Freshwater and coastal aquaculture development can benefit from internal and external experience for preventing environmental damage and for avoiding harmful effects of degradation on aquaculture resources. Strategies to compensate for the loss of aquatic fauna (e.g. due to physical obstructions) are directly linked to important environmental issues, such as the transfer of exotic species, the spread of diseases and loss of genetic diversity, eutrophication, impairment of aesthetic qualities and the disruption of indigenous fish stocks. There presently, conceptual frameworks for aquatic environment management backed by legal and administrative tools to create or enforce ration systems for water management, land use or fisheries and aquaculture development strengthened by adaptive institutionalization.

1. ENVIRONMENTAL ISSUES
IN
AQUACULTURE DEVELOPMENT
Submitted by,
MAHENDRA PAL
M.F.Sc.
COLLEGE OF FISHERIES,
JAU, VERAVAL

2. INTRODUCTION
The farming of aquatic organisms including fish, molluscs, crustaceans and
aquatic plants. Farming implies some sort of intervention in the rearing
process to enhance production.
Aquaculture depends largely upon a good aquatic environment.
Aquaculture is still the fastest growing food producing sector in the world.
Production of aquatic animals from aquaculture in 2014 amounted to 73.8
million tonnes.
World aquaculture production of aquatic animals accounted for 44.1 percent
of total production (including for non-food uses) in 2014, up from 42.1
percent in 2012 and 31.1 percent in 2004 (FAO, 2016a).

4. Environmental issues in
aquaculture
 All human activities – from walking through a field to building a
skyscraper – have an impact on the environment. Aquaculture is no
exception.
 Aquaculture is using extensively ecosystem goods and services.
Aquaculture needs water quality (oxygen, currents, etc).
 Aquaculture needs also wild fishes (to various extents according to
its type: eggs, spats, fingerling and also (trash, anchovy….) for its
feeds.

5. Cont…
 At the same time aquaculture may have many effects on the ecosystem such as:
 ‐enrichment in nutrient and organic matters in recipient waters resulting in
eutrophication processes;
 ‐changes in benthic communities;
 ‐potential contamination by the use of pharmaceutical, antifouling and other products;
 ‐potential depletion of resources due to cumulative effects and competition (e.g. water);
 ‐negative effects from escaped farmed organisms;
 ‐pressure on some fish stocks for fishmeal/oil, which are major constituents of
carnivorous/omnivorous species feeds. (FAO, 2009; FAO, 2007)

6. SITE SELECTION
 site selection processes is the next step for the sustainable development of
aquaculture.
 The processes of site selection include scientific knowledge, tools and legal
frameworks, as well as tools for decision making and management.
 Tools for site selection
 Environmental Impact Assessment (EIA)
 Geographic Information System (GIS)
 Licensing

7. Water Quality
 Dissolved oxygen in pond water is a critical factor for fish and shrimps. When low,
it reduces appetite and growth rate, and increases susceptibility to pathogens
 Optimum pH for fish or shrimps ranges from 6.5 to 9.0.
 The success of aquaculture may depend on maintenance of a stable pH in culture
ponds.
 Ammonia and nitrite, the end products of protein breakdown, are important
parameters of water quality.
 The presence of hydrogen sulphide (H2S) at just 1μg/l may result in mass mortality.
 The concentration of heavy metals in water can be reduced by adding the chelating
agent EDTA (disodium ethylenediamine tetra-acetate) at 1-5 ppm (Table IV), and
this procedure has been used widely in hatcheries in Asia.

8. Domestication
 Domestication in aquaculture is the acclimatisation to captive conditions, the total control of
the life cycle and the manipulation of breeding in captivity of aquatic organisms
 ‐to secure seed supply and improve production efficiency through the mastering of
breeding and
 feeding to select organisms that can grow faster;
 ‐to achieve better feed efficiency; and therefore
 ‐to alleviate the pressure on fishes used as feed.
 In the case of aquaculture, the risk posed by the escape of domesticated organisms is far
greater than that of terrestrial animals or plants in similar circumstances,
 because of their ability to disperse and the difficulty of recapture.
 ‐selective breeding of aquacultured organisms should be designed to reduce their capacity
to survive or
 reproduce in the wild;
 ‐research for domestication should be encouraged and supported, and the creation of gene
banks of
 wild species should be promoted as a reservoir of genetic sources.

