Man has utilized the oceans since the beginning of civilization. It has become evident in recent decades that this exploitation has led to the degradation and depletion of the marine environment. Fishery collapses, pollution, habitat and species losses, eutrophication and the consequences of climate change are now a common challenge to many of the world’s seas.
At the same time new scientific and technological developments provide opportunities for innovative uses of marine ecosystems which have the power to bring positive environmental benefits. If we can learn more about the potential benefits and impacts of these new uses and steer future development towards those which hold more promise, we may be able to proactively improve the state of the ecosystem while at the same time promoting sustainable economies.
Macroalgae harvesting and cultivation
As a result of eutrophication, the amount of filamentous macroalgae throughout the Baltic Sea has increased. Precise figures are missing due to lack of monitoring, but especially in South Sweden and Denmark substantial amounts of beach cast assemblages in the range of 70,000–85,000 tonnes of dry weight per year can be found.
Even though an inventory of reed areas and their biomass is missing, it can be assumed that the total area of reed in the Baltic Sea’s shallow bays and coastal lagoons has increased substantially over the last decades covering by now at least 300,000 ha with potentially a total annual biomass of approx. 1 million tonnes available for use
Despite being its most common macroorganism, the small size of Baltic Sea blue mussel – caused by slow growth due to low salinity – means that they can hardly be used in the world-wide thriving business of seafood. Mussel farming in the Baltic Sea can, however, serve as a possible measure to counteract eutrophication.
Large-Scale Microalgae cultivation
The global need for bioenergy is increasing and microalgae may be part of the solution. The biorefinery concept offers hope in its ability to integrate the production of the various algae commodities and ecosystem services to maximise the socioeconomic potential of algae cultivation while offering the most likely scenario for producing algae biofuels economically.