 Hello Blue Thumb friends,
Outdoor activities will be heating up at Blue Thumb because the season for summer fish and bug collections is just around the corner! During these collections, you get to interact with aquatic creatures first-hand, learn about what makes them unique, and see where they live. We strongly encourage volunteers and anyone else interested to join us during these collections because ultimately, these are the creatures we are trying to protect! Read Kim’s article in this edition of FTWE for more information on this summer’s fish collections below.
Briant Nguyen
Field Education Coordinator
PFAS is in the news. What is PFAS? PFAS is a group of chemicals that contain per- and polyfluoroalkyl substances. They have been widely manufactured since the 1940s. These chemicals hang around in the environment for a long time and can cause several human health impacts including increased risk of some cancers, increased cholesterol levels or obesity, a reduction in the body’s ability to fight infections, developmental impacts in infants and children, and decreased fertility in women. Here is a link to an EPA factsheet that contains additional information: https://www.epa.gov/pfas/pfas-explained
On April 10, EPA finalized drinking water standards that set Maximum Contaminant Levels for five PFAS chemicals and hexafluoropropylene oxide dimer acid (HFPO-DA), a chemical used in the manufacture of fluoropolymers. This rule will necessitate that public water supplies test for these chemicals and treat for chemicals if levels are found above the MCLs. Here is more information about the new drinking water regulations: https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas#Webinars
The impacts of PFAS on aquatic systems are not fully understood, but PFAS chemicals have been found in freshwater fish in waterbodies across the United States. Here is an article about PFAS and freshwater fish: https://www.scientificamerican.com/article/pfas-forever-chemicals-found-in-freshwater-fish-yet-most-states-dont-warn-residents/
Let us know if you would like more information about PFAS and freshwater ecosystems. We can learn together!
Rebecca Bond
Blue Thumb Director
Like the rest of my Blue Thumb co-workers and a good number of our volunteers, I have been out and about at festivals and other events this spring. At an Earth Day celebration last week, a naturalist friend was toting around a large tree “cookie” (the tree core), and I paused to admire it. He told me he had counted the rings and the tree had lived to be 85 years old. Trees in temperate regions produce an annual ring when the cambium (where new wood is made) awakens from its winter nap and cell division begins taking place. Okay, we know this about trees. Growth rings, or their equivalent, can also be used to age many animals! Here are a few examples:
Take a look at the scutes (squarish scales on the shell) on a turtle and you will see little lines that are actually growth rings. With a turtle, it is probably most accurate to count these rings and then divide by two, as the rings can be indicators of finding enough to eat. An extra ring can occur during a season of plenty.
The otolith of a fish (calcified structure in the inner ear) develops pretty much another calcified layer each year. Of course the fish will not survive the removal of this wee bone. Scales also have annual rings that can be seen under a microscope.
When at your stream if you are fortunate to see a freshwater clam, pick it up and see if you can find/feel ridges on the shell. Clams will form an additional ridge most years. Some clams can live for over 100 years. You don’t come by these ancient clams very often.
Coming to Oklahoma this year June 6 – 9 is the North American Native Fishes Association’s annual convention. This will be a get together for enthusiasts of native fish, and some of the Blue Thumb staff will be there. Even if you are unsure of whether you can make it to the conference, you should check it out at the link below. Also, NANFA sends its members a quarterly publication that is filled with beautiful native fish photographs, research projects, and places to purchase the tools needed (and even the fish!) for a native fish aquarium!
https://www.nanfa.org/convention/2024.shtml
Cheryl Cheadle
Volunteer Coordinator
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