Analyze the trends in the data and answer the following questions:
- How has the average fish size changed over time?
- How does the change in nitrate concentration relate to oxygen levels?
Clearwater Lake Data
| Year | Fish Size (cm) | Dissolved Oxygen (ppm) | Nitrate Concentration (mg/L) |
| ---- | ------------- | ---------------------- | ----------------------------- |
| 1990 | 25 cm | 9.0 ppm | 0.5 mg/L |
| 2000 | 22 cm | 7.5 ppm | 1.2 mg/L |
| 2010 | 18 cm | 5.0 ppm | 2.5 mg/L |
| 2020 | 15 cm | 3.0 ppm | 4.0 mg/L |
Answer (2)
Average fish size decreases over time.
Dissolved oxygen levels decrease over time.
Nitrate concentration increases over time.
There is an inverse relationship between nitrate concentration and dissolved oxygen levels.
The average fish size has decreased, and there's an inverse relationship between nitrate concentration and dissolved oxygen levels. The fish size decreased from 25 cm in 1990 to 15 cm in 2020. As nitrate concentration increases, dissolved oxygen levels decrease.
Fish size decreased; inverse relationship between nitrate and oxygen
Explanation
Analyzing the Data First, let's analyze the data provided. We have data for fish size, dissolved oxygen, and nitrate concentration in Clearwater Lake for the years 1990, 2000, 2010, and 2020. We need to identify trends in fish size and the relationship between nitrate concentration and oxygen levels.
Calculating Changes Over Time Now, let's calculate the changes in each parameter per decade.
Fish Size:
1990-2000: 22 c m − 25 c m = − 3 c m
2000-2010: 18 c m − 22 c m = − 4 c m
2010-2020: 15 c m − 18 c m = − 3 c m
Dissolved Oxygen:
1990-2000: 7.5 pp m − 9.0 pp m = − 1.5 pp m
2000-2010: 5.0 pp m − 7.5 pp m = − 2.5 pp m
2010-2020: 3.0 pp m − 5.0 pp m = − 2.0 pp m
Nitrate Concentration:
1990-2000: 1.2 m g / L − 0.5 m g / L = 0.7 m g / L
2000-2010: 2.5 m g / L − 1.2 m g / L = 1.3 m g / L
2010-2020: $4.0 mg/L - 2.5 mg/L = 1.5 mg/L
Identifying Trends From the calculations, we can observe the following trends:
Fish Size: The average fish size has decreased over time. The fish size decreased by 3 cm from 1990 to 2000, by 4 cm from 2000 to 2010, and by 3 cm from 2010 to 2020. This indicates a consistent decline in fish size over the observed period.
Dissolved Oxygen: Dissolved oxygen levels have also decreased consistently. The dissolved oxygen decreased by 1.5 ppm from 1990 to 2000, by 2.5 ppm from 2000 to 2010, and by 2.0 ppm from 2010 to 2020.
Nitrate Concentration: Nitrate concentration has increased over time. The nitrate concentration increased by 0.7 mg/L from 1990 to 2000, by 1.3 mg/L from 2000 to 2010, and by 1.5 mg/L from 2010 to 2020.
Analyzing the Relationship Between Nitrate and Oxygen Now, let's analyze the relationship between nitrate concentration and oxygen levels. As nitrate concentration increases, dissolved oxygen levels decrease. This suggests an inverse relationship between these two parameters. Higher nitrate concentrations may be contributing to lower oxygen levels, which can be detrimental to aquatic life, including fish.
Final Answer In summary, the average fish size in Clearwater Lake has decreased from 25 cm in 1990 to 15 cm in 2020. There is an inverse relationship between nitrate concentration and dissolved oxygen levels; as nitrate concentration increases, dissolved oxygen levels decrease.
Examples
Understanding the relationship between nitrate levels and dissolved oxygen is crucial in managing aquatic ecosystems. For example, excessive use of fertilizers in agriculture can lead to increased nitrate runoff into lakes and rivers. This, in turn, can cause a decrease in dissolved oxygen, harming fish and other aquatic organisms. By monitoring these parameters, environmental scientists can implement strategies to reduce nitrate pollution and maintain healthy aquatic environments. This could involve promoting sustainable farming practices, improving wastewater treatment, and restoring riparian buffers to filter out pollutants before they reach the water.
The average fish size in Clearwater Lake has decreased from 25 cm in 1990 to 15 cm in 2020, while dissolved oxygen levels dropped significantly as nitrate concentrations increased. There is an inverse relationship between nitrate concentration and dissolved oxygen levels, indicating that higher nitrates correspond to lower oxygen availability for aquatic life.
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