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Seafood plays a major role in the human diet. During transportation, without proper storage and supply chain, its quality deteriorates easily. The post-harvesting processes such as the storage of food play a crucial role in human health. So it is highly imperative to have a technique for identifying food spoilage earlier to ensure the food safety and security of the consumers. Herein we have developed a highly selective and sensitive fluorescent 'Turn-on' probe 2-amino-5-nitrobenzo [d] thiazol-2-yl) imino)methylphenol ANT based on aggregation induced emission (AIE). ANT molecule possesses both restricted intramolecular rotation (RIR) and excited state intramolecular proton transfer (ESIPT) properties leading to fluorescent enhancement rather than aggregation caused quenching (ACQ). The probe shows high selectivity and sensitivity towards the NH 3 vapor. This probe with the AIE property is employed for the real-time detection of NH 3 in both aqueous and gaseous phases. ANT molecule is deposited on the paper shred by a physical method is utilized to monitor NH 3 vapor from red snapper fish as a real-time sample during its degradation processes. After two days there is a ratiometric color change in the paper shred from yellow to orange for the fish stored at room temperature indicating its rotten and unpalatability nature. Paper shred is reused by immersing it into the tetrahydrofuran (THF), in which it retains its initial color due to deprotonation of NH 3 , keto to enol tautomerism discloses the reusability of the fluorescent probe. Studies carried out using UV-visible and fluorescence spectroscopy infer that the ANT probe has high affinity towards NH 3 vapor., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Identifying the factors that influence the citation of articles helps authors improve the impact and reach of their research. Analysis of publications in the Journal of Fish Biology between 2008 and 2021 revealed that variables such as the number of keywords, abstract length, number of authors, and page length were associated with higher impact papers. These trends applied to both review and regular papers. These findings suggest that papers that are more informative, have higher numbers of authors, and have more keywords are more likely to be cited. Adoption of some simple "best-practice" behaviors can improve the likelihood that a paper is cited., (© 2023 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

The anchoveta (Engraulis ringens) and sardine (Strangomera bentincki) are coastal pelagic species with important spawning areas off the coast of Chile. The discharge of secondary-treated effluents from a kraft pulp plant near one of these spawning areas has raised environmental concerns. Therefore, effluent effects on the development of anchoveta and sardine eggs were assessed by in vitro exposure. Eggs were sampled between 2007 and 2010 off Talcahuano, Chile. Subsequent toxicity tests (96 h duration, 12 °C) were performed using increasing effluent concentrations, a filtered seawater control, and two potassium dichromate concentrations (to verify consistent embryonic sensitivity). Egg mortality and hatching success were evaluated. For anchoveta, mortality (9.9 ± 7.1%) did not significantly differ among groups in five toxicity tests except the final toxicity test that showed significant differences in mortality (5.6% control vs 27.8% in 100% effluent). For sardines, no differences in mortality existed between the effluent dilutions (2.6 ± 3.6%) and control (6.3 ± 3.9%). Notably, anchoveta egg survival and hatching success rates were inconsistent, i.e., the highest rates of hatching failure occurred on the same sampling date with the highest rates of survival for the 100% effluent group (72%). In conclusion, the obtained results indicate that (i) anchoveta egg mortality and hatching failure increase only under 100% effluent exposure, coinciding with decreased egg quality near the end of spawning season and (ii) high effluent dilutions not significantly increase sardine and anchoveta egg mortalities. Nevertheless, the recorded adverse effects to the hatching process should be studied in greater detail, particularly considering interspecific variability and the complexity of reproductive processes, especially during early development.

Background: Paper is one of the important inputs for the printing industry, and the most important leading parameter in the printing process is its brightness. Brightness can be brought to paper using coatings and sizing. Desired surface properties and, most importantly, surface roughness can be achieved by changing the contents of the coating and sizing of the materials it contains. The use of biomaterials is becoming more important in the paper industry, as they represent substances with a lower carbon footprint. Fish scales are already used as a filling material, cosmetic material and fish food, as well as for determining the age of fish., Methods: Fish scales were brought to different sizes by a milling process. Paper formulations including different amounts of fish scales were prepared with fish scales, and coatings on raw paper were subjected to test printings in IGT-C1, with formulations and physical characteristics of coatings such as brightness, lightfastness, strength, adhesion etc. being determined., Results: Regarding the value of yellowness, mixtures of 2.5%-10% can be used. The maximum value of brightness was obtained from a mixture of 10%. Aging visibly changed the colors., Conclusions: The coatings obtained were brighter than the initial coating compositions. The top quality formulation was the coating with 5% medium-sized fish scale particles.

