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					 WATER QUALITY CONTROL
     IN FISH CULTURE
(ENVIRONMENTAL CRITERIA
   FOR AQUACULTURE)

   Yrd. Doç. Dr. Hakan TÜRKER
      Art & Science Faculty
     Department of Biology
              The importance of water

►   Why is water important?
►   When scientists search for life in other parts of our solar
    system, they begin by looking for water. Why? Water (in
    its liquid state) is essential to life as we know it. Your body
    is about 60 % water.
►   The reactions that sustain life need liquid water to work.
►   Liquid water is also used to transport molecules where
    they need to go, inside and outside of cells.
                 Why water supports life
► Water has many properties that help sustain life. Three of the most important
  properties are:
► 1. Water is a good solvent.
    A solvent is a substance that is capable of dissolving another substance.
      Water dissolves just about anything. In fact, it’s such a good solvent that
      water rarely exists as pure water. When water has one or more substances
      dissolved in it, we call it a solution. Even the water that comes out of your
      faucet is a solution. All of the water in your body has dissolved substances
      in it. Many reactions in living systems occur in solutions.
► 2. Water exists as a liquid at a large range of temperatures.
    Pure water freezes at 0°C and boils at 100°C. Add salt and you can lower
      the freezing temperature. Some salty solutions have freezing points below
      –10°C. Increase the pressure and the boiling temperature is raised.
► 3. Water has a high specific heat.
    Specific heat is the amount of heat needed to raise one mL of water by
      1°C. Water has one of the highest specific heats of any substance known.
      This means that it takes a lot of energy to raise the temperature of water
      even a few degrees. This high specific heat helps stabilize the
      temperatures in living systems.
                        Properties of water

►   Universal solvent
►   Unique density-temperature
    relationship
►   High specific heat
►   High viscosity
►   High surface tension
►   Water is called the "universal solvent" because it
    dissolves more substances than any other liquid.
►   This means that wherever water goes, either through the
    ground or through our bodies, it takes along valuable
    chemicals, minerals, and nutrients.
►   Water is the only natural substance that is found in all
    three states -- liquid, solid (ice), and gas (steam) -- at
    the temperatures normally found on Earth.
►   Earth's water is constantly interacting, changing and in
    movement.
►   The maximum density of water (1.0 g/ml) occurs at
    3.98°C.
►   Molecular expansion and decreasing density occur at
    progressively increasing rates both above and below 4°C.
►   The density difference between water at a given
    temperature and 1°C lower increases markedly at
    temperatures above and below 4°C.
►   Water has a high specific heat index.
►   This means that water can absorb a lot of heat before it
    begins to get hot.
►   The high specific heat index of water helps regulate the
    rate at which air changes temperature, which is why the
    temperature change between seasons is gradual rather
    than sudden.
►   The diagram below describes the various exchanges of
    heat involved with 1 gram of water.
►   Water viscosity is far greater than the viscosity of air and is
    inversely proportional to temperature.
►   Aquatic organisms have adapted to the more buoyant
    aquatic environment and to the resistance water imposed
    on locomotion; their distribution is often influenced by
    thermally induced stratification of water masses of differing
    density and viscosity.
►   Water has a very high surface tension.
►   In other words, water is sticky and elastic, and tends to
    clump together in drops rather than spread out in a thin
    film.
►   Surface tension is responsible for capillary action, which
    allows water (and its dissolved substances) to move
    through the roots of plants and through the tiny blood
    vessels in our bodies.
                  Earth’s water

►   Oceans;
     Cover 70% earth’s surface
     Keep 97% of the earth’s water volume
►   Lakes and streams;
     Cover 1% earth’s surface
     Keep <1% of the earth’s water volume
►   Estimate of total global water distribution:
    ~1,400,000,000 km3

       Source: Gleick, P. H., 1996: Water resources. In Encyclopedia of Climate and Weather, ed. by S.
        H. Schneider, Oxford University Press, New York, vol. 2, pp.817-823.
► 50-90% of the weight of living organisms is made up of water. Blood in
  animals and sap in plants is mostly water.
► The adult human body is composed of approximately 55 to 60% water--the
  brain is composed of 70% water, as is skin, blood is 82% water, and the lungs
  are nearly 90%t water.
► The world average rainfall is 860 mm.
► You can survive about a month without food, but only 5-7 days without water.
► It is possible to drink water today that was here in the dinosaur age.
► The average urban home of 4.6 people uses 640 litres of water per day.
► A dripping tap can waste as much as 60 litres per day or 1 800 litres per
  month.
► A leaking toilet can waste up to 100 000 litres of water per year, enough to
  take three full baths every day.
► It takes about 2.5 litres of water to cook pasta and about 5 litres to clean the
  pot.
► The average bath holds between 150 and 200 litres of water when filled to the
  brim.
► A toilet is the biggest user of indoor water. On average, it uses 11 litres of
  water when flushed.
    ÜLKEMİZDEKİ TATLI SU KAYNAKLARI
►   Türkiye’de dağlarda bulunan küçük göllerle birlikte 120’den
    fazla doğal göl bulunmaktadır.


