Muhammed Atamanalp1*, Gonca Alak1, Arzu Uçar1, Veysel Parlak2 and Muammer Kırıcı3
1Department of Aquaculture, Ataturk University, Turkey
2Department of Basic Science, Ataturk University, Turkey
3Department of Aquaculture, Bingol University, Turkey
Submission:January 05, 2019; Published: February 04, 2019
*Correspondence author: Muhammed Atamanalp, Department of Aquaculture, Ataturk University, Kampusu, 25030 Yakutiye/Erzurum,Turkey
How to cite this article: S Muhammed A, Gonca A, Arzu U, Veysel P, Muammer K. Environmental Concerns in Trout Breeding. Oceanogr Fish Open Access J. 2019; 9(1): 555754. DOI:10.19080/OFOAJ.2018.08.555754
As in other production branches, aquaculture facilities are also linked to the environment. Unlike these, aquaculture systems are more common in aquatic ecosystems because of their presence in wetlands, and the plant-environment relationship is more prominent than other food production branches. In this review, it is aimed to emphasize with the rapidly growing environment consciousness, which is fast developing fish breeding sector, with the intersection points of aquaculture and to reveal what can be done in this field.
Aquaculture has been the world’s fastest-growing food production technology during the last three decades, with an annual average growth rate of 6.2% since 2000 . Aquaculture is the most probable and feasible solution to providing the aquatic products for an ever-increasing market demand. It provides a consistent and reliable source of high-quality, fresh sea food that is nutritious, safe to eat and reasonably priced . The world human population is increasing exponentially. Such unrestrained population growth raises issues of food security while simultaneously maintaining a clean environment for future generations. As the human population grows, there is a corresponding increase in the demand for seafood . The evaluation of streams, lakes, ponds and seas in terms of aquaculture is important, as it is significant to monitor and control biological changes that may occur in these ecosystems in terms of sustainable aquaculture and conservation of aquatic ecosystems . The mediums, which livings have vital connections, affect and influence in different ways, are called environment. The environment of a creature; where is sustaining all kinds of biological, social, cultural, and economic activities of it, meeting the basic requirements of life such as nutrition, reproduction, and housing.
There is human at the center of all activities carried out in aquaculture and the main goal is to provide a source of protein to people. Therefore, the positive or negative aspects of these facilities will affect first the human being . When people enter these farms, the first thing that will attract their attention is the
appearance of these places. If the landscaping is nice, the person will be happy, but if there are repulsive views or structures, the aesthetic aspect of the human being will be hurt. Similarly, produced fish should not only have a taste but also have a nice view for appetite. As the health status of organisms grown in aquaculture farms will affect the health of people who will consume them, the necessary care should be taken at every stage of cultivation. The most important issue was evaluated as environmentally friendly aquaculture investments and management in the workshops conducted in 2010 in Latin America on aquaculture planning. It was foreseen that the use of technology in financial aspects such as pools used in aquaculture, stocking rates, feed and other material costs would reduce the impact on the environment . According to FAO, “sustainable development” is the protection and management of natural resources while continuously meeting the needs of current and future generations and successfully adapting technological and institutional changes. Sustainable development, including soil, water, plant and animal resources, is a socially acceptable approach that is harmless to the environment and has an economic life .
Negative environmental impacts attributed to aquaculture are often the results of these situations :
a) Bad planning
b) Unsuitable location selection
c) Improper management procedures
d) Disregard to environment protection
Aquaculture plants are produced in wetlands due to the
biology of fish. This situation causes the aquaculture plant and
environment relations to be more prominent than other food
Aquaculture has very specific characteristics for the following
I. Intersection with aquatic ecosystem which is the most
important element of the ecosystem.
II. Having very different plant structures (pool, hatchery,
cage, processing unit etc.)
III. Showing differences at physical, chemical and biological
parameters of aquaculture water.
IV. Containing high density living stock.
V. The main theme of production is the animal organisms
but the emergence of the product as human food.
VI. The wide spectrum of produced livings from plankton to
A misconception about aquaculture is that water taken into the
plants is considered as consumed water. However, the difference
between the amount of water entering the plant and the amount
of water exiting the plant is only the loss of evaporation and
leakage loss in the production processes. In well-planned facilities
this distinction is too small.
