LAKES AND LAKES AND PONDS PONDS

ECOSYSTEMECOSYSTEM

Ponds and LakesPonds and Lakes

Range in size from just a few square Range in size from just a few square meters to thousands of square meters to thousands of square kilometers.kilometers.

Ponds may be seasonal, lasting just a Ponds may be seasonal, lasting just a couple of months (such as sessile couple of months (such as sessile pools).pools).

Lakes may exist for hundreds of Lakes may exist for hundreds of years or more.years or more.

Ponds and LakesPonds and Lakes

May have limited species diversity May have limited species diversity

they are often isolated from one they are often isolated from one another and from other water another and from other water sources like rivers and oceans.sources like rivers and oceans.

Most ponds and lakes have outlet Most ponds and lakes have outlet streams and both are generally streams and both are generally temporary features on the landscape temporary features on the landscape

Formation of Lakes and Ponds:Formation of Lakes and Ponds:

Some of the oldest lakes and ponds Some of the oldest lakes and ponds (more than three hundred thousand years (more than three hundred thousand years old) were formed by tectonic activity old) were formed by tectonic activity related to movement of Earth's crust. related to movement of Earth's crust.

EXAMPLE: Lake Baikal in Siberia formed EXAMPLE: Lake Baikal in Siberia formed from the movement of tectonic plates from the movement of tectonic plates and is the largest freshwater lake by and is the largest freshwater lake by volume in the world. volume in the world.

Formation of Lakes and Ponds:Formation of Lakes and Ponds:

Lakes and ponds are formed through a Lakes and ponds are formed through a variety of events, including glacial, variety of events, including glacial, tectonic, and volcanic activity. tectonic, and volcanic activity.

Most lakes and ponds form as a result of Most lakes and ponds form as a result of glacial processes. glacial processes.

As a glacier retreats, it may leave As a glacier retreats, it may leave behind an uneven surface containing behind an uneven surface containing hollows that fill with water. hollows that fill with water.

Formation of Lakes and Ponds:Formation of Lakes and Ponds:

Volcanic activity can also lead to lake and Volcanic activity can also lead to lake and pond formation. pond formation.

EXAMPLE: the collapse of a volcanic cone EXAMPLE: the collapse of a volcanic cone of Mount Mazama in Oregon led to the of Mount Mazama in Oregon led to the formation of Crater Lake, the seventh formation of Crater Lake, the seventh deepest lake in the world. deepest lake in the world.

Lake Baikal

Crater Lake , Oregon

Ponds and LakesPonds and LakesTemperature varies seasonally.Temperature varies seasonally.

During summer the temp. is from 4°C During summer the temp. is from 4°C near the bottom to 22°C at the top.near the bottom to 22°C at the top.

During winter the temp. is from 4° C During winter the temp. is from 4° C while the top is 0° C (ice).while the top is 0° C (ice).

during the spring and fall seasons is during the spring and fall seasons is a mixing of the top and bottom a mixing of the top and bottom layers resulting in a uniform water layers resulting in a uniform water temperature of around 4° C.temperature of around 4° C.

Ponds and LakesPonds and Lakes

divided into four different divided into four different “zones” determined by depth “zones” determined by depth and distance from the shorelineand distance from the shoreline• littoral zonelittoral zone• limnetic zonelimnetic zone•profundal zoneprofundal zone•Photic zonePhotic zone•Benthic zoneBenthic zone

LittoralZone Limnetic

Zone

Profundal (aphotic) zone

Photic Zone

Benthic Zone

Littoral ZoneLittoral Zonewarmest since it is shallow and can absorb warmest since it is shallow and can absorb more of the Sun’s heatmore of the Sun’s heat

sustains a fairly diverse communitysustains a fairly diverse community

several species of algae (like diatoms) several species of algae (like diatoms)

rooted and floating aquatic plantsrooted and floating aquatic plants

grazing snailsgrazing snails

ClamsClams

InsectsInsects

CrustaceansCrustaceans

FishesFishes

amphibiansamphibians

Littoral ZoneLittoral Zonethe egg and larvae stages of some insects are the egg and larvae stages of some insects are found in this zonefound in this zone

vegetation and animals living in the littoral zone vegetation and animals living in the littoral zone are food for other creatures such as turtles, are food for other creatures such as turtles, snakes, and duckssnakes, and ducks