►   En büyük ve en derin göl olan Van Gölü’nün alanı 3 712
    km2 dir. İkinci büyük göl, İç Anadolu'daki Tuz Gölü'dür.
    Alanı ise 1 500 km2 dir.


►   Türkiye'de göllerin toplandığı başlıca dört bölge vardır:
    Göller Yöresi (Eğirdir, Burdur, Beyşehir ve Acıgöl), Güney
    Marmara (Sapanca, İznik, Ulubat, Kuş Gölleri), Van Gölü ve
    çevresi, Tuz Gölü ve çevresi.
►   Doğal göller dışında Türkiye’de 555 kadar baraj gölü
    bulunmaktadır. Bunlardan en büyüğü Atatürk Barajı 817
    km2 dir.


►   Türkiye göllerinin yanısıra akarsuları açısından da zengin bir
    ülkedir. Kaynakları Türkiye topraklarında olan birçok akarsu
    değişik denizlere dökülür. En uzunu Kızılırmak 1 355 km
    dir.
►   Türkiye su zengini bir ülke değildir. Kişi başına düşen yıllık
    su miktarına göre ülkemiz su azlığı yaşayan bir ülke
    konumundadır.


►   Kişi başına düşen yıllık kullanılabilir su miktarı 1 500 m3
    civarındadır.
►   Türkiye’nin Su Kaynaklari Potansiyeli
      Yıllık ortalama yağış : 643 mm/m 2
               The world average rainfall is 860 mm.
      Türkiye’nin yüzölçümü : 780 000 km 2
      Yıllık yağış miktarı : 501 milyar m 3
      Buharlaşma : 274 milyar m 3
      Yeraltına sızma : 41 milyar m 3
►   Yüzey Suyu
      Yıllık yüzey akışı : 186 milyar m 3
      Kullanılabilir yüzey suyu : 98 milyar m 3
►   Yer altısuyu
      Yıllık çekilebilir su miktarı : 14 milyar m 3
      Toplam Kullanılabilir Su (net): 112 milyar m 3
      WWF (Dünya Doğayı Koruma Vakfı) -Türkiye
                  verilerine göre;

►   Türkiye de son 40 yılda
    yaklaşık 1 milyon 300 bin
    hektar sulak alan (yaklaşık 3
    Van Gölü büyüklüğü) yok
    oldu.
►   Türkiye de son 20 yılda kişi
    başına düşen su miktarı 4000
    m3 den 1500 m3 e düştü.
UNESCO’nun hazırladığı “Dünya Su Gelişme Raporu”
                    na göre;

►   Ülkemiz su potansiyeli bakımından
    dünyada 45. sırada yer alıyor.
►   Dünyada su zengini ülkelerde kişi başına
    düşen su miktarı ortalama 10.000 m3
    üzerinde iken Türkiye’de bu rakam
    >1.500 m3.
►   Beyşehir Gölü adeta yok olma sürecinde,
    Tuz Gölü 35 yılda yarı yarıya küçüldü.
►   Dünya su rezervinin tahmini konusunda yapılan güncel çalışmalardan
    IHP-IV UNESCO projesinde dünyadaki 2 bin 500 adet hidroloji
    istasyonuna ait veriler kullanılarak, dünyadaki su potansiyeli bölge
    bölge hesaplandı. Bu çalışmaya göre, dünya yenilenebilir su rezervi,
    yıllık yaklaşık 42 trilyon 750 milyar metreküp (m3) düzeyinde
    bulunuyor.

    IHP-IV UNESCO projesine göre, dünyadaki aşırı nüfus artışı nedeniyle
    kişi başına düşen su miktarı azaldı.

    2,3 milyar kişi sağlıklı suya hasret ve yılda 7 milyon kişi su ile ilgili
    hastalıklardan ölüyor. Ayrıca, 800 milyon kişi gıda yetersizliği ile karşı
    karşıya ve en önemlisi de dünyadaki akarsuların yaklaşık yarısı ciddi
    boyutta kirlenmiş durumda.

