salvelinusfontinalis
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Saw this on Facebook. Dunno how new it is but thought I'd share it here.
I thought some of you interested in the smallmouth issues might find this interesting. This is not speculation about flatheads eating too many fish, or fracking waste coming down and hurting the river. This is the extremely thorough chemical analysis of what is in the water and spawning beds of smallmouth that are seeing sexual mutations and other problems. The study concludes that agricultural runoff is a large contributing factor. All of the dominant mutation-causing chemicals found were from crops and livestock.
In this study from Dr. Blazer of the USGS, they narrowed down some chemicals that occur in high concentrations in the spawning beds, and in the water during spawning. This is called correlation. It doesn't prove that these chemicals are causing our problems, but it does show that these chemicals could be causing the problems, and that they are present in high concentrations at the time when the eggs and fry are particularly vulnerable. These are Estradiol, or female cow hormones; Tetracycline, used mostly in livestock to promote growth; and Atrazine, an herbicide used in growing corn. Here are the conclusions. The study can be purchased by searching for "Chemical contaminants in water and sediment near fish nesting sites in the Potomac River basin: Determining potential exposures to smallmouth bass".
5. Conclusions
The 135 chemicals detected in water and/or bed-sediment samples associated with active SMB nesting sites can originate from various human and animal waste sources (e.g. WWTP, septic systems, animal feeding operations, crop land). These results, in conjunction with the companion study on the biological assessment of SMB at these same sites (Blazer et al., 2012), provide weight-of-evidence that agricultural activities (e.g. crop and livestock production) are important sources of endocrine disrupting chemical exposures to SMB during critical life stages in the Potomac River basin. Such evidence includes: (1) the detection of 17alpha-estradiol (the primary form of estradiol excreted by bovine); (2) the detection of veterinary pharmaceuticals used in animal agriculture (e.g. tetracycline and sulfonamide antibiotic compounds); (3) a statistically significant relation
between dissolved atrazine concentrations in the water column above active SMB nests and TOrank; and (4) a statistically significant relation between biogenic hormone/sterol concentrations in bed sediment
associated with active SMB nests and TOrank. This corroborates previous studies in the Chesapeake Bay watershed (Ciparis et al., 2012) which conclude that a more definitive assessment of the relative contributions of contaminants from agricultural activities is key to understanding the underlying factors causing the observed adverse effects to SMB. Such understanding is critical to making scientifically defensible management decisions regarding overall fish health in the Chesapeake Bay region.
I thought some of you interested in the smallmouth issues might find this interesting. This is not speculation about flatheads eating too many fish, or fracking waste coming down and hurting the river. This is the extremely thorough chemical analysis of what is in the water and spawning beds of smallmouth that are seeing sexual mutations and other problems. The study concludes that agricultural runoff is a large contributing factor. All of the dominant mutation-causing chemicals found were from crops and livestock.
In this study from Dr. Blazer of the USGS, they narrowed down some chemicals that occur in high concentrations in the spawning beds, and in the water during spawning. This is called correlation. It doesn't prove that these chemicals are causing our problems, but it does show that these chemicals could be causing the problems, and that they are present in high concentrations at the time when the eggs and fry are particularly vulnerable. These are Estradiol, or female cow hormones; Tetracycline, used mostly in livestock to promote growth; and Atrazine, an herbicide used in growing corn. Here are the conclusions. The study can be purchased by searching for "Chemical contaminants in water and sediment near fish nesting sites in the Potomac River basin: Determining potential exposures to smallmouth bass".
5. Conclusions
The 135 chemicals detected in water and/or bed-sediment samples associated with active SMB nesting sites can originate from various human and animal waste sources (e.g. WWTP, septic systems, animal feeding operations, crop land). These results, in conjunction with the companion study on the biological assessment of SMB at these same sites (Blazer et al., 2012), provide weight-of-evidence that agricultural activities (e.g. crop and livestock production) are important sources of endocrine disrupting chemical exposures to SMB during critical life stages in the Potomac River basin. Such evidence includes: (1) the detection of 17alpha-estradiol (the primary form of estradiol excreted by bovine); (2) the detection of veterinary pharmaceuticals used in animal agriculture (e.g. tetracycline and sulfonamide antibiotic compounds); (3) a statistically significant relation
between dissolved atrazine concentrations in the water column above active SMB nests and TOrank; and (4) a statistically significant relation between biogenic hormone/sterol concentrations in bed sediment
associated with active SMB nests and TOrank. This corroborates previous studies in the Chesapeake Bay watershed (Ciparis et al., 2012) which conclude that a more definitive assessment of the relative contributions of contaminants from agricultural activities is key to understanding the underlying factors causing the observed adverse effects to SMB. Such understanding is critical to making scientifically defensible management decisions regarding overall fish health in the Chesapeake Bay region.