Max
Published: April 2011

Three hypotheses regarding the movement patterns of the British Columbia salmon purse-seine fleet are considered. Two of these hypotheses, that boats move strictly in traditional patterns, or that boats attempt to maximize weekly landed value of catch are rejected. The third hypothesis, that boats move to optimize economic gain, modified by relative desirability of the areas appears to provide a better prediction of patterns. It is shown that when unusually large runs occur in an area, a sufficient number of boats will move into that area to reduce the catch per boat to a level typical of that area. Key words: boat movement, fleet dynamics, spatial pattern
A Culture Technique Using Marine Fish Kidney to Obtain Chromosomes
Authors: Park Eun Ho , Park Sang Dai
Published: April 2011

A relatively simple and reliable in vitro method for marine fish chromosome study was developed. The addition of 10% chick embryo extract to serum-supplemented Eagle's minimum essential medium with high concentration of NaCl resulted in marked growth of kidney cells in the marine conger eel (Astroconger myriaster) after activation by phytohemagglutinin (PHA). Culture medium without chick embryo extract or PHA and/or with normal concentration of NaCl did not induce substantial growth. In contrast to reports by others, humidified culture was not required for excellent cell growth of these teleost kidney cells. Numerous metaphases unmarred by overlapping chromosomes were recovered and excellent karyograms were available for detailed karyotype analysis. Key words: kidney, culture, marine fish, chromosome
In Vitro Maintenance of Amoebocytes from the American Oyster (Crassostrea virginica)
Authors: Brewster Frank , Nicholson Bruce L.
Published: April 2011

Explant and monolayer cell cultures were initiated from oyster heart and embryonic tissue and maintained for periods of a few days to 6 mo depending on the type of tissue and the culture medium. A pH of 7.0–7.3 and a temperature of 20 °C were optimum. Vertebrate cell culture media prepared in a marine saline and supplemented with fetal bovine serum and protein digests provided a suitable basal medium. Supplementation of the basal medium with oyster hemolymph or extracts of oyster tissue markedly prolonged cell maintenance. Explant cultures of heart tissue with the subsequent outward migration of individual cells were most easily initiated and maintained for periods up to 6 mo. Although several cell types were observed, actively motile, granular amoebocytes predominated. No mitotic cells were observed even following exposure to a variety of mitogens. Cultures initiated from disaggregated larvae did yield actively dividing cells. Key words: oyster, cell culture, amoebocytes
Planning of Aquaculture Development — An Introductory Guide.
Authors: Carey T. G.
Published: April 2011

not available
Detritus and Juvenile Salmon Production in the Nanaimo Estuary: II. Meiofauna Available as Food to Juvenile Chum Salmon (Oncorhynchus keta)
Authors: Sibert J. R.
Published: April 2011

The meiofauna of the Nanaimo Estuary are briefly described. Nematodes and harpacticoid copepods were the numerically dominant taxa and reached their maximum population densities in late summer. Harpacticus uniremis was very important to the early diet of juvenile chum salmon (Oncorhynchus keta) but was one of the least common harpacticoid copepods in the estuary. The productivity of H. uniremis was found to be only slightly greater than the calculated food requirement of the chum salmon fry; there was close coupling between prey and predator. The role of detritus and bacterially processed carbon in the feeding of H. uniremis are discussed. Key words: harpacticoid copepods, secondary production, detritus, Harpacticus uniremis, turnover ratios, meiofauna
Population-Genetic Study of the Effects of Selective Fishing on the Growth Rate of Trout
Authors: Favro L. D. , Kuo P. K. , McDonald J. F.
Published: April 2011

A mathematical model that simulates the effect of selective fishing on the size distributions of populations of trout is presented. The model assumes that the growth rate is genetically controlled by a small number of major genes. Empirical numbers for the growth and mortality rates of brown trout (Salmo trutta) in the Au Sable River of Michigan are used as input data. A computer is used to calculate the changes in the population subject to various degrees of fishing pressure for various size limits. Results are presented for periods of time ranging from 5–30 yr. The observed changes in the population over the period 1959 to 1977 in a test stretch of the Au Sable River agree quite well with the computations. Keywords: fish, trout, genetics, growth, size limit, population, Salmo trutta
Sorption of Cadmium and its Effect on Growth and the Utilization of Inorganic Carbon and Phosphorus of Two Freshwater Diatoms
Authors: Conway H. Lee , Williams Susan C.
Published: April 2011

