Progress 07/01/02 to 06/30/09
Outputs
OUTPUTS: A custom microarray (22,000 genes) was used for this study that included specific gene sequences we generated for fathead minnows by suppressive subtractive hybridization, in addition to sequences that were publicly available. The array was used to test model compounds ethinylestradiol (EE2) and trenbolone (TB) and fish exposed to effluents at 6 different field sites. The results show specific gene expression profiles for the model compounds and for the 6 different sites. We analyzed liver and gonads for gene expression changes by microarray and obtained specific patterns of gene expression for EE2 and TB in both tissues. In the liver, EE2 altered expression of about 600 genes. In the gonad, the expression of 160 genes was altered including genes important for steroidogenesis. Exposure to TB regulated a totally different set of genes, including about 250 genes in the liver and 350 in the gonad. The expression fingerprints for fish exposed to four different field locations showed unique patterns for fish within each location. Fish at each site showed similar gene expression profiles. Two sites were more closely linked to each other since they were on the same river, up-stream and down-stream from a sewage treatment facility. Changes in gene expression at the down-stream site were consonant with phenotypic observations in endogenous fish collected at this site previously and explained what appeared to be a higher susceptibility of fish to disease. In general, the gene expression profiles were complex and contained elements of both estrogenic and androgenic expression patterns in addition to unique patterns that were specific for each of the sites. This was to be expected since many of the sites were down-stream from municipal water treatment facilities that have complex effluents containing organic compounds, pharmaceuticals and personal care products. One other remarkable result was the variability of estrogenic response at the site immediately below the St. Paul, MN sewage treatment facility. We sampled there twice, once producing the expected pattern for an estrogenic response and once, showing that the effluent was not estrogenic. This variability in observed effects is consonant with a highly variable effluent. This finding suggests that gene array analysis may be a good substitute for chemical analysis, as a monitoring tool. TARGET AUDIENCES: The field of toxicogenomics is exploding. There are many new efforts to use this type of approach to understand the molecular effects of exposures to contaminants. Major efforts are underway in the US, Europe and Japan. The field is still in its infancy and will evolve as new information is gathered. The information that we have derived is cited in many manuscripts and is the basis upon which other research will be designed. PARTICIPANTS: Natalia Garcia-Reyero, Li Liuc, Nancy Denslow--Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville FL 32611 Candice Lavelle--Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, MN 55108 Dalma Martinovic--U.S. Environmental Protection Agency, Mid-Continent Laboratory, Congdon Blvd., Duluth, MN TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Gene expression patterns for estrogen (ethinylestradiol) and androgen (trenbolone) model compounds are distinct and complex. Among the genes that are changed are genes that are involved in steroidogenesis, steroid hormone receptor action and metabolism, covering all three modes of action for endocrine disruptors. A 48-h exposure of fish to model compounds or complex effluents is sufficient to elicit changes in gene expression that are prototypical of the effluent. The expression patterns of all fish exposed to an effluent are similar and distinct from expression patterns to different effluents, making specific effluent characterization possible. Expression patterns of fish exposed to effluents up-stream from a sewage treatment facility are closer to the expression patterns of control fish, than for those down-stream of a sewage treatment facility. Changes in gene expression down-stream from a sewage treatment facility showed that innate immune response was the most affected pathway and this was consonant with a higher susceptibility to infection in endogenous fish collected at the same site. This suggests that pathway analyses of gene expression changes may be useful to determine higher order effects in exposed populations. Exposures of fathead minnows to effluents at the same location at two different times suggests that the effluent is complex and varies considerably from one sampling time to the next. This suggests that microarray analysis could complement analytical techniques for effluent monitoring.
