Back to: MICROBIOLOGY 400 LEVEL
Welcome to class!
Hi there, champion! I’m excited to be here with you again. Today’s lesson will take your imagination to some really refreshing places—think of paddling a canoe across River Niger or standing on the shores of Lagos Beach, watching the waves. While those scenes may seem peaceful on the surface, there’s a whole world of living things beneath the water—microorganisms that call freshwater and marine environments home. Let’s learn about them and how they affect life as we know it!
Freshwater And Marine Microbes
Freshwater and Marine Microbes
Water bodies—whether rivers, lakes, oceans, or streams—are filled with countless microorganisms. These microbes play crucial roles in maintaining the health of aquatic ecosystems, supporting food chains, and even influencing climate patterns.
Let’s look at each type of water environment and the microbes that live there.
1. Freshwater Microbes
Freshwater bodies like rivers, lakes, ponds, and streams are homes to a variety of microbes such as bacteria, protozoa, algae, viruses, and fungi.
Algae are common in freshwater. They are like the plant life of the microscopic world, producing oxygen through photosynthesis. In water bodies like Kainji Lake or Oguta Lake, algae help maintain oxygen levels for fish and other aquatic life.
Protozoa such as Paramecium feed on bacteria and smaller particles. They help keep the ecosystem clean and balanced.
Bacteria in freshwater break down waste and recycle nutrients. Some even help purify the water by feeding on organic matter.
Cyanobacteria, also known as blue-green algae, are bacteria that also photosynthesise. In some cases, they can multiply too quickly and cause algal blooms, which can make the water toxic.
2. Marine Microbes
Marine microbes are found in saltwater environments like seas and oceans. The Atlantic Ocean that borders Nigeria is full of them.
Marine bacteria help in decomposing dead marine organisms and recycling nutrients. These bacteria are essential for keeping the water clean.
Phytoplankton, a type of microalgae, float near the water surface and carry out photosynthesis. They produce over half of the world’s oxygen!
Zooplankton, including small protozoa and larvae, feed on phytoplankton and serve as food for bigger fish.
Marine fungi play a smaller role but still contribute by breaking down organic material in the sea.
Archaea, a group of ancient microbes, thrive in extreme marine environments like deep-sea hydrothermal vents.
Microbes and Aquatic Balance
These microbes form the base of the aquatic food chain. Fish, crabs, and even whales depend on them—either directly or indirectly. Without them, water bodies would be polluted, oxygen levels would drop, and marine life would suffer.
In Nigeria, waterborne diseases are also closely linked to microbes. Contaminated rivers and lakes can carry harmful bacteria like Vibrio cholerae, which causes cholera. So while microbes can be helpful, they must be properly monitored in public water systems.
Summary
- Freshwater and marine environments are home to diverse microorganisms.
- Algae in freshwater produce oxygen and support aquatic life.
- Protozoa help keep freshwater ecosystems clean by feeding on bacteria.
- Freshwater bacteria decompose waste and recycle nutrients.
- Cyanobacteria can be helpful or harmful, depending on their growth.
- Marine microbes include bacteria, phytoplankton, zooplankton, fungi, and archaea.
- Phytoplankton produce a large portion of the Earth’s oxygen.
- Marine bacteria decompose organic matter and keep oceans clean.
- Microbes form the base of aquatic food chains and support life under water.
Evaluation
- Identify two freshwater microbes and describe their roles.
- What is the difference between phytoplankton and zooplankton?
- How do marine bacteria contribute to ocean health?
Every lesson brings you closer to becoming a skilled and thoughtful microbiologist. Keep asking questions, stay curious, and remember—Afrilearn is cheering for you always. See you in the next class, my brilliant friend!