Ocean Ecosystems and Parasitism
Tropical deep water open oceans are dynamic and full of life, especially plankton. Plankton are small organisms that float or drift in great numbers in bodies of salt and fresh water. Plankton are a primary food source for many animals, and consist of protozoans, algae, cnidarians, tiny crustaceans such as copepods, and many other organisms. Many of these planktonic organisms are marine ectoparasites.
Marine ectoparasites occur naturally on many different species of fish. When ectoparasites encounter marine fish they attach themselves to the skin, fins and/or gills of the fish and feed off the mucous, tissues, or interstitial fluid of the fish.
Deep water, open ocean aquaculture systems are less vulnerable to this type of parasite (and parasites in general) because the open nature of offshore pens interrupts the multi-stage life cycle of these organisms and prevents their accumulation within the system.
Cobia are a relatively hardy species. Like all fish, however, cobia must deal with ectoparasites, and those ectoparasites must be pro-actively managed in order to ensure that the fish are reared in a healthy and humane fashion. In the offshore sites, tracking these ectoparasites is a regular part of our fish care. Parasitic organisms such as Neobenedenia can be found in the sea pens. Neobenedenia, known more colloquially as a “skin fluke”, is an ectoparasite that attaches itself to the skin and eyes of our cobia. Neobenedenia feeds on the skin cells and mucus of the fish. Our veterinarians monitor for Neobenedenia and other ectoparasites on a regular basis.
Our monitoring protocol requires that 5 fish per pen are selected from a percentage of our pens for analysis every week. We count the ectoparasites on the selected fish then we bathe the fish in Hydrogen Peroxide, a safe non-antibiotic method of controlling ectoparasites. Hydrogen Peroxide is an effective treatment for parasites. It breaks down quickly into water and oxygen and does not accumulate in sediment. There is no withdrawal period for the fish following the treatment. Because Hydrogen Peroxide breaks down so quickly and completely it is considered a zero impact method of treating marine fish. Hydrogen Peroxide is listed by the third party certification group, the Aquaculture Stewardship Council, as the only parasiticide treatment with a 0 rating for persistence and toxicity in the environment, meaning Hydrogen Peroxide leaves zero toxic residues in the ocean after usage.
As part of our ongoing commitment to nourish current and future generations in harmony with the ocean, and because some of our stakeholders have an interest in understanding this part of our business, we are providing our ectoparasite data for public review. This data will be updated on a regular basis. Please feel free to contact us at firstname.lastname@example.org if you have any questions about this data.
Average number of parasites per fish by week: