Transcript Understanding the Environmental Requirements for Fish

Understanding the Environmental
Requirements for Fish
Next Generation Science/Common Core Standards Addressed!
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HS‐LS2‐6.Evaluate the claims, evidence, and reasoning that the complex
interactions in eco systems maintain relatively consistent numbers and types of
organisms in stable conditions, but changing conditions may result in a new
ecosystem.
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HS‐LS4‐5. Evaluate the evidence supporting claims that changes in
environmental conditions may result in: (1) increases in the number of individuals
of some species, (2) the emergence of new species over time, and (3) the
extinction of other species. [Clarification Statement: Emphasis is on determining
cause and effect relationships for how changes to the environment such as
deforestation, fishing, application of fertilizers, drought, flood, and the rate of
change of the environment affect distribution or disappearance of traits in
species.
Bell Work / Objectives
• Describe the factors affecting water
quality in our area.
• Explain water oxygenation.
• What area plankton and
phytoplankton.
Terms
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Aeration
Ammonia toxicity
Biomass
Eutrophication
Nitrogen cycle
Oxygenation
pH
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Phytoplankton
Plankton
Salinity
Water biology
Water chemistry
Zooplankton
Understanding the Environmental
Requirements for Fish
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Take a drink of water.
How god does it taste?
How important is water to your life?
How important is water to fish?
What factors affect water quality?
• Water is a simple compound consisting
of 2 parts hydrogen and 1 part oxygen.
• Water and its quality are very important
in fish production.
• Water quality has 3 characteristics.
– chemical characteristics
– physical characteristics
– biological characteristics
Chemical characteristics
• Water chemistry - many dissolved
molecules combined in the water.
• Common substances in water:
–Dissolved oxygen
–Nitrogen
–Hydrogen sulfide
–Carbon dioxide
–Iron
Chemical characteristics
• pH and salinity affect
water chemistry
• pH
– Measure of the
water’s acidity or
alkalinity.
• Salinity
– Amount of
dissolved salt in the
water.
Physical characteristics
• Temperature
–Determines physical characteristics
–Physical characteristics of water
• Solid
• Liquid
• Gas
–Fish have a specific range of
temperatures that they can survive
Water biology
• Water biology
–All of the living and non-living
organisms in the water.
–From the large aquatic plants to the
small microscopic organisms.
• Plankton
–Tiny plants and animals that float in
the water.
Plankton
Types of plankton
• Phytoplankton
–Algae plankton which produce oxygen
through photosynthesis
• Zooplankton
–Microscopic animal life that is often
used as food by many fish
Water biology
• Biomass
–All living organisms in a given
location.
What is water oxygenation?
• Fish rely on dissolved oxygen in
water to sustain their life functions.
• The amount of available oxygen is a
limiting environmental factor.
• When oxygen is limited, oxygen can
be added.
• This process is called oxygenation.
What is water oxygenation?
• One source of oxygen is from the air
above the water.
• This process of obtaining oxygen from
air above water is called aeration.
Methods of aeration
• Splashing
– Water is added to
system
– Water splashed
against concrete or
something similar
– Allows more water
molecules to come
into contact with air
molecules
• Pumping air or
oxygen into water
– Allows oxygen
molecules to come in
contact with water
molecules
– Allows oxygen to
become dissolved in
the water
– Commonly seen in
fish tanks
Methods of aeration
• Spraying water in air
–Use of a fountain or a paddle wheel.
–Water is sprayed into air causing it to
come into contact with oxygen.
–Water catches this oxygen and brings
back down into water.
Methods of aeration
• Using chemicals
– Potassium permanganate
added to ponds causing a
chemical reaction that
releases oxygen.
– Common method of using
chemicals is fertilizing the
pond.
• This allows aquatic plants
to grow increasing
photosynthesis.
What are the effects of nitrogen in water?
• Nitrogen is an abundant element in the
environment.
• Nitrogen circulates through the atmosphere,
soil, water, animals, and plants.
• This circulation is known as the nitrogen
cycle.
• Excessive nitrogen in water can be toxic to
fish.
• In highly intensive fish production systems,
nitrogen can be a problem.
Where does the nitrogen come from?
• Organic wastes in the water causes
excessive nitrogen in fish production.
• Organic material can be manure from
fish or uneaten feed.
• As this material decomposes, ammonia
is released.
• Ammonia is converted to nitrites.
• Ammonia and nitrites are both harmful
to fish.
Ammonia toxicity
• Ammonia toxicity
–Level of ammonia that
can cause harm
• High levels of nitrite in
the water will prohibit
blood in the fish from
effectively carrying
oxygen.
Ammonia toxicity
• Factors making ammonia more toxic
–Increasing temperatures
–pH becomes more alkaline
–Dissolved oxygen decreases
–Carbon dioxide increases
–Salinity decreases
Preventing nitrogen problems
• Intensive fish production cause
nitrogen levels to change quickly.
• Test nitrogen levels regularly.
• Care should be taken to prevent
over feeding of the fish.
• Design system to allow for proper
water flow to remove fish waste
from the system.
What are the effects of other common
compounds found in water?
• Phosphorus, chlorine, and heavy metals
may cause problems with water quality.
• Phosphorus
– Usually attributed to wastes entering water.
– In combination with nitrogen can cause
excessive nutrients in water.
– This is called eutrophication.
– This leads to algae blooms causing a
decrease in oxygen in water.
What are the effects of other common
compounds found in water?
• Chlorine
–Usually attributed to municipal
chlorinated water entering the system.
–Can cause problems for some species
of fish.
–To eliminate chlorine
• Water needs to be de-chlorinated by
aging or chemical treatments.
What are the effects of other common
compounds found in water?
• Heavy metals
– Lead and mercury.
– Attributed to water pollution from
manufacturing or illegal dumping.
– May not kill the fish, however absorbed into
fish and cause problems for humans
consuming the fish.
– Test water for heavy metals.
Review / Summary
• What factors affect water quality?
• What is water oxygenation?
• What are the effects of nitrogen in
water?
• What are the effects of other
common compounds found in
water?
The End!