What factors affect life in aquatic ecosystems?

Transcription

1 Aquatic Ecosystems: Notes Outline Today s Objective: Students will explain that different types of organisms exist within aquatic systems due to chemistry, geography, light, depth, salinity, and/or temperature. What factors affect life in aquatic ecosystems? ! Water Depth: Water depth strongly influences aquatic life because penetrates only a relatively short distance through. The sunlit region is known as the. The may be as deep as 200 meters in tropical seas, or deep or less in rivers and swamps. Photosynthetic algae, called live in the photic zone., or tiny free-floating animals eat phytoplankton and is often the first transfer of energy in many aquatic food webs. Below the photic zone is the dark where photosynthesis cannot occur because sunlight cannot penetrate. Organisms that live on the bottom of bodies of water are called and their habitat is called the. Draw a picture and label each of the three main zones of water depth: photic zone, aphotic zone, and benthic zone!

2 2.! Temperature & Currents (Flow): Aquatic habitats are near the equator and near the poles. in aquatic habitats often varies with. The deepest parts of lakes and oceans are often than surface waters. 3.! Nutrient Availability: Organisms need certain substances to live, such as. The and of these dissolved substances vary within and between bodies of water, greatly affecting the types of organisms that can there. What are the major categories of freshwater ecosystems? 1.! 2.! 3.! examples: bogs, swamps, marshes 1.! Rivers & Streams: Rivers, streams, creeks, and brooks often originate from in mountains or hills. Animals in many rivers and streams depend on and that live along their banks for food. 2.! Lakes & Ponds: The food webs in lakes and ponds often are based on a combination of and attached and plants. is a general term that includes both phytoplankton and zooplankton. Water flows in and out of lakes and ponds and circulates between the surface and the benthos (bottom), distribution 3.! Freshwater Wetlands: A is an ecosystem in which water either covers the soil or is present at or near the surface for at least part of the year. Water may or stay in place.

3 Wetlands are, highly productive, and serve as for many organisms. Freshwater wetlands water by filtering pollutants and help to prevent flooding by large amounts of water and slowly releasing it. The three main types of freshwater wetlands are,, and. Saltwater/freshwater wetlands are called. 4.! Estuaries: An is a special kind of wetland, formed where a river meets the sea. Estuaries contain a mixture of freshwater and saltwater, and are affected by the of ocean tides. Many are, which means that enough sunlight reaches the benthos to power. Estuaries serve as spawning and nursery grounds for many ecologically and commercially important fish and shellfish species. are temperate estuaries that have salt-tolerant grasses above the low-tide line and below water. are tropical estuaries that have several species of salt-tolerant trees, collectively called. The largest mangrove area in America is in How do ecologists usually classify marine ecosystems? Ecologists typically divide the ocean zones based on and from shore. Starting with the shallowest and closest to land, marine ecosystems include the,, and.

4 Draw a picture and label each of the three main ocean zones: intertidal zone, coastal ocean, and open ocean! 1.! Intertidal Zone: Organisms in the intertidal zone are submerged at and exposed to at low tide. The organisms are subjected to regular and extreme changes in temperature and are often bettered by. 2.! Coastal Ocean: The coastal ocean extends from the to the outer edge of the, the relatively shallow border that surrounds the continents. Water in the coastal ocean is, and is often supplied with nutrients by from land. As a result, coastal oceans tend to be. and are two important coastal communities. 3.! Open Ocean: More than of the world s ocean area is considered open ocean. Depth ranges from along continental slopes to more than in ocean trenches. The open ocean is divided into two zones based on light penetration: The open ocean typically has low nutrient levels and supports only the smallest species of. Still, because of its enormous area, most on Earth occurs in the sunlit top of the open ocean. The permanently dark includes the deepest parts of the ocean.

5 !