Air dalam Budidaya Perikanan Saifullah, S.Pi., M.Si Pertemuan ke-5 MK. Budidaya Perikanan Jurusan Perikanan Untirta

KUALITAS AIR KIMIA FISIKA BIOLOGI Oksigen Terlarut (DO) CO2 Ammonia (NH3 ) H2S NO2- NO3- Fosfat pH Kesadahan (Ca2+, Mg2+, Fe2+, Fe3+) Alkalinitas (OH-, HCO3-, CO32-) Salinitas (total garam-garam terlarut) Logam berat (Hg, Pb, Cd, Fe, Zn, Co, Al, dsb) Pencemar organik (Pestisida, deterjen, minyak, dsb.) suhu kekeruhan (TSS) Total Dissolved Solids (TDS) FISIKA BIOLOGI Predator Kompetitor Bakteri Virus Jamur Parasit Plankton 2

Water quality that have significance in assessing environmental impact : DO pH CO2 NH3 NO2 NO3 H2S Pesticides turbidity (Pillay, 2004)

DO Warm water fish survive at DO levels as low as 1 mgl-1; but their growth is slowed down by prolonged exposure. The desirable range is above 5 mgl-1

Hubungan antara kandungan oksigen terlarut dengan konversi pakan dari ikan mas pada suhu 23oC Huisman 1974 dalam Zonneveld, Huisman dan Boon 1991

Pengaruh kadar oksigen terlarut terhadap kelangsungan hidup ikan Kadar oksigen terlarut (mg/L) Pengaruh terhadap kelangsungan hidup ikan < 0,3 Hanya sedikit ikan yang dapat bertahan pada masa pemaparan singkat (short exposure) 0,3 – 1,0 Pemaparan lama (prolonged exposure) dapat mengakibatkan kematian ikan 1,0 – 5,0 Ikan dapat hidup, tetapi pertumbuhannya terganggu > 5,0 Hampir semua organisme akuatik menyukai kondisi ini

Namun demikian, dalam akuakultur, membuat konsentrasi DO menjadi tinggi merupakan hal yang mahal.

The challenge in aquaculture is to balance te economic benefits to health, feed conversion, and growth that an increased DO will provide against the cost of the aeration required to provide it.

pH 4 6 9 6,5 11 Desirable range Slow growth Alkaline death point Acid death point

Nilai pH Pengaruh Umum 6,0 – 6,5 1. Keanekaragaman plankton dan benthos sedikit menurun 2. Kelimpahan total, biomassa, dan produktivitas tidak mengalami perubahan 5,5 – 6,0 1. Penurunan nilai keanekaragama plantkon dan benthos semakin tampak 2. Kelimpahan total, biomassa, dan produktivitas masih belum mengalami perubahan yang berarti 3. Algae hijau berfilamen mulai tampak pada zona litoral

Nilai pH Pengaruh Umum 5,0 – 5,5 1. Penurunan keanekaragaman dan komposisi jenis plankton, perifiton dan bentos semakin besar 2. Terjadi penurunan kelimpahan total dan biomassa zooplankton dan bentos 3. Algae hijau berfilamen semakin banyak 4. Proses nitrifikasi terhambat 4,5 – 5,0 2. Penurunan kelimpahan total dan biomassa zooplankton dan bentos

CO2 Higher concentrations of free CO2, even up to 60 mgl-1, may be tolerated provided that DO concentration are high Namun demikian, pada konsentrasi yang tinggi, karbon dioksida dapat beracun karena keberadaannya dalam darah dapat menghambat pengikatan oksigen oleh hemoglobin.

NH3 Toxic levels of NH3 for short term exposure usually lie between 0,6 and 2,0 mgl-1 (EIFAC 1973) NH3 become more toxic in low concentration of DO

NO2 Safety limits is very limited. The suggested maximum level for prolonged exposure in hard freshwater is 0,1 mgl-1

NO3 Suggested nitrate levels are below 100 mgl-1

H2S Extremely toxic to fish, and could result in poor growth of channel catfish (Bonn&Follis 1967)

Pesticides Many pesticides, particularly insecticides is extremely toxic to fish Acute toxicity values for several commonly used insecticides range from 5 – 100 mgl-1 (Cope 1964) Even when they do not cause mortalilty of the species under culture, they may affect the growth of food organisms and thus reduce their growth and productivity

Turbidity Caused by suspended soil particles has usually no direct effect on fish and shellfish, but in restricts light penetration and limits photosynthesis Sedimentation of soil particles can destroy benthic communities and smother fish eggs Turbidity caused by plankton is not harmful to fish, but clay turbidity exceeding 20000 mgl-1 causes behavioural reactions in many species of fish Appreciable mortality occurs at turbidities above 175000 mgl-1

Kuantitas Air Open Water Sistem resirkulasi dan filtrasi : Filtrasi : pembuangan air minimal Tanpa pembuangan air Filtrasi : Biological filtration Chemical filtration Mechanical filtration Biofloc Technology

End of slide show selesai

Pembuangan air minimal

Diagnosing problematic issue with water quality