The relationship of the aquaculture facilities with the
environment starts before production. At this stage, visual
concerns should be kept in the foreground and designs should
be made to provide visual harmony. For example, in terrestrial
aquaculture, structures can be designed in harmony with the
environment in which they are located, and their exterior facades
can be painted appropriately . In the marine environment,
since the cage equipment is standard structures, there are no
visual problems. As it is in different structures and properties
in aquaculture plants (such as, hatchery, production, processing
etc.) it should be considered in more detail. It is important to
note that there is an existing ecosystem in a region before the
establishment of a facility. In inland aquaculture, it is significant
to show the necessary care for the protection of river beds during
the construction phase of the facilities, the current flow rate, the
physical, chemical and biological characteristics of the water
should not leave the original structure should be the basic rule
of this stage. The possibility of harboring endemic species in
these regions is important for preserving the authenticity of the
ecosystem. In the light of this sensitivity, the definition of water
pollution term has been shaped as moving away the physical,
chemical and biological properties of water from the originality.
Therapeutic chemicals should be given in the correct dosage
and time interval according to the conditions of use. Antibiotics
should not be used in discriminately and different antibiotics
should be used alternately instead of the same antibiotic .
Because of the chemicals used in the treatment of bacterial
diseases and other purposes used chemicals in the nearby
environment (fish, mussels, shrimp, lobster, aquatic plants)
bioaccumulation is concerned . The antibiotics are excreted as
the parent compounds or metabolites due to poor gut absorption
or incomplete metabolism resulting in frequent detection in
aquatic environment due to incomplete removal of antibiotics
during wastewater treatment and their continued release into
the environment . Antibiotic residues develop resistance
to bacteria in humans and there are problems in the treatment
of diseases. The chemicals used as disinfectants in aquaculture
may have toxic aspects so, the dose and time of use should be
determined well. Biocides are used for control of predators, pests
and weeds in fish farms usually before the start of aquaculture. In
this period, there are no significant discharges from the farm, and
there is no case of harmful effects in the environment. In addition,
the doses used in the aquaculture periods are not enough to cause
toxic effects to the fish in our own pools, so the amount of water
to be released into the environment is not worth considering. Due
to the high product variety in the chemicals, if there is a negative
effect of the used chemical in the environment, it is possible to use
The mixing of cultured aquatic species into the natural
environment leads to hybridization between species or the
exchange of genes among these species, changing the natural
structure. Cultured species that are involved in the natural
environment rival the domestic species in terms of nutrients,
occupy or change the habitat.
All animals produce wastes and compared to terrestrial
animals, aquatic animals produce relatively smaller amounts,
for several reasons. One is the fact that they are poikilothermic.
This means they burn no calories when maintaining an internal
body temperature higher than the environmental temperature.
Another reason aquatic animal produce fewer waste products is
that most secrete ammonia passively, directly from the blood into
the water through their gills. They don’t have to expend any energy
converting ammonia to fewer toxic forms such as urea (cows) or
uric acid (chickens). Also, aquatic animals live in, what is for them,
a basically weightless environment. Most can control buoyancy, so
they expend little or no energy fighting gravity. All these energy
savings mean it takes less feed to grow an aquatic animal. For
example, it takes 7 to 8 kg of feed to produce a kilogram of weight
gain in cows, 3 to 4 kg of feed in swine, and 2 to 3 kg in poultry.
However, for fish it takes only about 1.5 kg of feed. Because of this
relatively efficient feed conversion, less feed in means less waste
out. However, even in fish there is always some waste .
In aquaculture, fish stocking capacity varies depending
on the flow of source water on land, water circulation and
the size of cages in the sea. The higher the amount of stocks in
the enterprises, the higher the consumption of feed and the
use of chemicals. This may cause environmental pollution. In
addition, the metabolic wastes of the fish also cause an increase
in the amount of organic matter in the water . The rapid
development of aquaculture brings about some problems such as
solid and dissolved wastes left to the environment. In order to be
sustainable in aquaculture production, the issue that needs to be
given importance is environmentally conscious production .
In addition to feed losses during intensive feeding in aquaculture
enterprises, as a result of digestion and metabolic activities by the
fish, a waste is discharged into the environment. These wastes are
known to cause harmful effects, depending on the nature of the
environment . As the main component of the cost of fishery is
the feed, compliance with the rules at this stage will significantly
increase the economic efficiency.
