Fish Health, Pesticides and Endocrine Disruptors

Transcription

1 Fish Health, Pesticides and Endocrine Disruptors Vicki Blazer, PhD U.S. Geological Survey National Fish Health Research Laboratory Leetown Science Center, Kearneysville, WV

2 Fish Health Issues! 2003 first indications of major fish kills in the South Branch, Potomac! first observations of major kills in the North Fork and South Fork Shenandoah! 2009 major kill in the Monocacy! State agencies estimated losses of >60% of the adult bass populations in affected stretches of the rivers in first few years! Primarily centrarchids (smallmouth bass, sunfish) but also suckers, rock bass, etc.! Still have lesions and low chronic mortality

3 Adult Fish in the Potomac - Findings! Multiple bacterial pathogens, but no consistent findings! Aeromonas hydrophila and other motile Aeromonads! Aeromonas salmonicida! Flavobacterium columnare! Multiple, often heavy parasite infestations! Leeches, trematodes, myxozoans, cestodes! Opportunistic fungal infections! Skin papillomas! Largemouth Bass Virus! High prevalence of intersex, vitellogenin in male fishes Impaired Ecosystem Immunosuppression

4 Fish Health Issues Susquehanna River! 2005 mortalities of young-of-year! Demonstrated population declines! Adults have variety of skin lesions although fish kills have not been reported! Adult males have a high prevalence and severity of intersex

5 Middle Susquehanna River (Sunbury to York Haven Dam) YOY SMB cpue MEDIAN 25 fish/ 50m

6 Organisms Observed in YOY Susquehanna! Aeromonas hydrophila and other motile Aeromonads! Flavobacterium columnare! Largemouth Bass Virus! Trematodes! Myxozoan parasites

7 Overview of Findings Biological! Intersex is widely distributed in bass (smallmouth, largemouth) in the Potomac and Susquehanna drainages! Prevalence and severity at many sites is greater than we see at most other sites nationally Species differences (metabolic, life styles) Seasonal differences in intersex and Vtg! Intersex bass had significantly less sperm, less motile! Prevalence of intersex was not higher downstream of WWTP

8 Integrative Approach! Biological effects in wild fishes! Visual observations, microscopic pathology, parasitology, plasma hormone/vitellogenin, gene expression! In vitro, cell-based reporter assays! BLYES total estrogenicity, other yeast assays! Nuclear translocation assays NIH-NCI! Chemical analyses water, sediment, fish tissue! Grab water samples, integrated passive water samplers! GIS land cover, land use etc.! Telemetry fish movement

9 Factors to Consider Temporal nature of chemical exposures climatic and other factors that influence exposure Exposure pathways during critical life stage.

10 Correlations with Landuse and Chemicals PA Drainages Evaluated smallmouth bass and white sucker at 16 sites in three river drainages in the summer (low flow) Chemical Contaminants or Landuse Intersex Prevalence rho p Intersex Severity rho p Estrone (water) Agricultural landuse WWTP/sewage facilities Prevalence of males with vitellogenin Estrone (water)

11 Intersex and Land-use Spring Pre-spawn Study Potomac Landuse Characteristics Intersex Prevalence Intersex Severity r 2 p r 2 p Human population # WWTP WWTP flow Percent agriculture # Animal feeding operations Total animal numbers Animal density Poultry Houses

12 Results - Discrete Water 39 of 200 compounds detected (20%) Atrazine 86% herbicide Deethylatrazine 86 herbicide degradate Caffeine 86 stimulant Simazine 86 herbicide Iso-CT 71 antibiotic degradate Metolachlor 71 herbicide Epi-iso-CT 57 antibiotic degradate Galaxolide 57 fragrance Tetracycline 57 antibiotic Oxytetracycline 43 antibiotic

13 Results Passive Water 100 of 161 compounds detected (62%) Chlorpyrifos 100% insecticide Diazinon 100 insecticide Dieldrin 100 insecticide Androstenedione 80 biogenic hormone 17α-estradiol 60 biogenic hormone Estrone 60 biogenic hormone Triclosan 60 antimicrobial disinfectant 17β-estradiol 40 biogenic hormone 41 compounds detected via passive samplers were not found in discrete water samples

14 Results Bed Sediment 46 of 130 compounds detected (35%) Caffeine 100% stimulant Cholesterol 100 plant/animal sterol Indole 100 fragrance p-cresol 100 wood preservative sitosterol 100 plant sterol PCBs 86 industrial compound Stigmastanol 86 plant sterol Trans-chlordane 86 insectide Trans-nonachlor 86 insecticide Dieldrin 71 insecticide Estrone 71 biogenic hormone

