Global WarmingGlobal Warming

1. Meteorological conditions2. Nutrient inputs, concentrations,

and cycling rates3. Food web interactions 4. Sediment characteristics5. Morphology

Aquatic systems are often strongly nutrient -limited

Functions of the EcosystemFunctions of the Ecosystem The energy is assimilated

and the required food is produced

The Consumers feed on the producers

The return of the nutrients to their primary place

Energy Flow through the Ecosystem

NPP among ecosystemsNPP among ecosystems

Controls on primary production in aquatic ecosystems

Types of Aquatic EcosystemsTypes of Aquatic Ecosystems

Freshwater Ecosystems Standing Water- lakes &

ponds Moving Water- rivers &

streams Transitional

Communities Wetlands- bogs/fens,

swamps, marshes Estuaries

Marine Ecosystems Shorelines Barrier Islands Coral Reefs Open Ocean

Freshwater Ecosystems:Freshwater Ecosystems: Freshwater ecosystems cover 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. Aquatic ecosystems perform many important environmental

functions. For example: They recycle nutrients, purify water, attenuate floods,

recharge ground water and provide habitats for wildlife. Aquatic ecosystems are also used for human recreation,

and are very important to the tourism industry, especially in coastal region.

There are three basic types of freshwater ecosystems: Lentic: slow-moving water, including Pools, Ponds,

and Lakes. Lotic: rapidly-moving water, for

example Streams and Rivers. Wetlands: areas where the soil is saturated with water

or inundated for at least part of the time

Freshwater EcosystemsFreshwater Ecosystems1. Freshwater ecosystems cover 0.8% of the

Earth's surface and contain 0.009% of its total water.

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

3. Usually 0.005% saltSome exceptions:

Great Salt Lakes- 5-27% salt

Dead Sea- 30% salt

4. Moving water- high elevations; cold; high O2; trout; streamlined plants

5. Standing water- lower elevations; warmer; less O2; bass, amphibians; cattails, rushes

6. There are three basic types of freshwater ecosystems:

1. Lentic: slow-moving water, including Pools, Ponds, and Lakes.

2. Lotic: rapidly-moving water, for example Streams and Rivers.

3. Wetlands: areas where the soil is saturated with water or inundated for at least part of the time

Food Web: Micro levelFood Web: Micro level <0.2µm bacteria and

viruses 0.2-2µm prokaryotes 2-20µm eukaryotes,

fungal zoospores, macrozooplanktons…

20-200µm phytoplanktons > 200µm multicellular

zooplankton,

HerbivoreSnailTurtleMusselsAquatic insectsZooplankton

HerbivoreSnailTurtleMusselsAquatic insectsZooplankton

CarnivoreCray fishBluegill SunfishLarge mouth bassFrog

CarnivoreCray fishBluegill SunfishLarge mouth bassFrog

Primary ProducersPhytoplanktonPlantsAlgae

Primary ProducersPhytoplanktonPlantsAlgae

Food Web : Macro levelFood Web : Macro level

DecomposersDecomposers

Biotic Components:Biotic Components:1) Producer Organisms:

1) It includes submerged, free floating and amphibious macrophytes (like; Hydrilla, Utricularia, Wolfia, Azolla, Typha etc.) and minute floating and suspended lower phytoplanktons (like; Ulothrix, Spirogyra, Oedogonium etc.)

2) Consumer Organisms: 1) Primary consumers: These are zooplanktons (ciliates, flagellates, other

protozoan, small crustaceans) and benthos.

2) Secondary consumers: These are carnivores like insects and fishes feeding on herbivores

3) Tertiary consumers: These are the large fishes feeding on small fishes.

3) Decomposers: Micro – organisms like bacteria, fungi and actinomyctes.

A biotic component:These are the inorganic as well as organic substances present in the bottom soil or dissolved in water. In addition, to the minerals, some dead organic matter is also prese

Lakes & Pond Ecosystem:Lakes & Pond Ecosystem:1. A pond is a place where living organisms not

only live but interact with biotic & abiotic components.