Publications
- Garcia-Reyero1, N., I. Adelman, D. Martinovic, and N. Denslow. 2009. Site-specific effects on gene expression in fathead minnows (Pimephales promelas) exposed in situ to sewage treatment plant impacted streams. BMC Bioinformatics.(Submitted for publication)
- Adelman, I.R., L.I. Kusilek, J. Koehle, and J. Hess. 2009. Acute and Chronic Toxicity of Ammonia, Nitrite, and Nitrate to the Endangered Topeka Shiner (Notropis Topeka) and Fathead Minnows (Pimephales promelas). Environmental Chemistry and Toxicology.(Submitted for pulication)
- Woodward, G. 2008. Brain Aromatase Activity, Vitellogenin Induction, and Bio-concentration in Fathead Minnows (Pimephales promelas) Exposed to Nonylphenol during Sexual Differentiation. Master's Thesis. University of Minnesota.
- Garcia-Reyero, N., I. Adelman, L. Liu, and N. Denslow. 2008. Gene expression pro profiles of fathead minnows exposed to surface waters above and below a sewage treatment plant in Minnesota. Marine Environmental Research 66: 134-136.
- Koehle, J. and I.R. Adelman. 2007. The Effects of Temperature, Dissolved Oxygen, and Asian Tapeworm Infection on Growth and Survival of the Topeka shiner Notropis Topeka. Trans. American Fish. Soc 136 (6): 1607-1613.
|
Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: A custom microarray (22,000 genes) was used for this study that included specific gene sequences we generated for fathead minnows by suppressive subtractive hybridization, in addition to sequences that were publicly available. The array was used to test model compounds (ethinylestradiol (EE2) and trenbolone (TB)) and fish exposed to effluents at 6 different field sites. The results show specific gene expression profiles for the model compounds and for the 6 different sites. Male fathead minnows were exposed to EE2 (2, 10, 50 ng/L) and to TB (0.05, 0.5, 5 ug/L) to obtain prototypical gene expression fingerprints. The exposures were for 48 hr. Using tissue samples for the highest concentrations, we analyzed liver and gonads for gene expression changes by microarray. As expected we obtained specific patterns of gene expression for ethinylestradiol and trenbolone in both liver and the gonad. In the liver, EE2 increased gene expression for vitellogenin (Vtg) and estrogen receptor
alpha, as expected and in addition, altered about 600 other genes. In the gonad, the expression of 160 genes was altered including genes important for steroidogenesis, namely steroidogenic acute regulatory protein (StAR), CYP 17, 17?-HSD, 11?-HSD and aromatase. Exposure to TB regulated a totally different set of genes, including about 250 genes in the liver and 350 in the gonad. The expression fingerprints for fish exposed to four different field locations showed unique patterns for fish within each location that differed among the six regions picked (sites 3, 7, 11, 13, 12 and X) for both the liver and the gonad. Fish at each site showed similar gene expression profiles. Sites 11 and 12 were more closely linked to each other since they were on the same river, up-stream and down-stream respectively from a sewage treatment facility. Changes in gene expression at the down-stream site were consonant with phenotypic observations in endogenous fish collected at this site previously and
explained what appeared to be a higher susceptibility of fish to disease. In general, the gene expression profiles were complex and contained elements of both estrogenic and androgenic expression patterns in addition to unique patterns that were specific for each of the sites. This was to be expected since many of the sites were down-stream from municipal water treatment facilities that have complex effluents containing organic compounds, pharmaceuticals and personal care products. One other remarkable result was the variability of estrogenic response at site 3, immediately below the St. Paul, MN sewage treatment facility. We sampled there twice, once producing the expected pattern for an estrogenic response and once, showing that the effluent was not estrogenic. This variability in observed effects is consonant with a highly variable effluent, as found by others. This finding suggests that gene array analysis may be a good substitute for chemical analysis, as a monitoring tool.
PARTICIPANTS: Collaboraators: Natalia Garcia-Reyeroa, Li Liuc, Nancy Denslow--Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville FL 32611 Candice Lavelle, Dalma Martinovic--Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, St. Paul, MN 55108
TARGET AUDIENCES: The field of toxicogenomics is exploding. There are many new efforts to use this type of approach to understand the molecular effects of exposures to contaminants. Major efforts are underway in the US, Europe and Japan. The field is still in its infancy and will evolve as new information is gathered. The information that we have derived from this support is cited in many manuscripts and is the basis upon which other experiments will be designed.