Limnetic ZoneLimnetic Zone

near-surface open water surrounded by near-surface open water surrounded by the littoral zone the littoral zone well-lighted (like the littoral zone) and is well-lighted (like the littoral zone) and is dominated by plankton, both dominated by plankton, both phytoplankton and zooplanktonphytoplankton and zooplanktonplankton are small organisms that play a plankton are small organisms that play a crucial role in the food chain – most life crucial role in the food chain – most life would not be possible without themwould not be possible without them variety of freshwater fish also occupy this variety of freshwater fish also occupy this zonezone

Profundal ZoneProfundal Zone

much colder and denser much colder and denser little light penetrates all the way little light penetrates all the way through the limnetic zone into the through the limnetic zone into the profundal zone profundal zone Plankton have short life spans—when Plankton have short life spans—when they die, they fall into the deep-they die, they fall into the deep-water part of the lake/pondwater part of the lake/pondAnimals found are decomposersAnimals found are decomposers

Photic zonePhotic zone

Primary production in the photic zone is influenced by Primary production in the photic zone is influenced by three major factorsthree major factors

NutrientsNutrientsLight- For photosynthesisLight- For photosynthesisGrazing Grazing pressure-the rate at which the plants are -the rate at which the plants are eaten by herbivores. eaten by herbivores. 

Photic zonePhotic zone

Nutrients, especially phosphate and nitrate, are often , especially phosphate and nitrate, are often scarce in the photic zone because they are used up scarce in the photic zone because they are used up quickly by plants during photosynthesis. quickly by plants during photosynthesis. External inputs of nutrients are received through:External inputs of nutrients are received through:RainfallRainfallRiverflowRiverflowWeathering of  of rocks and soil  and soil Human activities- sewage dumping. Human activities- sewage dumping.

Benthic ZoneBenthic Zone

The area of the bottom. The area of the bottom. 

Many groups and varieties of animals live here, a few Many groups and varieties of animals live here, a few are worms, crustaceans, and protozoa.  are worms, crustaceans, and protozoa.  

The life in this zone is mostly made up of bottom The life in this zone is mostly made up of bottom dwellers which get most of their food from dead and dwellers which get most of their food from dead and decaying organisms.  decaying organisms.  

most of the organisms in the benthic zone are most of the organisms in the benthic zone are scavengers because they depend on dead flesh as scavengers because they depend on dead flesh as their main food source. their main food source.

LAKES LAKES ECOSYSTEMECOSYSTEM

Clasification of LakeClasification of LakeOligotrophic lakesOligotrophic lakes- deep, nutrient-poor lakes - deep, nutrient-poor lakes in which the phytoplankton is not very in which the phytoplankton is not very productive. productive.

The water is usually clearThe water is usually clear

Eutrophic lakesEutrophic lakes-shallow, nutrient-rich lakes -shallow, nutrient-rich lakes with very productive phytoplankton. with very productive phytoplankton.

The waters are usually murky due to large The waters are usually murky due to large phytoplankton populations phytoplankton populations the large amounts of matter being the large amounts of matter being decomposed may result in oxygen depletion.decomposed may result in oxygen depletion.

Lakes EcosystemLakes Ecosystem

A lake is bigger than a pond, and is too deep to A lake is bigger than a pond, and is too deep to support rooted plants except near the shore. support rooted plants except near the shore. Some lakes are big enough for waves to be Some lakes are big enough for waves to be produced. produced.

Lakes may exist for hundreds of years or more. Lakes may exist for hundreds of years or more.

Lakes are often classified as oligotrophic or Lakes are often classified as oligotrophic or eutrophic, depending on the amount of organic eutrophic, depending on the amount of organic matter produced. matter produced.

Oligotrophic lake Eutrophic Lake

Examples of lakesExamples of lakes

Taal volcano lakeMitchigan lake

Grasmere lake

Silver lake Lake lamonia

Layers of lake separated by density gradient.

1. Epilimnion1. Epilimnion  the top-most layer in a thermally the top-most layer in a thermally stratified lake.stratified lake. It is warmer and typically has a It is warmer and typically has a higher pH and dissolved oxygen higher pH and dissolved oxygen concentration than the hypolimnion. concentration than the hypolimnion. It typically mixed as a result of surface It typically mixed as a result of surface wind-mixing. wind-mixing. Free to exchange dissolved gases (ie Free to exchange dissolved gases (ie O2 and CO2) with the atmosphere. O2 and CO2) with the atmosphere. It contains the most phytoplankton. It contains the most phytoplankton.