Cadmium was rapidly sorbed by Asterionella formosa and Fragilaria crotonensis during the first 5–10 min of exposure (0.05 to ~9 μg Cd∙L−1), followed by a hyperbolic increase in the cellular cadmium content as a function of time. Results obtained from experiments conducted in the light and dark, experiments using live and dead populations, and cellular site location studies imply that the sorption of cadmium by A. formosa is partially an active process, but for F. crotonensis it appears to be passive. Populations of A. formosa exhibited a corresponding decrease in the growth rate as the ambient cadmium concentration was increased from ~2 to ~9 μg∙L−1. In contrast, the growth rate of F. crotonensis was unaffected at levels ranging from ~0.05 to ~9 μg Cd∙L−1. The utilization of inorganic carbon by A. formosa was unaffected at ~4 μg Cd∙L−1, but reduced 45% at ~9 μg Cd∙L−1. The utilization rates of carbon and phosphorus by F. crotonensis were reduced at the lower cadmium concentrations and enhanced at the highest. Key words: cadmium, toxicity, sorption, diatom, Asterionella formosa, Fragilaria crotonensis
Rapid Decompression Stress Accelerates Fibrinolysis in Fingerling Salmon
Authors: Woodward John J. , Casillas Edmundo , Smith Lynwood S. , D'Aoust Brian G.
Published: April 2011

Rapid decompression of fingerling coho salmon (Oncorhynchus kisutch) after simulated dives of 30.5- and 40.5-msw (metres seawater) increased the activity of the fibrinolytic system. Anticoagulated blood samples were analyzed for fibrinolytic activity by measuring the rate of lysis after clotting the blood with a thrombin solution. Immediately and at 1 h postdecompression from 30.5 msw the lysing rate was above normal but returned to normal within 3 h and remained stable for ~24 h, but at 48 h it was depressed. The activity of the fibrinolytic system appeared to follow that of the coagulation system, indicating that the lytic system of fishes is sensitive and responsive to stress-induced changes in hemostatic parameters. Key words: Oncorhynchus kisutch, fibrinolysis, decompression stress, bubbles, coagulation
Depression of pH in Lakes and Streams in Central Ontario During Snowmelt
Authors: Jeffries D. S. , Cox C. M. , Dillon P. J.
Published: April 2011

The snow pack that accumulated in central Ontario in the winter of 1977–78 had a pH of 4.0–4.5. The resultant runoff in the following spring in three intensively studied watersheds was characterized by a 2–13-fold increase in H+ content. Between 36 and 77% of the year's export of H+ from the watersheds occurred in April. Similar pH depressions were observed in almost all of 17 other streams that were less frequently sampled and in the littoral zones, surface waters, and outflows of five lakes. Key words: acidification, snowmelt, hydrogen ion
Bioeconomics of Commercial Fisheries Management
Authors: Mitchell C. L.
Published: April 2011

Canada has indicated that its management of fisheries is based on the "best-use" principle. This principle as an operational concept can be defined as the maximization of socioeconomic returns subject to both biological and economic constraints. This paper examined how this principle can become operational in a management sense by defining the similarities and differences in the approach to fisheries management by biologists and economists and by indicating how these roles can be combined for this management. Key words: fisheries, management, biology, economics, bioeconomics
Development of Fishes of the Mid-Atlantic Bight. An Atlas of egg, larval and juvenile stages.
Authors: Faber Daniel J. , McAllister Don E.
Published: April 2011

not available
Introduction to the Symposium on Managing Fishing Effort
Authors: Pearse Peter H.
Published: April 2011

not available
Evolution of Canadian Fisheries Management Towards Economic Rationalization
Authors: Needler A. W. H.
Published: April 2011

The evolution of the regulation of fisheries in Canada is outlined as background for a discussion of their economic rationalization through restriction of entry. The objectives of fishery regulation are discussed and questions noted that must be answered if limitation of entry is to be beneficial and acceptable. Key words: regulation, rationalization, management, limitation of entry
Morphological Examination of Fibrillar Colloids Associated with Algae and Bacteria in Lakes
Authors: Massalski A. , Leppard Gary G.
Published: April 2011