Impacts
Gene expression patterns for estrogen (ethinylestradiol) and androgen (trenbolone) model compounds are distinct and complex. Among the genes that are changed are genes that are involved in steroidogenesis, steroid hormone receptor action and metabolism, covering all three modes of action for endocrine disruptors. A 48-h exposure of fish to model compounds or complex effluents is sufficient to elicit changes in gene expression that are prototypical of the effluent. The expression patterns of all fish exposed to an effluent are similar and distinct from expression patterns to different effluents, making specific effluent characterization possible. Expression patterns of fish exposed to effluents up-stream from a sewage treatment facility are closer to the expression patterns of control fish, than for those down-stream of a sewage treatment facility. Changes in gene expression down-stream from a sewage treatment facility showed that innate immune response was the most
affected pathway and this was consonant with a higher susceptibility to infection in endogenous fish collected at the same site. This suggests that pathway analyses of gene expression changes may be useful to determine higher order effects in exposed populations. Exposures of fathead minnows to effluents at the same location (Site 3) at two different times suggests that the effluent is complex and varies considerably from one sampling time to the next. This suggests that microarray analysis could complement analytical techniques for effluent monitoring.
Publications
- No publications reported this period
|
Progress 01/01/06 to 12/31/06
Outputs
The goal of this project is to develop cDNA microarrays for fathead minnows that will provide a means for early detection of endocrine disrupting chemicals in the aquatic environment, allowing timely remediation to reduce the impact of the contaminants and preserve the health of the ecosystems. The microarrays consist of regulated genes that have been cloned, sequenced, and arrayed on a glass slide. The steps to be taken in achieving the goal are to develop cDNA microarrays of estrogen- and androgen-responsive genes in the fathead minnow and to determine the effectiveness of the microarrays in identifying the presence of estrogens and androgens in the environment. To identify the regulated genes, fathead minnows were exposed to various concentrations of two estrogenic (estradiol and methoxychlor) and two androgenic (trenbolone and ketotesterone) chemicals in the laboratory. Livers and gonads were excised from the fish and subjected to Suppression Subtractive
Hybridization (SSH) to identify genes that were expressed as a result of the exposures. The SSH technique allows comparison of messenger RNA from the exposed fish and control fish to identify genes that were activated by the exposures. The SSH work is completed and the genes that were activated have been identified. Finally, we placed caged fathead minnows in six rivers around Minnesota where we suspected that androgens and estrogens might be present from animal feeding operations or municipal sewage treatment plants. We are almost finished with testing the tissues from these field-exposed fish against the printed microarrays to determine if endocrine disrupting chemicals were present at the field sites.
Impacts
Once the microarrays have been developed and tested, they will be made available to researchers and regulatory agencies so that androgenic and estrogenic chemicals can be identified in the aquatic environment. This will be more effective than chemical analyses because there may be hundreds of chemicals that disrupt endocrine systems. Their collective presence will be identified by the microarrays without having to analyze for individual chemicals.
Publications
- Koehle, J.J. 2006. The effects of high temperature, low dissolved oxygen, and asian tapeworm infection on growth and survival of the Topeka shiner. Master's thesis. University of Minnesota, St. Paul, MN.