Building on breakthroughs recently made at kraft mills, a survey of mechanical pulp and paper mill effluents was undertaken to gain insights concerning potential effects on fish reproduction. Effluents from seven Canadian mills were characterized chemically for conventional parameters such as biochemical oxygen demand (BOD) and total suspended solids (TSS). Each sample was further subjected to solvent extraction followed by gas chromatographic separation for the determination of resin/fatty acids and for the estimation of a gas chromatography (GC) profile index. Each mill effluent was assessed for the potential to affect fish reproduction in the laboratory using a five day adult fathead minnow (Pimephales promelas) egg production bioassay with exposures to 100% effluent. The seven effluents were found to have substantial variation both in terms of chemical characterization and effects on fish reproduction. Temporal variations were also noted in effluent quality at mills sampled on different occasions. Similar to what has been observed for kraft mills, a general trend of greater reductions in egg production caused by effluents with greater BOD concentrations and GC profile indices was noted. Effluents with BOD > 25 mg/L and GC Profile indices >5.0 caused a complete cessation of egg production. At the same time, about half of the total effluents sampled had BOD < 25 mg/L and GC profile indices <5.0 and caused no significant effects on egg production, suggesting these values may be useful as effluent quality targets for mechanical pulp and paper mills. However, 3 out of 14 effluents sampled had BOD < 25 mg/L and GC profile indices <5.0 and caused significant reductions in egg production. The reason(s) for reproductive effects caused by such effluents is presently unclear. The effluent quality parameters considered in this study may require further refinement to address their utility in predicting the adverse reproductive effects induced by effluents from mechanical pulp and paper mills.

Aromatic sensitizers and related compounds (SRCs) originating from thermal recording material as impurities in waste paper have been detected in aquatic environments near cities where the paper industry is flourishing. In the present study, the levels of exposure to such SRCs and the stable isotope ratios (δ(13)C and δ(15)N) in different fish species (Konosirus punctatus, Takifugu niphobles, and Tribolodon hakonensis) were analyzed. These fish species were collected from the vicinity of waste paper recycling plants in Japan. Eleven SRCs were identified in fish muscle at total concentration levels (ΣSRCs) of 64 to 818 ng/g wet weight (mean 181 ng/L wet wt). The dominant SRCs in the fish samples were 1,1-di(4-methylphenyl)ethane, 1,2-bis(3-methylphenoxy)ethane, and 1,4-dibenzyloxybenzene. Stable isotope ratios showed that, although three species feed on the same trophic level, K. punctatus and T. niphobles live in waters farther offshore than those in which T. hakonensis live. The contributions of various factors to the accumulation were also assessed. The lipid content (r(2) = 0.512, p < 0.001) was found to be the significant factor that influenced accumulation of SRCs in fish. The results also revealed significant positive correlation between the accumulation patterns and SRC components in water (r(2) = 0.512-0.658, all p values <0.05), but they showed negative correlations between the SRCs in fish and log K(OW) values. This suggests that the aqueous route is the predominant route for the accumulation of SRCs in fish. This is the first study on the accumulation of aromatic sensitizers in aquatic biota., (Copyright © 2012 SETAC.)

Physiological changes have been seen in individual fish exposed to pulp and paper mill effluent (PPME), but it is unclear whether community-level changes are seen in fish in PPME receiving waters. We conducted a study of 4 PPME receiving streams (Codorus Creek, PA, USA), the Leaf River (Forrest and Perry Counties, MS, USA), and the McKenzie and Willamette rivers (Lane County, OR, USA) over 9 y to assess temporal patterns in the type and relative abundance of fish species and measures of community structure and function related to PPME discharge. We used boat and backpack electrofishing to sample large- and small-bodied fish from the McKenzie and Willamette rivers, boat electrofishing to sample large-bodied fish from the Leaf River, and backpack electrofishing to sample the entire fish community from Codorus Creek. Study streams represented different ecoregions, warm- and coldwater systems, gradients of PPME concentration (<1%-33%), and mill process types. Bray-Curtis similarity and nonmetric multidimensional scaling showed high variation in fish communities across sites, seasons, and years. Significant site differences in fish communities were seen in most streams and community types, but distinct separation of sites was seen only in Codorus Creek and unrelated to PPME discharge. No seasonal differences were seen in fish community structure in any stream, with only weak annual patterns in large-bodied fish in the Leaf River and small-bodied fish in the McKenzie River. General linear models were used to examine spatial and temporal variation in fish metric response (abundance, species richness, Simpson's diversity, % dominant species, standing crop, % DELT, % intolerant, % omnivore, % piscivore). Significant site differences in metric response were largely limited to Codorus Creek and unrelated to PPME. Significant reductions of % dominant taxa of small-bodied fish and % large-bodied piscivores were also observed downstream of the PPME discharge on the McKenzie River relative to upstream sites. Seasonal changes in fish metric response were rare, and changes with year were variable. The relationship between fish community structure and water quality variables (pH, color, conductivity, total phosphorus, total nitrogen) was weak in all streams for all community types. The results of this study show that PPME exposure has little effect on fish communities in these streams and aid in addressing management strategies. The high spatial and temporal variability reiterate the importance of long-term studies to elucidate patterns in receiving waters.