2. Thermocline2. Thermocline(sometimes (sometimes metalimnionmetalimnion) is a thin but distinct ) is a thin but distinct layer in a large body of fluid (e.g. water, such as an layer in a large body of fluid (e.g. water, such as an ocean or lake, or air, such as an atmosphere).ocean or lake, or air, such as an atmosphere).Temperature changes more rapidly with depth than Temperature changes more rapidly with depth than it does in the layers above or below. it does in the layers above or below. Thermoclines may be a semi-permanent feature of Thermoclines may be a semi-permanent feature of the body of water in which they occur, or they may the body of water in which they occur, or they may form temporarily in response to phenomena such form temporarily in response to phenomena such as the radiative heating/cooling of surface water as the radiative heating/cooling of surface water during the day/night.during the day/night. Factors that affect the depth and thickness of a Factors that affect the depth and thickness of a thermocline include seasonal weather variations, thermocline include seasonal weather variations, latitude, and local environmental conditions, such latitude, and local environmental conditions, such as tides and currents. as tides and currents.

3. Hypolimnion3. HypolimnionThe The hypolimnionhypolimnion is the dense, bottom layer of  is the dense, bottom layer of water in a thermally-stratified lake. It is the layer water in a thermally-stratified lake. It is the layer that lies below the thermocline.that lies below the thermocline.Typically the hypolimnion is the coldest layer of a Typically the hypolimnion is the coldest layer of a lake in summer, and the warmest layer during lake in summer, and the warmest layer during winter. Being at depth, it is isolated from surface winter. Being at depth, it is isolated from surface wind-mixing during summer, and usually receives wind-mixing during summer, and usually receives insufficient irradiance (light) for photosynthesis to insufficient irradiance (light) for photosynthesis to occur.occur.In deep, temperate lakes, the bottom-most In deep, temperate lakes, the bottom-most waters of the hypolimnion are typically close to waters of the hypolimnion are typically close to 4°C throughout the year. The hypolimnion may 4°C throughout the year. The hypolimnion may be much warmer in lakes at warmer latitudes.be much warmer in lakes at warmer latitudes.

BLUE LAKE

Dal LakeMono Lake

Okanagan Lake Lake Titicaca 

Lac Pavin in France is a meromictic crater lake

Lake Hoare

Freshwater: biological communities of Freshwater: biological communities of lakeslakes

PONDS PONDS ECOSYSTEMECOSYSTEM

Ponds EcosystemPonds EcosystemA pond is a small, shallow body of fresh, A pond is a small, shallow body of fresh, standing water in which relatively calmstanding water in which relatively calmwater and extensive plant growth.water and extensive plant growth.

The amount of dissolved oxygen may vary The amount of dissolved oxygen may vary greatly during a day. In really cold places, the greatly during a day. In really cold places, the entire pond can freeze solid. entire pond can freeze solid.

Water temperature is fairly even from top to Water temperature is fairly even from top to bottom and changes with air temperature. bottom and changes with air temperature.

Types of pondsTypes of ponds

Cypress Ponds Cypress Ponds

Bog PondsBog Ponds

Meadow-Stream PondsMeadow-Stream Ponds

Mountain PondsMountain Ponds

Farm PondsFarm Ponds

1. Cypress Ponds1. Cypress Ponds

Commonly found in the central or lower Commonly found in the central or lower Mississippi Basin Mississippi Basin

Waters are described as being brownish Waters are described as being brownish in colorin color

Many dry out during parts of the year. Many dry out during parts of the year.

Willows, bay trees mixed with cypress Willows, bay trees mixed with cypress trees, grow along the shore and are often trees, grow along the shore and are often found out in the waters. found out in the waters.

Cypress Pond on the Conecuh River near River Falls, Alabama

2. Bog Ponds2. Bog Ponds

Bog Ponds are often found in the Bog Ponds are often found in the moist temperature regions of North moist temperature regions of North America. America.

Water is highly acidic and often Water is highly acidic and often muddy. muddy.

Alders and cedar trees dominate Alders and cedar trees dominate

Floating-leaf plants usually cover the Floating-leaf plants usually cover the surface. surface.

