Today’s Photography 101 topic is practically made for me: water! Here’s my choice of photo:
This is a waterfall on the same creek I shared yesterday, in Sabino Canyon just outside Tucson, AZ. I share it because it’s water, but also bacause it illustrates something important in stream habitats, a natural barrier. This creek is full of crayfish. Crayfish don’t belong in Arizona and every species you can find there is invasive. They compete with native species in the state’s streams and alter the habitats as they burrow into streambeds. I always hated coming across crayfish when I was working in streams in Arizona as the streams where you found them were often highly impaired.
However, a lot of aquatic species have a hard time moving further upstream once they encounter a natural barrier like a waterfall. In Arizona, waterfalls are often the furthest upstream you’ll find invasive species like crayfish. In fact, in this particular stream, you find crayfish up to a point called Anderson Dam (a little further upstream from this waterfall), but not any further upstream. That also means that some species are only found above the dam, such as a cool species of damselfly called the Sabino dancer. The species is found outside of this canyon in a few other places nearby, but this is one of the best places to see them.
Waterfalls are beautiful, but also important dividers in stream systems. That makes them both beautiful AND interesting to me, so I’m always happy to come across a waterfall.
I am going to be traveling tomorrow, so probably won’t be able to get a post up until Friday, but I’m going to keep at it for a while. Look for another new post coming soon!
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Unless otherwise stated, all text, images, and video are copyright © C. L. Goforth.
The Dragonfly Woman 
Love it :)
Thank you so much!
I like the close angle. Brought it out well.
Thank you!
Awesome shot!
Thank you!
Given the relatively recent worldwide political discussions regarding refugees and immigration, I find incidences of biological xenophobia fascinating. What do you mean by, “Crayfish don’t belong in Arizona and every species you can find there is invasive.”? Here’s a NYT’s article that discusses the possibilities of a different POV… http://www.nytimes.com/2016/03/01/science/invasive-species.html?smid=tw-share&_r=0. Cheers.
Crayfish didn’t end up in Arizona naturally – they were brought to the state by people who released them into the waterways. They are not naturally occurring in AZ and they trash the environments where they are found. Most aquatics people in AZ hate them and there are efforts to get them out of several locations and a lot of money and effort goes toward preventing their spread above natural barriers. In a few places, the crayfish are eating endangered spring snails and other endemic species, so they’re problematic. That’s why I say they don’t belong and are invasive. And I don’t hate crayfish overall! There are several native species in North Carolina that are lovely to find, but they evolved in NC and fit into the ecosystem. They don’t fit in AZ.
Interesting take on an invasive species in the article you linked! I know a lot of crayfish people who are desperately trying to keep certain particularly invasive species of crayfish from spreading that probably disagree with that article quite vehemently…
When emotionally and culturally constructed terms, like “hate”, get mentioned with regard to “science”, I tend to side-eye.
Humans introduce things all the time, e.g., honey bees across North America and salmon in the Deschutes River in Olympia, WA. Our determination of what is good and what is bad seems so random and fickle to fashion… and what can make a quick buck. It’s sad.
What a lovely shot, and a most interesting post. I learn something new every day. :)
Thanks!