DYNAMICS OF AQUATIC
DYNAMICS
OF AQUATIC
ECOSYSTEMS
SET 2011
SET
2011
Class nº 2
Luis Chícharo ([email protected])
QUESTIONS TO DISCUSS:
5 MAJOR CAUSES OF AQAUTIC ECOSYSTE DYNAMIC
5 MAJOR THREATS TO AQUATIC ECOSYSTEMS
5 MAJOR IMPACTS ON AQUATIC ECOSYSTEMS
3 TYPES OF SOLUTIONS FOR RESTORING AQUATIC ECOSYSTEMS
GROUP DISCUSSION – 4-5 STUDENTS
SEND REPLIES BY EMAIL TO [email protected]
Solutions
Human impacts reduction
Population awareness
Fisheries regulation
Resources management
Environmental education
Global warming
Pollution
Nutrient load
overfishing
Wind
Salinity
Tides
Input of
freshwater
Latitude
currents
Upwelling and downwelling
Climate
Human interactions/intervention
Hydrologic processes
Changes in
Trophic levels/
Shift in foodwebs
Nutrient conc
Geo‐natural processes
Primary productivity
Natural events ‐ catastrophes
Coral bleaching
Coral bleaching
Sediments
Interaction dif species
Pressures/causes
Eutrophication
HABs
Alien species
Acidification
Mutation
Migration patterns
New diseases
Biodiversity reduction
Threats/Impacts
Creation of protected areas
Conservation
Restoration
WHAT IS AN ECOSYSTEM?
Etymologically the word ecosystem
derives from the Greek oikos, meaning
"home," and systema,
y
or "system."
y
Nineteenth- and early 20th-century
ecologists, who were well aware of the
complex interdependence of living
and nonliving matter, coined several
terms, such as biocoenosis,
microcosm,
i
holocoen,
h l
biosystem
bi
and
d
geobiocoenosis.
It was nott until
til B
British
iti h ecologist
l i tA
A.G.
G
Tansley proposed the word
"ecosystem" (1935) that American
Raymond L
L. Lindeman offered the now
classic definition (1942).
Ecosystems are composed of a variety
of abiotic and biotic components that
function in an interrelated way.
WHAT ARE AQUATIC ECOSYSTEMS?
Basic ecological unit composed of living and non-living
elements
l
t interacting
i t
ti iin an aqueous milieu
ili
Any watery environment, such as rivers, lakes, wetlands,
and estuaries, in which plants and animals interact with the
chemical and physical features of the environment
WATER PHYSICAL-CHEMICAL
SC
C
C C
CHARACTERISTICS
C
S CS + BIOTA
O CO
COMMUNITIES
U
S
COMMENT THIS DEFINITION
Ecosystem - A functional system which includes the organisms of a natural
community together with their environment. (McGraw Hill Dictionary of
S i tifi and
Scientific
dT
Technical
h i lT
Terms, 4th ed)
d)
DO YOU AGREE?
HOW WOULD YOU DEFINE ECOSYSTEM?
WHAT ARE AQUATIC ECOSYSTEMS?
Freshwater lake ecosystem
Artic ecosystem
Ocean beach ecosystem
Temporary ponds ecosystem
WHAT BONDS THEM TOGETHER?
WATER CYCLE RESIDENCE TIME AND LONG TERM
ROBUSTNESS
Estimated Flows of Water in the Global Water
Cycle
15
Flows given in units of 10 kg/year
Inventory of Total amount of water:
1 385 990 5 x 1015 kg
1,385,990.5
Residence times
Data from Chahine, 1992, The hydrological cycle and its influence on climate, Nature, v. 359, p. 373-380;
AQUATIC ECOSYSTEMS REQUIREMENTS..?
NEED TO BE PERMANENT?
and TEMPORARY LAGOONS,
and...TEMPORARY
LAGOONS PONDS
NATURAL OR ARTIFICIAL?
and LAKES FROM DAMS
and...LAKES
PRESENT STABLE
CHARACTERISTICS?
and ESTUARIES
and...ESTUARIES
IS A MINIMUM OR MAXIMUM
SIZE?
and...SMALL
d SMALL PONDS / OCEAN
NEED TO BE IN PRISTINE FOR and
d CHRONIC POLLUTION
FUNCTIONING?
HIGH VARIABILITY IN
SPATIAL TEMPORAL,
SPATIAL,
TEMPORAL BIOTIC AND ABIOTIC FEATURES
Actual status of water resources and Global pressures on aquatic ecosystems
Freshwater availability for humans and
Ecosystems
y
Only 3% of Earth
Earth’ss water is freshwater,
freshwater and only 0.03%
0 03% is both accessible
and suitable for human use (Bhandari, 2003).
THE ALLERTS
Global freshwater consumption rose sixfold between 1900 and 1995 more than twice the rate of population growth. About one third of the
world's population already lives in countries considered to be 'water
stressed' - that is, where consumption exceeds 10% of total supply.
If present trends continue, two out of every three people on Earth will
live in that condition by 2025.
Kofi Annan
Annan, in We The People,
People 2000
ANTHROPOCEN ERA
Human pressure on aquatic ecosystems
Map of Africa, Europe, and Asia shows projected population change for 2025. This
map was developed by the Center for Climate Systems Research (CCSR) of the
Earth Institute at Columbia University shows the human migration to the coast.
Credit: Stuart Gaffin, Lee Hachadoorian, and Robert Engelman