3. Meadow-Stream Ponds3. Meadow-Stream PondsWhere streams widen and the speeds Where streams widen and the speeds of its currents slow down of its currents slow down tremendously. tremendously. The shallow part of the pond usually The shallow part of the pond usually has an abundance of pondweeds, has an abundance of pondweeds, cattails, stoneworts and other plants.cattails, stoneworts and other plants.Floating leafy plants on the surface Floating leafy plants on the surface of the water, such as lilies and water of the water, such as lilies and water shields. shields.

4. Mountain Ponds4. Mountain PondsFormed by glaciersFormed by glaciers

Bottoms range from being rocky, graveled Bottoms range from being rocky, graveled or muddy. or muddy.

Most of the time Mountain Ponds have ice Most of the time Mountain Ponds have ice in them and they usually dry up at some in them and they usually dry up at some point during the summer. point during the summer.

Sedges grow along its margins. In spite of Sedges grow along its margins. In spite of the pond’s short summer season, a variety the pond’s short summer season, a variety of animals and plants live in these icy of animals and plants live in these icy waters. waters.

5. Farm Ponds5. Farm PondsMan-made ponds built to help keep the Man-made ponds built to help keep the farmlands fertile. farmlands fertile. It should also have a spillway to control It should also have a spillway to control the water level. the water level. Farm ponds usually become abundant in Farm ponds usually become abundant in fish, and are usually good waters for fish, and are usually good waters for swimming and boating. swimming and boating. They should also fill from seepage, not They should also fill from seepage, not from another stream which would fill the from another stream which would fill the basin of the pond with silt and eventually basin of the pond with silt and eventually kill the pond. kill the pond.

Examples of pondsExamples of ponds

VEGETATION IN LAKES AND VEGETATION IN LAKES AND PONDS ECOSYSTEMPONDS ECOSYSTEM

Bitterling 

Bullfrog Common Carp

Great Crested Grebe 

Great White Pelican 

Green and Gold Bell Frog 

Lake Trout 

Largemouth Bass 

Animals in Lakes and PondsAnimals in Lakes and Ponds

PlatypusZambesi Softshell 

Functions:Functions:Lakes and ponds typically contain a diversity of organisms Lakes and ponds typically contain a diversity of organisms that perform different ecological functions. that perform different ecological functions. Lakes and ponds are an important source of fresh water Lakes and ponds are an important source of fresh water for human consumptionfor human consumptionWater has a high capacity for heat and earth is mostly Water has a high capacity for heat and earth is mostly covered with water, so the temperature of the atmosphere covered with water, so the temperature of the atmosphere is kept fairly constant and able to support life.is kept fairly constant and able to support life.

Plankton which account for most of the photosynthesis on Plankton which account for most of the photosynthesis on Earth found in lakes, ponds and oceans. Without, there Earth found in lakes, ponds and oceans. Without, there might not be enough oxygen to support such a large world might not be enough oxygen to support such a large world population and complex animal life.population and complex animal life.

We fish from the ponds and we often eat the fish we catch. We fish from the ponds and we often eat the fish we catch. Most of the time our water comes from the lakes and Most of the time our water comes from the lakes and ponds, but purified.ponds, but purified.

Environmental Problems:Environmental Problems:Freshwater biomes have suffered mainly from Freshwater biomes have suffered mainly from pollution.pollution.

Runoff containing fertilizer and other wastes, Runoff containing fertilizer and other wastes, and industrial dumpings enter into rivers, and industrial dumpings enter into rivers, ponds, and lakes tend to promote abnormally ponds, and lakes tend to promote abnormally rapid algae growth- rapid algae growth- ARTIFICAIL ARTIFICAIL EUTROPHICATIONEUTROPHICATION

When algae die, dead organic matter ends up in When algae die, dead organic matter ends up in the water. This makes the water unusable, and the water. This makes the water unusable, and it kills many of the organisms living in the it kills many of the organisms living in the habitat.habitat.

Possible Solution:Possible Solution:

Pond AerationPond AerationTo restore a pond or lake to a healthy condition, To restore a pond or lake to a healthy condition, we must restore the natural processes that we must restore the natural processes that allow them to assimilate the nutrient load that it allow them to assimilate the nutrient load that it receives. receives.

Ideally, nutrient inputs should be reduced or Ideally, nutrient inputs should be reduced or eliminated wherever possible. Only use eliminated wherever possible. Only use phosphorus-free fertilizers on lawns.phosphorus-free fertilizers on lawns.

Preventing nutrients from flowing down storm Preventing nutrients from flowing down storm sewers is a good way to prevent pollution. sewers is a good way to prevent pollution. 

THE END……THE END……