|
Progress 01/01/05 to 12/31/05
Outputs
The goal of this project is to develop cDNA microarrays for fathead minnows that will provide a means for early detection of endocrine disrupting chemicals in the aquatic environment, allowing timely remediation to reduce the impact of the contaminants and preserve the health of the ecosystems. The microarrays consist of regulated genes that have been cloned, sequenced, and arrayed on a glass slide. The steps to be taken in achieving the goal are to develop cDNA microarrays of estrogen- and androgen-responsive genes in the fathead minnow and to determine the effectiveness of the microarrays in identifying the presence of estrogens and androgens in the environment. To identify the regulated genes, fathead minnows were exposed to various concentrations of two estrogenic (estradiol and methoxychlor) and two androgenic (trenbolone and ketotesterone) chemicals in the laboratory. Livers and gonads were excised from the fish and subjected to Suppression Subtractive
Hybridization (SSH) to identify genes that were expressed as a result of the exposures. The SSH technique allows comparison of messenger RNA from the exposed fish and control fish to identify genes that were activated by the exposures. The SSH work is about is completed. The next step in the procedure is to identify the genes that have been activated. We are about a third through that process and have thus far identified 450 distinct genes. We will print the microarrays by the end of the year. We will then test them against tissues from the laboratory-exposed fish to determine how the chips respond. Finally, we placed caged fathead minnows in six rivers around Minnesota where we suspected that androgens and estrogens might be present from animal feeding operations or municipal sewage treatment plants. We will test tissues from these field-exposed fish against the printed microarrays to determine if endocrine disrupting chemicals were present at the field sites.
Impacts
Once the microarrays have been developed and tested, they will be made available to researchers and regulatory agencies so that androgenic and estrogenic chemicals can be identified in the aquatic environment. This will be more effective than chemical analyses because there may be hundreds of chemicals that disrupt endocrine systems. Their collective presence will be identified by the microarrays without having to analyze for individual chemicals.
Publications
- No publications reported this period
|
Progress 01/01/04 to 12/31/04
Outputs
The goal of this project is to develop cDNA microarrays for fathead minnows that will provide a means for early detection of endocrine disrupting chemicals in the aquatic environment, allowing timely remediation to reduce the impact of the contaminants and preserve the health of the ecosystems. The microarrays consist of regulated genes that have been cloned, sequenced, and arrayed on a glass slide. The steps to be taken in achieving the goal are to develop cDNA microarrays of estrogen- and androgen-responsive genes in the fathead minnow and to determine the effectiveness of the microarrays in identifying the presence of estrogens and androgens in the environment. To identify the regulated genes, fathead minnows were exposed to various concentrations of two estrogenic (estradiol and methoxychlor) and two androgenic (trenbolone and ketotesterone) chemicals in the laboratory. Livers and gonads were excised from the fish and subjected to Suppression Subtractive
Hybridization (SSH) to identify genes that were expressed as a result of the exposures. The SSH technique allows comparison of messenger RNA from the exposed fish and control fish to identify genes that were activated by the exposures. The SSH work is about 2/3 completed. The next step in the procedure is to identify the genes that have been activated. We are about a third through that process and have thus far identified 226 distinct genes. Extrapolating from these initial results, we should have over 500 distinct genes to array. Following that we will design the microarrays and print them. We will then test them against tissues from the laboratory-exposed fish to determine how the chips respond, and finally we will test tissues from the field-exposed fish to determine if endocrine disrupting chemicals were present at the field sites.
Impacts
Once the microarrays have been developed and tested, they will be made available to researchers and regulatory agencies so that androgenic and estrogenic chemicals can be identified in the aquatic environment. This will be more effective than chemical analyses because there may be hundreds of chemicals that disrupt endocrine systems. Their collective presence will be identified by the microarrays without having to analyze for individual chemicals.
Publications
- George, L.J. 2004. The influence of temporal and spatial variation in nearshore fish species richness on an index of biotic integrity for lakes. Master's Thesis. University of Minnesota, St. Paul, MN.
