Review of the problems

1979 ◽  
Vol 286 (1015) ◽  
pp. 399-424 ◽  
Keyword(s):  
Polychlorinated Biphenyl ◽  
Sublethal Effects ◽  
Swimming Performance ◽  
Cell Structure ◽  
Blood Chemistry ◽  
Marine Organisms ◽  
Reproductive Failure ◽  
Continuous Sampling ◽  
Full Life Cycle ◽  
High Concentrations

Sublethal effects of pollution may be significant to survival of a stock of marine fish or even a species. Such effects sometimes lead to reproductive failure and have been identified so far only in freshwater systems. Atlantic salmon have disappeared from many streams in Europe and eastern North America, partly as a result of pollution in their freshwater spawning areas and in their estuarine nursing grounds. Reductions in populations of marine fishes due to pollution solely have not yet been demonstrated. However, Baltic Sea seals, where reproductive failure is apparently associated with high concentrations of DDT and polychlorinated biphenyl in the blubber, may have suffered a decline owing to the presence of these organochlorines. Sublethal effects of pollutants have been studied in the laboratory, essentially under four categories: (1) physiology (growth, swimming performance, respiration, circulation); (2) biochemistry/cell structure (blood chemistry, enzyme activity, endocrinology, histochemistry); (3) behaviour/neurophysiology; and (4) reproduction. Not all pollutants elicit meaningful responses in all categories, and a response is not always linear with pollutant concentration. For application to survival of populations the response has to be ultimately related to a healthy progression through a full life cycle, including successful reproduction. In recent time, physiological studies have moved into polluted marine environments with mobile laboratories having continuous sampling capability, to observe effects of pollutants in situ on marine organisms. The Controlled Ecosystem Pollution Experiment (Cepex) in Saanich Inlet, British Columbia, endeavours to investigate the effects of low concentrations of pollutants on marine organisms in large plastic silos having a slow replacement of water.

Effect of caffeine on the growth and photosynthetic efficiency of marine macroalgae

2021 ◽  
Vol 64 (1) ◽  
pp. 13-18
Author(s):  
Ira Gray ◽  
Lindsay A. Green-Gavrielidis ◽  
Carol Thornber
Keyword(s):  
Growth Rate ◽  
Photosynthetic Efficiency ◽  
Sublethal Effects ◽  
Marine Species ◽  
Marine Organisms ◽  
Marine Macroalgae ◽  
Chondrus Crispus ◽  
Coastal Environments ◽  
Codium Fragile ◽  
High Concentrations

Abstract Caffeine is present in coastal environments worldwide and there is a need to assess its impact on marine organisms. Here, we exposed two species of ecologically important marine macroalgae (Chondrus crispus and Codium fragile subsp. fragile) to a suite of caffeine concentrations and measured their response. Caffeine concentrations of 10–100 ng L−1 had no significant effect on the growth rate or photosynthetic efficiency of either algae. Extremely high concentrations (100–200 mg L−1), which may occur acutely, produced sublethal effects for both species and mortality in C. fragile subsp. fragile. Our results highlight the need to understand how caffeine impacts marine species.

Polychlorinated Biphenyls in Food: A Review

1985 ◽  
Vol 48 (5) ◽  
pp. 442-448 ◽  
Author(s):  
BRIJ L. SAWHNEY ◽  
LESTER HANKIN
Keyword(s):  
Polychlorinated Biphenyls ◽  
Human Milk ◽  
Food Chain ◽  
Dairy Products ◽  
Polychlorinated Biphenyl ◽  
Packaging Materials ◽  
Processed Food ◽  
High Concentrations ◽  
Electrical Transformers

Literature published from 1970 through mid-1984 on polychlorinated biphenyl (PCB) contamination of foods, including fish, dairy products, packaged and processed food and human milk, is reviewed. Sources of the contamination are discussed. The reports show that although PCBs are no longer manufactured in this country, large quantities have entered the environment. High concentrations in sediments of some streams and lakes are a continuing source of PCB entry into the food chain via the fish caught in these waters. Accidental leakage and spills from electrical transformers containing PCBs, which are in use, can also be a source of contamination. Other sources of PCB contamination such as silo sealants and packaging materials manufactured from carbonless paper containing PCBs have been essentially eliminated.

Arsenic species in seafood: Origin and human health implications

2010 ◽  
Vol 82 (2) ◽  
pp. 373-381 ◽  
Author(s):  
Kevin A. Francesconi
Keyword(s):  
Human Health ◽  
Arsenic Species ◽  
Marine Organisms ◽  
Current Status ◽  
Human Toxicology ◽  
Important Food ◽  
Arsenic Compounds ◽  
Inorganic Species ◽  
Organoarsenic Compound ◽  
High Concentrations

