are not being used in the EU due to societal concerns and regulations. Meanwhile, DNA vaccines are now authorised in the EU. There are challenges in fish vaccine development, immune response due to lack of potent adjScientists are considering microdose application in future. But there are also exciting opportunities in aquaculture vaccinology due to the low cost of technology, regulations change and novel antigen expression and delivery systems. In Norway subunit vaccine (VP2 peptide) against infectious pancreatic necrosis is being used. In Canada, a licensed DNA vaccine against Infectious hematopoietic necrosis has been launched for industry use. Fish have large mucosal surfaces, so the preferred route is immersion, intraperitoneal and oral respectively. Nanoparticles are in progress for delivery purposes. The common antibodies produced are IgM and IgT. Normally booster is not required ifn Fish because more memory cells are produced in response to the booster rather than an increased level of antibodies. mRNA vaccines are alternative to DNA vaccines because they are more safe, stable, easily producible at a large scale and mass immunization potential. Recently these are used in cancer prevention and therapeutics. Studies in rabies has shown that efficacy depends on dose and route of administration. These are still in infancy. Economic gains In 2014, the aquaculture produced fish overtook wild caught fish, in supply for human food. This means there is a huge demand for vaccines, in prevention of diseases. The reported annual loss fish, calculates to >10 billion USD. This is from approximately 10% of all fishes dying from infectious diseases. The high annual losses increases the demand for vaccines. Even though there are about 24 traditionally used vaccines, there is still demand for more vaccines. The breakthrough of DNA-vaccines has sunk the cost of vaccines. The alternative to vaccines would be antibiotics and chemotherapy, which are more expensive and with bigger drawbacks. DNA-vaccines have become the most cost-efficient method of preventing infectious diseases. This bouts well for DNA-vaccines becoming the new standard both in fish vaccines, and in general vaccines. Salinization/acidification of soils Sediment from abandoned aquaculture farms can remain hypersaline, acidic and eroded. This material can remain unusable for aquaculture purposes for long periods thereafter. Various chemical treatments, such as adding lime, can aggravate the problem by modify the physicochemical characteristics of the sediment. Plastic pollution Aquaculture produces a range of marine debris, depending on the product and location. The most frequently documented type