- Bacigalupi, J. N. 2004. Effects of estrogenic compounds on walleye, Sander vitreus, near the metropolitan sewage treatment plant, Saint Paul, Minnesota. Master's Thesis. University of Minnesota, St. Paul, MN.
|
Progress 01/01/03 to 12/31/03
Outputs
Work on determining the relationship between induction of vitellogenin (VTG) by the Twin Cities Metropolitan Sewage Treatment Plant (STP) effluent on reproductive success of walleye (Sander vitreus) has been completed. Elevated levels of VTG, a female egg yolk protein precursor, have been measured in male fish from the Metro STP effluent, confirming exposure to estrogenic compounds. This research attempted to determine if those estrogenic compounds had a significant effect on the reproductive potential of male walleye exposed to the effluent. Estrogenic compounds, estradiol, estrone, and nonylphenol were detected in Metro STP effluent water near or below minimum detectable levels and levels of alkyphenols in walleye whole body tissues were below minimum detectable levels. In 2000, 2001, and 2002 walleye were collected from the Metro STP effluent channel and a reference site 17 km upstream prior to and during the spawning season. Male walleye collected from the Metro
STP effluent channel had elevated VTG and estradiol levels, decreased gonad size and testosterone levels, and no expressible milt. Upstream reference site males had low VTG and estradiol concentrations, larger GSIs, lower testosterone levels, and expressible milt. The effect of the temperature of the effluent on expression of milt was studied with laboratory exposures of males that were expressing milt at the start of the exposure. In these exposures, temperature did not affect expression of milt or sperm density. Laboratory exposure to the Metro STP effluent resulted in decreased sperm density in male fish but did not eliminate milt expression. The reproductive potential of the male walleye may have been affected by exposure to the Metro STP effluent. Although the males from the effluent channel clearly showed effects of exposure to estrogenic compounds, we could not determine whether the severe abnormality of lack of milt expression was caused by estrogenic compounds or water
temperature. Work on developing cDNA microarrays of estrogen- and androgen-responsive genes for the fathead minnow is underway with exposures to both estrogens and one of two androgens completed. Development of the microarrays is proceeding in the Kapur lab (University of Minnesota) and Denslow lab (University of Florida).
Impacts
Although exposure of walleyes to the Twin Cities Metropolitan Sewage Treatmen Plant effluent affects the reproductive potential of walleye, affected fish probably comprise a small percentage of pool 2 fish. Thus, walleye population abundance is unlikely to be affected by the effluent. Remedial measures to reduce or eliminate the problem causing estrogenic compounds, at least with respect to walleye, do not appear to be warranted at this time.
Publications
- No publications reported this period
|
Progress 01/01/02 to 12/31/02
Outputs
Work on determining the relationship between induction of VTG by the Twin Cities Metropolitan Sewage Treatment Plant (STP) effluent on reproductive success of walleye (Stizostedion vitreum) is nearing completion. Endocrine disrupting compounds (EDCs) appear to be affecting the reproductive physiology of males and females exposed to the STP effluent. During the pre-spawning and spawning periods of 2000, 2001 and 2002, male walleye collected from the Metro STP effluent channel had elevated vitellogenin (VTG) levels, no expressible milt, and reduced gonad size, while upstream males had low VTG concentrations and expressible milt. VTG in male fish is an indicator of exposure to estrogenic compounds (compounds acting like female hormones). Male walleye sampled from the STP effluent channel also had elevated levels of serum estradiol (characteristic of females) and depressed levels of testosterone, while 11-ketotestosterone levels (characteristic of males) were not
significantly different from the upstream site. Female walleye were found with atretic ovaries at the Metro STP and the upstream site. The causes of these apparent reproductive abnormalities cannot yet be clearly attributed to the presence of EDCs in the effluent. The elevated VTG levels indicate exposure, but we are still uncertain if it is the EDCs that are causing the observed effects, aside from induction of VTG in males. Winter temperatures of the effluent water are considerably higher than river water temperatures and abnormal winter temperatures could interfere with reproductive development. In the coming year we will expose male walleye collected in the field and expressing milt at time of capture to cold and warm temperatures in the laboratory to see if the warm temperature shuts down milt production. Experiments to determine the degree of bioconcentration of nonylphenol and relate that to VTG induction and reproductive success are underway, but no results are available yet.
Work on developing cDNA microarrays of estrogen- and androgen-responsive genes for the fathead minnow will get underway next summer.
Impacts
This project will help us to understand whether or not environmental pollutants that act as hormones are impacting reproductive success of fish. If so, measures will need to be taken to prevent the addition of these hormone-like pollutants to public waters in order to protect fishery resources.
Publications
- Eldridge, W.H., M.D. Bacigalupi, I.R. Adelman, L.M. Miller, and A.R. Kapuscinski. 2002. Determination of relative survival of two stocked walleye populations and resident natural origin fish by microsatellite DNA parentage assignment. Canadian Journal of Fisheries and Aquatic Sciences 59: 282-290.
- Levitt, James T. 2001 Effects of environmental estrogens on walleye and common carp reproduction near a metropolitan sewage treatment plant, St. Paul, Minnesota. Master's thesis. University of Minnesota, St. Paul, MN.
|
Progress 01/01/01 to 12/31/01
Outputs
Our objective is to determine if reproduction of walleye (Stizostedion vitreum) and carp (Cyprinus carpio)from the vicinity of the Twin Cities Metropolitan Sewage Treatment Plant (STP) effluent channel is affected by putative estrogenic compounds (pollutants acting as female sex hormones). With regard to walleye, endocrine disrupting chemicals may be affecting the reproductive physiology of males and females exposed to the STP effluent. During the pre-spawning and spawning periods of 2000 and 2001, male walleye collected from the Metro STP effluent channel had elevated vitellogenin (VTG) levels, no expressible milt and one case of intersexed testes, while upstream males had low VTG concentrations and expressible milt. VTG in male fish is an indicator of exposure to estrogenic compounds. Male walleye sampled from the STP effluent channel also had elevated levels of serum estradiol (characteristic of females) while 11-ketotestosterone levels (characteristic of males)
were not significantly different from the upstream site. Female walleye were found with atretic ovaries at the Metro STP and the reference site. The causes of these apparent reproductive abnormalities cannot yet be clearly attributed to the presence of estrogenic compounds in the effluent. The elevated VTG levels indicate exposure, but we are still uncertain if it is the endocrine disrupters that are causing the observed effects, aside from induction of VTG in males. Winter temperatures of the effluent water are considerably higher than river water temperatures and abnormal winter temperatures could interfere with reproductive development. In the coming year we will use a thermal effluent from a power plant as a reference site--warm water but little likelihood of estrogenic compounds. During the carp spawning season, male carp sampled at the STP channel had significantly elevated levels of VTG. Computer assisted sperm analysis of carp milt did not reveal significant differences in the
quality of sperm being produced but a trend toward decreased total number of sperm cells and motile cells was found. These preliminary findings address the need for further investigation into the effects of the effluent on gonadal histopathology, sex steroid concentrations, intersex, and reproductive potential of exposed fish.
Impacts
Findings thus far have raised concerns that the Metro Waste Treatment Plant is releasing endocrine disrupting chemical that are impacting fish reproduction. However, to date, we have not been able to verify a direct link between the reproductive abnormalities we have seen and the presence of endocrine disrupting compounds in the efflect. Other environmental factors, namely temperature, may be involved in causing the abnormalities. Future work will attempt to establish causation.
Publications
- Levitt, J.T., H. Schoenfus, and I.R. Adelman. 2001. Possible effects of endocrine disrupting compounds on walleye near the Metro Sewage Treatment Plant, St. Paul, MN. Pages 191-202 in R. Masters, ed. Proceedings 2nd International Conference on Pharmaceuticals and Endocrine Disrupting Chemicals in Water. National Ground Water Assoc. Westerville, OH.
