Presentation on theme: "Compare and Contrast What are some ways in which life in an aphotic zone might differ from life in a photic zone Apply Concepts What is a wetland and."— Presentation transcript:
1 Compare and Contrast What are some ways in which life in an aphotic zone might differ from life in a photic zoneApply Concepts What is a wetland and why are they importantPredict How might a dam upriver affect an estuary at the river’s mouthReview List the three major marine ecological zones and give two abiotic factors for each.
2 Ch 4 Ecosystems and Communities 4.5 Aquatic Ecosystems
3 Nearly three-fourths of Earth’s surface is covered with water.
4 Aquatic organisms are affected primarily by the water’s depth, temperature, flow, and amount of dissolved nutrients.
5 Water DepthSunlight penetrates only a relatively short distance through waterPhotic zoneSunlit region near the surface in which photosynthesis can occurMay be as deep as 200 meters in tropical seasMay be much, much less.
6 Photosynthetic algae (phytoplankton) live in the photic zone Zooplankton (tiny free-floating animals)eat phytoplankton.
7 Aphotic zone Benthic zone Benthos Photosynthesis cannot occur Rocks and sediments and on bottom of lakes and streamsBenthosAquatic organisms that live in the benthic zone.
8 Temperature and Currents Warmer near the equator and colder near the polesDeepest parts of lakes and oceans are often colder than surface watersCurrents can carry different temperature waters.
9 Nutrient Availability Not consistent in aquatic habitats.
10 Freshwater ecosystems can be divided into three main categories: rivers and streams, lakes and ponds, and freshwater wetlands.
11 Rivers and StreamsOften originate from underground water sources in mountains or hillsHave plenty of dissolved oxygen but little plant life near sourceSediments build up and plants establish themselves downstreamDepend on terrestrial plants and animals that live along their banks for food.
12 Lakes and PondsBased on a combination of plankton and attached algae and plantsWater flows in and out of lakes and ponds and circulates between the surface and the benthos, distributing heat, oxygen, and nutrients.
13 Freshwater Wetlands Wetland May have flowing water Water either covers the soil or is present at or near the surface for at least part of the yearMay have flowing waterNutrient-rich, highly productive, and serve as breeding grounds for many organismsPurify and filter waterFreshwater bogs, freshwater marshes, and freshwater swamps.
14 Estuary Saltwater wetland Where river meets the sea Affected by tides Spawning and nursery grounds for many ecologically and commercially important fish and shellfish species.
15 Marine EcosystemsOcean divided into zones based on depth and distance from shore:Intertidal zone, the coastal ocean, and the open ocean.
17 Intertidal ZoneSubmerged in seawater at high tide and exposed to air and sunlight at low tideBarnacles and seaweed attached to rocks.
18 Coastal OceanExtends from the low-tide mark to the outer edge of the continental shelfWater is brightly lit, and is often supplied with nutrients- very productive.
19 Open OceanBegins at the edge of the continental shelf and extends outwardMore than 90 percent of the world’s oceanDepth ranges from 500 m along to more than 10,000 mDivided into photic and aphotic zones.
20 Photic ZoneTypically has low nutrient levels and supports only small phytoplanktonMost photosynthesis occurs in the top 100 meters of the open ocean.
21 Aphotic ZonePermanently darkDeepest parts of the ocean.