Fish farming lessons from German to Ugandan farmers

Plaice fish species displayed by scientists at Thuein Institute of Sea fisheries in Humberg, Germany in the Lab where they are studying the female behavior in egg production. Photo by Lominda Afedraru

What you need to know:

  • These are mainly none invasive but there are invasive fish species which feed on other aquatic life. They include among others black shelfish, stripped pipe fish, blotched snakehead, brook trout and Alewife mainly found in Baltic Sea and North Sea
  • According to Dr Kraus, fish living in deep seas and oceans are less prone to diseases apart from those omnivorous feeding on small fish stocks. Sometimes fish deaths are recorded on a small scale due to ocean acidification but it is not common because dilution would have taken place

Germany- Fish farming in Germany and other countries in Europe like Holland, Norway, Finland, Austria, Spain and United Kingdom among others is a major activity with almost all the fish farmers concentrating mainly in Baltic Sea, North Sea and Atlantic Ocean which are a major marine resource for the countries.

Unlike in Uganda where majority of the fish farmers catch their fish from fresh water bodies like Lake Victoria, Lake Albert, Lake Kyoga, Lake Edward and River Nile among others including aquaculture, it is not the case in Germany.

Scientists working in various fisheries institutes explain the best practices adopted by fish farmers in German and other European countries during the global press tour 2017 on the topic Seas and Oceans.

Fish Species in the seas and Atlantic Ocean
The director Thuein Institute of Sea fisheries in Humberg Dr Gerd Kraus explaining the recent trends in fisheries and the role of fisheries research in sustaining marine resource noted that there are differences in fish species in the seas and the fresh waters in Africa such as lake Victoria with the main ones categorized as flat fish species namely sole, plaice and dab, round fish category namely Cod and Saithe.

The other category is the swimrun fish species namely plague fish and herring, mackerel and cod.

They live mainly in the middle part of the water
These are mainly none invasive but there are invasive fish species which feed on other aquatic life. They include among others black shelfish, stripped pipe fish, blotched snakehead, brook trout and Alewife mainly found in Baltic Sea and North Sea.

These fish species especially love living in deep sea inland sand bottoms about 330ft below sea level.

The German North Sea coastal fishery also harvests shrimp (Crangon) and Octopus which are commercially viable.

Unlike in Uganda most fish farmers concentrate on catching fish species such as Tilapia, Nile Perch and Silver fish among others mainly in Lake Victoria but there are number of fish species in Lake Albert, Lake Eward and River Nile.

They include Nile tilapia (niloticus oreochromis), Catfish (Bagrus and Clarias species), Tiger fish (hydrocynus), Lung fish (Protopterus), Pebbly fish, electric fish and Brycinus nurse among others.

Fishing methods in the Seas and Oceans
Dr Kraus explained that fish farmers in Europe including Germany do it on large scale using heavy ship vessels. This includes those owning fish companies while others do it in medium and small scale using motorized boots.

Fish farmers are encouraged to catch fish species which are mature enough depending on every fish species. In the case of shrimp fish the recommended size is of trawling net is 1 mill meter and a minimum time of one years should be given for the fish to grow and the female ones are good at laying eggs of about 200,000 in a period of three months.

For the case of cod fish it is advisable for farmers to catch those beyond one year but it is equally good enough to allow them grow for as far as beyond five years. The same applies to cat fish on Pacific Ocean with recommended size of 1.2 – 1.6 meters and net size is approximately 24 inches.

In general fish farmers are advised to use the right net size for every fish species with the average estimate of 88mill meters and above.
For the case of Shrimp fish species the required net size is about 1 mill meter.

Fishing is mainly done using bottom trawling which involves pulling a fish net through the water to the boat and the nets contain big hooks at the age. Marine police keep monitoring the fishermen and once small fingerlings are caught, it I advisable to let them back in the waters there and done.

According to Dr Kraus, fish living in deep seas and oceans are less prone to diseases apart from those omnivorous feeding on small fish stocks. Sometimes fish deaths are recorded on a small scale due to ocean acidification but it is not common because dilution would have taken place.
Fish processing
Unlike in Africa including Uganda where fish processing is done both fresh and smoked or salted, it is not the case in Europe. Fish stock is sold fresh at fish habours on days which are gazetted. Some fishermen prefer to deepfreeze frozen fish fillet with fresh I Kg of plaice sold between 1 – 2 euros and cod fish goes for about 6 euros per Kg. Uganda is mainly benefiting from sale of Tilapia fillet in the EU market.

Challenges
Just like in Uganda where overfishing is a major challenge, the same applies to the European fishermen because most fishermen look at it as an employment opportunity
Dr Rainer Froese from Geomar Helmholtz Centre for Oceans and Seas in Keil city explained that fish farmers worldwide do not abide to best practices and as such this leads to illegal and overfishing causing decline in fish stock in the water bodies.

In Europe, fishermen go fishing across the sea and ocean water bodies but each country has its fish management instrument which is monitored by the European Union.
He said that the level of overfishing in European water bodies is 20% and in Africa it could be more and challenging because most fish companies are foreign owned.

Aquaculture
Dr Marisol Beltran Gutierrez from Bremen who carried out case study about integrated aquaculture of seaweed and sea cucumber in Zanzibar and Tanzania noted that there is an increasing use of coastal areas worldwide that has created an opportunity for more sustainable practices such as integrated multi trophic aquaculture.

In Zanzibar and Tanzania, farmers living along the coastal area of Indian Ocean occupy a portion of the shoreline for fish farming integrated with ocean weed for the fish to feed on.

By 2010, the statistics indicated that fish farmers harvested sea cucumber of 26 different species with an annual production of 32.5 dried tones valued at $26,500 which they export to European as fish feed.

Comparison of fresh water and marine fishing
The Director National Fisheries Resources Research Institute (NaFRRI) in Jinja Dr Anthony Taabu Munyaho explain that difference saying most farmers practicing aquaculture do it in ponds as well as cage fish farming where they use pellets to feed the fish.

In marine fishing there is open territory and fishermen from Russia can go fishing in Indian Ocean. It is a natural resource for all fishermen but under guided fish agronomy.
Unlike fresh water, this can only be possible if regional bodies sign an agreement and for the case of Uganda, anyone can purchase a boat and a net and go fishing to a nearby lake and the agronomy is controlled by individual countries which in most times are not followed.

Fish diseases he says are common on fresh inland water bodies. This is due to pollution caused by inflows from the land surface like flooding and sewer channels like for the case of Lake Victoria. The size of the fishing gears differ and in the ocean fishermen are given periodic quarters to fish within a given period of time to allow recovery of fish stock.

Global statistics
Dr Kraus citing the recent FAO statistics says that about 10 – 12% of world’s population depends on fish farming producing 160 million tons per annum with total revenue of $129.2 billion and net export of 35.3 billion tons.

The global capture production is 93.7 metric tons out of which 81.5 metric tons are from marine fishing.

Global capture from aquaculture constitutes 90.4 metric tons providing half of the fish consumed globally
In Europe, about 414,000 million people depend are employed in the sector job and the total production is about 6.05 million metric tons worth 30 billion Euros with people from Spain mainly engaged in aquaculture.