Last week started with DNA work in the morning and electrofishing at night. Our goal for DNA processing last week was to start processing our new samples and reach a stopping point by the end of Wednesday. To achieve our goal, we needed to extract the DNA from the tissue. This was completed by passing through a serious of steps including centrifuging multiple times to extract the tissue and leave behind the DNA. We reached our goal on Wednesday and finished in the lab by suspending our DNA samples and placing them in the freezer. We went electrofishing at our research sites Z3 and Z2. Prior to electrofishing, we met at the lock house at 8:30 p.m. to prepare our research vessel. For electrofishing, we need two generators (one for the electrofishing unit and one for the bow lights), electrofishing unit, anodes, four nets, lights, two live wells, five gallon bucket, weighing scales, two meter sticks, data book, and all required safety equipment. Z3 is directly downstream of the power plant and Z2 is directly upstream. At both of these locations, we caught a significant amount of minnows. We also sampled numerous other fish species as well. Each fish was weighed and measured before being released back into the river.
On last Wednesday, we had a seminar with Dr. Monte McGregor. Dr. McGregor is a world-renowned malacologist that has worked on numerous mussel conservation projects. During his talk, he discussed mussel history, issues, and a method he recently developed to culture larval mussels. He explained how mussels are some of the rarest species on the planet, but the Mississippi and Ohio have very diverse species. Interestingly, there are more species of mussels in Kentucky then there is in all of Europe. The life history of mussels is unique as well. Once an upstream male fertilizes the eggs, the female lures a host fish over and sprays her larvae onto the fish. The glochidia (mussel larvae) attach to the host fish gills and incubate there for up to two week. When the glochidia reach a juvenile stage, they detach from the fish gills. Each mussel species has very specific host fish and the females lure directly targets these host species. The female lures can range from mimicking a baitfish to a worm. This poses as an irresistible snack to the unsuspecting fish. The historical significance with mussels originated with Indians. The Indians used mussels for tools and jewelry. Eventually, a large button industry was developed around the freshwater mussels. These destructive industries led to an overharvest of mussel populations. Another important fact about mussels is that they are pollution intolerant and are a great indicator species. However, they have been affected by habitat loss, pollution, disease, climate change, invasive species, siltation, poor agricultural practices, and coal in the sediment. To combat the losses of native mussel species, Dr. McGregor developed a method for successfully raising mussels. His method produces glochidia without the fish host stage. Instead, he incubates larval mussels on petri-dishes with a rabbit blood or fish blood serum. This technique is very successful and can produce thousands of juvenile mussels. These mussels are then inserted into streams and rivers that are in need of mussel conservation.
We had our private tour of the Zimmer power plant facility last Thursday. It was interesting to tour the power plant that we sampled all summer. While on our tour, we were required to wear a hard hat, safety glasses, and earplugs in certain locations. The tour began with a brief overview of the power plant. It produces approximately 1300 megawatts of electricity per day and burns about 600 tons of coal per hour. Only forty percent of that is converted into electricity. The rest of the energy escapes as steam at the cooling tower. We then toured the maintenance room, control room, boiler room, and various other aspects of the power plant. The most intriguing part of the tour was when we entered the nuclear reactor! Zimmer was originally constructed to be a nuclear power plant, but converted to coal at the last minute. There was not much left in the reactor, most of the material had been scrapped. During the tour, we learned that the power plant turbines were constructed on a separate foundation to prevent them from shaking the entire building. When we stepped onto the turbine foundation, we felt a considerable amount of vibration. The tour concluded 350 feet up on a rooftop overlooking the power plant. It provided a gorgeous view of the Ohio River (I apologize in advance for the blurry pictures below).
On Friday, we began conducting habitat assessments of our four research sites. The methods that we used to conduct our habitat assessments were developed by ORSANCO. For this assessment, we needed a 100 ft. tape measure, a 100-meter tape measure, and two 10 ft. copper poles. The copper poles are used to determine the type of substrate. By lowering the copper poles down and tapping them gently on the bottom, we were able to distinguish between boulders, cobble, gravel, sand, fines, and hardpan. We began at Z4 and marked off a 500-meter section of the shoreline placing a marker at every 100 meters starting at 0 meters. At each 100 meters, we would start at the shoreline and sample the substrate at intervals of 10 ft. until we reach 100 ft. out on the river from the shoreline. This procedure was repeated at the six 100 meter marks of the research site. At each transect, we also recorded the percent riparian cover, percent shoreline cover, percent of wood cover, and the percent of aquatic vegetation. Furthermore, we recorded the percent of barges, docks, boat ramps, residential lawns, mooring cells, and industry. This procedure was repeated at the six 100 meter marks of the research site. We completed habitat assessments at Z4 and Z3, but intend to perform habitat assessments at Z2 and Z1 on Tuesday. After we finished our habitat assessments at Z4 and Z3, we conducted zebra mussel scraping on the furthest downstream mooring cell of the power plant. This yielded a few hundred zebra mussels. In previous years, Dr. Lorentz said that they have sampled and collected over a thousand with this method.
Last week we also finished the construction of the mulch bed and fossil garden. To complete these two projects, Dr. Lorentz wants us to develop some trivia questions about the Ohio River for the mulch bed. He also wants us to create an educational sign for the fossil garden about the rich geologic history in this area. These projects have complimented the lock house very well.
The beginning of this week has been busy as well and will continue to be until our final presentations on Friday. Currently, we are working on organizing our final draft of the Standard Operation Procedures for performing a bioassessment of the power plant, constructing our PowerPoint presentation, and creating a poster. Additionally, this week Dr. Monte McGregor’s is giving us a tour of his mussel lab. We are also going to complete habitat assessments of Z1 and Z2, attend a seminar on Wednesday evening, perform zebra mussel scraping upstream of the power plant, and collecting Hester Dendys.
Thanks for reading,