ENVIRONMENTAL SCIENCE 20 - AQUATIC ECOSYSTEM

aquatic ecosystem

a group of organisms dependent on one another and a water environment for nutrients and shelter

Oligotrophic

low productivity

Estuary

a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it

Biodiversity

the number of variety of organisms in a certain region.

species diversity

measure of diversity in an ecological community. accounts for richness and total number of different species in a community.

ecosystem diversity

variations in ecosystems

Resistant ecosystems

"essentially unchanged" when subject to some sort of disturbance.

Resilient ecosystems

the capacity or ability of an ecosystem to recover from a disturbance or withstand ongoing changes or pressures.

indicator species

indicates the state or level of something
ex.) frogs

keystone species

a species n which other species largely depend on

Bioaccumulation

when an organism absorbs a substance (usually toxic) at a rate faster than that at which the substance is lost by catabolism and excretions

Biomagnification

the concentration of toxins in an organism as a result of its ingesting other plants or animals in which the toxins are more widely dispersed.

how much space do aquatic ecosystems take up on our planet?

71%

what are methods to get rid of oil spills in water

oil dispersants
booms & skimmers
leaving the oil alone
in situ burning

booms & skimmers

booms are floating barriers placed around the oil and the
-skimmers are boats

oil dispersants

work like dish soap
-breaks up the oil into tiny suspended droplets in the water
-naturally occurring bacteria would then consume the droplets & the dispersant would rapidly biodegrade/

leaving the oil alone

some scientists argue that oil spills should be left to disperse naturally. oil spills are dispersed by natural physical processes in high-energy environments where strong wind current and wave action help to break up the oil.

in situ burning

freshly spilled oil is ignited while it's still floating on the water.

uses of water

food
shelter & energy
health & hygiene
manufacturing
transportation

Role of water in life

- most organism contain over 50% liquid water by weight. water fills cells and supports their structure and provides a medium in which life-sustaining chemical reactions can take place. such as regulating body temperature.

water pollution

any physical

non-point sources of water pollution

run-offs from farm fields and feedlots

point sources of water pollution

factories

common types of water pollutants

pathogens
plant nutrients & other organic matter
heavy metals
other inorganic chemicals
sediment
petrochemical and other organic chemicals
heat

Pathogens

microscopic disease-causing bacteria. viruses

plant nutrients and other organic matter

urine and feces from animals as well as nitrates & phosphate from fertilizers

heavy metals

inorganic chemicals including: mercury

Cholera

extremely virulent disease that can cause severe acute watery diarrhea.
- takes between 12 hours to 5 days for a person to show symptoms after ingesting contaminated food or water.
-can kill within hours if untreated

typhoid fever

an acute illness associated with fever caused by the Salmonella typhi bacteria. The bacteria is deposited in water or food by a human carrier and are then spread to other people in the area.

typhoid Mary

a carrier of typhoid fever who worked as a cook and spread it to multiple wealthy families. she was eventually caught and quarantined in a deserted island where she escaped and returned to working as a cook

infectious hepatitis

Hepatitis A is a liver disease caused by the hepatitis A virus. The virus is primarily spread when an uninfected/unvaccinated person ingests food or water that is contaminated with the feces of an infected person.
-does not cause chronic liver disease and is rarely fatal

Polio

poliomyelitis is a highly infectious viral disease

Jonas Salk

He discovered and developed one of the first successful polio vaccines.

coliform bacteria

intestinal bacteria whose presence in a water sample indicates fecal contamination

testing for coliform bacteria

1. take a water sample
2. place the sample on a growth medium
3. after 24 hours

Catabolism

the breakdown of complex molecules in living organisms to form simpler ones

Aquatic Ecosystems in Canada

ponds
lakes
rivers
floodplains
wetlands

organisms in aquatic ecosystems

bacteria

lake

sizable body of water surrounded by land and fed by rivers

two types of lakes

-oligotrophic
-eutrophic

eutrophic

shallower

pond

smaller bodies of still water located in natural hollows or created by dams

rivers & streams

fresh

ocean

salt water that covers 70% of the world's surface

sea

typically have a salinity content between that of an ocean and a fresh water ecosystem

estuary

a partially enclosed body of brackish water with one or more rivers or streams flowing into it

four main types of estuaries

-coastal plain
-tectonic
-bar built
-fjord

coastal plain estuary

Formed at end of last ice age when rising sea level invaded low lying coastal river valleys.
ex.) The Thames (England)

tectonic

created when the sea fills in the 'hole' or basin that was formed by the motion of the earth's crust that creates cracks and faults on the land
ex.) San Francisco Bay