The impact of aquaculture on the environment; Firstly, it
is caused by the release of dissolved - undissolved, organic and
inorganic substances from the not consumed feed and feces. The
following factors determine the effects of aquaculture on the
a) The physico-chemical and hydrographic properties of
b) The type of feed
c) Feed rations
d) Feeding technology
The most important part of the waste is suspended solids.
Suspended solids in aquaculture facilities must be limited due to
the following reasons :
I. Suspended solids can reduce light penetration and
phytoplankton activity in the water mass in the discharge
II. Turbidity-restricted light penetration can affect aquatic
plants, corals and other vulnerable underwater habitats.
III. Sedimentation in shallow waters can damage local
travel, fishing and other activities.
IV. Organisms in affected marshy areas may experience
stress or die as a result of excessive sedimentation.
V. Excess sediment can create undesirable anaerobic
conditions and reach the water, resulting in toxic metabolites
(ammonium, methane and hydrogen sulfide etc.) which can
damage sensitive aquatic life.
VI. Modern treatment facilities have been developed
according to the type of wastes. Considering the features of
the facility, it will be solved without any problems with the
Waste generated in aquaculture facilities; It should be
examined under two headings as waste observed during
the cultivation practices and during the sea food processing.
Current information should be followed, and solutions should
be developed according to the type of waste to ensure that the
wastes will be reintroduced into the economy. The feces and feed
wastes accumulated in the filters can be dried in the sun and
used as agricultural fertilizers. In general, fish leave dry weight
of 260 kg per kg of feed as feces. The content of this feces varies
according to the feed, rate of ingestion and the fish species. Trout
feces contain 30% carbon, 4% nitrogen and 2% phosphorus .
The performed studies by our research team have shown that
the aquaculture wastes using as a fertilizer for vegetable crops
produce gives better results than the other fertilizers [17- 19].
Therefore, aquaculture wastes can be considered as fish manure
and can be evaluated in agricultural areas alone or in combination
with other fertilizers.
The waste or by-products from sea food processing plants is
made reusable by operations that do not require much cost. They
can be evaluated as fish food, fish oil or silage. The silage improves
the durability of these wastes and turns them into feeding
materials of fish and brings them to economy. The use of the head
and internal organs of the fish as an additive for animal feeds
is an appropriate recommendation for protein content. Some
aquaculture plants use these products especially in the nutrition
of brood stocks . The knowledge and available technology
within this field has however grown substantially in recent years
and is still growing. With increased scientific understanding of
the properties of proteins and fish oil, the by-raw materials have
been transformed to highly valuable products, in some cases even
higher in value than the fillets .
The advantages of fish by-products or wastes :
a. With simple interventions, there is a possibility of returning
into the economy.
b. Equipment required for processing these by-products is
not too detailed.
c. These by-products are the parts of high-quality fish
produced for human consumption but not currently used for
food. So, the quality of these wastes is unquestionable.
d. Skin, carcass, head and similar high-quality internal
organs can be obtained directly from the processing line. It
also does not require labor or cost of transport etc.
e. High quality fish proteins and oils are obtained
At this stage, it will reduce the burden of wastes to the
environment and add value to the aquaculture farms with the
regulations and activities that do not require too much labor.
1. Adding to fish feed of seafood processing wastes
2. In this stage, attention should be paid for hygiene to
avoid the diseases of aquaculture.
3. Recycling of scales, snail shells, etc. into cosmetics,
textiles, decoration, etc.
The most important problems in the environment are fish
faces and feed residues, a significant portion of which accumulates
on the floor of the ponds. After harvest or with periodic cleaning,
they are collectively removed from the pool floor without having
The wastes of fish and crustaceans are important because of
the components of them :
• Myofibrillar proteins
• Sarcoplasmic proteins
• Stroma proteins
• Digestive enzymes
4. Collagen and gelatin
5. Fish oil
6. Chitin and Chitosan
Considering these substances in the content, it will be
seen that these are raw materials that are not waste. It will be
possible to use such rich content materials in many areas with
new ideas to be produced. If these waste products are used as
sources in the production of different living things, the impact
on the environment can be reduced. For this purpose, especially
in cage farming, nutrients that are fed by using wastes, such as
mussels and oysters, are also cultured (polyculture) and nutrient
contamination can be prevented in the environment.