Conjugated resin acids (RAs) in fish bile are considered a sensitive chemical indicator of exposure to pulp and paper mill effluent, and were used in this study to monitor the post-spill situation of a lake area (Southern Lake Saimaa) contaminated by black liquor discharged from a mill in June 2003. From the exposure perspective of populations of wild roach and perch, which were studied for their bile RAs at four time periods (July 2003, September 2003, May 2004, July 2004), the exceptional event passed in 2 months or less. Perch had lower concentration of RAs in bile than roach in all sampling areas and all times. Besides the current emissions present in the water column, part of the exposure status of the roach population to RAs seemed to derive from historically contaminated sediments. In order to test this hypothesis, a laboratory experiment with perch and roach, along with three teleosts (rainbow trout, brown trout and whitefish), was conducted. The species were simultaneously exposed for 7 days to RAs (23 microg/l). We calculated a perch/roach-ratio to investigate the difference in origin of exposure between perch and roach populations in the wild and in the laboratory. One year after the spill, the perch/roach-ratio of bile RAs was 0.25 (CV 25%) at 1 km from the mill. This is in contrast to that found under the sole waterborne conditions (0.44; CV 24%), supporting the idea that sediments serve as an additional source of RAs in roach. Additionally, bioconcentration factor log BCF(bile(RA)) was calculated to assess hepatobiliary performance and the capacity to excrete RAs in fish.

For the last 20 years, studies conducted in North America, Scandinavia, and New Zealand have shown that pulp and paper mill effluents affect fish reproduction. Despite the level of effort applied, few leads are available regarding the factors responsible. Effluents affect reproduction in multiple fish species, as evidenced by decreased gonad size, decreased circulating and gonadal production of reproductive steroids, altered expression of secondary sex characteristics, and decreased egg production. Several studies also have shown that effluent constituents are capable of accumulating in fish and binding to sex steroid receptors/ binding proteins. Studies aimed at isolating biologically active substances within the pulping and papermaking process have provided clues about their source, and work has progressed in identifying opportunities for in-mill treatment technologies. Following comparisons of manufacturing processes and fish responses before and after process changes, it can be concluded that effluent from all types of mill processes are capable of affecting fish reproduction and that any improvements could not be attributed to a specific process modification (because mills normally performed multiple modifications simultaneously). Improved reproductive performance in fish generally was associated with reduced use of molecular chlorine, improved condensate handling, and liquor spill control. Effluent biotreatment has been effective in reducing some effects, but biotreated effluents also have shown no difference or an exacerbation of effects. The role of biotreatment in relation to effects on fish reproduction remains unclear and needs to be resolved.

In previous experiments, bleached kraft chemical recovery condensates generated during softwood pulp production have been identified as a primary source of substances causing testosterone depressions in mummichog (Fundulus heteroclitus). Recent toxicity identification evaluations have encountered inconsistencies in the potential of condensates and fractions to reduce steroid concentrations between three repeated exposures. To assess the sources of these inconsistencies, temporal assessments of condensate extractives and analytical methodologies were evaluated. Condensates were collected during a six-month period, extracted by solid-phase extraction (SPE), and analyzed by gas chromatography-mass spectrometry and gas chromatography-flame photometric detection. All unique extractives were cataloged by mass spectra, peak area, and gas chromatographic retention time, and nine were confirmed and quantified against authentic standards. Confirmed components included phenolic guaiacyl-based lignin degradation products, sulfur (S9), three diterpenoids, and a dimethoxy stilbene. Concentrations of confirmed condensate extractives were consistent in all samples collected. Spiking experiments of confirmed extractives revealed substantial losses following high-pressure liquid chromatographic fractionation and three different methods of fraction preparation. In an effort to propose chemical classes associated with biological activity, all unique condensate extractives in previously established bioactive and inactive fractions were classified based on their potential to depress testosterone in mummichog. Of 39 unique components in bioactive SPE extracts of condensates, six were associated with hormonal activity. Mass spectral interpretation indicated hydroxylated diterpenoids, sesquiterpenoids, and a lignin-derived stilbene as classes of chemicals associated with steroid depressions.

Aquatic habitat is affected by paper mill effluent discharge in many ways. The effect of paper mill effluent on the gill ATPases was studied in freshwater fish Channa punctata (Bloch) exposed to 1%(v/v) of effluent for 15, 30, and 60 days. There was a time-dependent significant (P<0.05-0.001) decrease in all the ATPase activities measured, viz., total, Na(+), K(+)--and ouabain-insensitive ATPase in gill. ATPases play an important role in maintenance of functional integrity of plasma membrane and in several intracellular functions and are considered to be a sensitive indicator of toxicity. In addition to this, branchial ATPases are intimately involved in osmoregulation, acid-base regulation, and respiration of fish. The inhibition of ATPases in gills by, e.g., paper mill effluent could cause disruption of these processes. It is suggested that measurement of ATPases could also be used as a surrogate biomarker of exposure to chemical pollutants.

