Water Quality ADI (5) by Jessika Dorcas https://padlet.com/jessika_dorcas/37y7m6mk0qpf Why is the sport fish population of Lake Grace decreasing in size? en-us 2018-02-01 12:46:00 UTC 2018-02-01 17:21:58 UTC hello@padlet.com Josh, Jacob, Bailey Rose https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227098610 Claim: The sport fish population of Lake grace is decreasing because the town of Aidanville keeps advancing and growing.

Evidence:
1. With the population of Aidanville increasing and the lake open for public boat use, more people are able to fish.
2. The dam was established causing fish populations to decline.
3. The Aidanville City Council added herbicides to the water to kill off the invasive species.

Reasoning: 
1. The more people that are fishing and have access to the water, the quicker the fish population decreases because of the influx of fishing.
 2. Since the dam blocks off where the fish came from, they cannot get back upstream to reproduce.
3. The herbicides being introduced to the water might have polluted the water, causing fish to live in poor conditions and eventually die. ]]> 2018-02-01 15:40:43 UTC https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227098610 Cameron, Hailey, Emma S., Patrick https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227099202 Claim: The sport fish population is decreasing in size in Lake Grace because of excessive build up of nitrates and triclopyr, and industrialization of Aidanville.

Evidence:
- From 2002 to 2005, water quality in Lake Grace decreased because of land development and the beginning of using herbicides.
- The fish population has decreased due to lower dissolved oxygen content.
-Increasing phosphate stimulated plant growth which caused algae blooms to accumulate leading to eutrophication.

Reason: 
- The use of herbicides polluted the water and caused harsh environments for fish to live in. Also the increased amount of pollution in Lake Grace would cause fish to have abnormal adaptations or die. 
- A low dissolved oxygen level causes fish to die because they can not breathe.
- Eutrophication lowers dissolved oxygen levels which causes hypoxia in fish thus killing them.

]]> 2018-02-01 15:41:36 UTC https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227099202 Nathan, Anthony, Jessie, & Casey https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227100503 Claim: The sport fish population of Lake Grace is decreasing in size because of eutrophication and decreased pH levels.
Evidence:
1. Increase in use of fertilizers containing nitrates and phosphates, and with runoff, this added fertilizer polluted the water.
2. More algae blooms because of runoff fertilizer caused bacteria to use up more oxygen, which caused dissolved oxygen levels to decrease.
3. Decreased pH levels in the water resulted from increased pollution from building hotels and hog farms killed off many Gammarus amphipods, because they are sensitive to low pH levels.
Reasoning:
As more people came into the Lake Grace area, there was an increase in building hotels, using fertilizer, and farming hogs.  First, an increase in hotels caused pollution from the building process to enter the water, lowering the pH levels.  This lowered pH caused many Gammarus amphipods, who are sensitive to lowered pH level to die off, and they were a major food source for the rest of the larger animals in the lake.  Also, increased fertilizer led to more nitrates and phosphates entering the water which polluted the water.  This caused algae blooms, which eventually led to eutrophication and dissolved oxygen levels in the water to drop, which further caused the sport fish population in the Lake Grace area to decrease.]]> 2018-02-01 15:43:21 UTC https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227100503 Dominic, Sully, Sophia, Elisabeth, Gabe https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227105967 Claim: As the Town of Aidanville and tourism grows, sport fish population of Lake Grace decreases due to the increase in people fishing, human interactions, and lake altering for hydropower.
Evidence:
  1. The Lake Tort Dam produces hydroelectric power to the people living around the area. 
  2. In 2004, Aidanville City Council begins to use herbicides to slow the spread of invasive water plants in Lake Grace. 
  3. From 1995 to 2005, pH decreased from 6.6 to 5.8
Reasoning:
  1. Due to the dam connecting to the lake, the fish have a hard time swimming upstream to their normal home which causes fish to die due to them not successfully swimming upstream to where they normally reproduce. 
  2. The herbicides in the lake water decreases the oxygen levels in the water which leads to fish dying.
  3. The pH decreasing over time means that the water of Lake Grace progressively got more acidic. This causes a worse environment for fish to live. With this toxic water, the most fish will be affected and can even die. 
]]> 2018-02-01 15:51:48 UTC https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227105967 Emily, Payton, Ellie, Lauren, Sam https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227112731 Claim: The Sport fish population of Lake Grace is decreasing in size because of environmental and habitat changes. 

Evidence: 
  • From 1995-2003, there were only 1 or 2 ppb of triclopyr in Lake Grace, which is a safe amount. However, in 2005 it dramatically increased to 11 ppb of the herbicide. 
  • Warm water temperatures leading to a decrease in the Daphnia population. 
  • From 1995 to 2005 the PH levels has decreased from 6.7 to 5.8 making the water more acidic. In 2005 the nitrate levels were 36 ppm and the phosphate levels were 0.12 mg/l making the water quality harmful to aquatic life. 
Reasoning: 
  • When Daphnia and other small organisms ingest Triclopyr they are not harmed. However, when the sport fish eat these small organisms they are ingesting large amounts of the herbicide which is toxic to them. This is an example of harmful bioaccumulation, where the animals at the top of the food chain are the most heavily affected. 
  • The Daphnia population is a major food source for fish and an important link to the food chain. Their population is decreasing in the lake because they require temperatures below 20 degrees celsius and the water in the center of the lake is becoming warmer and is at 22 degrees celsius. This environment is not stable for the Daphnia causing them to die and when they die the food goes away for the sport fish. Without the major food source, the sport fish population will decrease. 
  • With a growth in population, the effects of development leads to a high concentration of phosphate and nitrate level in the water due to farming.  The effect of runoff from these farms eventually leads to eutrophication and not enough dissolved oxygen. The phosphate and nitrate levels are very high for the fish to survive. An excess of nitrate levels (above 30 ppm) can inhibit the growth of fish causing them to eventually decrease in size. The pH is too acidic (low) for fish to be able to survive in the habitat causing the sport fish to decrease in size. 
]]> 2018-02-01 16:01:56 UTC https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227112731 Leila, Chris, Jack, Sarah https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227120690 CLAIM: The population of fish in Lake Grace is decreasing because of rampant population growth which has caused an increase in the use of herbicides. These herbicides have altered the pH of the lake and thus led to eutrophication.  

EVIDENCE: 
-From 1995-2005 the pH decreased from 6.7 to 5.8 
-Nitrates increased from 12 ppm to 36 ppm 
-The population almost tripled between 1940-2000

REASONING: 
- The pH decreasing over time means that the water of Lake Grace progressively got more acidic. This causes a worse environment for fish to live. With this toxic water, the most fish will be affected and can even die.
-  The herbicides in the lake water increases nitrates and decreases the oxygen levels in the water which leads to fish dying.
- Population increase means more people are fishing in the lake.

]]> 2018-02-01 16:14:34 UTC https://padlet.com/jessika_dorcas/37y7m6mk0qpf/wish/227120690