2. Ponds are often exposed to tremendous anthropogenic pressure which significantly affects the system.

3. Lakes are usually big standing freshwater bodies.

4. They have a shallow water zone called Littoral zone; an open water zone where effective penetration of solar light takes place, called Limnetic zone and a deep water zone where light penetration is negligible, called Profoundal zone.

Pond ecosystem

Lake ecosystem

Frog

Bass

Cray fish

Bluegill

Carp

Turtle

Snail

Mussels

Zooplankton

Phytoplankton

Food Food Chain: Chain:

PondPond

Ponds and Lakes

lake stratification: what lives in lake stratification: what lives in each leveleach level Epilimnion- upper layer of

warm water; high light & O2; ex: water striders, phyto- & zooplankton, fish

Thermocline (mesolimnion); middle layer; medium light & O2; ex: phyto- & zooplankton, fish

Hypolimnion- lower layer of cold water; lower light & O2; ex: fish

Benthos- bottom level; no light & little O2; ex: anaerobic bacteria, leeches; insect larvae

Littoral- near the shoreline; cattails, rushes, amphibians, etc.

Food Chain : Food Chain : LakeLake

Streams & Rivers

River River ContinuumContinuum

Heterotrophic: respiration exceeds production with photosynthesis respiration ratio less than one. The biotic community is dependent on the organic matter washed in from the terrestrial watershed

Autotrophic:Middle section the streams become wider and less shaded; algae, aquatic green plantsgrow; species diversity reaches the peak.

Down streams the river widens and deepens: More no of tertiary consumers dwell in this stretch of the river.

Food Chain : StreamsFood Chain : Streams

Importance Importance of Wetlandsof Wetlands

Highly productive- get lots of sunlight, ↑ plants =↑ animals

Nesting, breeding ground for migratory birds

Slows flooding by absorbing runoff

•Silt settles, making water clearer & nutrient rich

•Trap & filter water

•Natural chemical neutralize and detoxify pollutants

•Gives H2O time to percolate thru soil & replenish underground

aquifers.

•Threats- artificial eutrophication, draining, sedimentation via

construction

•“Nature’s Septic Tank”

Wetlands

River Otter Damselfly Dragonfly Mayfly

Crayfish Snails Leech Bluegill

Bass

Catfish Sculpin Minnow Snakes

Great Blue Heron Canadian Goose Frog

Turtle

Transitional CommunitiesTransitional Communities WETLANDS Land saturated at least

part of the year Swamps- have trees like

bald cypress; high productivity

Marshes- no trees; tall grasses; high productivity

Bogs/Fens- may or may not have trees; waterlogged soil with lots of peat; low productivity Fens- fed by groundwater

& surface runoff Bogs- fed by precipitation

BogFen

Marsh

Swamp

Transitional Communities: Transitional Communities: EstuariesEstuaries Where freshwater

dumps into ocean Brackish (less salty

than seawater) Has rich sediments

that often form deltas Productive & biodiverse Organisms adapted to

varying levels of salinity as tide ebbs & flows

“Nursery” for larval forms of many aquatic species of commercial fish & shellfish

Food Chain : EstuariesFood Chain : Estuaries

Estuary food chains often overlap, making food webs.

Relative Importance Of Food Web Linkages

Primary (75-100% of Total)

Secondary (50-74% of Total)

Tertiary (25-49% of Total)

Incidental (0-24% of Total)

PacificStaghornSculpin

Great BlueHeron

PenpointGunnel

SharpnoseSculpin

Small Fish (inc.herring, perch)

BuffaloSculpin

ChumSalmon (juv.)

TubenosePoacher

Mysids

GammaridAmphipods

Detritus

Cumaceans

PaddedSculpin

Tunicates

StarryFlounder (juv.)

Sanderlings,Long & Short-billed

Dowitchers, Greater Yellowlegs

SaddlebackGunnel

BenthicMeiofauna

Hippolytid, Crangonid,

And PenaeidShrimp

PolychaeteAnnelids

GastropodMolluscs

SaltmarshPlants & Eelgrass

Phytoplankton

MicrophyticAlgae

Whimbrel, Mallard, Northern Shoveler, Pintail,

Western Sandpiper

EnglishSole (juv.)

