8 Micro Food Chains-High

Micro Food Chains FOCUS Question What kinds of food chains exist at a very small scale?

Chains of Every Size Think of a typical food chain diagram. Energy comes from the Sun. Grass uses sunlight to make food. A mouse eats the grass, and a hawk eats the mouse. The plants and animals in this food chain are familiar. But in nature, most living things are not fluffy animals with legs or wings. In fact, most living things on Earth are so small that we can't see them without a microscope. They are called microorganisms. Just like mice and hawks, microorganisms are part of food chains. You might call them "micro food chains."

Staying Small, Growing Big Micro food chains have all the same links as larger food chains. They start with producers. Single-celled algae use sunlight to make food, just as plants do. Moving up one link are consumers. They eat other living things. Bacteria, fungi, and very tiny animals are micro consumers. Some larger microorganisms are secondary consumers. They eat consumers below them on the chain. There are even decomposers in this micro world. Micro food chains can also form the base of larger-scale food chains. Tiny sea creatures, such as krill, eat algae. Krill are food for fish, squid, and even enormous whales. You can move from the smallest to the largest animals on Earth in just a couple of links of a food chain!

Plentiful Plankton The ocean is home to many micro food chains. It is full of living things called plankton— organisms that drift on ocean currents. There are two main types of plankton. Phytoplankton are tiny producers. Just like plants, they use energy from the Sun to make food. Zooplankton are consumers that eat phytoplankton. Phytoplankton might be the most important living things on Earth! They are the base of almost every ocean food chain. They also give off oxygen as they make food from sunlight. Scientists think that most of the oxygen in the atmosphere today may have come from phytoplankton long ago. Phytoplankton even become part of Earth itself. When they die, their shell-like bodies pile up on the ocean floor. Over time, they get buried, and pressure turns the plankton bodies into solid rock. Limestone and chalk are rocks made from ancient plankton.

Some zooplankton are made of just a single cell. Others, like krill, are made of many cells. The zooplankton group even includes the eggs and young of some larger animals. For example, clams, crabs, and sea stars spend the first parts of their lives as zooplankton. Zooplankton are also incredibly important to ocean food chains. They are food for sponges, clams, and even whales. These animals filter large amounts of zooplankton from the water. The energy moves up and up the food chain. Do You Know? As plankton die, they sink and become part of marine snow— tiny bits of material such as plant parts and sand that fall through the water from the upper ocean to the ocean floor. Marine snow is an important food source for organisms that live deeper in the ocean.

Under Your Feet The ocean is not the only place that's full of microorganisms. Micro food chains are right under your feet! Soil is a mixture of small rock particles, dead plant and animal matter, and millions and millions of microorganisms. Bacteria by the billions live in soil. There are plenty of molds and fungi, too. For most of their life cycle, fungi, such as mushrooms, live in soil as tiny, hairlike hyphae (HI-fee). Fungi hyphae grow alongside plant roots. They help the roots take up water, nutrients, and minerals. Without fungi, many crops and trees could not grow. Wowser! Microorganisms even live up in the clouds. They may help form raindrops and snowflakes by providing a surface for water to condense upon.