Chapter 7. Aquatic Ecology: Biodiversity in Aquatic Systems Miller – Living in the Environment 13 th ed.

Who lives in a pineapple under the sea?

Aquatic Life Zones 1)Saltwater or Marine estuaries, coastlines, coastal marshes, mangrove swamps, and oceansestuaries, coastlines, coastal marshes, mangrove swamps, and oceans 2)Freshwater lakes and ponds, streams and rivers, inland wetlandslakes and ponds, streams and rivers, inland wetlands

Types of organisms PhytoplanktonPhytoplankton –cyanobacteria and algae ZooplanktonZooplankton –primary and secondary consumers NektonNekton –Swimming consumers (fish, turtles, and whales) BenthosBenthos –bottom dwellers Barnacles and oystersBarnacles and oysters WormsWorms Lobsters and crabsLobsters and crabs DecomposersDecomposers –bacteria

Factors Limiting Life in Aquatic Life Zones 1)Temperature 2)Access to sunlight Euphotic zoneEuphotic zone 3)Dissolved oxygen 5 ppm5 ppm 4)Available nutrients Shallow waterShallow water upwellingupwelling

Fig. 6-5, p. 130 Darkness Twilight Photosynthesis Sun Continental shelf Estuarine Zone High tide Low tide Coastal Zone Bathyal Zone Euphotic Zone Abyssal Zone Sea level Open Sea The Coastal Zone

Coastal Wetlands River mouthsRiver mouths InletsInlets BaysBays SoundsSounds Mangrove forest swampsMangrove forest swamps Salt marshesSalt marshes

SaltMarsh

Mangrove Forests Are found along about 70% of gently sloping sandy and silty coastlines in tropical and subtropical regions.Are found along about 70% of gently sloping sandy and silty coastlines in tropical and subtropical regions.

Estuaries and Coastal Wetlands: Centers of Productivity Estuaries and coastal marshes provide ecological and economic services.Estuaries and coastal marshes provide ecological and economic services. –Filter toxic pollutants, excess plant nutrients, sediments, and other pollutants. –Reduce storm damage by absorbing waves and storing excess water produced by storms and tsunamis. –Provide food, habitats and nursery sites for many aquatic species.

Importance of coral reefs Removing CO 2 from atmosphereRemoving CO 2 from atmosphere Natural barrierNatural barrier –Waves and storms –Allows oceans to replenish beach sand Supports marine lifeSupports marine life Source of global fish catchSource of global fish catch Provides food, jobs, and building materials for world’s poorest countriesProvides food, jobs, and building materials for world’s poorest countries Supports fishing and tourismSupports fishing and tourism Scientific researchScientific research

coral bleaching caused by the loss of algae

Ocean warming Soil erosion Algae growth from fertilizer runoff Mangrove destruction Coral reef bleaching Rising sea levels Increased UV exposure from ozone depletion Using cyanide and dynamite to harvest coral reef fish Coral removal for building material, aquariums, and jewelry Damage from anchors, ships, and tourist divers

Biological Zones in the Open Sea: Light Rules Euphotic zone: brightly lit surface layer. –Nutrient levels low, dissolved O 2 high, photosynthetic activity. Bathyal zone: dimly lit middle layer. –No photosynthetic activity, zooplankton and fish live there and migrate to euphotic zone to feed at night. Abyssal zone: dark bottom layer. –Very cold, little dissolved O 2.

Fig. 6-5, p. 130 Darkness Twilight Photosynthesis Sun Continental shelf Estuarine Zone High tide Low tide Coastal Zone Bathyal Zone Euphotic Zone Abyssal Zone Sea level Open Sea The Coastal Zone

Effects of Human Activities on Marine Systems: Red Alert Human activities are destroying or degrading many ecological and economic services provided by the world’s coastal areas.

Lakes: Water-Filled Depressions Lakes are large natural bodies of standing freshwater formed from precipitation, runoff, and groundwater seepage consisting of: –Littoral zone –Littoral zone (near shore, shallow, with rooted plants). –Limnetic zone –Limnetic zone (open, offshore area, sunlit). –Profundal zone –Profundal zone (deep, open water, too dark for photosynthesis). –Benthic zone –Benthic zone (bottom of lake, nourished by dead matter).

