Dissolved Oxygen and Aquatic Life

Leroy Creswell from Orca Killroy Academy demonstrates how salinity and temperature affect dissolved oxygen in water. The experiment involves measuring dissolved oxygen at different temperatures and salinities using a YSI 55 meter. Results show that higher temperatures and salinities decrease dissolved oxygen levels, impacting aquatic life. The video concludes with a discussion on the implications of these findings, particularly in warm climates where fish kills are more common.

What is the main challenge for aquatic animals in extracting oxygen compared to terrestrial animals?

• Aquatic animals have more oxygen available.

• Aquatic animals need to extract oxygen from water.

• Terrestrial animals have less oxygen in the air.

• Terrestrial animals need to extract oxygen from water.

What is the purpose of using different water baths in the experiment?

• To measure the effect of light on oxygen levels.

• To observe the effect of temperature and salinity on dissolved oxygen.

• To test the effect of different fish species on oxygen levels.

• To measure the effect of air pressure on oxygen levels.

What tool is used to measure dissolved oxygen in the experiment?

• A YSI 55 dissolved oxygen meter.

• A barometer.

• A thermometer.

• A salinity meter.

At what temperature and salinity was the highest level of dissolved oxygen observed?

• 35°C and 0 parts per thousand salinity

• 5°C and 30 parts per thousand salinity

• 35°C and 30 parts per thousand salinity

• 5°C and 0 parts per thousand salinity

What is brackish water?

• Water with high salinity.

• A mix of freshwater and seawater.

• Water with no salinity.

• Water with low oxygen levels.

How does an increase in salinity affect the level of dissolved oxygen at the same temperature?

• It increases the level of dissolved oxygen.

• It stabilizes the level of dissolved oxygen.

• It has no effect on the level of dissolved oxygen.

• It decreases the level of dissolved oxygen.

What is the effect of temperature on the ability of water to hold dissolved oxygen?

• Higher temperatures increase dissolved oxygen levels.

• Temperature has no effect on dissolved oxygen levels.

• Lower temperatures decrease dissolved oxygen levels.

• Higher temperatures decrease dissolved oxygen levels.

What happens to dissolved oxygen levels in water as temperature increases?

• They remain constant.

• They fluctuate randomly.

• They decrease.

• They increase.

Why might trout struggle to survive in warmer waters?

• They cannot tolerate high temperatures.

• They need more sunlight to survive.

• They require higher levels of dissolved oxygen found in colder waters.

• They are not used to high salinity levels.

What typically causes fish kills in warm climates?

• High temperatures and low dissolved oxygen levels.

• High levels of dissolved oxygen.

• Low temperatures.

• Excessive sunlight.