Nutrient balance in ponds can be hard to
control since there are multiple nutrients such as phosphorous, nitrogen, and
ammonium (scholarworks.montana.edu) Phosphorus is
used as a source of food for algae which helps the algae to increase. The algae
will then produce dissolved oxygen in the water to help sustain animals living
in the water(syngentaprofessionalproducts.com). Ammonia comes
from the waste of fish (pondexpert.ca).
It also comes from decaying plants, animals, and algae. Ammonia in ponds will
affect the fish that are surrounded by it (pondexpert.ca). The fish will become stagnant and swim
near the surface fighting to breathe. Their scales will also become a red color
from the loss of blood circulation (pondexpert.ca).
Nitrogen and phosphorous are food sources for
algae (phoslock.eu). Nitrogen is not as big of a concern as phosphorus because
algae can get nitrogen from the environment (phoslock.eu). Phosphorous is a
limiting nutrient which can stop algae from growing (phoslock.edu). When
there is excess phosphorus, algae can use it to help grow and sustain life (phoslock.eu). The growth of some more nasty algae will
fight off healthier ones (phoslock.eu). Macrophytes
use up most of the phosphorus as a bundle of weeds (syngentaprofessionalproducts.com).
is cycled through the water as ammonia, nitrate and nitrite. As ammonia becomes
excessive, bacteria called Nitrosomonas use it as a food source and
change it to nitrites (pondexperts.ca).
Nitrites are less harmful than ammonia, but if in excess, they can become
dangerous. As nitrites increase, a bacteria called Nitrobacter changes
the nitrite into nitrates which are even less dangerous (pondexperts.ca).
As the Nitrobacter increase, nitrites will decrease. (pondexperts.ca).
The cycle ends with nitrates. Nitrates will appear in a pond that has no plants
or algae and are not broken down by bacteria. (pondexperts.ca). The immune systems of fish cannot
handle accumulated amounts of nitrite(pondexperts.ca).
When nutrients become excessive in ponds,
eutrophication occurs. “Eutrophic is the term used to describe the condition of
nutrient enrichment when aquatic plant growth becomes excessive. One of the key
concerns of eutrophication is the impact of oxygen levels.” (Bruulsema, et al.,
Large sprouts of algae occur because of eutrophication (nature.com). These
large sprouts of algae can block the sunlight which can kill off algae, plants,
and animals in the water (nature.com).
Predators are also affected by the blocking
of sunlight because they need the light to see and catch their prey (nature.com). After
the algal sprouts die off, the decomposition process begins which uses up the
oxygen in the water (nature.com).
The decomposition process causes anoxic and hypoxic conditions. Anoxic means there
is no oxygen present and hypoxic means there is only little oxygen and not
enough of it (ozcoast.gov.au). Hypoxic water can cause the death of animals living in the
water and can cause a specific
temperature effect (ozcoast.gov.au). This effect
is where the warm water mixes with the water that has little oxygen this causes
stress for the fish (wtop.com). Hypoxic water can make harmful chemicals
such as hydrogen
sulfide and ammonia gas, which can harm the animals in the water
(ozcoasts.gov.au). Anoxic water can also cause the death of animals living in the water (ozcoasts.gov.au).