The fish community in sublittoral and profundal waters, at stony shores, and densities of vendace larvae were studied in the southern Lake Saimaa, Finland. The objective was to investigate the possible recovery of fish populations after modernizations at the pulp and paper mills discharging into the lake. Sublittoral and profundal waters were studied by gill net trial fishings, stony shores by electrofishing, and vendace larvae by beach seine. The research area was divided in a polluted (0.5-4.0% effluent), an intermediate (0.1-0.5%) and a 'clean' reference area. The fish community in sublittoral and profundal waters in the lake was dominated (> 60%) by perch and roach. Relative abundance of fish was highest in the polluted area, and lowest in the reference area. The number of species caught was similar among areas. The abundance of bleak and ruffe was highest in the polluted area, while the abundance of vendace and whitefish was highest in the intermediate and reference area. The fish fauna of stony shores in the lake was dominated by bullhead, stone loach and minnow, densities were lowest at polluted shores and highest in the intermediate area. Minnow, apparently a more sensitive species to pulp mill effluents, were not caught at the most polluted shores. The catch of vendace larvae was similar among areas, larvae were also caught in the vicinity of the mills. Compared with before the modernization at the mills, the relative abundance of perch in the polluted area was increased, ruffe decreased, while populations of whitefish and vendace showed signs of recovery. These changes may be explained by the reduced nutrient load and toxicicity of pulp mill effluents. At present, the fish community in the polluted area can be considered typical for a moderate eutrophication.

This study compared the use of sentinel species- and community-based field approaches for assessing the biological status of fish living in a river receiving pulp and paper mill effluents. Three approaches were compared. Two approaches used sentinel species. One of these involved an internal/external examination of the fish that leads to the calculation of a fish health assessment index (HAI) and the other involved biochemical measurements of hepatic mixed function oxidase (MFO) activity and plasma steroid levels. The third approach characterized the fish community structure according to an index of biotic integrity (IBI). The comparison focused on how the methods respond to the hypothesis that recent process modifications/effluent treatment changes, resulting in demonstrable improvements in effluent quality, have beneficial effects on fish. Neither of the approaches using sentinel fish indicated clear mill-related influences either before or after the process modifications/effluent treatment changes. There was no evidence of depressed plasma steroids and increased MFO activity in fish frequently associated with mill effluent exposure in previous studies. While the HAI was higher at stations downstream from two mills, this could not be linked to effluent exposure alone. In contrast, the study of community structure showed a substantial improvement in fish assemblages at all the mill sites.

Exposure of fish to water of impaired quality has been shown to disrupt the function of the hypothalamo-pituitary-interrenal (HPI) axis and alter the interpretation of data from field studies due to the varying effects of handling and delayed sampling on exposed and reference animals. In the present study, juvenile whitefish, Coregonus lavaretus, were exposed for 6 weeks to diluted (4-8%) untreated and biologically treated bleached kraft mill effluent (BKME) and their response to acute handling was investigated. Liver microsomal EROD activity and glycogen phosphorylase (GPase) activity, in addition to gill Na+-K+-ATPase activity, and blood hemoglobin and hematocrit levels were increased in whitefish exposed for 6 weeks to untreated BKME, whereas those exposed to treated BKME exhibited increased blood hemoglobin and red blood cell K+ concentrations. Both handling procedures, exposure to a shallow water (10 cm, 5 min) and to an air challenge (10 s air/10 s water/30 s air/10 s water/10 s air), resulted in acute physiological stress, as recorded after 5-, 60-, and 120-min recovery periods. Following air exposure, the levels of plasma cortisol, blood glucose, hemoglobin, and hematocrit as well as the liver GPase activity were increased, and liver glycogen concentration decreased in control fish. These responses were attenuated in fish exposed to untreated or treated BKME. Plasma estradiol and testosterone levels were not affected by the BKME exposures or by the air challenge. Handling also resulted in attenuated EROD induction in fish exposed to untreated BKME. According to the present findings, the sensitivity of some widely used cellular and physiological variables may be improved by time-dependent standardization when interpreting data obtained following delayed sampling.

Perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) populations in a state of late vitellogenesis were studied downstream of two pulp and paper mills and at upstream references in southern Lake Saimaa, Finland. The mills used elemental chlorine-free bleaching and activated sludge effluent treatment technologies. The exposure of fish to pulp mill effluents, as measured by concentrations of chlorophenolics in the bile and liver ethoxyresorufin-O-deethylase (EROD) activity, was low and almost similar to the references. Nevertheless, bile resin acid concentrations in exposed perch and roach (260-320 micrograms/ml) and bile beta-sitosterol concentrations in exposed roach (1.5-3.5 micrograms/ml) were, respectively, 10 to 30 times and 2 to 5 times higher compared with the references. Reproductive parameters like plasma 17 beta-estradiol and testosterone levels were lower in exposed male and female perch but the same in roach. Vitellogenin concentrations in plasma and liver cytosol of roach were similar. Gonad weight and fecundity were lower in exposed female perch but similar in roach. The relative liver weight was higher in exposed roach but not in perch. The body condition and immunologic parameters in fish were the same. The growth and age at maturity of exposed perch and roach were similar to the references. The size and age distribution of perch in the recipient of one of the mills was shifted toward smaller and younger fish. Our results show that several reproductive variables were altered in late vitellogenic perch in the vicinity of the mills, but they were not altered in roach.