|
Progress 01/01/00 to 12/31/00
Outputs
Our objective was to determine if reproduction of walleye and carp from the vicinity of the Twin Cities Metropolitan Sewage Treatment Plant (STP) effluent channel was affected by putative estrogenic compounds (pollutants acting as female sex hormones). During the spring 1999 walleye spawning season, we collected fish from the STP channel and from about 11 miles upstream. MN DNR also obtained information on milt production for us from fish taken from about 35 miles downstream.We intended to artificially breed the male walleye from the STP channel with a reference group of unexposed female walleye that we had purchased from a commercial grower. We could not strip milt from any of the 14 male walleyes that we captured from the effluent channel at any time; not immediately after capture, not after being held in the tanks for up to a month, and not after hormone injections to stimulate final maturation. All of these males had very high levels of vitellogenin (VTG), an egg
yolk protein normally found only in females but frequently present in males exposed to estrogenic compounds. Of the 6 male walleye from the upstream site, 83% had running milt. VTG levels in these fish ranged from none to moderate. Interestingly, the one male that did not produce milt had the highest VTG concentration. Of the 19 male walleyes examined by DNR, 90% produced milt. VTG analyses were not done on these fish. Because walleye from the channel did not produce milt, the breeding experiments could not be done. We have four hypotheses, which will be investigated in the next year, as to why the walleye didn't produce milt: 1) We were too late. Because of the warm water in the effluent channel, the fish may have spawned before our first sampling. 2)The walleye were in an arrested state of sexual development because of the warm water in the channel throughout the winter. 3) Estrogenic compounds arrested these fish in an early state of sexual development. 4) Chemicals other than
estrogenic compounds arrested the fish in an early state of sexual development. During the 2000 carp spawning season, we collected male carp from the STP channel and males and females from about 60 miles upstream. The latter were to be our reference fish for the breeding experiments. Because we were unable to obtain good eggs from the females, even after a hormone injection to stimulate ovulation, we used a sperm analyzer to compare sperm quality of the STP and upstream males. There was no detectable difference in sperm quality. The logistics of getting males from the STP site, along with males and females from a reference site that are in the same state of sexual maturation at the same time, proved very difficult to accomplish. Thus our chances of conducting fertilization experiments in 2001 are very uncertain. Given the far greater societal interest in sustainable walleye populations, we will focus on that species and discontinue work on carp.
Impacts
It is possible, although not yet verified by the research, that reproduction of an important game fish species, walleye, is being impacted by the Twin Cities Metropolitan Waste Treatment Plant. If verified, the population of walleye in Mississippi River Pool 2 could be affected and the sewage treatment plant may have to undertake remedial measures to reduce or eliminate the problem causing chemical(s).
Publications
- BACIGALUPI, M. D. 2000. Growth and survival of two populations of stocked walleye and naturally spawned walleye in the same lakes. M.S. Thesis. University of Minnesota.
- ADELMAN, I.R. 2000. Fish testing below metro sewage plant underway. Advocate Update 26: 7.
- MILLER, D. and I. R. ADELMAN. 2000. Changes in the professional certification program. Fisheries 25: 34.
|
Progress 01/01/99 to 12/31/99
Outputs
This new project began in July 1999 and all work thus far has been preparatory for the upcoming field season. Progress to date includes exploring locations in the vicinity of the Twin Cities Sewage Treatment Plant (STP) to determine where fish might be captured to determine the effect of environmental estrogens on their reproductive success. Walleye and carp will be captured during their upcoming spawning seasons and fish that show exposure to estrogenic compounds through the presence of vitellogenin, a bioindicator of exposure, will be artificially mated with each other and with control fish. In the laboratory, experiments are underway to determine the appropriate sperm concentration to use in the artificial matings. Also in the laboratory we are verifying that an assay for cyprinid vitellogenin will be effective with walleye.
Impacts
(N/A)
Publications
- ADELMAN, I.R. and B.W. MENZEL. 1999. An Inter-university partnership in distance education. Trans. 64th North Amer. Wildl. & Nat. Resources Conf. Pp 378-392.
|
|