Phytoplankton and bacteria were sampled in eight Canadian lakes and prepared immediately for thin-section analyses by transmission electron microscopy. Fibrillar colloids of probable biological origin were present at the cell surface–lake water interface of many species. Fibrillar colloids that form distinctive surface coatings on algae and bacteria are described in detail. The most common structural unit of these coatings is a ribbon-like fibril. Several types of fibril associations are documented and circumstantial evidence is presented for some possible roles of fibrillar colloids in promoting complex microbial associations and in promoting physical associations between cells and other suspended particles. The biogenesis of fibrils is also discussed. Key words: colloid, algae, bacteria, lakes, fibrils, electron microscopy
Dietary Intake and Nutritional Characteristics in Wild American Lobsters (Homarus americanus)
Authors: Leavitt D. F. , Bayer R. C. , Gallagher M. L. , Rittenburg J. H.
Published: April 2011

Nutrient and essential amino acid analyses of the stomach contents of wild adult American lobsters (Homarus americanus) collected from offshore and inshore populations indicated lobsters consumed varying nutrient levels according to their stage of molt. For example, soft-shell lobsters ate a higher level of mineral constituent. The location of the animal had no effect on the level of nutrient intake. The essential amino acid composition of the protein in the stomach remained the same throughout the molt cycle, but indicated a change in protein source with the location of the animal. The relationship between crude protein and gross energy was constant suggesting its importance in the nutrition of the lobster. Based on this study, we recommend a basal level of nutrient constituents for ration formulation. Key words: American lobster, natural intake, dietary formulation
D-Mannitol Interferes with Amino Acid Analysis of Marine Organisms
Authors: Fong W. , O'dor R. K.
Published: April 2011

Acid hydrolysis of a protein in the presence of D-mannitol, a common constituent of marine algae, can cause significant reductions in the recovery of a number of amino acids. The new compounds formed by the interactions of D-mannitol and these amino acids may interfere in the chromatographic analysis of other amino acids. The recoveries of most of the amino acids appear to be either directly or inversely proportional to the amount of D-mannitol added to a protein sample before acid hydrolysis. These results suggest that it is necessary to determine the effects of contaminants in a sample of protein(s) on the recoveries of amino acids during routine acid hydrolysis. Key words: kelp, amino acids, carbohydrates, D-mannitol
The Aqueous Chlorination of Organic Compounds: Chemical Reactivity and Effects on Environmental Quality.
Authors: Clarke R. McV.
Published: April 2011

not available
Changes in the Apparent Temperature Optima of the Plankton of Lake Michigan at Chicago, Illinois
Authors: Makarewicz J. C. , Baybutt R. I. , Damann K.
Published: April 2011

Forty years (1937–76) of data from Lake Michigan water intakes at Chicago, Illinois, were examined to explain reported differences in the apparent temperature optima of phytoplankton. The bimodal seasonal plankton distribution, typical at Chicago, still occurs. However, there has been a shift in seasonal periodicity with spring peaks occurring in March from 1957 to 1976 instead of May–June as previously reported for 1937–56. An optimum temperature of 10 °C for the plankton community was observed between 1936 and 1956, while for the last 20 yr an optimum temperature range from 0 to 4 °C was observed. This change in optimum temperature of the plankton community is related to a change in the abundance of the genera Asterionella, Fragilaria, Stephanodiscus, and Tabellaria. Asterionella and Fragilaria were the dominant spring plankton with maximum standing crops observed around 10 °C prior to 1956. Stephanodiscus first increased significantly in 1957 and was the dominant spring plankter through 1976. More recently (1972–76), blue-green algae have increased in numbers. Differences in apparent temperature optima reported are real and are caused by the emergence of cold water species of Stephanodiscus as the dominant spring plankter from 1957 to 1976. Key words: plankton, temperature optima, Lake Michigan
Olfactory Bulbar Electrical Responses of Rainbow Trout (Salmo gairdneri) Exposed to Morpholine During Smoltification
Authors: Hara Toshiaki J. , Brown S. B.
Published: April 2011

Exposure of rainbow trout (Salmo gairdneri) to 5.7 × 10−10 M (5 × 10−5 mg/L) morpholine during smoking period did not influence the subsequent neural response to this substance, when tested immediately and 12 mo after smoking. No significant difference in the morpholine-induced responses was obtained between the exposed and unexposed fish. Using N-ethylmaleimide, a sulfhydryl reagent, it was further confirmed that the morpholine-effect is caused by a mechanism not directly associated with the normal olfactory function. Perfusion of the olfactory organs with 1.0 × 10−1 and 1.1 × 10−1 M (1%) morpholine for 10 min irreversibly inhibited the olfactory responsiveness to odorants. Sensitization of the olfactory bulbar electrical response is discussed in connection with homing of morpholine-imprinted salmonid fishes. Key words: olfaction, olfactory bulbar response, rainbow trout, salmon, imprinting, morpholine, homing, migration
Energy Content Analysis from Weight and Liver Index Measurements of Immature Pollock (Pollachius virens)
Authors: Jensen Arne Johan
Published: April 2011

