Aquaculture

The rising concern about the environment is encouraging fish farmers to look for sustainable ways of producing fish. Geothermal water is one of them. The use of hot water stored underground enables the farming of fish in colder climates all year round compared to conventional fish farming. Heat from the earth’s interior is a limitless resource that can be utilised to farm fish. Many regions are already employing geothermal energy as an affordable, easily available and sustainable alternative to fossil fuels. Geothermal activity is concentrated around the Pacific Ocean and the Pacific Plate, from Indonesia, the Philippines and Japan, to Alaska, Central America, Mexico, the Andes and on to New Zealand. Europe also has access to geothermal water, from hot water geysers or in the depths of under the earth’s surface. Hence, the use of geothermal water in aquaculture depends on the geographical location of the country.

Although the price of fishmeal tended to fall during the course of 2014, and further progress was made with regard to reducing the share of fishmeal in aquafeed, the situation on the fishmeal market is still tense. Supply remains scarce and prices are still high. In spite of this, most feed producers are optimistic that supplies to aquaculture will be secure in future, too.

Next to feed, oxygen is the most important factor for determining the success of an aquaculture enterprise. Sufficient quantities of oxygen in the water ensure that the fishes grow well and stay healthy. Oxygen encourages their appetites and general well-being. It can even lessen the impact of temperature induced stress. That is why all fish farmers take particular care that their fishes grow under optimal O2 conditions.

In October this year, at the Cromaris adriatic fish farms, a new cage cleaning robot was presented. The device offers several benefits.

A shrimp farming project is currently underway in Riga, Latvia, producing high quality organic shrimp in a Recirculating Aquaculture System (RAS). The project was launched in May 2014 and uses an intensive biofloc RAS. This system recirculates 100% of the water and has zero discharge, causing no negative effect on the external environment and ensuring the quality of organic shrimp production.

When evaluating the environmental sustainability of aquaculture operations water consumption and water discharge quality are important criteria. Today water usage is governed by more or less strict rules almost everywhere in the world. For aquaculture, this often means the obligation to clean and treat the water discharge in such a way that natural ecosystems remain unaffected.

Biofilters are bioreactors (also called biocatalysts) that make use of highly complex metabolic activities of various microorganisms to clean water or air. Here “clean” means, above all, to eliminate or render harmless various pollutants or toxic substances. The term “filter” in the sense of holding back or removing unwanted material is not appropriate in so far as biofilters in fact only transform the substances.

Global aquaculture has to face some major challenges in the coming years. On the one hand it has to produce more fish and seafood to meet the rising needs of a growing world population. And on the other hand we are already now reaching the limits of what the available locations can offer for new farms. One way out of this dilemma would be to shift farming into the offshore region but this necessitates new concepts, independent systems, more robust technology – and more risk capital.

As energy costs continue to rise, energy efficiency in aquaculture becomes an increasingly important topic. And addressing the topic of energy efficiency isn’t just about the power requirements of individual devices; it means taking a holistic view of all processes that require energy... because sustainable production also means producing more fish with less energy.

Zander is considered to be one of the most promising fish species for production in closed recirculating aquaculture systems. One problem, however, is that there are not enough fry available that have been adapted to dry feed. This could change now, however, because in May 2013 Fischmaster IP Services GmbH opened an ultramodern facility for the reproduction and farming of zander fry. The investment was made without any subsidies.