Food industry waste is an important source of environmental
pollution. As a result of conducted researches on the transformation
of these wastes into useful products, it has been seen that they can
be used again in the following areas :
Water movement, which is the main necessity in electricity
production, is naturally present in aquaculture facilities. As the
discharge water flow rate is high in the facilities which produce
especially large capacity, the power needs of the facility can be
provided by the stands, which will be built in front of this water
plant. Considering the energy deficit, which is the problem of many
countries today, it is a fact that this amount will not underestimate
the environmental contribution, but also a significant decrease in
the expenses of the plant. With this arrangement which will be
made without requiring too much investment, the energy cost
which is one of the important inputs in production will decrease
the cost of the product and thus the profitability will increase.
Recirculated aquaculture systems (RAS) are one of the
intensive fish culture technologies where a significant percentage
of water can be reused after the necessary applications. Since
water resources are not as limiting as they were in the past,
the wastewater treatment systems became more efficient,
recirculating systems (RAS) have been widely used in fish farming.
These systems are used in the cultivation of aquaculture species
with continuous production strategies and economically more
important fish species due to high investment and operating costs
compared to conventional production systems .
RAS has improved faster than expected in recent years
. While this model of aquaculture is the system where
environmental waste is minimized, the main determinant of
planning is the economic part of the production. Since the existing
fish farms difficult to transform into this structure, planning at the
new plant stage will provide economic and labor advantage.
More intensive stock is done in these systems. The living
beings are kept in safer environments with all controlled
environmental conditions. Temperature, salinity, pH, alkalinity,
chemical composition and oxygen are continuously monitored
and kept under control. In addition, they are open to operations
and innovations for daily market trends . The amount of water
used in closed circuit systems should only be renewed (3-5%) due
to evaporation and leakage loss. However, in order to maintain
the water quality, the cost of filtration and ventilation limits this
application types. RAS allow effective economics on scale, which
results in the highest production per unit area and per unit
worker of any aquaculture system. RAS’s are environmentally
sustainable; They use 90 to 99 % less water than conventional
aquaculture systems, less than 1% of the land area, and they
provide for environmentally safe waste management treatment [2,
27]. Considering organic matter-nutrients (especially inorganic
nitrogen and phosphorus), RASs are highly environmentalfriendly
Aquaculture facilities have a positive aspect which is very
important for the environment but does not attract attention.
Populations are highly diluted as a result of intensive hunting gathering of living species that have benefits for people with
different purposes or food. For example, the fact that leeches,
whose medical use has become widespread in recent years, are
collected from nature intensively, have weakened these species
in the ecosystem . The provision of leeches from the nature
for using in alternative medicine provides problems in terms of
hygiene in patients. In order to meet this demand, only plants
that produce leeches can be considered, and in some of the
plants producing existing fisheries, this and similar species can
be produced . The production of more than one species
(integrated fish farming) will reduce the amount of waste
generated from the plant and increase the income in aquaculture
Aquaculture not only covers a single production model,
but also hundreds of species of fish, crustaceans and aquatic
plant cultures. This diversity in the production models and the
cultivated species requires considerations of the environment
in many different dimensions . Compliance with the rules
at every stage of the aquaculture will decrease the negative
impacts on the environment as in every sector. Aquaculture
has more positive effects besides some negative environmental
effects. for example, aquaculture can be used as a means of
improving waste water. Water and nutrients can be recycled by
aquaculture operation . Increasing aquaculture was initially
encouraged for economic reasons, but in recent years many
countries have started to implement strict regulatory rules to
ensure environmental concerns and sustainability . The
negative impact of ecosystem and the loss of biodiversity limits
the development of aquaculture. In conclusion, management of
fish wastes represents an attracting topic, since this suggests a
possible way to solve environmental impacts of fishery discards
and, at the same time, it provides a tool to exploit them as a
source of feeds for farmed fish, so promoting future aquaculture
growth in a sustainable way . Aquaculture activities should
be environmentally friendly as well as economical. Sustainable
growth in aquaculture can easily be achieved with some measures
to be taken. In order to minimize the negative impact of the
organic load generated by wastes in the areas where aquaculture
systems will be established, the number of enterprises and total
capacity should be determined considering the “carrying capacity
of the environment” and investments exceeding the carrying
capacity should not be allowed. Environment-friendly fishing is
not an obstacle to be economical .