Fish Hatchery Management - fisheries & aquaculture

FISH HEALTH MANACEMENT 267TABLE 36. TNFECTIOUS DISEASESCOMMONI,Y CONSIDERED TO BE STRESS,MEDIA'I'EDIN PACIFIC SALMON, TROUT, CATFISH, COMMON CARP, AND SHAD. (SOL]RCE:WNDEMEYER AND WOOD I971.)STRESS T'ACI'ORSD ISEASIPRLT)ISPoSING'f O I N I, I]C-I'IONFurunculosisBacterial gill diseaseColumnaris (Flexibacter columnaris)Corynebacterial kidney diseaseAeromonad and Pseudomonadhemorrhagic septicemiasVibriosis (V i brio angui llarum)Costia, Trichodina, HexamitaSpring viremia of carpFin and tail rotInfectious hematopoietic necrosis (IHNJCold water diseaseChannel catfish virus diseaseLow oxygen; crowding; handling in the pres'ence of Aeromonas salmonicida; handling amonth prior to an expected epizootic;elevated water temperatures.Crowding; chronic low oxygen (4 pp-);elevated ammonia (1 ppm NH3-N)t parti'culate matter in water.Crowding or handling during warmwaterLowperiods (59"F) if carrier fish are present inthe water supply; for salmonids, a temperatureincrease to about6tl"F if thepathogen is present, even if fish are notcrowded or handled.total water hardness (less than about199 ppm as CaCO3).Protozoaninfections such as Coslia, or l-richotlina;accumulation of organic materialsin water leading to increased bacterial loadin water; particulate matter in water; handling;low oxygen; chronic sublethal exposureto heavy metals, pesticides, or poylchlorinatedbiphenyls (pCS's); for commoncarp, handling after over-wintering.Handlingl dissolved oxygen lower than (ippm, especially at water temperatures of50-51)"F; brackish water of 10 l5ppt.Overcrowding of fry and fingerlings; lowoxygen; excessive size variation amongfish in ponds.Handlingafter over-wintering at low temperatures.Crowding; improper temperaturesl excessivelevels of metabolities in the water; nutritionalimbalances; chronic sublethal exposureto PCB's.Temperature decrease from 50"F to 4ii-55"!'.Temperature decrease (from 50 59'F to45-50"F) if the pathogen is present; highwater flow duringyolk absorption, e.g.,more than five gallons per minute inHeath incubators.Temperature above (itl"F; handling; low oxygen;co-infection wilh F'lexibatler, Aeromonas,or Pseudomonas; crowding.