15 Sediment Chemical Results 6 5 Intersex Metric* ρ = 0.986, p< Total Biogenic Hormone+Sterol, in µg/kg

16 Water Results Chemicals and TO 6 Intersex Metric* ρ = 0.868, p = Number of Herbicides Detected in Water

17 Intersex and Chemical Contaminants Spawning Study Chemical Contaminants Intersex Prevalence Intersex Severity rho P rho p Atrazine Deethylatrazine Acetochlor Metolachlor

18 Shenandoah Small Tributary Study Land-use Characteristics Estrogenicity rho p % Forest % Pasture/ Hay % Crop % Developed Poultry Density Beef Density Dairy Density WWTP (MGD) No fish data Total estrogenicity based on the estrogen equivalents using the BLYES POCIS pesticides (26 total) Estrogenicity rho Desethylatrazine Metolachlor Atrazine Simazine p

19 Correlations of Intersex and Estrogenicity with Herbicides! Is there some type of synergy with the herbicides and co-occurring contaminants?! Does the use of herbicides lead to high levels of phytoestrogens or algal products in the water/sediment?

20 Correlations of Herbicides with Intersex and Estrogenicity Atrazine has been associated with intersex in frogs controversial Atrazine is not thought to bind to the estrogen receptor Has been shown to alter phytoplankton and algal populations, increase trematode infections and cause immunosuppression Could algal/cyanobacteria and their toxins be contributing to endocrine disruption and fish health issues

21 Potential Association of Atrazine and Health! Atrazine augments the richness and abundance of gastropods! Intermediate hosts for trematode parasites! Atrazine and other herbicides decrease phytoplankton which tend to increase periphytic algae! Increase the abundance of the cercariae (infective stage of trematodes for fish and amphibians! Low doses of atrazine have been shown to be immunosuppressive in frogs, fish and salamanders! Exposure increased susceptibility to A. hydrophila infections in fish and viral infections in salamanders

22 Current Studies! Identifying most important agricultural sources and potential management actions! 13 sites in the Potomac and Susquehanna with varying intensity and types of ag! Biological responses in adult and young-of-year bass! Comprehensive chemical analyses of water, sediment and fish tissue! Coordinating with the water quality investigations in show case watersheds to assess temporal and spatial changes in hormone activities (estrogenic, androgenic, glucocorticoid)! Studies on association of lesions, estrogenicity with algal populations and algal toxins

23 Current Studies! Identifying pathways and timing of exposures! Adults water, sediment during nest-building and guarding, food web! Young maternal sources through the egg, water and sediment in the nesting areas! Two potentially important exposure periods:! Reproductive cycle in late summer/early fall recrudescence begins. Germ cells undergo division and begin development into eggs and sperm. Yolk begins to be incorporated into the egg.! Fry as they go through sexual differentiation! Chemical analyses of eggs immediately prior to spawn as well as young

24 Temporal Studies! Understanding temporal changes within a year and between years! Hormone activity passive samplers, grab water South Branch (3 sites); 4 sites MD mainstem sites 2011 and South Branch Seneca Falls Dep1 Dep 2 Dep 3 Dep 4 Dep5 Dep6 3/8-4/27 4/27 6/7 6/7 7/18 7/18 9/13 9/13-10/19 10/19 11/28

25 Young of Year Smallmouth Bass Tissue Analyses! Compared whole body contaminants! 10 fish from LSC ponds and 16 fish from two sites on the Susquehanna! Suite of organic contaminants including pesticides (legacy and current-use), PCBs, BDE, triclosan! LSC ponds mean # of detects was 4 (range 2-5)! BDE 99, BDE 200, PCB 180, hexachlorobenzene! Susquehanna mean # of detect was 19 (range 14-28)! BDE 47, 7 PCBs, dieldrin, chlorpyrifos, nonachlors, chlordanes, pentachloroanisole, triclosan, pyraclostrobin

26 Herbicide Concentrations (ng/l) Monocacy Big Pipe Creek Storm Storm Storm Dates Atrazine Metolachlor Simazine May 15, June 8, June 11, July 11, Aug 28, April 4, April 14, April 25, April 30, May 12, May 16, May 30,

27 Conclusions! Hormone activity animal and potentially plant sterols, estrogenic chemicals as well as pesticides appear to be associated with intersex and adverse health affects in fish! Need to better understand specific sources, how these chemicals interact in the complex mixtures fish are exposed to, the factors affecting temporal changes in chemical concentrations and hormone activity, timing of exposure and the factors contributing to species differences in sensitivity