Bar Built

formed when sandbars build up along the coastlines. usually shallow

Fjord

valleys that have been cut deeper by moving glaciers and then invaded by the sea. They are narrow with steep sides and usually straight and long

difference between ocean and sea

seas are smaller than oceans and are usually located where the land and ocean met. a sea is part of the ocean partially enclosed by land.

healthy aquatic ecosystem

human disturbances have not impaired the natural functioning

unhealthy aquatic ecosystem

natural state is out of balance. can be physical

symptoms of a poor or unhealthy ecosystem

-loss of species
-accelerated growth of organisms
-tumours or deformities in animals
-change in chemical properties
-loss of Aboriginal culture associated with ecosystems

Why is the health of an ecosystem important?

everything is interconnected

things we can do to restore the health of an aquatic ecosystem

-environmental legislation to protect water from toxic substances
-integrated resource planning; consider relationships among land development and water
-technology
-environmental monitoring
-compensatory measures

wetlands

a land area that is saturated with water

hydric soil

soil that is saturated permanently or seasonally by water
- characterizes wetlands

what do wetlands contribute to the environment?

- absorb the impact of hydrologic events ( large waves or floods )
- filter sediments and toxic substances
- supply food and essential habitat
- also provide products for food

types of wetlands

swamp
marsh
bog

swamps

wetlands characterized by the presence of trees growing on silty organic muck soils.
- dominated by trees and are often named for the type of trees that grow in them.
- they are transition areas

two main types of swamps

freshwater swamps
saltwater swamps

freshwater swamps

commonly found inland and form around lakes and streams.

saltwater swamps

they are found and form on tropical coastlines.
-plants that are able to tolerate tidal flooding grow ( mangrove trees ) and decay

Florida Everglades

One of the largest freshwater swamps in the United States.
-it is a slow moving river flowing from the Kissimmee River

Mangrove Swamps

A saltwater swamp that grows mangrove trees.

marshes

a type of wetland

herbaceous

plants that have no persistent woody stem above ground

types of marshes

tidal saltwater marshes
tidal freshwater marshes
inland freshwater marshes

tidal saltwater marsh

form a grassy fringe near river mouths

tidal freshwater marsh

lie farther inland than saltwater marshes

inland freshwater marshes

found along the fringes of lakes and rivers where the water table

bogs

a freshwater wetland of soft

types of bogs

blanket bogs
cataract bogs
quaking bogs
raised bogs
string bogs
valley bogs

How do bogs form?

they take hundreds or thousands of years to develop
- a bog is forrmed when a lake slowly fills with plant debris.
-plants grow out from the lake's edges until it eventually covers the lake's entire surface

blanket bogs

develop in highland areas with significant rainfall: the bog "blankets" the entire area

cataract bogs

ecosystems that feature a permanent freshwater stream.

quaking bogs

develop over a lake or pond

raised bogs

vaguely dome-shaped

string bogs

have a varied landscape

valley bogs

develop in shallow valleys

North American Waterfowl Management Plan ( NAWMP )

A significant program that aims at protecting our remaining wetlands. Signed by Canada and the United States in reaction to the sharp decline in waterfowl populations associated with the destruction of their habitat.

abiotic factors in an ecosystem

atmosphere
water
air
soil
sun
UV radiation
salinity

Biotic factors in an ecosystem

parasitism
predation
competition for food
competition for space
fungi
plants

abiotic factors

affect the ability of organims to survive and reproduce. they restrict the growth of populations and help determine the number and types of numbers of organisms able to exist within an environment.

biotic factors

living organisms that affects another organism in its ecosystem. this inlcudes the organisms themselves

significance of abiotic and biotic factors

their interaction with each other. for a community of an ecosystem to survive

eutrophic

a lake or body of water rich in nutrients and so supporting a dense plant population

Process of Eutrophication

A lake

oligotrophic

characterized by a low accumulation of dissolved nutrient salts

oligotroph

an organism that can live in an environment that offers very low levels of nutrients

oligotrophic lake

-cool temperatures
-high oxygen concentrations
- low availability of nutrients
-low biological productivity
-steep shorline and deep bottom reduce heating during summer and help maintain lower water temperatures

eutrophic lake

-warm temperatures
-low oxygen availability
-high availability of nutrients
-high biological productivity
-shallow bottom reduces total water volume and increases heating during summer

step by step process of eutrophication

- nitrogen and phosphate fertilizer is spread on fields to help crops grow
- rain causes runoff to streams