The presence of arsenic in marine samples was first reported over 100 years ago, and shortly thereafter it was shown that common seafood such as fish, crustaceans, and molluscs contained arsenic at exceedingly high concentrations. It was noted at the time that this seafood arsenic was probably present as an organically bound species because the concentrations were so high that if the arsenic had been present as an inorganic species it would certainly have been toxic to the humans consuming seafood. Investigations in the late 1970s identified the major form of seafood arsenic as arsenobetaine [(CH3)3As+CH2COO–], a harmless organoarsenic compound which, following ingestion by humans, is rapidly excreted in the urine. Since that work, however, over 50 additional arsenic species have been identified in marine organisms, including many important food products. For most of these arsenic compounds, the human toxicology remains unknown. The current status of arsenic in seafood will be discussed in terms of the possible origin of these compounds and the implications of their presence in our foods.

scholarly journals The effects of salinity change on the exercise performance of two Atlantic cod (Gadus morhua) populations inhabiting different environments

1996 ◽  
Vol 199 (6) ◽  
pp. 1295-1309 ◽  
Author(s):  
J Nelson ◽  
Y Tang ◽  
R Boutilier
Keyword(s):  
Metabolic Rate ◽  
Exercise Performance ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Swimming Performance ◽  
Extracellular Fluid ◽  
Blood Chemistry ◽  
Data Set ◽  
Environmental Salinity ◽  
Full Strength

The objective of this study was to determine whether differences in exercise physiology between Atlantic cod (Gadus morhua) populations from different salinity environments could be changed by acclimating individuals of each population to the natural salinity of the comparison population. The exercise-associated blood chemistry of cod from the brackish Bras d'Or lakes, which had previously been shown to be quite different from that of 'open-ocean' cod, changed to resemble the blood chemistry of their oceanic relatives after only 2 months of acclimation to full-strength salinity. In contrast, the blood chemistry of cod from the Scotian Shelf of the Northwest Atlantic Ocean showed little change after 2 months of acclimation to brackish water. These results demonstrate that the degree of osmoconformity to changes in environmental salinity is a population-specific not a species-specific trait. The blood chemistry differences between populations and salinities did not translate into differences in exercise performance: i.e. critical swimming speeds were statistically uniform across all combinations of population and salinity, although performance was more varied in fish swimming in 'non-native' waters. Other 'whole-animal' physiological characteristics, such as metabolic rate and the aerobic cost of transport, were dependent upon both population origin and the environmental salinity. Vigorous swimming was more energetically expensive at full-strength salinity than at 20 salinity, yet estimates of standard (i.e. resting) metabolic rate were lower for full-strength salinity. Environmental salinity also influenced the relative appearance of lactate and metabolic acid in the extracellular fluid compartment, with full-strength salinity favouring the relative appearance of lactate in the blood. Multivariate statistical analyses of this data set showed that, in contrast to other fish species and studies, differences in blood oxygen transport appear to account for some of the swimming performance differences seen in Atlantic cod at 2 °C. The two experimental populations were cleanly separated by a principal components analysis, regardless of the salinity to which they were acclimated, confirming our earlier contention that these cod populations are physiologically distinct. A key feature of that distinctness is the greater phenotypic plasticity exhibited by the population from the more euryhaline, more eurythermal environment.

scholarly journals Influence of mycotoxin zearalenone on the swine reproductive failure

2013 ◽  
pp. 121-129 ◽  
Author(s):  
Jasna Prodanov-Radulovic ◽  
Radoslav Dosen ◽  
Igor Stojanov ◽  
Ivan Pusic ◽  
Milica Zivkov-Balos ◽  
...  
Keyword(s):  
Anaerobic Bacteria ◽  
Reproductive Failure ◽  
Swine Production ◽  
Reproductive Disorders ◽  
Swine Feed ◽  
High Concentrations ◽  
Layer Chromatography ◽  
Detrimental Impact ◽  
Aerobic And Anaerobic ◽  
Feed Samples

Reproductive failure in swine is often a difficult diagnostic problem. If diagnoses of infectious disease or management related problems are not obtained, feed quality and safety may be questioned. Mycotoxins are often present in swine feed in the amount that can have detrimental impact on production and reproduction. Problems are expressed only as alterations of the reproductive cycle, reduced feed intake, slow growth or impaired feed efficiency. In Serbia, generally speaking, high concentrations of mycotoxins were noticed, especially mycotoxin zearalenone. High presence of zearalenone in swine feed is probably due to climatic influence and should be monitored constantly. This paper includes field observations regarding the influence of moldy feed containing mycotoxin zearalenone on the occurrence of the reproductive failure in swine breeding categories (sows, gilts and boars). The material for this research was obtained from four swine farms where certain reproductive disorders and health problems in breeding animals were detected. Depending on the specificity of each evaluated case and available material, the applied research methods included: anamnestic and clinical evaluation, pathomorphological examination, standard laboratory testing for detection of aerobic and anaerobic bacteria, and microbiological feed testing, in order to examine the presence of fungi and mycotoxins by applying the method of thin layer chromatography. On the basis of the obtained results, it could be concluded that mycotoxin zearalenone was detected in all examined feed samples. The presence of mycotoxin in feed was directly related to the reproductive failures in the examined swine categories (vulvovaginitis, endometritis, rebreeding, infertility). Swine reproduction represents the base for intensive swine production. The presence of mycotoxins in swine feed have influence on the reproduction and health status of pigs and under certain conditions may significantly disturb the production process.