    2025 yılı itibariyle dünya nüfusunun üçte ikisi (5 milyar kişi) su sıkıntısı
    yaşayacak, bunun 1 milyardan fazlası açlıkla karşı karşıya kalacak.
►   Dünya genelinde 1 milyar 400 milyon kişinin temiz içme suyundan mahrum olduğu
    günümüzde dakikada 15 kişi sağlıksız su tüketimi sonucu hayatını kaybediyor.

    16-22 Mart Dünya Su Günü nedeniyle Birleşmiş Milletler (BM), tarafından
    düzenlenen çeşitli etkinliklerle dünya genelinde günden güne artan su krizine dikkat
    çekiliyor.

    BM verilerine göre, dünyada 1 milyar 400 milyon kişi temiz içilebilir sudan mahrum.
    Yine dünya nüfusunun yüzde 40'ına denk gelen 2 milyar 600 milyon kişi de
    arıtılmamış sağlık açısından sakıncalı suyu tüketmek zorunda.

    Sağlık şartlarına uygun olmayan suların neden olduğu kolera, ishal ve tifo gibi
    hastalıklardan da sadece 1dakikada 15 kişi hayatını kaybediyor. Bir diğer ifadeyle
    yılda yaklaşık 8 milyon kişi sudan kaynaklanan hastalıklar sonucu ölüyor.

    Dünyadaki su krizine çareler arayan BM'nin Milenyum Kalkınma Hedeflerine
    ulaşılması için her yıl bu alanda 30 milyar dolarlık bir yatırım şart. Dünya Su
    Konseyi, 2015' kadar yıllık 30 milyar dolarlık yatırımla da ancak temiz içilebilir su
    bulamayanların yarısının sağlıklı suya kavuşabileceğini bildirdi.
►   Dünya nüfusunun artmasına bağlı olarak 20. yüzyılda su tüketimi tam 6 kat arttı.
    1950'de kişi başına düşen su tüketim miktarı 16 bin 800 metreküp iken bu miktar
    2000'de 7 bin 300 metreküpe düştü. Dünya nüfusunun 8 milyarı bulmasının
    beklendiği 2025'te ise kişi başına su tüketiminin yaklaşık 4 bin 800 metreküpe
    düşeceği tahmin ediliyor.

    Günlük su tüketimi Afrika kıtasında kişi başına 10-20 litre arasında değişirken
    Avrupalıların kişi başına günlük su tüketim miktarı 200 litre, Kuzey Amerika ve
    Japonya'da ise tam 350 litre.

    Suların kullanımı konusunda şimdiden bir çok bölgedeki ülkeler arasında tansiyon
    yükselmiş durumda. ABD'den Ortadoğu'ya, Güney Asya'ya kadar geniş bir alanda
    küresel ısınmaya da bağlı olarak susuz ülkelerin sayısı artıyor. Uzmanlar, su krizinin
    muhtemel "su savaşlarına" neden olabileceği uyarısında bulunuyor.

    BM'nin raporunda su krizinin, su kaynaklarının yetersizliğinden ziyade suyun kötü
    kullanımından kaynaklandığı da belirtiliyor.

    BM Dünya Su Konseyi, su ile ilgili alanlarda yatırım yapılmasıyla yılda 1.5 milyondan
    fazla kişinin kurtarılabileceğini belirtiyor.
►   1. Oxygen: A gas upon which most life depends. Water contains dissolved
    oxygen. The amount of oxygen has a direct relationship between the size and
    number of animals found in a body of water.
►   2. Phytoplankton: Microscopic free-floating green plants. These small plants
    form the beginning of an aquatic food chain. Additionally, phytoplankton take
    in sunlight, convert the sunlight into food and release oxygen into the water to
    be used by another life. This process is called photosynthesis.
►   3. Zooplankton: Microscopic free-floating animals. These small animals eat
    phytoplankton and, in turn, are eaten by larger animals along the aquatic food
    chain.
►   4. Fish: A vertebrate (animal with a spine) that lives in water. Healthy bodies
    of water have different kinds and sizes of fish.
►   5. Bottom Life: Animals that live on the bottom of a healthy body of water.
    Bottom life includes worms, snails, crayfish, mussels, clams and insect larvae.
►   6. Sediment: Mud, Sand, or Gravel which has settled to the bottom of a body
    of water. A healthy body of water has sediment that is free of chemical
    pollution that settle to the bottom and are harmful to fish and bottom life.
            An Introduction to Water Quality
               in Freshwater Aquaculture


