Biol 612 Final 2022

1 Biology 612 Fall 2022 Final. Please work on your own and submit your answers on the canvas assignment. 150 points total. Note that the final is worth 15% of your grade, so the point total will be divided by 10 to get the final point contribution to your grade. Also if you want to work out some of the equations by hand and snap a cell photo to submit your answer, that should work. There are two lakes near Manhattan, Kansas. You have just taken a job as an extension agent and have received a number of questions about management of these lakes, requiring you to understand why both lakes are different and what might be controlling various aspects of them. Some physical characteristics of the lakes are: Parameter Lake Molly Lake Raihan Lake Area (km 2 ) 1 1 Average depth (m) 1 3 Watershed area (km 2 ) 18 21 Maximum depth (m) 2 6 Annual outflow rate plus evaporation (m 3 per year) 1,000,000,000 1,000,000,000 Length of shore (km) 10 15 Summer chlorophyll concentration (μg/L) 100 30 Surface light (μmol quanta/m 2 /s) 2000 1800 Light at 1 m deep (μmol quanta/m 2 /s) 2 300 Lake Molly is an oxbow lake near the Kansas River. It is in the flood plain so the ground is relatively flat around it. Much of the land is in fertilized cropland above the lake and there are very few trees around the lake. There is a resort on the lake where people come to camp, swim, and fish. The owner of the resort is not happy because green scum has been forming on the lake during summer, so people don’t want to swim and the fish they catch to eat taste bad. Additionally, in the winter he has observed some fish kills, particularly when ice forms on the lake . Finally, he stated that there used to be a “moss” problem in the lake. Talking to him you find out that he means there were more macrophytes than he wanted and they were interfering with fishing and people swimming. He said he dealt with the problem when some consultant suggested putting grass carp in. He said the consultant said to put in 10, but he put in 30 because he really wanted the moss gone. He said it worked well and all the “moss” was gone and the carp got really big. He also has a large lawn that goes to the edge of the lake that he fertilizes

2 regularly, and upon questioning you find out that his septic drain field is in the sandy bank about 20 feet from the shore of the lake. You sample the lake in the summer and find it does have cyanobacterial blooms. The nutrients are high in the water, and the temperature is constant from top to bottom. Lake Raihan is in a valley in the Flint Hills. It is surrounded by some trees and has a dam with a standpipe to let water out of the surface. Most of the watershed is moderately grazed by cattle, but there also is a cattle holding area on one of the tributaries feeding the lake where the rancher keeps the cattle during really cold weather and when she is trying to fatten some cattle up with corn for local sales. The area straddles the tributary so the cattle can get water to drink. The lake has some macrophytes around the edge and is mostly clear, though there have been some fish kill problems after large rains. You sample the lake in summer immediately following a large rain and find high levels of organic carbon in the lake as well as high levels of ammonium and coliform fecal bacteria. The lake water is much cooler at the deepest point of the lake than it is at the surface, and the deepest point of the lake has no dissolved oxygen in the water. 1. What process do you think formed Lake Molly? (5) The process that formed Lake Molly is erosion and deposition from a nearby River. The river used to take the path of t he now “U” shaped lake but made a shortcut to take a straighter/shorter path leaving behind an Oxbow Lake. 2. Calculate the Shoreline Development Index for Lake Molly and Lake Raihan and which do you expect to be more productive based on this calculation? hint: if you do not show your work, you cannot receive partial credit for incorrect answers (12) Lake Molly= 2.82 Lake Raihan= 4.23 D L = 𝐿 2√𝜋𝐴 Lake Molly: D L = 10 2 √𝜋 (1 ) = 2.82 Lake Raihan: D L = 15 2 √𝜋 (1 ) = 4.23 3. Calculate the volume of Lake Molly and Lake Raihan, and the retention times of each lake. hint: if you do not show your work, you cannot receive partial credit for incorrect answers (12) Volume of Lake= average depth times lake area Lake Molly: 1 km 2 =3280.84 ft ; 3280.84ft= 1000m ; 1000 x 1= 1000 m 2 Lake Raihan: 1 km 2 = 3280.84 ft ; 3280.84ft= 1000m ; 1000 x 3 = 3000m 2 Retention Time= Lake Volume/Lake Outflow Rate Lake Molly: 1000m 2 = 31622.78 m 3 ; 31622.76 / 1,000,000,000= 0.00003162276 m 3 Lake Raihan: 3000m 2 = 164316.77 m 3 ; 164316.77/1,000,000,000= 0.00016431677 m 3 4. Why do you think that Lake Raihan is stratified but Lake Molly is not? (5) I think that Lake Raihan is stratified, and Lake Molly is not because Lake Raihan is deeper. The middle/bottom of the lake is not receiving as much light/heat if any as the top of the lake. While Lake Molly is only 2m deep and has no macrophytes to block the sun like Lake Raihan. Lake Molly also has no trees surrounding it that would cut back on wind and therefore the wind can mix the water of Lake Molly more efficiently that Lake Raihan.