9. Effluents and Waste Management
Within the objectives of sustainable development, as a
principle, the organic matter in the effluents from aquaculture
farms should be capable of assimilation by the ecosystem, in
quantity and quality, thereby not producing negative effects
on the local environment.
The introduction of plants, such as Gracilaria sp., can purify
effluents rich in nutrients.
Various biological filtration systems have been used
successfully.

10. DISEASES AND THEIR CONTROL
 Poor environmental conditions or bad management may increase the susceptibility
of fish to a pathogen, although it is necessary for a specific pathogen to be present.
 Certain bacterial diseases, such as vibriosis, pseudotuberculosis, streptococcosis,
and Edwardsiella, Flexibacter coiumnaris and Aeromonas hydrophila infections
commonly occur among fish kept in fresh, brackish or sea water in Asia.
 Certain bacterial diseases, such as vibriosis, pseudotuberculosis, streptococcosis,
and Edwardsiella, Flexibacter coiumnaris and Aeromonas hydrophila infections
commonly occur among fish kept in fresh, brackish or sea water in Asia.
 The use of drugs in aquaculture may result not only in pollution and increased
bacterial resistance, but also in a risk to human health from drug residues.

11. Capture of Wild Stocks for Aquaculture Needs
 It is preferable that organisms to be raised in aquaculture farms
should have been produced in hatcheries.
 The capture of specimens to be used as broodstock in hatcheries
should not distort wild populations
 Wild stocks from endangered species should not be used, except for
rehabilitation or recovery plans, in order to maintain biodiversity.
 The sourcing of individuals for stocking the aquaculture farms done
through their capture from wild stocks should be exercised in a
sustainable manner.

12. Feed Ingredients
 Feed is the main exogenous input into the aquaculture system, and
the quantity of feed required is, in general, two or three times the
volume of the output produced.
 For the manufacturing of these feeds, large volumes of natural raw
materials are needed. This is the most difficult issue regarding
sustainability.
 The future development of aquaculture is strongly linked to the
possibility of providing sustainable aquafeed ingredients.

13. Effects on Local Flora and Fauna
 The interaction of aquaculture with nearby wild flora and fauna is of
concern in relation to its development.

14. EFFECT OF BIRDS
 Interaction between fish and birds
are very significant. fish farms are
constructed near marshy lands and
mangroves that are important
nesting and over-wintering areas for
many species of birds.
 Many sps of birds act as predators
of fish-kingfishers, cormorants, fish
eagles, herons

15. Aquaculture and Marine Protected Areas
 The role that they can play in sustaining local livelihoods and alleviating local
poverty issues.
 Low density aquaculture might be a good solution for sustaining the
livelihoods of the local population around marine protected areas.
 Areas where traditional aquaculture takes place could be designated as marine
protected areas.
 The concept of the carrying / holding capacity is key to this issue.

16. Strategies for control on issues
 select a site for aquaculture purposes if it is excellent for agriculture or
livestock.
 The carrying capacity of the water bodies from the sites considered to
supply the farms or used as effluent discharge places.
 It is necessary to have the most possible knowledge about the biology and
ecology of the organism that is pretended to be farmed (life cycle, feeding
habits and nutritional requirements, tolerance to environmental parameters,
and etc.).
 The stocking density and the consequent biomass harvested are absolutely
related to the sustainability of aquaculture.
 The possibility of farming simultaneously two or more species
(polycultures or integrated multitrophic aquaculture (IMTA)).

17. Cont…
 The possibility of farming simultaneously two or more species
(polycultures or integrated multitrophic aquaculture (IMTA).
 IMTA is mostly referred to organisms from different trophic levels and
inclusively different environments.
 The promotion, management, and rational utilization of natural feed,
including microorganisms (biofilm, biofloc), are considered as a
promising strategy for the culture of shrimp, fishes, and mollusks.
 There are different ways to conduct bioremediation: in situ, ex situ,
biostimulation, bioaugmentation, and others.
 Finally, there is an unavoidable need to improve research and legislation
regarding evaluation and solutions for aquaculture impacts.

18. Leverage the latest information technology to drive gains
in productivity and environmental performance.
Shift fish consumption toward low-trophic farmed species.

19. Conclusion
 Aquaculture is still at an early stage of development although some
productions (molluscs) have already a long tradition.
 Its sustainable development needs a better integration in the society
and to take better into consideration basic principles.
 At the international / regional level there is a current effort to
streamline the sector, its framework and its communication tools.

20. Thank you