Transcript Marine Ecology Terms

Marine Ecology Terms
• Ecology - study of
the relationships of
living organisms
(biota) to the
environment (abiotic
or non-living part)
• Major marine
habitats are divided
into 2 groups:
1. Pelagic Zone - photic
zone containing
plankton (floaters) and
nekton (swimmers).
a. neritic - coastal
areas
b. oceanic - open
water
2. Benthic Zone substrate on the
margins or basins.
a. aphotic - 90% dark
area of open water
b. abyssal - deep
bottom of the ocean
These habitats are
occupied by 5 levels
of biota:
1. Individual - one plant
or animal of a specie
a. plankton - organisms
that can not make a
forward motion against a
current.
• Phytoplankton photosynthetic producers
• Zooplankton - primary
consumers
b. nekton: swimming
animals
ex: fish mammals,
birds, reptiles
c. benthos - bottom
dwellers
• Epifauna - live on
substrate.
Ex: crabs
• Infauna - live in
substrate.
Ex: worms
d. demersal - hover or
walk.
Ex: lobsters
e. sessile - attached
Ex: barnacles
2. Populations
• 2 or more individuals of the same
species who must compete for
mates, food, light, and space
because they occupy the same
niche and habitat.
• DNA studies are used to identify
which individuals are part of a
population.
• Population density is the number
of individuals divided by the size
of the habitat.
• Population density is effected by
–
–
–
–
Geography
Season factors
Pollution
Birth-death ratio based on the
number of adults
3. Communties
• 2 or more populations occupying
different niches in the same
habitat.
• Community living has an
advantage by reducing
competition, increasing variety and
diversity.
The general niches are:
a. Producers phytoplankton, start the
food chains.
b. Consumers herbivores, carnivores,
omnivores - eat others
c. Decomposers scavengers, break down
organic compounds into
nutrients for producers
Communities age in a process called biological
succession.
a. Pioneer - first populations move into a habitat such
as the polychaete worm.
b. Juvenile - young populations; simple food chains
c. Mature - older communities with complex food webs,
stable populations are those where natality =
mortality
4. Ecosystems
• have two or more
communities whose
lifestyle is related to a
unique habitat.
• Ex: coral reefs, polar
seas
• Changes in the
components will have
unpredictable effects,
but ecosystems have
remarkable ways of
restoration.
5. Biosphere
• composed of many
ecosystems,
• exhibiting great
diversity, that are
related by the
interdependence of
living things.
Energy Relationships
In ecosystems, energy is
cycled through these
niches:
• Autotrophs - produce
food by photosynthesis
• Heterotrophs consume autotrophs
and other heterotrophs
• Decomposers rearrange organic
materials into nutrients
for autotrophs
• The amount of energy
available to support life
is called the carrying
capacity.
• Food chains represent
the steps in transferring
energy through the
ecosystem. Complex
and integrated food
chains are called food
webs.
• A keystone specie is
the critical biomass in
an ecosystem because
the food web is built
around that particular
organism.
• Energy can be
representations by
trophic pyramids
that compare the
number of
organisms in a
population, or the
weight (biomass)
of organisms, or
the productivity
(energy calories).
Why does the amount of
energy change if energy is
never created or
destroyed?
1. It can be converted into
unusable forms such as
heat or for organisms’
respiration, metabolism,
and predation.
2. Not all parts of an
organism have food value
or provide calories.
Ex: bones, scales
• The amount of energy available is
calculated as net productivity or
primary productivity.
• Primary productivity of the ocean is
22-28 billion tons of carbohydrates
(mostly glucose)
• Gross productivity - respiration = net
productivity given in units of g/m2/yr.
• Respiration is the amount of energy
used at each level to maintain life
(estimated at 90% of the available
calories.
• If one trophic level has 100,000
calories available, only 10,000 can
potentially be transferred to the next
trophic level.
• The more levels in the
ecosystem pyramid the
less energy is available
in a useable form at the
next higher level.
• Shorter food chains are
more efficient. The
reason the ocean can
support the tremendous
expense of endothermic
mammals is because
they eat low on the food
chain
Building Ecosystems
• When competition is
fierce, communities form
symbiotic relationships
to improve survival odds
and build healthy
ecosystems.
• Symbiosis - closely
associated life styles
exhibited by more than
half of all marine
animals.
1. Parasitism
– the most
common type of
association
– One benefits,
one is fatally
harmed (+-)
– Ex: worms,
bacteria
2. Mutualism
• Both organisms benefit (++)
• Ex: wrasses set up “cleaning stations” where they are allowed
to eat the parasites off larger reef fish. They get an easy meal
and help reduce parasites on fish.