Plants synthesize many phytochemicals, including flavonoids, which may be present in the heartwood of trees used in the pulp and paper industry. Extracts were prepared from wood pulp and mill effluent collected from a bleached kraft mill in Ontario, Canada, and these extracts were subfractionated by LH-20 gel filtration chromatography and analyzed by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) and LC-ESI-tandem mass spectrometry (LC-ESI-MS-MS). Initial LC-MS analysis in negative ion mode was conducted by monitoring ions corresponding to the deprotonated molecular ions of a range of flavonoid compounds. The presence of chromatographic peaks generated by selected ion monitoring (SIM) in samples of both mill effluent and wood pulp encouraged further analysis. Of the compounds highlighted by LC-ESI-MS-SIM analysis, the isoflavonoid genistein was positively identified by LC-ESI-MS-MS. Genistein was quantified at a concentration of 30.0 microg/kg in air-dried wood pulp and concentrations of 13.1 microg/L and 10.5 microg/L in untreated and treated (final) effluent, respectively. Genistein is a known endocrine disruptorsubstance and,therefore, could contribute to the alterations in sex steroid levels and reduced reproductive capacity observed in fish captured near the discharges of pulp mills.

The present study was designed to examine, whether, effluents from a modern pulp and paper mill using elemental chlorine-free/total chlorine-free (ECF/TCF) bleaching, exert effects on the immune system of fish and, in addition, to relate these findings to physiological parameters known to be affected by bleached kraft-mill effluents (BKME). Roach (Rutilus rutilus) were exposed in laboratory conditions to primary- or secondary-treated effluent from a pulp and paper mill. In order to study their capability to respond to foreign antigens they were immunised with bovine gamma-globulin (BGG) prior to exposure. The number of anti-BGG antibody-secreting cells (ASC) and the number of immunoglobulin-secreting cells (ISC) in the spleen and blood as well as the level of anti-BGG specific antibodies and concentration of plasma immunoglobulin (IgM) were studied. Phagocytosis and migration of granulocytes of the head kidney were also determined. In addition to the immunological parameters, the activity of hepatic biotransformation enzymes, the carbohydrate metabolism and osmoregulation were examined. Exposure of roach for 21 days to BKME affected several immunological parameters. Both effluents, primary- and secondary-treated, impaired the immunoreactivity of the fish. Sex-related differences in the immune responses were evident in many parameters e.g. in the number of blood ISC and splenic ASC. Sex also had effects on cortisol levels and in the induction of 7-ethoxyresorufin O-deethylase (EROD). These results demonstrate that both primary- and secondary-treated effluent from a pulp and paper mill using ECF/TCF bleaching have effects on fish immune functions. Further, these findings suggest that steroids may contribute to immunomodulation in fish.

In the early 1990s, many Canadian pulp and paper mills implemented process changes to comply with new regulations that came into effect in 1993. These regulations placed stricter guidelines on a number of parameters in effluent discharges, including limits on acute toxicity, on the discharges of suspended solids, and on biochemical oxygen demand. To meet these new regulations, many of the older Canadian pulp and paper mills had to install secondary treatment systems. The investment by the Canadian pulp and paper industry was in excess of $5 billion, and the implementation of the new regulations and the process changes took several years. The new regulations were an extension of regulations designed in the early 1970s and were not designed specifically to address the reproductive responses recently reported in fish collected downstream of mills in Scandinavia and North America. This report describes a series of projects conducted between 1991 and 1996 to evaluate the effectiveness of the new regulations to address the issue of reproductive responses in fish associated with exposure to pulp-mill effluents. These studies have shown that the existing short-term bioassays do not adequately predict the potential of effluents to affect reproduction in wild fish. Laboratory testing using fathead minnows exposed over a full life cycle confirmed depression in sex steroid production, delay in sexual maturity, reduced egg production, and changes in secondary sex characteristics documented at some sites. Our studies demonstrated that both steroid hormone changes and induction of liver detoxification enzymes take place quickly. While short-term exposures can predict the potential of some effluents to impact steroid hormone production, there is no readily available assay that can be widely applied. In the absence of a usable and transferable laboratory bioassay, field collections were conducted at a number of sites. Generalizations are not possible at this time, but impacts have been seen at a variety of sites, and partial recovery has been documented at five sites in North America following various process and waste treatment changes. Data gaps and critical research areas are identified.

