Bee resin used to save fish

Dr Garth Cambray


A honeybee harvesting propolis

From the beehives in the arid karoo of South Africa, Paul Collet and Ernst Thompson have found and harnessed an ancient medicine which is changing the world of aquaculture.

Propolis is a sticky black resinous substance produced by honeybees. As it is normally built into walls at the entrance of a beehive, and the ancient Greeks considered bees to live in cities, it was named Pro (in front) polis (city) i.e. Propolis, the stuff in front of the city – it's almost like a security gate.

Thousands of years later, we as humans now also live in big cities, and, just as is the case with honeybees, huge numbers of bacteria, yeasts, fungi, viruses and other single celled pathogens are often unwelcome guests.

Bees produce propolis by collecting the little scabs that form on wounded plants. When a browsing animal or nibbling insect wounds a plant, it  quickly forms a scab filled with substances which kill or disable organisms which could infect the plant – such as bacteria, yeasts and viruses. The bees methodically pick these scabs off and roll them into a ball which they pack on their hind legs and then fly back to the hive where other bees relieve them of their load. Once in the hive the propolis is used to build entrance barriers at the front of the hive, as well as to paint the surfaces of the hive and fill in any cracks that are undesirable. This ensures that the hive remains a relatively clean, sanitized and sealed place for the bees to live.


Honeybees pack propolis at the entrance to their hives.

In recent years, aquaculture – the cultivation of fish and sea animals for food production has become big business. In many countries, cultivated aquatic animals now represent a vital protein source. To rear a young fish from egg to adult is not an easy task – fish eggs are prone to attack by fungi, which reduce the numbers of eggs which hatch dramatically. Larval fish are also easily killed by fungi.

Commercial aquaculturists used to use various chemicals, many of which are toxic to humans, to kill these fungal pathogens. Recently however, international food laws and/or standards have been passed which ban the use of traditional antifungals in aquaculture. This has caused many problems in the industry, as without these medications, far fewer eggs hatch, and far fewer larvae make it to adulthood, reducing the productivity of the global aquaculture industry.

Paul Collett and Ernst Thompson are both trained ichthyologists and aquaculturists – Paul with an MSc from Rhodes University in Grahamstown and Ernst completing a PhD in Aquaculture, also at Rhodes. Both are also avid beekeepers. Out of this synergy, an idea was formed to test whether the very same propolis which protects bees could also protect fish. Effectively taking the front of the city of the bees, into the seas, and onto your plate.

Propolis extracts produced by Paul and Ernst, under the brand name of their company, Speelmanskop Apiary Products, were tested on various fish pathogens. The result  of this is the award winning Speelmanskop Biobalsam, specifically developed for the aquaculture market, which is able to achieve the same, or better levels of control than the now banned alternative traditional aquaculture antimicrobials. Better still, propolis is generally regarded as safe for humans, is a known source of antioxidants and is already in products as diverse as toothpaste, lip balm and chewing gum. The use of small amounts of propolis in aquaculture is therefore entirely safe to humans and allows aquaculture to continue growing and feeding us good quality, safe protein.

After winning top honours for their invention at a regional competition, the industrious pair walked off with a R 250 000 prize from the Innovation Fund's National University Innovation competition after winning second place. The prize money forms part of the South African Department of Science and Technology's initiatives to encourage African Techno - Entrepeneurs.

This innovative scientific duo have now, possibly for the first time in history combined apiculture (the farming of the sky with bees) and aquaculture (the farming of the sea and inland waters with aquatic lifeforms) to create perhaps a new phenomonen, or a so-called apiquicultural product - bee biobalsam.


October 2008