Water Quality ADI (4) by Jessika Dorcas https://padlet.com/jessika_dorcas/8gytgaj6w4df Why is the sport fish population of Lake Grace decreasing in size? en-us 2018-02-01 12:45:30 UTC 2026-01-30 23:07:22 UTC hello@padlet.com Reid, Lucas & Ally https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227065557 Claim: The fish population of Lake Grace is diminishing due to the Tolt River Dam which increases the tourist population and disrupts migration patterns.

Evidence: Information about some organisms found in Lake Greece chart tells us that most of the fish need to be around 20 degrees Celsius and at a certain depth of water.

Reasoning: The dam that is built can increase the chance of a drought, using all of the available water and draining the lake.

Evidence: the water quality in the lake is decreasing over the years, such as the PH or dissolved oxygen. As the temp increases, the dissolved oxygen decreases (thermo pollution).

Reasoning: Hydroelectric power increases thermo pollution, decaying many species that live by a certain temp. (20 degrees C)

Evidence: The largemouth bass are important predators in freshwater ecosystems and help maintain the population size

Reasoning: once on fish dies out and another one depends on it to survive, a chain reaction slowly kills off the rest of the species or could increase the size, depending on the fish. ]]> 2018-02-01 14:49:18 UTC https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227065557 Garrett, Laina, Rishu & Sam https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227066125 Claim: The sport fish population are declining due to anthropogenic causes such as people over fishing, eutrophication, and the invasive species.

Evidence 1: According to the census, the population increased from 2,016 to 3,824 people from 1980 to 2000.
Reasoning: Due to the increase of population more people started to fish which lead to a decrease of over all population

Evidence 2: from 2001 the nitrate level was 12ppm and in 2005 it tripled to 36ppm
Reasoning: This increase in nitrate levels lead to a bloom of algae which lead to eutrophication which lower the oxygen levels of the lake which decreased fish populations

Evidence 3: In 1998 invasive species such as hydrilla and water hyacinth apreade into Lake Grace. These species provent light from getting into the water, which can stave the organisms from oxygen
Reasoning: The depletion of oxygen cause my the invasive species to reduce the fish populations. ]]> 2018-02-01 14:50:14 UTC https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227066125 Nicole, Daniel, Colton & Grace https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227070134 Claim: The sport fish population is most likely decreasing in size due to the herbicide put in the lake to kill invasive plants that most likely disrupts the fish too.

Evidence: The triclopyr increased from 1-11 over ten years, probably disrupting the fish and their habitats.
Reasoning: Higher levels of triclopyr can be toxic to aquatic organisms.

Evidence: The Tolt River Dam is completed which can attract tourism and disturb sport fish.
Reasoning: With more tourists and a public boat launch, fish are more likely to become crowded and disturbed due to increased visitors.

Evidence: In 1998 invasive species entered the lake which would keep light from entering the water, and starving the fish of oxygen.
Reasoning: For example, the number of largemouth bass decreases from 2,422 to 1,152 in 16 years - from the depleted oxygen.]]> 2018-02-01 14:56:25 UTC https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227070134 Chloe, Adam, Matthew, Michael https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227070556 Claim: The sport fish population decreased because of the increased amounts of triclophyr, phosphates, and nitrates, decreased dissolved oxygen levels, and increase in temperature.

Evidence: The temperature of the middle of the lake is well over 20°C, the nutrient levels increased after farms were closed, and herbicides were introduced.

Reasoning: Daphnia and gammarus amphipod cannot survive over 20°C, and multiple of the fish species eat those. Increased levels of nutrients happened due to the runoff from the closed farms, which led to eutrophication and increased turbidity. The increased turbidity made it harder for the bluegill and the white bass to thrive. The eutrophication decreased the dissolved oxygen levels, which made it difficult for the fish populations to survive. With the introduction of herbicides the level of Triclopyr increased over the safe level of 2 to the level of 11 which is highly toxic to the plants which leads to bioaccumulation of the toxins. ]]> 2018-02-01 14:57:04 UTC https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227070556 Lindsay, Haley, Anna, McAulay and Walker https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227076194 The Guiding Question: Why is the sport fish population of Lake Grace decreasing in size? 
Our Claim: The fish population is decreasing because of pollution from different sources and human impacts on the lake. 

1.) Evidence: In 2004 Aidanville city council begins to use herbicides to slow the spread of invasive water plants in Lake Grace

Reasoning: The pH level has become more acidic in Lake Grace because nitrate levels have increased and phosphate levels have decreased as a result of the herbicides killing plants, which are then unable to create the nutrients

2.) Evidence: The town uses hydroelectric power to generate electricity

Reasoning: Using hydroelectricity causes thermal pollution, which affects temperature and oxygen supply. The fish need the temperature to be below 20° C to survive, in the case of the daphnia, and to reproduce, in the case of the white bass. Anything higher, and the ecosystem will be affected badly.

3.) Evidence: Daphnia, gammarus, and amphipods consume the invasive plant species

Reasoning: Because herbicides are being used to prevent the spread of this invasive plant, the fish are consuming toxic chemicals that harm them and the surrounding fish that consume them. This leads to bioaccumulation as higher trophic levels continue to be ingested by animals infected with these chemicals and future offspring won’t develop properly.  
]]> 2018-02-01 15:06:05 UTC https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227076194 Alexis, Cole, Kylie, Taylor https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227077301 Claim: Fish population of Lake Grace is decreasing in size because fish are dying due to a decrease in food and dissolved oxygen and the building of a dam that had long term effects.

Evidence:
  • 2004, the Adenville city council began to use herbicides to slow the spread of invasive water plants
  • 1952, Dam was built 
  • High concentration of dead organic matter, which then starts to decay
Reasoning:
  • It kills food source for daphnia and daphnia is food source for larger fish
  • This would lead to less fish being able to travel downstream and enter the lake. The population would mostly be limited to the fish already in the lake. Also they would have trouble mating if they couldn’t leave the lake to go to those mating ground.
  • This causes a consumption of dissolved oxygen which fish need to survive. 
]]> 2018-02-01 15:07:48 UTC https://padlet.com/jessika_dorcas/8gytgaj6w4df/wish/227077301