Aquatic Ecosystems Unit 4 (Ch 4)

Watersheds A region drained by or contributes to a stream, lake, or other body of water Also called a drainage basin Large watersheds are broken into smaller sub-watersheds Anything that happens on the land in a watershed can affect the quality of the water that it empties into As well as the organisms that live there

PA Watersheds All the freshwater in PA eventually drains into the Atlantic Ocean There are 5 major watersheds in PA which are broken down into 104 sub-watersheds

Great Lakes Basin Only 1% of this lies in PA The Conneaut, Elk and Walnut Creeks (in PA) all empty into Lake Erie PA areas

Ohio River Basin 2nd largest watershed in PA Covers ~16,000 square miles of the state Contains the Ohio and Allegheny Rivers along with some others in the western part of PA

Susquehanna/Chesapeake Basin Largest watershed in PA Contains the Susquehanna River (which starts in NY) Empties into the Chesapeake Bay which flows into the Atlantic Ocean

Potomac Basin Only about 1% of the state is in this watershed even though the Potomac River is not The Shenandoah River is a tributary (feeder) into the Potomac

Delaware Basin Covers 6,500 square miles in PA 3rd largest watershed in PA Much of the water from the Delaware River and its tributaries empty into the Hudson basin which provides most of the drinking water for New York City

Freshwater Ecosystems Divided into two groups Lotic: relatively fast moving water Rivers, streams, brooks, creeks and human-made channels Lentic: relatively slow moving water Lakes, ponds, and wetlands What is the difference between a lake and a pond? Lakes larger, too deep for plants to root Pond smaller, shallow enough for rooted plants to grow across the bottom

Streams Streams are classified by their size Sometimes called creeks or brooks First order stream- smallest Second order – form when two first order streams meet This area of meeting is called a confluence Third order – a confluence of two second order streams This process continues until the stream empties into a larger body of water

Arrows show areas of confluence- where streams meet to make larger streams before emptying into larger bodies of water

Floodplains Areas of flat land along a stream or river that is periodically flooded These areas contain organisms that are adapted to living in wetter ecosystems Amphibians, algae, insects thrive in these ecosystems

Aquatic Habitats Surface Film  place where water meets the air Organisms found here are mostly insects Open Water  area where rooted plants do not reach the surface of the water Organisms include large fish, turtles, and birds Bottom  are of rocks, sand or mud that is the habitat for small organisms Bacteria, snails, worms, sponges, crayfish and larvae or insects Water’s Edge  where water meets the land Greatest number of plants and animals found here

Surface Film Bottom Open Water Water’s Edge

Checkpoint What characteristic is used to classify a body of water as a lake or a pond? Which aquatic habitat would contain the largest variety of organisms? How does a watershed form?

Answers Depth and the ability of plants to take root The water’s edge. It would have plants and animals from the land and aquatic ecosystem A watershed forms where ever the majority of water in an area drains into.

Marine Ecosystems Water with high salt content Life depends on temperature and amount of sunlight

Zones of the Oceans

Estuaries Salt water wetland Place where fresh water from rivers meets salt water from oceans Delaware Bay, Chesapeake Bay Most bay areas and harbors

Adaptations Estuaries are very productive (lots of organic matter) Lots of sunlight and nutrients available Large populations of plants that are rooted into the mud Lots of phytoplankton (microscopic plants) and zooplankton (microscopic animals) Organisms are able to tolerate variations in salinity (salt content) and depth Some animals- dolphin, manatees, oysters, clams, variety of fish

                                           

Threats Pollution- sewage, industrial waste, agricultural runoff Ship waste, oil Development- adds to pollution and overfishing

Coral Reefs

Coral Reefs Corals- small marine animals that live on a limestone skeleton they create Small polyps anchor to an area, release limestone (calcium carbonate) and form amazing reefs Found only in warm, tropical salt water Have a mutualistic relationship with some algae that helps maintain reefs They need light for photosynthesis

Adaptations There are very few plants in coral reefs- they need shallow water and warm temperatures Corals are predators- they have stinging tentacles that catch plankton or fish that swim too close Other animals are adapted to specific habitats with in the reef There are many mutualistic relationships in reefs

Bulldozer shrimp and goby fish – mutualistic relationship Sea anemone and clownfish

Threats Pollution Change in water temperature (global warming) Sedimentation Too much sediment from rivers, block sunlight so algae die and smother corals

Dead coral reef in Indonesia

The Ocean Ocean cover about 75% of the earth’s surface Most ocean life is in shallow waters near coasts There, sunlight is plentiful and lots of nutrients from land and river runoff

Plant Adaptations Plants are only found around shores and where sunlight reaches Phytoplankton is main source of food for herbivores in open ocean

Animal Adaptations Smallest herbivores- zooplankton Include jelly fish, tiny shrimp, fish larvae Dozens of fish feed on zooplankton Fish bodies are shaped for movement through the water Camouflage Deep ocean- mutualistic relationship with bacteria for bioluminescence to occur

Threats to the Oceans Pollution Overfishing Global warming

Polar Regions Ice covered polar caps of the North and South Poles Nearly all food is provided by phytoplankton No plants

The Arctic (N) No land The arctic is made up of massive frozen part of the Arctic Ocean surrounded by floating icebergs Food web relies on phytoplankton which provides food for many fish Whales, seals, penguins and polar bears are some organisms that make their homes here

Antarctic (S) Only continent never settled by humans Is governed by an international commission and is only used for research Plankton is base of food web Fish, whales, penguins and other birds are some organisms found here

Threats Mineral and Oil extraction