abiotic

This is the correct answer. Sunlight is an abiotic factor.

This is the correct answer. Bacteria are living organisms and thus biotic factors.

This is incorrect. Temperature is a physical factor that influences the environment and is an abiotic factor.

This is incorrect. pH is a chemical factor that influences the environment and is an abiotic factor.

This is the correct answer. Sunlight is the primary energy source for most ecosystems, driving photosynthesis.

This is incorrect. While sunlight influences temperature and thus species distribution, it is not the primary factor impacting distribution.

This is incorrect. While sunlight influences temperature and thus water evaporation, it is not the primary factor affecting water availability.

This is the correct answer. Sunlight impacts ecosystems in all the ways listed.

This is correct. Soil provides a home for a wide variety of organisms.

This is correct. Soil provides stability for plants.

This is correct. Soil contains essential nutrients for plant growth.

This is the correct answer. Soil plays all these roles in an ecosystem.

This is correct. Deforestation reduces water absorption and increases runoff.

This is correct. Pollution introduces harmful substances into the environment.

This is correct. Climate change is causing significant shifts in abiotic factors.

This is the correct answer. Human activities can impact abiotic factors in numerous ways.

This is incorrect. While soil temperature can be influenced by sunlight, it is not the direct impact of sunlight on survival.

This is the correct answer. Sunlight directly influences temperature, impacting organism survival.

This is incorrect. While sunlight influences plant growth and thus mineral uptake, it does not directly impact mineral availability.

This is incorrect. While sunlight can influence soil pH through decomposition, it is not the direct impact of sunlight on survival.

Possible abiotic factors and explanations:

• **Increased nutrient levels (e.g., phosphorus and nitrogen):** Runoff from agricultural fields or sewage discharge can introduce excess nutrients into the lake, fueling the algal blooms.
• **Water temperature:** Warmer water temperatures can accelerate algal growth and reduce oxygen solubility, leading to more intense algal blooms and oxygen depletion.
• **Sunlight availability:** Increased sunlight penetration due to less cloud cover or reduced water clarity (from sediment) can further stimulate algal growth.

Possible solutions:

• **Reduce nutrient input:** Implement best management practices in agriculture to minimize fertilizer runoff. Upgrade sewage treatment facilities to prevent nutrient discharge.
• **Control water temperature:** Explore options like planting vegetation around the lake to provide shade and reduce water temperature.