This review describes the research that has been carried out into estrogenic effects occurring in aquatic environments, both freshwater and marine, and the substances found to be responsible. In summary, estrogenic (and probably some anti-androgenic) activity has mainly been detected in a variety of treated sewage and other effluents, but also as a result of certain chemical spills and deliberate applications. This activity has resulted in a number of effects in vertebrate wildlife that can best be described as feminization, although the severity of these effects ranges from biomarkers of exposure such as vitellogenin induction in males through to morphological changes in sex organs and complete sex reversal. The implications of these changes for the future of aquatic wildlife populations have not yet been thoroughly explored. It is unlikely that all the causative substances have yet been discovered, but those which have been positively identified include natural and synthetic estrogenic hormones, natural plant sterols, synthetic alkylphenols, and certain organochlorine substances. The review concludes that there is now a need to investigate the consequences for wildlife populations of exposure to these materials, by means of a variety of field experiments and investigations.

The results and interpretations of published Canadian field studies on the reproductive status of fish in waters receiving pulp and paper mill effluent discharges were reviewed. Most of the information was obtained from indicator measurements such as gonad size, fecundity, and serum steroid levels in wild fish sampled at reference and effluent-exposed sites. Difficulties in selecting appropriate sampling sites, natural variability, and the ecological relevance of the indicator measurements were identified as major complicating factors for the interpretation of the field data. Consequently, it was not possible to conclude to what extent, if any, widespread effects on fish reproduction are being caused by pulp and paper mill effluents or that specific manufacturing processes are causing such effects. Further research on the normal variability and predictive capability of reproductive indicators, for example, using an integrated approach (i.e., laboratory testing, mesocosm studies, and field work), is recommended.

To determine whether a 7- to 10-d embryo toxicity/teratogenicity test with the inland silverside fish, Menidia beryllina, is a sensitive indicator for evaluation of bleached kraft mill effluents, we compared this test with the Microtox(R) 15-min acute toxicity test and the Ceriodaphnia dubia 7-d chronic toxicity test. Water samples used in each test were collected from three areas in a bleached kraft pulp and paper mill using a 100% chlorine dioxide bleaching process: 1) river water prior to use in the mill; 2) the combined acid/base waste stream from the pulping process prior to biological treatment in the aerated stabilization basin (ASB); and 3) the effluent from the ASB with a retention time of approximately 11 d. Relative toxicity determined by the three tests for each water sampling location was compared. All three toxicity tests were predictive indicators of toxicity; however, the C. dubia and M. beryllina tests were the more similar and sensitive indicators of toxicity. Process water (ASB influent) prior to biological treatment in the ASB was toxic at all concentrations using the Microtox(R) and C. dubia tests. The fish embryo test showed no toxicity at 1% concentrations, slight toxicity at 10%, and acute toxicity at the 100% ASB influent concentration. Tests with biologically-treated ASB effluent indicated a substantial reduction in observed toxicity to Microtox(R) bacteria, C. dubia, and M. beryllina. No toxic responses were observed in any test at a 1% ASB effluent concentration which was the approximate effluent concentration in the receiving river following mixing. No relationship was found among any toxicological response and effluent levels of adsorbable organic halides, polychlorinated phenolic compounds, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran, total suspended solids, color, chemical oxygen demand, or total organic carbon.

An investigation was made of cytochrome P4501A (CYP1A) induction, determined by the activity of EROD (7-ethoxyresorufin O-deethylase), and formation of benzo[a]pyrene-diolepoxide-DNA (BPDE-DNA) adducts, measured by synchronous fluorescence spectrophotometry, in liver microsomes of perch (Perca fluviatilis), bream (Abramis brama), and roach (Rutilus rutilus). Fish were collected from the southern part of Lake Saimaa (Finland), an area polluted by effluents from the pulp and paper industry. In addition, two conjugation enzymes (UDP-glucuronosyltransferase and glutathione S-transferase) were determined. Overall, when compared to an upstream reference, EROD activity was higher in fish at waters downstream of the mill sewer. In bream EROD activity was threefold and in roach twofold. The changes in conjugation enzymes were not clearly related to the pollution gradient. The formation of BPDE-DNA adducts by liver microsomes was in correlation to both the pollution gradient and the EROD activity. This implies that CYP1A enzymes may play an important role in carcinogen activation in natural fish populations and that the formation capacity of DNA adducts may be a useful indicator when evaluating the potential toxicity of industrial water pollution.

