Water, water everywhere…

May 10th, 2005

Today I had the opportunity to speak with Dr. Thomas Harter, Ph.D, a hydrologist from UC Davis, on my radio program. While he dropped a couple of “bombs” on us regarding the truth about water availability and quality in California, it was what he said after the program that I found really intriguing.

We started talking about the trace quantities of pharmaceuticals that are ending up in our water, since, contrary to popular belief, our bodies don’t absorb everything that we put into them. Whatever doesn’t get absorbed is excreted in our waste. Those waste products sometimes aren’t broken down completely, and can be biologically active. It is a concern of many biologists that the biologically active substances (sex hormones, neurotransmitters, antibiotics, etc.) might affect the reproduction and survival of wild species, especially aquatic animals like fish.

One of Thomas’ grad students recently compared the levels of various hormones in groundwater, the effluent from waste treatment plants, and in salmon spawning areas. There was basically nothing found in the groundwater samples. So, breathe deep that sigh of relief, that means we’re not yet drinking someone else’s birth control prescription.

Hormones were found in the water from waste treatment plants, which does end up in the river and stream systems as they flow out to sea. And, similar amounts of hormones were found in the salmon spawning areas of aquaculture facilities. The interesting catch is that the hormones weren’t from our human waste, they were a product of the horny salmon and their mating activities. The salmon themselves are filling their streams with sex hormones. What does all this mean for us and salmon?

The hormones produced by the salmons’ own natural activities are thought to be a part of the mechanism that allows the fish to return to the same spawning site year after year. The fish may form an imprinted memory of the hormonal scent of the stream site, which they can follow back when it is their turn to reproduce. Great. Makes a nice little story.

The story has the potential for confusion, however, when the hormones released from the waste treatment plants enter the picture. There is no evidence for this yet, but if human hormones were to reach high enough levels they could interfere with salmon migration by muddying the waters, so to speak. An overabundance of hormones in the wrong place could lead to fish confusion, and impair their abilities to find their home grounds.

Additionally, there is the chance that human hormones could have effects on the reproduction or proper development of many different species. Unlike us land-walkers, aquatic animals are enveloped in, breathing and drinking water, and even absorbing it through their skin. There is no question that they will encounter compounds in water. The question is whether and how those compounds will affect them.

Along other lines, I also heard that if the sea levels rise with the onset of global warming that the salty sea water would have an effect on the aquifers supplying low lying coastal communities. The aquifer saline content would increase, and compromise the quality of water being supplied to millions of people. Fantastic.

Anyhow, I can report on all the dismal prospects for the world or I can try to be a little more positive. For myself, I am positive. I recently received a fellowship to work at WNBC-TV for 10 weeks, learning the ins and outs of TV science writing and production. I couldn’t be more thrilled. First, about the job itself, and second, about getting to live in NYC for the duration. I am but a wee country mouse, and this should be quite the city adventure.

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