CrescentGunnel

Nemerteans

TidepoolSculpin

ShinerPerch

BrachyuranCrabs

HarpacticoidCopepods

SnakePrickleback

GastropodMolluscs

Anthozoans

BivalveMolluscs

Snow Goose, Canada Goose,

black Brant, American coot

FlabelliferanIsopods

MacrophyticAlgae

SilverspottedSculpin

Tanaids

BayPipefish

ValviferanIsopods

From Simenstad et al. 1979

Because many animals eat more than one thing, tracing energy through the estuary can get messy.

Inside Marine or Ocean Inside Marine or Ocean Ecosystem:Ecosystem:

Marine or Ocean Ecosystem:Marine or Ocean Ecosystem:1. Marine ecosystems are among the Earth's aquatic ecosystems.

They include: Oceans,  Estuaries and Lagoons, Mangroves and Coral reefs, the Deep sea and the Sea floor.

2. These are the gigantic reservoirs of water covering approximately 71% of the Earth's surface (an area of some 361 million square kilometers).

3. These ecosystem is different from freshwater ecosystem mainly because of its salty water.

4. The salt concentration in an open sea is usually 3.5% (35 parts per thousand (ppt) ). Dominant ions are sodium & chloride.

5. Average temperature of Marine ecosystem is 2-3 degree centigrade, devoid of light.

Biotic components:Biotic components:1) Producers: It includes phytoplanktons (diatoms, dinoflagillates),

large seaweeds (mainly algae like chlorophyceae, phaeophyceae & rhodophyceae; angiosperms like Ruppia, Zostera, posidonia etc.), and mangrove vegetation (like Rhizophora, Carapa etc.)

2) Consumers:1) Primary consumers: These are herbivores and feed directly

on producers (Crustaceans, Mollusks, fish etc.)2) Secondary consumers: These are carnivorous

fishes(Herring, Sahd and Mackerel)3) Tertiary consumers: These are top carnivorous fishes (Cod,

Haddock, etc.)

3) Decomposers: These are micro – organisms like bacteria, fungi

A biotic components:High Na, Ca, Mg and K salt concentration, variable dissolved oxygen content, light & temperature make a unique physiochemical conditions in marine water.

Food Chain : OceanFood Chain : Ocean

Food Chain: Hot SpringsFood Chain: Hot Springs

1. Autotropes: The photosynthetic mats by algae

2. Herbivores: Ephydrid flies in the cooler areas of the spring which feed on bacteria and algae

3. Carnivores: Dolichopodid fly feeds on eggs of larvae and herbivores

4. Decomposers

The simplest form of food chain

Table 1. Average net primary production and biomass of aquatic habitats. Data from R.H. Whittaker and G.E. Likens, Human Ecol. 1: 357-369 (1973).

Primary Production

Winter Spring Summer Fall

North Atlantic- temperate climate

zooplanktonphytoplankton

biomass

Winter Spring Summer Fall

Arctic

zooplanktonphytoplankton

Winter Spring Summer Fall

Tropical

zooplanktonphytoplankton

Pyramids Pyramids

Eltonian PyramidEltonian Pyramid

Fig. 3-16, p. 52

Tertiaryconsumers(human)

Secondaryconsumers(perch)

Producers(phytoplankton)

Primaryconsumers(zooplankton)

Usable energy availableat each trophic level

(in kilocalories)

HeatDecomposers

10

100

1,000

10,000

Heat

Heat

Heat

Heat

Ecological PyramidsEcological Pyramids

Pyramid of energy flow

Ecological efficiency

Pyramid of biomass

Pyramid of numbers

Energy loss between trophic levels

Pyramids of biomass represent the ecological consequence of low trophic efficiencies. Less energy is transferred at higher trophic

levels.

In some aquatic ecosystems, the pyramid is inverted.

phytoplankton grow, reproduce, and are consumed rapidly.

turnover time is short

Pyramid of energy is always upright. It is so because at each transfer about 80 - 90% of the energy

available at lower trophic level is used up to overcome its entropy and to perform metabolic activities.

Only 10% of the energy is available to next trophic level (as per Lindemann's ten percent rule).

Pyramid of Energy in a Food Chain