Water FOR LifE
All living things need water to live. Plants, animals, us humans… we need it to drink, and without it, plants, animals, and any other living organism that needs drinking water would thirst.
Large bodies of water like lakes and oceans have different layers or zones. Some organisms may live in only one or two zones, while other organisms can live in three.
Large bodies of water like lakes and oceans have different layers or zones. Some organisms may live in only one or two zones, while other organisms can live in three.
Oceans have similarities to lakes in terms of zones, but with greater differences in water motion, salinity and depth, diversity is much greater in the oceans.
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ADAPTATIONS FOR AQUATIC LIFE
An adaptation is a physical characteristic or behavior of a species that increases that species' chances of survival in a particular environment. All living things are adapted to live in particular environments. In Canada lakes are affected by extreme changes in temperature.
Organisms living in the freshwater ecosystem of a lake or pond must be able to adapt to these changes in order to survive. As changes occur within their environment, those organisms that can adapt to the changes have a better chance of surviving than those organisms that cannot adapt to the changes. Many aquatic organisms filter the water to get their food.
There are five factors that have led to the development of adaptations by aquatic species:
Organisms living in the freshwater ecosystem of a lake or pond must be able to adapt to these changes in order to survive. As changes occur within their environment, those organisms that can adapt to the changes have a better chance of surviving than those organisms that cannot adapt to the changes. Many aquatic organisms filter the water to get their food.
There are five factors that have led to the development of adaptations by aquatic species:
Temperature | Fish that live in cold water have adapted to the temperature. Their body would overheat in warm water. Fish that live in extremely cold water (Arctic) have a natural anitfreeze that keeps their blood and tissues from freezing. In the very deep parts of the ocean, near volcanic vents, organisms can actually survive in extremely hot water |
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Light | Most organisms need light. Plants need light to photosynthesize (make food). In the deepest parts of the ocean some organisms have adapted to the absence of light by producing their own light from spots on their bodies called photophores. |
Pressure | As you travel deeper in the ocean, the pressure increases. Those animals that have adapted to different regions of the ocean would perish in other regions because they would be unable to survive the pressure difference. |
Salinity | The salt content of the ocean water can be very high. Those organisms that live in this ecosystem cannot survive in freshwater. Freshwater organisms cannot live in saltwater, because the salt makes fluid leave their bodies. Salmon can survive in freshwater (where they are born) and saltwater (where they live most of their lives). |
Water Movement | Some organisms are able to live in fast moving water. Some organisms are adapted to dig themselves into the sand for protection. (Clams do this) Clams show at the edge of the surf line when you pound the beach with a shovel handle or your foot. They may squirt sand and water out of the hole where they are located. Barnacles attach themselves to rocks or other objects in the water. Many aquatic animals use the buoyancy of the water to help them move and their streamlined shape in the water reduces drag. |
AQUATIC PLANTS
There are two types of aquatic plants: those attached to the bottom and those that float freely in the water. Aquatic plants need sunlight and therefore can only survive in water where sunlight can penetrate. Attached plants are rooted in the soil on the bottom of a pond, or at the edge of a lake. Seaweed attach themselves to the bottom. Getting oxygen to waterlogged roots is accomplished by open channels in their spongy stems.
Aquatic plants must push their flowers above the water surface, so that insects or the wind can spread pollen and seeds. Seaweeds are marine plants, that do not have roots, flowers or leaves. They do photosynthesize and use the energy of the sun to create food. Phytoplankton are tiny plants that live on the surface of lakes and oceans and produce oxygen. Their tiny irregular shape, and long spines are adaptations that help them stay in the zone of water where light can penetrate.
Aquatic plants must push their flowers above the water surface, so that insects or the wind can spread pollen and seeds. Seaweeds are marine plants, that do not have roots, flowers or leaves. They do photosynthesize and use the energy of the sun to create food. Phytoplankton are tiny plants that live on the surface of lakes and oceans and produce oxygen. Their tiny irregular shape, and long spines are adaptations that help them stay in the zone of water where light can penetrate.