4 all most if not all the fish and the lake will be inoperable if this occurs. You would first have to remove most grass carp from the lake, as well as stop the algal blooms. Then you could reintroduce macrophytes back into the lake. 11. What processes in the nitrogen cycle do you expect to dominate in the bottom of Lake Raihan, and what form of inorganic nitrogen do you expect to dominate? (5) I expect mineralization and ammonification to dominate the bottom of Lake Raihan. I expect ammonia to be the inorganic nitrogen. 12. What is the light attenuation at 1 meter in Lake Molly and Lake Raihan? Why do you think they differ? (5) Lake Molly has a light attenuation of 2 μmol quanta/m 2 /s and Lake Raihan has a light attenuation of 300 μmol quanta/m 2 /s at 1 meter. I think they differ because of the cyanobacteria blooms in Lake Molly. As well as Lake Raihan being clear so more light can reach lower parts of the lake. But since Lake Molly has cyanobacteria bloom they cover the surface of the water and block light from reaching the bottom. 13. How would you expect the River Continuum Concept to vary when comparing a temperate forested stream to a prairie stream dominated by tall grasses in the headwaters with respect to primary production, allochthonous and autochthonous inputs, and invertebrate functional groups? (5) I would expect the River Continuum Concept to vary by the temperate forested stream having a gradient that is much longer than the prairie stream. As the prairie stream is not as big as the temperate forest and probably not as wide, so it would take a shorter amount of time to see that gradient in the prairie stream. 14. How does the stream biome gradient framework use the balance between potential evapotranspiration and annual precipitation to predict stream intermittence, and how is that ratio influenced by both latitude and altitude? (5) The stream biome gradient framework uses the balance between evapotranspiration and annual precipitation to predict stream intermittence by calculating how and where the intermittent stream(s) will be. Latitude and altitude influences this because depending on the area of stream it can affect the evapotranspiration of the stream. 15. Why does scale invariance allow us to extrapolate small-scale experiments to watersheds or greater areas (for example if metabolism scales by mass of animals and proceeding to use those measurements to compare the influence of rotifers and fish to nutrient cycling in a lake)? (5) Scale invariances allow us to see the effects on watershed at the scale we are looking for. 16. Describe how water velocity, temperature, and nutrient limitation are expected to influence the water column portion of spiral length. (5) Velocity affects the influence of the water column portion of spiral length because the higher the velocity the more it mixes up the substrate in steams. Due to the enriching effect of turbulence and water velocity, nutrient limitation in streams differs from that in

5 lakes. As lakes have more nutrient limitations than streams because they are restricted on the input of nutrients. 17. What are your top 3 favorite subjects of biography boxes in the book and why is each one someone you particularly admire? (9) Ruth Patrick: I find Ruth as someone I admire because she was not only a woman in science, but a woman in science when it wasn’t traditionally accepted. She accomplished so much during her career, and I hope to do the same someday.\ Rachel Carson: She is someone I particularly admire because she brought the pollution of pesticides to light. As someone who works with organic and inorganic pesticide and have been around them my whole life I know and have seen the effects of pesticides to the surrounding environment. But have had no power to do anything to regulate them. So, for her to be the first person to enact laws to control the release of pesticides she is admirable to me because I want to make that impact one day for our environment. David Schindler: Dr.Schindler is another person I admire because of his research on human-caused pollution. After college I would like to get a job in the environmental sciences field, so for someone else to care about the preservation of the environment from human interference is very interesting to learn about. 18. Describe the process of seasonal succession in lakes and factors that influence timing of diatom blooms, zooplankton populations, cyanobacterial blooms, and grazing resistant algae. (10) Natural assemblages' relative abundance and dominance of species are subject to regular and obvious temporal shifts. These changes frequently occur in roughly the same order and phase in recurrent annual cycles. This is to ensure successful is successful for diatom blooms, zooplankton populations, cyanobacterial blooms, and grazing resistant algae. 19. How does redox potential control the order in which different compounds are used to oxidize organic compounds and why will methanogenesis not happen until sulfate is depleted? (5) Redox potential controls the order of which compounds are used to oxidizes organic compounds because the different compounds either require anoxic conditions or anerobic conditions. Methanogenesis won’t happen until sulfate is depleted becau se methanogens are weaker competitors for the substrates H2 and acetate, both of which they consume. Therefore, methanogenesis is often poor when sulfate is present. However, methanogens play a crucial role as H2-scavengers and in the final mineralization of acetate in sulfate- depleted, anaerobic habitats, particularly in freshwater sediments, sewage digesters, the rumen, and at some depth in marine sediments. 20. What do you think the five biggest threats to freshwaters are and why? (10) Human Pollution, Climate Change, Agricultural runoff, The overuse of water, Human Expansion. I think these are the biggest threats to freshwaters and freshwater ecosystems because they aren’t regulated or actively regulated but are what cause the most harm to freshwaters.

7 that duplicated existing federal requirements — which of course did nothing to reduce the discharge of harmful organisms, and which the courts rejected. Now, EPA is proposing to re-issue precisely the same discharge standards, word-for-word. Meeting trade-offs for a net-zero America Banning energy exports is a terrible idea Under the Clean Water Act, ballast water discharge standards are supposed to require the use of the best available treatment technology , but EPA’s proposed standards would allow ships to use treatment systems that are tens to thousands of times less effective at eliminating harmful organisms than the best commercially-available systems. Clearly, we know how to do a good job of removing or killing organisms that are trapped in a tank of water. The law says EPA must require ships to use that ability to treat their ballast discharges. After 50 years, it is long past time for EPA to do so. EPA must establish the discharge standards required by the Clean Water Act and protect the health and environment of all Americans as Congress intended. Andrew Cohen conducts and publishes research on the science and policy

8 22. Here is a lifecycle of the parasite Schistocephalus solidus . How would this life cycle be influenced by eutrophication (which turned the whole lake eutrophic) with respect to altering the ecology of the three hosts in ways that might influence the rate of transmission of the parasite. (12). The influence of eutrophication might decrease the influence rate of transmission of the parasite. Since the parasite requires a second host (three-spined stickleback fish) to complete the circle of the life cycle if the lake were to eutrophic the fish would be hidden among the plants and algae. Making it harder for the bird to see the fish and maybe not eating the infected fish at all. This would create a dilemma for the parasite as it would be stuck in the fish longer than intended or not make it to the bird stomach/intestine at all. This would slow the rate of the parasite because it would take longer for the lifecycle to complete and may kill the parasite all together.