More wildlife fish are experiencing ‘intersex’. What could be causing this?

Strange reproductive anomalies are more common in wildlife, but why? The U.S. Geological Survey released a study last year that showed that the U.S. Fish and Wildlife Service (USFW), tested male smallmouth and largemouth basses from 19 National Wildlife Refuges. The Researchers found that The smallmouth bass had signs of female reproductive organs in 85%. The largemouth bass had 27% intersex. This could be caused by a number of factors.

Luke Iwanowicz is a USGS research biologist, and the lead author of this paper.

“It isn’t clear what causes intersex in these fish. This study was intended to identify potential areas that warrant further investigation. Chemical analyses of fish or water samples at collection sites were not conducted, so we cannot attribute the observation of intersex to specific, known estrogenic endocrine–disrupting chemicals.”

Fred Pinkney, a USFWS contaminants biologist, and study coauthor, refers to an older study that examined Intersex occurrences in freshwater fishes in America between 1995 and 2004.

The results of the new study reveal that refuge lands are contaminated with endocrine disrupting chemical substances. They use bass to indicate exposures that could affect fish and other aquatic species. The U.S. has taken steps to address this problem. The Fish and Wildlife Service encourages management practices that reduce runoff from streams, ponds and lake — on and off refuge lands.

Potential Chemical-Culprits

Pinkney pointed out that chemical runoff could pose a problem. These reproductive problems could be caused by a variety of chemicals and contaminants, including:

Monsanto & Syngenta produce two agricultural chemicals, glyphosate et atrazine. These chemicals are widely used and can leak into U.S. streams, lakes, streams, and reservoirs. Multiple studies have also shown that they are toxic. are endocrine disruptors This could negatively impact reproductivity. [1]

According to a Fact sheet on atrazine Michigan State University

Atrazine can be used to treat crops like sugarcane, corn and pineapples as well as on evergreen tree farms for regrowth and evergreen forest growth. It can also be used to prevent weeds growing on railroad and highway rights-of-way. You can spray atrazine on croplands before they start to grow and after they emerge from the soil.

The herbicide seeps into waterways and lakes. Some of the herbicide moves below the soil surface and into the deeper soil layers where it can contaminate the groundwater.

MSU continues to:

“There are very few studies that have examined the effects of atrazine on human health. These reports indicate that atrazine may cause premature births or slow growth in pregnant women. These effects may have been caused by other chemicals, however, as the women involved in the studies were also exposed to other chemicals.

Animal studies have shown that Atrazine can cause blood hormone changes in animals. These effects could affect ovulation and reproductive ability. Because of differences in biological biology between humans and these animals, these effects are unlikely to occur in humans. Animal studies have shown that atrazine can cause liver, kidney and heart problems in some animals. However, this possibility has not been explored in detail.

Glyphosate The other hormone disruptor has been It can be found in urine, blood, and breast milkAs Three studies have confirmed this conclusion. Monsanto, a biotechnology company, is not. The evidence is refuted Based on non-human studies, there have been other studies that show glyphosate could cause problems in reproduction. These include studies on female Jundia, Zebrafish and Rats. [2] [3] [4]

Still, some research It may not be the most serious culprit.:

“Our primary goal was to assess the stress response of juenile largemouth Bass, micropterus saltmoides, to aquatic herbicides diquat, endothall 2,4-D and fluridone (Rodeo).

Analyses of glucose and osmolality levels revealed that each herbicide had a different intensity and rate of stress response. These differences could also be attributed to the herbicide’s concentration and duration of exposure. Glyphosate was the most effective herbicide in eliciting the bass’s lowest stress response. This response was independent of either the dose or the exposure period. 2,4-D produced the strongest stress response in bass.

This study suggests that glyphosate, endothall and other aquatic herbicides may be the most stressful to juvenile largemouth bass.

Due to its physicochemical characteristics, such as its low molecular weight (low organic solvent solubility) and its low molecular weight, it has been difficult to determine the amount of glyphosate found in the environment.

However, innovative study A magnetic particle immunoassay was used to determine the presence of glyphosate from groundwater samples taken from Catalonia in Spain. The journal published the results. Analytical and Bioanalytical Chemistry, This is what we found 41% of samples contained glyphosate “above the limit for quantification”. This shows that glyphosate does not rapidly break down in the environment, contrary to manufacturer claims. There are significant amounts of accumulations.”

It is obvious that more research is required.

The study that examined Intersex in freshwater fishes in the U.S. from 1995 to 2004 mentioned other chemicals but didn’t identify them as the cause.

“Total mercury, Trans-nonachlor, p,p‘-DDE, p,p“-DDD and total PCBs were found at the highest levels at all sites. This was regardless of intersex.

We can conclude that these endocrine disruptors are likely to pose a threat to wildlife in our most protected waters, those of our National Wildlife Refuges. Therefore, we need to take additional measures to protect both the environment and the animals.


Environmental Health News


[2] Pubmed/21783773

[3] Pubmed/24364672

[4] ScienceDirect

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