The rate of technical development in bleaching of chemical pulp and the upgrading of process control and wastewater treatment systems in the pulp industry have been extremely rapid over the past few years. When assessing the environmental impacts of bleached kraft pulp mill effluents (BKMEs), it is therefore more important than ever to carefully characterize the bleaching process, the composition of the treated effluent, and the degree of exposure of sensitive target organisms in the receiving water body. These requirements have not always been fulfilled in previous reports on biological effects of BKMEs in Scandinavia. This work presents the results of a comprehensive field study of the impacts of a 350,000-tonne kraft mill, bleaching softwood and hardwood pulp in campaigns according to the sequence O(D25,C70+D5)(EOP)D(EP)D. The effluent is treated in an aerated lagoon with a mean retention time of 8-9 days, practically eliminating chlorate and resin acids, and reducing the discharge of adsorbable organic halogen (AOX) to an average of 1 t/day (1.3 and 0.4 kg/ADt for softwood and hardwood, respectively). The treated effluent is discharged through a 1.3-km-long diffuser, at a water depth of 9-12 m, into a well ventilated coastal area, giving a 1000-fold dilution within 3-4 km from the diffuser. The actual exposure of the coastal ecosystem to BKME components was determined by analysis of extractable organic chlorine in suspended solids and of conjugates of chlorophenolics in the bile of feral perch. Despite a major damage to the benthic communities that occurred about 10 years ago, and was due to large chlorate discharges at the time, no direct detrimental effects on benthic flora and fauna could be ascribed to the present BKME discharge. Instead, a clear recovery of the Fucus community, although not yet completed, could be demonstrated. Studies of the composition, abundance and biomass of the fish community, the recruitment and survival of fish fry, and the physiological status of perch, using a set of biomarkers, revealed that even in the most BKME-exposed area, only minor effects were detected. These effects were related to eutrophication/enrichment rather than to the action of toxic substances. The general effect picture, thus, was essentially of a different type than the one recorded in previous studies of mills, which used older technology and less effective process and effluent treatment control, and which were discharging into enclosed, shallow bays of the Baltic Sea.

Since 1988, the State of Maine has monitored dioxin levels in the tissues of predatory and bottom feeding species of fish taken from the state's major water bodies, including five rivers which receive the effluent of bleached kraft paper mills. Data are also available on dioxin concentrations in the effluent of these mills. Monitoring results were analyzed using simple models to yield field bioaccumulation factors (BAFs) for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Maine rivers. Three BAFs were computed for each fish species at each site to account for declining TCDD levels in mill effluents over time. Mean BAFs (across rivers) ranged from 11,500 to 24,600 for smallmouth bass fillets, from 17,900 to 28,300 for brown trout fillets, from 3000 to 7500 for white perch fillets, and from 78,500 to 106,000 for white sucker whole bodies. Field BAFs obtained in this analysis are similar to factors obtained in recent laboratory studies of TCDD accumulation in fish. Our results suggest that EPA's currently recommended BCF value of 5000 is probably too low. Instead, a value between 15,000 and 25,000 is considered a reasonable estimate of the BAF to use for regulatory purposes in the state of Maine.

Fish populations residing in a river receiving bleached kraft mill effluents (BKME) and in an uncontaminated river were investigated to evaluate causal relationships between exposure to BKME and various indicators of fish health. The Index of Biotic Integrity demonstrated that species richness and composition were much lower in the contaminated river with an obvious imbalance in the trophic structure of the fish community. Biomolecular and biochemical responses such as DNA damage and elevated activity of detoxification enzymes indicated that fish in the contaminated river had been exposed to toxicants. The status of various condition indices such as the liver and visceral somatic indices suggested metabolic and nutritional imbalances in sunfish as a result of exposure to pulp mill effluents. Fish populations in the contaminated river also demonstrated an abnormal size distribution and age structure. Female redbreast sunfish from the BKME-impacted river contained a large number of atretic oocytes and had lower serum levels of estradiol than fish from the reference site. These observations plus data from previous developmental toxicity studies suggest that the primary mechanism by which BKME may affect fish populations in this river is through reproductive dysfunction and recruitment failure. Decreased recruitment may have caused a reduction in population size and resulted in decreased competition and increased resource availability. With increased food and habitat availability, more energy may have been available for growth and lipid storage of survivors in the contaminated river.

Our recent studies have demonstrated reproductive problems in white sucker (Catostomus commersoni) exposed to bleached kraft pulp mill effluent (BKME) at Jackfish Bay on Lake Superior. These fish exhibit delayed sexual maturity, reduced gonadal size, reduced secondary sexual characteristics, and circulating steroid levels depressed relative to those of reference populations. The present studies were designed to evaluate sites in the pituitary-gonadal axis of prespawning white sucker affected by BKME exposure. At the time of entry to the spawning stream, plasma levels of immunoreactive gonadotropin (GtH)-II (LH-type GtH) in male and female white sucker were 30- and 50-fold lower, respectively, than the levels in fish from a reference site. A single intraperitoneal injection of D-Arg6, Pro9N-Et sGnRH (sGnRH-A, 0.1 mg/kg) increased plasma GtH levels in male and female fish at both sites, although the magnitude of the response was greatly reduced in BKME-exposed fish. Fish at the BKME site did not ovulate in response to sGnRH-A, while 10 of 10 fish from the reference site ovulated within 6 hr. Plasma 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17,20 beta-P) levels were depressed in BKME-exposed fish and unlike fish at the reference site, failed to increase in response to sGnRH-A. Testosterone levels in both sexes and 11-ketostestosterone levels in males were elevated in fish from the reference site but were not further increased by GnRH treatment. In contrast, BKME-exposed fish exhibit a transitory increase in testosterone levels in response to the GnRH analog. In vitro incubations of ovarian follicles obtained from fish at the BKME site revealed depressed basal secretion of testosterone and 17,20 beta-P and reduced responsiveness to the GtH analog human chorionic gonadotropin and to forskolin, a direct activator of adenylate cyclase. By comparison, ovarian follicles from fish collected at BKME and reference sites produced similar levels of prostaglandin E basally and in response to a phorbol ester and calcium ionophore A23187, suggesting that BKME effects on ovarian function are selective and do not reflect a general impairment of ovarian function. BKME-exposed fish had plasma levels of testosterone glucuronide proportionately lower than those of reference fish, suggesting that there are site differences in the peripheral metabolism of steroids. These studies demonstrate that BKME exposure affects reproduction by acting at multiple sites in the pituitary-gonadal axis.

