摘要:

Lead concentrations in spotted wolffish (Anarhichas minor) collected from the vicinity of a sphalerite–galena mine and an ore concentration plant in West Greenland have been measured through a period of 2 yr before and 4 yr after mining operations started. Lead levels increased significantly since mining started, and accumulation takes place in liver and kidney, not in muscle tissue. The increased lead levels are not a risk to public health. Small fish have higher lead concentrations than larger ones.Key words: wolffish, arctic, liver, muscle, kidney, lead, zinc–lead mining

ISSN:0706-652X    

DOI:10.1139/f79-144

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Diel migrations of the golden shiner (Notemigonus crysoleucas) from the littoral to limnetic zone of a small Michigan lake were documented through visual observations and gill netting. During the day golden shiners schooled in the littoral zone. Just after sunset schools broke up and the golden shiner migrated to the open water regions of the lake. Feeding by the golden shiner was largely coincident with the evening migration. The majority of the shiner population fed onDaphniaand most prey were obtained within 1 h of sunset. Feeding was minimal through the night with some feeding evident at dawn.Daphniaunderwent a strong diel vertical migration, especially larger individuals, and showed a strong horizontal gradient of decreasing size and density from the limnetic into the littoral region. Size ofDaphniaeaten by the shiner increased dramatically across the evening feeding period. This increase is due to the horizontal gradient inDaphniaand availability of largerDaphniaas they migrate to the surface. On only one date when prey densities were highest did the shiners actively select largeDaphnia. The golden shiner faces a dynamic prey system both in time and space which influences prey "selection." We relate adaptations of planktivorous fishes that migrate to relative abundances of fishes in small lakes.Key words: coevolution,Daphnia, diel migration, fish, foraging behavior, golden shiner,Notemigonus, planktivore, predator–prey

ISSN:0706-652X    

DOI:10.1139/f79-145

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

A method of estimating the bioconcentration factor of organic chemicals in fathead minnows (Pimephales promelas) is described. Water at 25 °C was intermittently dosed with the chemical at a nontoxic concentration in a flow-through aquarium. Thirty minnows are placed in the aquarium, and composite samples of five fish are removed for analysis after 2, 4, 8, 16, 24, and 32 d of exposure. The bioconcentration process is summarized by using the first-order uptake model, and the steady-state bioconcentration factor is calculated from the 32-d exposure. A structure-activity correlation between the bioconcentration factor (BCF) and then-octanol/water partition coefficient (P) of individual chemicals is summarized by the equation log BCF = 0.85 logP − 0.70, which permits the estimation of the bioconcentration factor of chemicals to within 60% before laboratory testing. The facilities and resources for testing need be used only for those chemicals that are likely to result in substantial bioconcentration in organisms. The bioconcentration factors derived from tests of mixtures of chemicals are shown to be the same as those derived from tests with the chemicals individually.Key words: bioconcentration factor, bioaccumulation, structure-activity, bioassay

ISSN:0706-652X    

DOI:10.1139/f79-146

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Growth of juvenile coho salmon (Oncorhynchus kisutch) fed a limiting ration (70% of satiation) in experimental stream channels was not altered significantly by prolonged exposure to untreated or laboratory-treated (fermented) bleached kraft pulpmill effluent (BKME), although mean weights for control fish were consistently lower than those for all effluent-exposed groups from 100 to 200 d. Body protein, fat, and moisture content were unaffected by treatment at 30, 90, and 200 d. Fish exposed to all strengths of untreated or treated BKME (i.e. untreated concentrations equivalent by volume to 0.05, 0.1, 0.2, 0.3, and 0.5 of the untreated effluent's 96-h LC50 value; and treated concentrations equivalent by volume to 0.2 and 1.0 LC50) showed significant decreases in serum albumin levels at 30 d, whereas these recovered to control values at 90 and 200 d. The serum electrolytes Na+, K+, and Ca++were unaffected by treatment at 200 d and not measured for other exposures. Liver and muscle glycogen reserves were decreased significantly by continuous exposure of fish to untreated or treated BKME concentrations for 30 d. These values recovered to control levels at 90 d and were unaffected or depressed at 200 d. Plasma glucose levels at 30 d were elevated significantly in all BKME-exposed groups except those held in the lowest concentration of untreated or treated effluent. Blood sugar values at 90 d were increased only by the highest strength of untreated or treated BKME; whereas at 200 d these values were elevated from control levels in all effluent-exposed groups. Levels of plasma lactic acid were unmeasured at 30 d, increased at 90 d in all BKME-exposed groups except the lowest strength of untreated effluent, and elevated at 200 d in all effluent-exposed groups. The stamina of these fish as determined by critical swimming speeds in freshwater was unaffected by exposure to pulpmill effluent for 90 d and unmeasured for other exposures. Based on the changes in intermediary metabolism for BKME-exposed fish at 30, 90, and 200 d, it was concluded that these fish remained in a state of chronic stress and did not acclimate to prolonged exposure to pulpmill effluent. Treatment of this waste reduced or removed its acute (lethal) toxicity but did not alter the biochemical effects caused by chronic exposure.Key words: stress, growth, proximate analyses, albumin, electrolyte, glycogen, glucose, lactate, critical swimming speed, acclimation

