The Threat: Harmful Pathogens
Published on Jan 21, 2015

The Threat

The threat of harmful pathogens:
Sustainable seafood that includes, Salmon, Halibut, Sea Bream, Cobia, Rainbow Trout, and Oysters are all valuable commodities threatened by harmful pathogen infestation. But they’re not the only ones. Public exhibits of fish, invertebrates, mammals, reptiles, and birds—all living examples of our natural world—are also in constant danger of coming in contact with harmful pathogens.

It’s no secret that our world is faced with declining water purity and availability. This, combined with increased disease outbreaks, has resulted in continued pollution and the introduction of new waterborne pathogens to natural waters.

There is a solution... UV Disinfection.
The chart on the next page lists the most common pathogens found in Aquaculture and identifies their required Fluence (UV dose) for inactivation.

Harmful Waterborne Pathogens:

Aquaculture has used UV disinfection to control harmful waterborne pathogens for many years, but few design-consultants, purchasers, and operators truly understand UV’s limitations well enough to use it successfully and cost-effectively. To achieve successful UV disinfection one must apply it correctly! The first step in applying UV disinfection correctly is to familiarize yourself with the targeted pathogens. This helps to establish the application’s UV disinfection requirements. Keep in mind, no two pathogens are exactly alike and all require their own specific UV-C dose.


                          Microorganism Complex Life Cycle



The diagram above demonstrates the complex life cycle of the warm water protozoa Cryptocaryon (marine white spot). The diagram illustrates the four life-cycle stages of this lethal protozoan. It reveals the microorganism’s physical size and actual life-span based of its life-cycle stage. The free-swimming Tomite excyst or infective stage, when the microorganism is smallest (25-60 µm), is the life-cycle stage where UV Disinfection is most effective.

Harmful Pathogens Associated With Aquaculture:

Chlorella vulgaris 22 mJ/cm2
Aeromonas salmonicida 3.6 mJ/cm2 (log-3)
Pseudomonas fluorescens (fin rot) 11 mJ/cm2 (log-3)
Listeria monocytogenes 16 mJ/cm2 (log-5)
Streptococcus sp. (seawater) 20 mJ/cm2
Bacillus subtilis (spores) 22 mJ/cm2 (log-3)
Vibrio anguillarum 30 mJ/cm2
Yersinia ruckeri 30 mJ/cm2
BKD (Bacterial Kidney Disease) 60 mJ/cm2 (estimate)
Flavobacterium psychrophilum
(Salmonid Bacterial Coldwater Disease)
126 mJ/cm2
Vibrio sp. (oyster) 155 mJ/cm2
Saprolegnia diclina (zoospores) 40 mJ/cm2 - 170 mJ/cm2
Sarcina lutea (Micrococcus luteus) 26 mJ/cm2 (log-3)
Ceratomyxa shasta 30 mJ/cm2 (log-3)
Perkinsus marinus (dermo disease) 30 mJ/cm2
Trichodina sp. 35 mJ/cm2 (log-3)
Myxobolus cerebralis (TAMs, Whirling Disease) 40 mJ/cm2
Ichthyophthirius multifiliis (freshwater white spot) 100 mJ/cm2
Amyloodinium ocellatum 105 mJ/cm2
Trichodina nigra 159 mJ/cm2
Cryptocaryon irritans (marine white spot) 280 mJ/cm2
Costia necatrix 318 mJ/cm2 (log-3)
KHV (koi herpesvirus) 4 mJ/cm2
ISA (Infectious Salmon Anemia) 8 mJ/cm2
CCV (Channel Catfish Virus) 20 mJ/cm2
IHNV (Infectious Hematopoietic Necrosis/CHAB) 20 mJ/cm2
OMV (Oncorhynchus masou Virus) 20 mJ/cm2
IHNV (Infectious Hematopoietic Necrosis/RTTO) 30 mJ/cm2
VHS (Viral Hemorrhagic septicemia) 32 mJ/cm2
CSV (Chum Salmon Virus) 100 mJ/cm2
AHNV (Atlantic Halibut Nodavirus) 105 mJ/cm2
IPNV (Infectious Pancreatic Necrosis Virus) 246 mJ/cm2
Log-1 = 90% • Log-2 = 99% • Log-3 = 99.9% • Log-4 = 99.99% • Log-5 = 99.999%


UV doses not accompanied by a specific log value, should be considered a minimal dosage. The listed data was collected from various sources and Pentair Aquatic Eco-Systems, Inc. does not accept any responsibility for the accuracy of this information. This information is meant to be a guideline and should be used as such.