Aquatic ecosystems

Aquatic Ecosystems An ecosystem located in water bodies Marine eco systems Open sea Coastal Estuary and salt marshes Coral reefs and mangroves Open sea Estuary and salt marshes Coral reefs and mangroves rivers, streams and springs ponds lakes Fresh water ecosystems Flowing water (rivers, streams and springs) Static / slow moving water (ponds, lakes, pools / swamps)

An ecosystem located in water bodies

Marine eco systems

Open sea

Coastal

Estuary and salt marshes

Coral reefs and mangroves

Fresh Water Ecosystems Fresh water covers 0.8% of the Earth's surface and contain 0.009% of its total water. Freshwater ecosystems contain 41% of the world's known fish species. Two types of freshwater ecosystems: Lotic : Flowing water (rivers, streams and springs) Lentic: Static / slow moving water (ponds, lakes, pools)

Fresh water covers 0.8% of the Earth's surface and contain 0.009% of its total water.

Freshwater ecosystems contain 41% of the world's known fish species.

Two types of freshwater ecosystems:

Lotic : Flowing water (rivers, streams and springs)

Lentic: Static / slow moving water (ponds, lakes, pools)

Lotic Ecosystems Variation in lotic ecosystems (even within a river or a stream) is considerable and is determined by Shape of stream / river bed (can form microhabitats) Stream / river bed's gradient Quantity of water Velocity of the current Faster moving water has higher concentrations of dissolved oxygen, and therefore supports greater biodiversity Light Temperature most lotic species are poikilotherms, whose internal temperature varies with the surrounding temperature Water chemistry (which changes in large rivers) Species adapted to live in conditions of constant flow

Variation in lotic ecosystems (even within a river or a stream) is considerable and is determined by

Shape of stream / river bed (can form microhabitats)

Stream / river bed's gradient

Quantity of water

Velocity of the current

Faster moving water has higher concentrations of dissolved oxygen, and therefore supports greater biodiversity

Light

Temperature

most lotic species are poikilotherms, whose internal temperature varies with the surrounding temperature

Water chemistry (which changes in large rivers)

Lotic Ecosystems riparian Sunlight nutrients decomposers Primary producers Macroinvertebrates Fish Frog amphibians reptiles Mammals (dolphins, otters) Fish Macro invertebrates Insects Molluscs (snails, clams, mussels) Crustaceans (crabs) Bacteria Primary producers Algae, Mosses, Liverwort, Duckweed, Water hyacinth Reptiles (turtles, crocodiles, snakes) Amphibians (salamander)

Macro invertebrates

Insects

Molluscs (snails, clams, mussels)

Crustaceans (crabs)

Lentic Ecosystems Lakes are heterogenous and not a uniform mass of water Biodiversity within a lake is also variable and depends on Physical characteristics Light Temperature Water currents Chemical characteristics Nutrients Contaminants

Lakes are heterogenous and not a uniform mass of water

Biodiversity within a lake is also variable and depends on

Physical characteristics

Light

Temperature

Water currents

Chemical characteristics

Nutrients

Contaminants

Lake zones Terrestrial plants Littoral zone Emerged plants Floating plants Limnetic zone (open water) Submerged plants Euphotic zone Benthic zone

Lake organisms Creatures that go where ever they choose to go Creatures that go where ever the water takes them Creatures that live on the lake bottom fish amphibians Larger zooplanktons Living creatures – planktons Animals: zooplanktons Algae : phytoplankton Bacteria : bacterioplankton Dead creatures –Detritius Internal: produced within lake External: washed in from wash shed Animals Aquatic insects, clams, snails worms, cray fish Plants macrophytes periphyton Bacteria and fungi Sewage sludge

The food chain in a lake NUTRIENTS EAT USE RECYCLE EAT EAT PISCIVOROUS FISH PLANKTIVOROUS FISH ZOOPLANKTON ALGAE BENTHIC ORGANISMS

Food and energy web in a lake DECOMPOSERS LOSS THROUGH OUTLET LOST TO SEDIMENTS RECYCLED NUTRIENTS TERITIARY CONSUMERS SECONDARY CONSUMERS PRIMARY CONSUMERS PRIMARY PRODUCERS OUTSIDE NUTRIENTS SOLAR ENERGY RECYCLED NUTRIENTS

Ocean zones 6,000m 10,000m 2000 to 1,000m 200m 700 to 1,000m 4 degree C 10 degree C

Marine ecosystems Spread over 71% of the Earth’s surface Open sea Coastal Estuary and salt marshes Coral reefs and mangroves Each is a complex ecosystem Producers, consumers and decomposers as in other ecosystems http://www.earthhistory.org.uk/ http://www.nu.ac.za http://www.learnnc.org/ http://www.geocities.com http://www.minresco.com/australia

Spread over 71% of the Earth’s surface

Open sea

Coastal

Estuary and salt marshes

Coral reefs and mangroves

Each is a complex ecosystem

Producers, consumers and decomposers as

in other ecosystems