Variations in energy contents of liver and musculature of immature pollock (Pollachius virens) were analyzed by bomb calorimetry and then correlated to the liver index (liver weight as a percentage of body weight). For fish weighing between 400 and 1500 g, relationships between energy contents of liver and musculature and the liver index were described by mathematical functions. The mean energy content of other fish tissues, excluding liver, musculature, and gonads was constant. The total energy content of an immature pollock can thus be determined. The same relationships should be adaptable to other species that store their primary fat reserves in the liver. Key words: Pollachius virens, liver index, energy content
Establishment of Sockeye (Oncorhynchus nerka) and Chinook (O. tshawytscha) Salmon Runs at Frazer Lake, Kodiak Island, Alaska
Authors: Blackett R. F.
Published: April 2011

Runs of sockeye salmon (Oncorhynchus nerka) and chinook salmon (O. tshawytscha) were established at Frazer Lake, Kodiak Island, Alaska by adult spawner transplants, fry plants, and eyed-egg plants. Falls in the lake outlet formed a barrier to natural ascent of anadromous fish until construction of a fishpass in 1962. Accounts of successful introduction and development of viable and self-sustaining runs of salmon where none previously existed and the lake was inaccessible are scarce in the history of salmon fisheries on the Pacific Coast. The first sockeye returning to Frazer Lake in 1956 were produced from egg plants in 1951. Annual sockeye returns have progressively increased over a 28-yr period reaching record passage of 141 981 in 1978. Sockeye spawning has extended into new areas as returns increased. Spawning area capacity is projected to be sufficient for 365 000 sockeye while rearing area is estimated to be sufficient to support fry production from 400 000 sockeye. Sockeye returns per spawner have averaged 3.2 for six parent years (1966–71) in which returns are complete. A chinook run was created from plants of 160 000 fry over a 4-yr period beginning in 1966. Chinook have returned to spawn in specific sites of fry release above the falls and in the lower river. Key words: salmon introduction, enhancement technique, sockeye, chinook, Frazer Lake, salmon establishment
External Morphology of the Pink Salmon, Oncorhynchus gorbuscha, Introduced into Lake Superior
Authors: Berg Richard E.
Published: April 2011

Meristic and morphometric measurements were taken from 33 male and 44 female mature pink salmon, Oncorhynchus gorbuscha, collected in three Lake Superior tributaries in Marquette County, Michigan. Significant sexual differences were found for eight characteristics in males and two in females. The male fish had a greater degree of differentiation in the head and hump regions; females had larger and longer anal fins. The Lake Superior fish were found to have shorter bodies, larger and longer fins, and more exaggerated development in the male head and hump than has been reported for the Pacific populations. Key words: pink salmon, salmonids, exotic species, Lake Superior, morphology
Effects of Pollutants on Aquatic Organisms.
Authors: Klaverkamp J. F.
Published: April 2011

not available
Temperature and Photoperiod Effects on Gill (Na + K)–ATPase Activity in Chinook Salmon (Oncorhynchus tshawytscha)
Authors: Ewing R. D. , Johnson S. L. , Pribble H. J. , Lichatowich J. A.
Published: April 2011

Juvenile Rogue River spring Chinook salmon (Oncorhynchus tshawytscha) reared at two temperatures and photoperiods for a 2-yr period were examined for cyclic changes in gill (Na + K)–ATPase specific activity. Three peaks in activity were observed: a peak in October of the first year, a second higher peak the following May, and a peak in October of the second year. Exposure to photoperiods artificially advanced 3 mo (July–October) suppressed the October peak during the first year, but did not greatly alter the subsequent two peaks in activity. The temperature at which the fish were reared did not directly affect the changes in enzyme activity. However, growth rates varied in response to water temperature. Altered growth rates resulted in differences in the cyclic changes in gill (Na + K)-activated ATPase activity in the two temperature groups. A threshold of 8 cm was suggested as the minimal size at which the fish could respond to the appropriate photoperiod by altering the gill (Na + K)–ATPase activity. Key words: (Na + K)–ATPase, chinook salmon, temperature, photoperiod, Oncorhynchus tshawytscha.