• Ex: coral is an animal that allows zooanthellae (algae) to live
inside the protection of its hard skeleton. The algae makes
food for the sessile animal.
3. Commensalism
• One benefits, the other
not affected (+ o)
• Ex: The remora fish is
allowed to attach itself
to the chin of the shark,
who is a very messy
eater. The remora has
someone to catch food
for it. The shark is not
affected.
Sea as a Resource
• The UN Law of the Sea
Treaty (1982) establishes an
Exclusive Economic Zone
(EEZ) up to 200 nautical
miles off shore.
• Coastal nations are given
jurisdiction over 40% of the
ocean’s resources, but they
must share with land-locked
countries.
• In return, they are
responsible for pollution
clean-up in the EEZ.
Territorial waters have
increased from 3 to 12 miles.
The primary resources to
be exploited are:
1. Minerals – primarily oil,
– but also Mn, Mg, Cu, Al,
salt, sand, and many
others
– Most are difficult to
reach
2. Mariculture
• The science of farming
the sea
• It will not solve the
world hunger problem,
but will certainly help.
• Farms must be located
in coastal areas where
pollution is often the
highest
3. Fisheries
• Commercial fishing is a $50
billion industry worldwide.
• Of the thousands of species,
only 9 major groups are
harvested and many are
overfished.
• Finfish and shellfish provide
10% of the animal protein
worldwide. Not all of this is for
human consumption
• The maximum sustainable yield
is the largest number of fish that
can be harvested and still allow
the species to continue.
Destroying Ecosystems
• In the past “dilution was the
solution to pollution”.
• Today we realize that “we all live
downstream”.
• Pollution is generally divided into
2 classes:
a. point source - where the
source can be identified,
regulated & prosecuted
b. non-point - where no single
entity is responsible, such as
runoff from over-fertilized
yards or oil stained highways
and parking lots.
Types of Pollution:
1. Sewage
• greatest single source of
ocean pollution
• It is most harmful because
it often contains mixtures
of all the other types of
pollution.
• High bacteria counts,
particularly E.coli (also
called fecal coliform) points
to serious pollution and
potential health hazards.
2. Oil
• Sources are oil tanker
accidents (Exxon Valdez),
offshore drilling (BP), runoff,
and eco-terrorism
• Oil mats marine bird’s
feathers so they can’t fly,
catch food or keep warm.
• When marine mammals
ingest it, the result is liver
damage and hypothermia.
• Oil also coats benthic
organisms, larvae and eggs.
It prevents evaporation and
gas exchange at the surface,
resulting in suffocation.
3. Thermal
• Sources are
discharges from
industries using water
for cooling which
raises the temperature
an average of 12
degrees.
• Most organisms can
only tolerate 3-5
degree increase.
4. Chemical
• Sources are industry,
pesticides, runoff into storm
drains
• Biomagnification is a
process by which
organisms concentrate
toxins in the exchange of
energy in food webs.
• Notable examples such as
Minimata Bay (Japan) and
Chernobyl (Russia)
produced birth defects and
cancers in humans.
• Birds developed reproductive
disorders like soft shelled and
crossed bills.
• There may be many hidden
connections linking chemicals
in our food, water, and air to a
variety of disorders and
disease.
• High phosphate and nitrates
cause algae blooms that block
sunlight and gas exchange.
Bacteria decomposing organic
material further reduce oxygen
levels.
5. Garbage &
Dumping
• Sources may be
individuals, industry
or the government
• Activities such as
dredging, fisheries,
and ships dumping
million/tons/yr of
trash increases the
problem.
• Animals become
entangled in pop-tops,
six-pack rings or
mistake nonbiodegradable
substances and plastics
for food.
• It may later cause
suffocation,
strangulation or
digestive blockages
6. Acid rain
• Created by emissions from industry, cars, and space
shuttle launches.
• When pH is altered, enzymes for metabolism are
affected and limits for tolerance of other tissues may
be exceeded.
• Acid rain is formed when sulfur and nitrogen oxide
are emitted into the air from burning of fossil fuels.
• As precipitation (rain,
dew, snow) falls, it
combines pollutants with
oxygen and water to
form carbonic, sulfuric,
and nitric acids.
• Acids restrict the
formation of shells and
prevents enzyme
activity.
7. Greenhouse Effect
• Results in atmospheric heating
• It is caused by an increase in carbon dioxide levels
that prevent infrared light from escaping the
atmosphere.
• This results in world-wide temperature increases
• With warmer temperatures, the sea level could rise as
glacial ice melts.
• Salinity, density, and coastlines would change.
However, scientists do not agree on many of these
issues.