ISSN:0706-652X    

DOI:10.1139/f79-147

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Upstream movements of radio-tagged and control adult chinook salmon (Oncorhynchus tshawytscha) were monitored during spring and fall 1976 and spring 1977 in the lower Snake River, southeastern Washington. Travel time from point of fish release and percent return to upstream trapping facilities were compared for experimental and control fish. Experimental fish carried anchor tags, and either external or internal radio transmitters. Control fish carried anchor tags only. Chinook salmon that lost external transmitters moved upriver more slowly than control fish although percent returns to upriver trapping facilities were similar. Travel times and percent returns of chinook salmon that retained external transmitters did not differ significantly from those of control fish. Although some salmon tagged with internal transmitters moved upriver, all failed to cross Little Goose Dam 6.5 km from the release site. Most internally tagged salmon eventually swam downstream.Key words: chinook salmon, biotelemetry, behavior, migration, radiotelemetry, bioengineering

ISSN:0706-652X    

DOI:10.1139/f79-148

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

During surveys to assess fish stocks, the acoustic scattering properties of the fish population are required to obtain stock size measurements. The recently developed dual beam technique of target strength measurement has shown great promise as a method for fish target strength measurement. An improved dual beam target strength measurement system is described, and we report the application to a marine population of walleye pollock (Theragra chalcogramma). In addition, we discuss field calibration using a ping-pong ball as a standard target. Results of target strength measurements of the fish and ping-pong ball are compared with predicted values based on simulation analyses of the technique operating under the noise conditions observed in the field. The agreement between field results and theoretical predictions were quite good.Key words: hydroacoustic, walleye, pollock, dual beam, target strength measurement, fish assessment

ISSN:0706-652X    

DOI:10.1139/f79-149

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The rainbow trout (Salmo gairdneri) gill was examined with scanning (SEM) and transmission (TEM) electron microscopic techniques as well as an improved glycol methacrylate embedding procedure for light microscopy. The gill epithelium on primary and secondary lamellae contained distinctive surface features consisting of whorled patterns of ridges (microfolds) with intervening grooves, measurements of which were correlated with measurements obtained from TEM tissue sections. The SEM and TEM data complimented each other concerning physical measurements and presence of lamellar ridges and grooves. The microfolds consisted of cellular membrane evaginations with furrows (grooves) between adjacent microfolds. The ridges and grooves on the primary lamellar surface were quite regular in their architecture whereas the ridges of secondary lamellae were farther apart and discontinuous. The gill raker surface also contained low ridges in a whorled pattern with wide intervening grooves. Small pores of variable diameter were observed on the secondary lamellar surface and much larger pores occurred on the primary lamellar and gill raker surface. TEM sections revealed the presence of chloride, pillar I and II, and epithelial cells and the fine structure of their relationship to the capillary bed. These observations were discussed with reference to their possible adaptive value to the trout.Key words: rainbow trout, branchial epithelium, primary lamella, secondary lamella, pillar cell, scanning electron microscopy, transmission electron microscopy

ISSN:0706-652X    

DOI:10.1139/f79-150

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Movement and dispersion patterns of the giant freshwater prawnMacrobrachium rosenbergiiwere assessed through sonic tagging and a novel quadrate sampling technique. Females moved greater distances at night than males, and females exhibited a weaker tendency than males to return to a home site. Reproductive condition and proximity to ecdysis were related to the distance females moved at night. Environmental heterogeneity, productivity, and habitat utilization differed between two ponds. In the more heterogeneous environment, late premolt and early postmolt prawns were apparently avoiding hard intermolt and early premolt prawns by occupying a less preferred habitat of deep, soft mud.Key words: Dispersion, habitat utilization, home range,Macrobrachium rosenbergii

ISSN:0706-652X    

DOI:10.1139/f79-151

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The influence of coal ash effluent upon the densities of macrobenthic invertebrate and mosquitofish (Gambusia affinis) populations in a swamp drainage system was studied for a period of 50 mo. Density of the aquatic biota was periodically altered by three major perturbations: (1) heavy ash siltation from inefficient basin operation, (2) lowered pH from the fly ash addition, and (3) coal ash associated elemental concentrations. Siltation appeared to be most influential in reducing the invertebrate densities while low pH (mean change from 7.2 to 5.5, extreme of 3.5) was more effective in reducing mosquitofish populations and retarding the recovery of invertebrates. Dipterans (chironomids) and odonates (Plathemis lydiaandLibellulaspp.) were the invertebrates most tolerant to coal ash stress. Upon the completion of an efficient primary–secondary retaining basin system, most invertebrate groups in the swamp were able to recover to a level of abundance equal to or greater than that which existed 4 yr earlier.Key words: coal ash stress, heavy ash siltation, fly ash acidity, elemental accumulation, benthic macroinvertebrates,Gambusia affinis

ISSN:0706-652X    

DOI:10.1139/f79-152

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

In Puget Sound, Wash., the incidence of viral erythrocytic necrosis (VEN) varied geographically from 0 to 17% in chum salmon (Oncorhynchus keta) and from 4 to 59% in Pacific herring (Clupea harengus pallasi). The disease was experimentally transmitted by intraperitoneal injection to chum, pink (O.gorbuscha), coho (O.kisutch), chinook (O.tshawytscha), sockeye (O.nerka), and Atlantic (Salmo salar) salmon, and rainbow (S.gairdneri), brown (S.trutta), and brook (Salvelinus fontinalis) trout. The disease was transmitted to chum salmon and brook trout by waterborne virus. Virus obtained from herring was experimentally transmitted into chum salmon by intraperitoneal injection.Key words: viral erythrocytic necrosis, fish disease, transmission

ISSN:0706-652X    

DOI:10.1139/f79-153

出版商:NRC Research Press    

年代:1979

数据来源: NRC