scholarly journals Lethal and Sublethal Effects of Ingested Hydroprene and Methoprene on Development and Fecundity of the Common Bed Bug (Hemiptera: Cimicidae)

2020 ◽  
Vol 57 (4) ◽  
pp. 1199-1206
Author(s):  
Angela Sierras ◽  
Coby Schal
Keyword(s):  
Insecticide Resistance ◽  
Sublethal Effects ◽  
Bed Bugs ◽  
Bed Bug ◽  
Alternative Interventions ◽  
Hormone Analog ◽  
High Prevalence ◽  
Cimex Hemipterus ◽  
The Common ◽  
High Concentrations

Abstract In the last two decades, bed bugs (Cimex lectularius L. and Cimex hemipterus F.) have become perennial and difficult to control indoor pests. Current pest control options are severely constrained by high prevalence of insecticide resistance and availability and relatively high costs of alternative interventions. Among various measures to counter the drawbacks of insecticide resistance include efforts to diversify the modes of action of insecticides with residual applications of combinations of insecticides, which include a juvenile hormone analog (JHA). JHAs, such as hydroprene and methoprene, have a desirable safety profile and are effective against a variety of indoor pests. We evaluated the potential of hydroprene and methoprene to be incorporated into an ingestible bait, with dose–response studies on fifth-instar male and female bed bugs. Females were more susceptible than males to both JHAs, and methoprene was more effective by ingestion than hydroprene at inducing both lethal and sublethal effects. Ingestion of ≥10 µg/ml blood of either JHA by last instar nymphs reduced oviposition; untreated females that mated with males exposed to high concentrations of either JHA also exhibited lower oviposition. We suggest that methoprene could be incorporated into integrated pest management programs in liquid baits and residual sprays in combination with other active ingredients.

Zoospore Germination in Blastocladiella Emersonii

1972 ◽  
Vol 10 (2) ◽  
pp. 315-333
Author(s):  
D. R. SOLL ◽  
D. R. SONNEBORN
Keyword(s):  
Osmotic Shock ◽  
Cell Structure ◽  
Ion Selectivity ◽  
Choline Chloride ◽  
Exposure Period ◽  
Monovalent Cation ◽  
Continuous Exposure ◽  
Initial Exposure ◽  
Cell Conversion ◽  
High Concentrations

Zoospore germination in B. emersonii is accompanied by a series of abrupt, dramatic changes in cell structure. Membranes appear to be variously involved in many of these changes. Germination is subject to simple manipulations of the ionic environment: swimming zoospores can be maintained for long periods in the buffered CaCl2 solution into which they are initially released, whereas dilution into a solution containing KCl and MgCl2 in addition to CaCl2 results in rapid, semisynchronous germination of entire zoospore populations. The control of germination by ionic means has been characterized in the following ways: (a) Very brief (40 S to 2 min) exposure to GS, followed by replacement with buffered CaCl2 is as effective as continuous exposure in eliciting rapid germination of the entire zoospore population. (b) The effective component of GS is KCl: GS lacking KCl does not elicit rapid germination; conversely, buffered KCl alone is as effective as complete GS in eliciting germination. (c) Zoospore populations are sensitive to KCl concentration; as the KCl concentration is reduced, the proportion of cells which undergo rapid germination is also reduced. (d) At optimal concentration (5 x 10-2 M), the following salts are equally as effective as KCl in eliciting germination: KI, KBr, NaCl, CsCl, RbCl, and choline chloride. (e) At high concentrations (2.5-5 x 10-2 M), CaCl2 and MgCl2 elicit semi-synchronous conversion of zoospores to round cells, but only after sizeable delays (v. KCl). Conversion of round cells to germlings does not occur in MgCl2 and is enormously delayed in CaCl2; when formed, the germ tubes appear abnormal. (f) Monovalent cation salts of complex divalent anions (sulphate, tartrate, molybdate, tungstate) also exhibit decreased effectiveness (v. KCl) in eliciting germination. (g) The monovalent cation salts NH4Cl and LiCl, the divalent cation salt MnCl2, and the non-ionic compound sucrose are all ineffective in eliciting rapid germination. When in combination with an effective elicitor (KCl), LiCl totally blocks germination, MnCl2 and sucrose lead to significant delays in zoospore to round cell conversion, while NH4Cl has no effect on the population kinetics. (h) LiCl can block germination even when added after the completion of the otherwise sufficient early exposure period to GS (see (a) above). The blocking effect of LiCl can be almost completely reversed by replacement with KCl. On the basis of this characterization it is concluded that (1) rapid germination is not elicited simply by osmotic shock; rather, the cells are capable of responding to other (especially ionic) properties of their chemical environment; and (2) while brief exposure to KCl is sufficient to elicit germination, there are evidently other ion-sensitive steps occurring after the completion of this initial exposure period. Implications of the results in relation to the regular ion selectivity patterns found in other ion-dependent systems, the possible site(s) of action of the eliciting compounds, and the newly discovered ‘zoospore maintenance factor’ are discussed.

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