Surface distribution of Nipigon Bay larval fish was characterized by high abundance, between 500 and 2100 larval fish/10,000 m3 near shore, particularly in proximity to the pulp and paper mill effluent discharge, and low abundance, less than 100/10,000 m3 away from shore. Static bioassay indicated that approximately 60% effluent concentration was intolerable to the natural mixed larval fish community. No wood fibre was found among stomach contents and no difference was apparent in stomach contents of fish caught in influenced and uninfluenced areas. Data therefore suggest that larval fish either were not greatly influenced by plume conditions or were transients.

The effects of tetrachloro-1,2-benzoquinone (TCQ), a component in bleached kraft mill effluents (BKME), on vertebral and physiological parameters were investigated in juvenile fourhorn sculpin, Myoxocephalus quadricornis L. After about 4.5 months of exposure to 0.1 and 0.5 mg TCQ/liter in 7% salinity brackish water, the fish demonstrated vertebral deformities, aberrant mechanical properties of the vertebrae, effects on white and red blood cell counts, enhanced activity of delta-aminolevulinic acid dehydratase in erythrocytes, and increased levels of ascorbic acid in the liver. The effects are discussed in relation to those previously observed in fish exposed to complex BKME in the field and the laboratory.

In a laboratory investigation fourhorn sculpin (Myoxocephalus quadricornis) were exposed for 5-9 months to wastewater from pine and birch lines from a bleached kraft pulp plant. This long-term exposure to bleached kraft mill effluent (BKME) affected the hematology, the ion balance, and the vertebral structure. Decreased values for hematocrit and hemoglobin and a reduced red blood cell count, as well as increased levels of methemoglobin, indicated disturbances in the red blood cell status. The white blood cell picture was not significantly affected by the BKME exposure. Decreased levels of potassium and chloride ions in the blood plasma in some of the exposed fish suggest an impaired ability to maintain ion homeostasis. Elevated frequencies of vertebral deformations in fish exposed to BKME confirm previous observations of vertebral damage in feral fourhorn sculpin caught in the receiving body of water of the same bleached kraft pulp industry. Many of the parameters analyzed in this investigation may be used as health indicators in future laboratory and field studies on fish exposed to BKME.

In a laboratory investigation, fourhorn sculpin (Myoxocephalus quadricornis) were exposed for 5-9 months to waste water from pine and birch lines from a bleached kraft pulp plant. The bleached kraft mill effluents (BKME) affected both the carbohydrate metabolism and the xenobiotic metabolism. Thus, an elevated muscle glycogen content in fish exposed to effluent from the pine pulp line suggests a metabolic imbalance. A liver enlargement and a strong elevation of the hepatic cytochrome P-450-dependent ethoxyresorufin-O-deethylase activity after exposure to the bleached pine pulp effluents indicate the presence of cytochrome P-450-inducing agents in the BKME. The results also demonstrate that many physiological test parameters may be used as good indicators of sublethal disturbances in fish to BKME exposure.

Hepatic monooxygenase (MO) and conjugation enzyme activities, metabolites of chlorinated phenolics in the bile, and blood ionoregulatory parameters were studied in juvenile whitefish (Coregonus muksun Pallas and C. muksun X Coregonus peled Gmelin hybrid) held in cages downstream from a mill producing chlorine-bleached kraft pulp and printing paper. MO activities, measured as benzo[a]pyrene hydroxylase, 7-ethoxycoumarin O-deethylase, and 7-ethoxyresorufin O-deethylase, were significantly induced in whitefish caged about 5 km from the effluent outlet. The highest mean increase detected was 17 times the control value. In the nearest caging station (3 km) the induction was lower, indicating inhibition or toxicity caused by the effluent. The levels of bile metabolites of chlorinated phenolics showed highest concentrations at the nearest station and decreased levels at more distant locations over the whole water area studied (15 km). Bile metabolites in whitefish exposed in control areas confirmed low-level background pollution of the lake system due to chlorinated phenolics. Observations on blood ionic concentrations suggest that whitefish were able to regulate their hydromineral balance despite the environmental pollution affecting physiology of biotransformation.