Numerous food supplements can be traced back to compounds of marine origin. Microalgae, for example, are commonly used as a food supplement, with some of the most valuable products being polyunsaturated fatty acids (omega-3 fatty acids) and antioxidants (e.g. β-carotenoid). From the aquaculture perspective, there is a great challenge in providing new cheaper feed products, as the feed constitutes about 50 % of the cost drivers (for fish). New healthy feed products are also necessary to prevent diseases and to enhance the quality of the cultivated organisms. Animal proteins should be replaced by plant products, such as those from algal origin. Cultured microalgae are already used as a feed additive in mollusk and shrimp aquaculture54 as well as in feed for poultry, pigs and some pets. The microalgae pigment astaxanthin is an especially valuable feed additive in salmon farming, giving the pink colour of the fish meat. 

Surfaces in the marine environment are rapidly colonised by microorganisms such as bacteria, a process which is then followed by colonisation by macroorganisms such as barnacles. This usually poses a problem for ships when a biofilm grows on the bottom, resulting in reduced cruising speed, high fuel consumption and thus increased CO 2 emissions. 62 Anti-fouling coatings are thus used containing chemical substances that prevent the formation of biofilms. Because these coatings often have toxic effects, legal regulations such as the International Convention on the Control of Harmful Anti-Fouling Systems on Ships (AFS Convention) – adopted in 2001 by the International Maritime Organisation – are in place to promote restriction or even ban of toxic compounds such as tributyltin (TBT) used for anti-fouling.

Though this is still a very new field, over the past decade the medical, pharmaceutical and biotechnological industries have directed increasing attention towards biomaterials such as biopolymers of marine origin. Microbial biopolymers are polysaccharides, chitins or collagens, which have numerous applications ranging from bioplastics (such as polyhydroxyalkanoate, also known as PHA, which is synthesized by various marine bacteria) to pharmaceutical and medical polymers for sealing wounds, bio-adhesives, dental biomaterials, tissue regeneration and 3D tissue culture scaffolds. In comparison to conventional polymers, biopolymers have the advantage of being biodegradable, less toxic and based on renewable resources. Marine biopolymers may have a major future market potential but are currently still in development stage.

Enzymes for Industrial Processes 

This relatively novel application involves the use of oil-degrading bacteria to improve water quality. Oilis a complex mixture of hundreds of different compounds generated from dead biomass over millions of years. In parallel, certain microorganisms, some of which are a common part of the marine microbial community in the Baltic Sea, have developed special enzyme systems to be able to use some of the oil components as substrate. Research is therefore going into the identification of microorganisms that might be able to mitigate the negative effects of accidental oil contamination from ship accidents or leakage of oil platforms. So far, no microbes are known that are able to degrade the whole spectrum of oil components. To estimate the amount of active oil-degrading species as well as the cocktails of enzymes they produce for these purposes will require both molecular-ecological and metagenomic approaches. But the starting point is an encouraging one, as investigation of the microbial diversity in Baltic Sea sediments has already revealed the presence of microbial strains possibly involved.