►   Water quality determines not only how well fish will grow
    in an aquaculture operation, but whether or not they
    survive.
►   Fish influence water quality through processes like
    nitrogen metabolism and respiration.
►   Knowledge of testing procedures and interpretation of
    results are important to the fish farmer.
►   Some water quality factors are dissolved oxygen,
    temperature, ammonia, pH, alkalinity, hardness and
    clarity.
►   What may be toxic and cause mortalities in one
    situation, can be harmless in another.
►   The importance of each factor, the determination
    method and frequency of monitoring depends on the
    type and rearing intensity of the production system.
►   Each water quality factor interacts with and influences
    other parameters, sometimes in complex ways.
►   Water Quality Variables
►   Temperature
     All biological and chemical processes in an
      aquaculture operation are influenced by temperature.
     Fish adjust their body temperature and metabolic rate
      by moving into cooler or warmer water.
     Each species has a preferred or optimum temperature
      range where it grows best.
     At temperatures above or below optimum, fish
      growth is reduced.
     Mortalities may occur at extreme temperatures.
►   Dissolved Oxygen
     The minimum dissolved oxygen (DO) level that fish can
      safely tolerate depends on temperature and to a certain
      extent the species.
     Volubility of   oxygen    increases   as   temperature
      decreases.
     In ponds, DO can change dramatically over a 24 hour
      period.
     During the day oxygen is produced by photosynthesis.
     During the night and day oxygen is consumed by
      respiration.
     Typically, oxygen levels are lowest just before dawn and
      highest in the late afternoon.
 DO in a culture system must be maintained above levels
  considered stressful to fish.
 Warmwater fish (species that grow best at
  temperatures above 26.5°C) can tolerate lower DO
  concentrations than coldwater fish (species that grow
  best at temperatures below 15.5°C).
 As a rule of thumb, DO should be maintained above 3.0
  ppm (or mg/L) and 5.0 ppm for warm and coldwater
  fish, respectively.
►   Nitrogenous Wastes
     Most fish and freshwater invertebrates excrete ammonia
      as their principle nitrogenous waste.
     Analytical methods are     used   to   determine   total
      ammonia-nitrogen (TAN).
     The proportion of TAN that exists in ionized (NH4) and
      un-ionized form (NH3) varies with pH and temperature.
     As pH and temperature increase, the amount of TAN in
      the toxic un-ionized form increases.
 Fish continuously exposed to more than 0.02 ppm of
  the un-ionized form may exhibit reduced growth and
  increased susceptibility to disease.
 When fish are cultured intensively and fed protein-rich
  feeds they can produce high concentrations of ammonia
  in the water.
 Concentrations of 0.5 ppm have reduced growth and
  adversely affected fish.
►   pH
     The concentration of bases and acids in the water
      determines its pH.
     A low pH is acidic and a high pH is basic; a pH of 7 is
      neutral.
     Fish survive and grow best in waters with a pH between
      6-9.
     If pH readings are outside this range, fish growth is
      reduced.
     At values below 4.5 or above 10, mortalities occur.
     In well-buffered ponds (with alkalinity over 50-100
      ppm), pH typically fluctuates one or two units daily.
 In the morning, carbon dioxide levels are high and pH is
  low as a result of respiration during the night.
 After sunrise, algae and other green plants produce
  carbohydrates and oxygen from carbon dioxide and
  water by photosynthesis.
 As carbon dioxide is removed from the water, its pH
  increases.
 The lowest pH of the day is typically associated with the
  lowest level of dissolved oxygen.
 The highest pH of the day is typically associated with
  the highest level of dissolved oxygen.
►   Alkalinity
     The buffering capacity of culture water, expressed as
      ppm calcium carbonate, is its alkalinity.
     Alkalinity is a measurement of carbonate            and
      bicarbonate ions dissolved in the water.
     As the amount of carbon dioxide fluctuates, the pH of
      water changes.
     The magnitude of this shift is determined by the water’s
      buffering capacity or its ability to absorb acids and/or
      bases.
 Photosynthetic activity in a poorly buffered pond can
  cause pH to increase.
 In a pond with higher alkalinity, the pH shift is reduced.
 A suitable range of alkalinity is 20 to 300 ppm.
 Alkalinity in excess of 300 ppm does not adversely
  affect fish, but it does interfere with action of certain
  commonly used chemicals (e.g., copper sulfate).
 Alkalinity can be increased by adding agricultural
  limestone to ponds or sodium bicarbonate to
  recirculating systems.
►   Hardness
     Calcium and magnesium ions determines hardness.
     Test procedures usually determine both ions as “total
      hardness,” expressed as ppm calcium carbonate.
     In most waters the concentrations of alkalinity and
      hardness are similar, but they can differ as alkalinity
      measures negative ions (carbonate, bicabonate) and
      hardness measures positive ions (calcium, magnesium).
     If hardness is deficient, these species do not grow well.
     Hardness should be above 50 ppm; low hardness can
      be adjusted by the addition of lime or calcium chloride.
►   Carbon Dioxide
     Only when using groundwater, transporting fish at high
      densities, or in recirculating systems are carbon dioxide
      problems likely to develop.
     At high concentrations, carbon dioxide causes fish to
      lose equilibrium, become disoriented and possibly die.
     Careful planning, aeration or oxygenation, and buffering
      of water will keep carbon dioxide at acceptable levels
      when large numbers of fish are hauled extended
      distances or cultured in recirculating systems.
►   Salinity
     The total concentration of all ions in the water is its
      salinity.
     Freshwater fish exhibit a range in salinity tolerance.
     Many commercially important species (e.g., channel
      catfish, largemouth bass, tilapia) survive and grow well
      in slightly salty water.
     After they smelt, salmon and trout can tolerate salt
      water.
     Salinity not only affects osmoregulation it also
      influences the concentration of un-ionized ammonia.
     During the planning stage of an aquaculture operation,
      salinity should be measured and the water’s
      appropriateness determined.
►   Chlorine
     To control bacteria, municipal water supplies are
      typically treated with chlorine at 1.0 ppm.
     If municipal waters are used to culture fish, residual
      chlorine must be removed by aeration, with chemicals
      such as sodium thiosulfate, or filtration through
      activated charcoal.
     Chlorine levels as low as 0.02 ppm can stress fish.
►   Hydrogen Sulfide
     Ponds with oxygen-poor bottoms and accumulated
      organic material can release hydrogen sulfide when
      seined or disturbed.
     Substratum beneath heavily fed cages/net pens can
      accumulate wastes (e.g., uneaten food, feces) and
      produce hydrogen sulfide gas if oxygen becomes
      deficient.
     Hydrogen sulfide gas has a rotten egg odor and is
      extremely toxic to fish.
►   Water Clarity
     In pond and cage culture, water clarity can affect fish.
     If fish that prefer turbid waters (e.g., bullhead, catfish,
      walleye) are cultured in relatively clear water they will
      experience stress; survival and growth will be adversely
      affected.
     Accumulation of suspended solids and discoloration of
      culture water occur in recirculating systems which can
      irritate fish and precipitate disease.
     Some suspended and dissolved materials can cause off-
      flavor in fish.
     Filtration and flocculent can be used to remove solids
      and reduce discoloration.
►   Monitoring Methods
     A variety of methods are available to monitor water
      quality.
     In pond, cage, and low intensity culture, the high
      precision of sophisticated analytical methods is not
      needed to make informed management decisions.
     However, intensive culture in recirculating and reuse
      systems requires frequent and sophisticated monitoring.
     If fish are maintained at high densities, then
      temperature, dissolved oxygen, ammonia, nitrite, and
      pH should be monitored daily or more frequently.
 Water clarity, alkalinity, and hardness can be measured
  less frequently, perhaps one or two times per week, as
  they do not fluctuate as rapidly.
 Salinity and chlorine should be determined when a
  potential water source is first examined so corrective
  measures may be incorporated into the production
  system during the design or planning stage.
 Carbon dioxide should be measured when first using a
  new groundwater source and routinely in recirculating
  systems.
 When hydrogen sulfide and carbon dioxide problems are
  likely, systems should be monitored closely and the
  means to correct problems should be readily available.
 At lower stocking densities, water quality parameters
  can be monitored less frequently or not at all.
 Regardless of the frequency, monitoring should be
  conducted at a standard time and depth where fish are
  located.
 Time of measurement and observed values should be
  recorded; good record keeping is essential to successful
  aquaculture.
 In pond and cage culture it is preferable to monitor
  dissolved oxygen early in the morning, when conditions
  stressful to fish are most likely to occur (e.g., low
  oxygen).
 Conversely, temperature and pH in ponds are best
  measured during the late afternoon.

				
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