GeoSIL in Aqua Culture

Aqua Culture is the rapid growth of fish and seafood by artificially feeding heavily stocked fish and

seafood systems.

As a result of this increased feeding, the metabolic activity of fish and seafood is increased, thus increasing the levels of organic wastes and toxic compounds.

Algae, bacteria, viruses and other micro-organisms begin to grow. As a result, the pond’s natural ecosystem cannot be preserved. Proper balances cannot be maintained and organic wastes build up to toxic levels. Therefore, massive blooms of micro-organisms appear, which cause fish and seafood disease and off-flavour.

The flesh of live, healthy fish is sterile, but bacteria will start growing immediately after death (catch) and, when only lightly preserved, spoilage of fish and seafood is most often caused by bacterial growth. Any set of preserving parameters will select only a few bacterial species amongst the vast heterogeneous population originally present on the fish and seafood. Of the selected species, only one or two will be responsible for the production of metabolites associated with the off-odours and off-flavours of the spoilage. These are called the “specific spoilage organisms“ and their number is inversely proportional to the storage life of the product.

With a number of fish and seafood products, particularly lightly preserved ones, bacteriological problems cannot be solved, as the bacteria in question will be present and able to grow under the preservation conditions currently used. Therefore, alternative, consumer-friendly preservation techniques must be developed.

All systems, from the fish-egg containers up to the delivery of the fish, must be handled in such a way that a build-up of germs on the working surfaces, in the water and on the fish and seafood is avoided as far as possible.

The most important effect of a disinfectant is the prevention of a cross-contamination of a new generation of fish and seafood, which has not yet developed the immunity to the pathogenic organisms that remain from the previous harvest, embedded in the wastes at the bottom of the pond or in the plastic lining.

Fish Diseases

q       Ulcer disease

s primarily an infection of brood trout, but brown and lake trout are also susceptible. Rainbow trout are resistant to the disease, but not immune.

q       Streptococcosis

Is a septicemic disease that affects both freshwater and saltwater fishes.

q       Bacterial gill disease (BGD)

Pathologic changes in gills are caused also by other diseases, among which five are particularly important: 1) nutritional gill disease, 2) aneurysmal, or hemorrhagic gill disease, 3) necrotic gill disease of carp, 4) mycotic gill necrosis, and 5) columnaris disease.

q       and much more like:

Photobacterium phosphoreum, Listeria monocytogenes, Ichthyophomus hoferi, Vibrio cholerae, Shewanella putrefaciens, etc.

Conditions for a Successful Treatment

Disinfectants used in the fish-breeding and seafood processing industry should:

q       Be universally applicable, i.e. should eliminate as many pathogens as possible,

q       Have no side-effects on fish and seafood,

q       Sharply reduce the fish and seafood mortality rate,

q       Be environmentally-friendly and, if possible, be completely decomposable,

q       Have a long-lasting effect,

q       Combat the biofilm wherever possible,

q       Be simple and non-hazardous to handle,

q       Be competitively priced,

q       Have a long shelf life,

q       Be fully effective in both fresh water and salt water,

q       Have a product effectiveness that is unaffected, or only minimally reduced, by chemical and/or organic additives in the water (e.g. ammonia, etc.),

q       Allow simple dosage and on-site concentration measurement,

q       Be such that the fish and seafood prepared for human consumption contains no residues of the disinfectants used, and must comply with strict national and international quality standards.

With the exception of GeoSIL, no disinfectant available on the market fulfils all these conditions