Life Zones Found in Freshwater Littoral zone – consists of shallow water near the shore to the depth at which rooted plants quite growing.Littoral zone – consists of shallow water near the shore to the depth at which rooted plants quite growing. Limnetic zone – the open sunlite water surface away from the shore. The main photosynthetic body of the lake.Limnetic zone – the open sunlite water surface away from the shore. The main photosynthetic body of the lake. Profundal zone – deep, open water, too dark for photosynthesis.Profundal zone – deep, open water, too dark for photosynthesis. Benthic zone – at the bottom of the lake. Cool temperatures and low oxygen levels.Benthic zone – at the bottom of the lake. Cool temperatures and low oxygen levels.

Sunlight Painted turtle Green frog Pond snail Blue-winged teal Muskrat Plankton Northern pike Bloodworms Yellow perch Diving beetle Littoral zone Limnetic zone Profundal zone Benthic zone

Lakes: Water-Filled Depressions deep temperate zone lakesstratified into temperature layersoverturn.During summer and winter in deep temperate zone lakes the become stratified into temperature layers and will overturn. –This equalizes the temperature at all depths. –Oxygen is brought from the surface to the lake bottom and –nutrients from the bottom are brought to the top.

Epilimnion Hypolimnion Thermocline SummerFall overturn 22 ˚ 20 ˚ 18 ˚ 8˚8˚ 6˚6˚ 5˚5˚ 4 ˚C 0˚0˚ 2˚2˚ 4˚4˚ 4˚4˚ 4˚4˚ WinterSpring overturn 4˚4˚ 4˚4˚ 4˚4˚ 4˚4˚ 4˚4˚ 4 ˚C Dissolved O 2 concentrationHighMediumLow 4˚4˚ 4˚4˚ 4˚4˚ 4˚4˚ 4˚4˚ 4 ˚C Seasonal Changes in TemperateLakes

Effects of Plant Nutrients on Lakes: Too Much of a Good Thing Plant nutrients from a lake’s environment affect the types and numbers of organisms it can support. –Oligotrophic (poorly nourished) lake: Usually newly formed lake with small supply of plant nutrient input. –Eutrophic (well nourished) lake: Over time, sediment, organic material, and inorganic nutrients wash into lakes causing excessive plant growth.

Effects of Plant Nutrients on Lakes: Too Much of a Good Thing Cultural eutrophication:Cultural eutrophication: –Human inputs of nutrients from the atmosphere and urban and agricultural areas can accelerate the eutrophication process.

Sunlight Little shore vegetation Limnetic zone Profundal zone Oligotrophic lake lake Low concentration of nutrients and plankton Sparse fish population Narrow littoral zone deeply sloping shorelines Sand, gravel, rock bottom Sunlight Much shore vegetation Limnetic zone Profundal zone Eutrophiclake High concentration of nutrients and plankton Dense fish population Wide littoral zone Gently sloping shorelines Silt, sand, clay bottom oligo = little + trophic = nutrition eu = truly + trophic = nutrition

Rain and snow Water Sediment Lake Glacier Rapids Waterfall Tributary Flood plain Oxbow lake Salt marsh Delta Ocean Deposited sediment Source Zone Transition Zone Floodplain Zone Major Characteristics of Freshwater Streams and Rivers

Freshwater Inland Wetlands: Vital Sponges Inland wetlands act like natural sponges that absorb and store excess water from storms and provide a variety of wildlife habitats.

Freshwater Inland Wetlands: Vital Sponges Filter and degrade pollutants.Filter and degrade pollutants. Reduce flooding and erosion by absorbing slowly releasing overflows.Reduce flooding and erosion by absorbing slowly releasing overflows. Help replenish stream flows during dry periods.Help replenish stream flows during dry periods. Help recharge ground aquifers.Help recharge ground aquifers. Provide economicProvide economic resources and recreation.

Impact of human activities Fragmentation by dams, diversions, or canals Flood control levees and dikes –Alter or destroy aquatic habitats –Disconnect rivers and floodplains –Eliminate wetlands Draining or filling of wetlands Cities and farmlands add pollutants and excess plant nutrients to streams and rivers.