People in the West Bank (Palestine) suffer from the decreasing availability of agricultural land. Population growth has led to increased urbanization and higher food demand (Palestinian National Authority, 2016). The labile economical, ecological and political situation in Palestine makes it crucial to foster research on sustainable agricultural techniques. This background was the motivation for my research on the combination of fish farming and vegetable cultivation (aquaponics) in the West Bank. Aquaponics is a water- and space-efficient technique that does not depend on synthetic fertilizer. It further helps decrease the dependency on imports of agricultural products from foreign countries and is therefore an ideal system to offer new opportunities for the people in the West Bank.
How aquaponics work
The concept is easy to understand: Water from a fish tank, enriched with feces, is channeled to a growing bed. The ammonia in the feces is transformed by bacteria to nitrite and then to nitrate which acts as a fertilizer for the vegetables (Sommerville et al., 2014). The cleaned water is then channeled back to the fish.
Beside small amounts of water and electricity, fish food is the only input needed (Viladomat and Jones, 2012). Nowadays it usually contains fishmeal as a source of protein. This fishmeal can be derived from wastes occurring from processing fish. But due to an increasing demand, a branch of deep-sea fishery specialized only on catching fish to produce fishmeal. That way, fish farming contributes to overfishing. By using insect larvae, fed on compost or manure, fishmeal could be replaced (Sealey et al., 2011). This alternative protein source was examined in my master thesis in spring 2016.
Research in Bethlehem, West Bank
Research took place at the Palestinian Museum of Natural History (PMNH) at Bethlehem University. Three small-scale units consisting of two square meter growing area and a fish tank were built inside a greenhouse. Two systems were stocked with fish and used as aquaponics whereas the third system without fish was used as a hydroponic system. Fish were fed with insect larvae (Hermetia illucens) and conventional fish food based on fishmeal. During my research I measured the biomass of the plants and monitored several water parameters. Further, I measured and weighed the fish once a month.
Harvests in the hydroponic system were increased significantly compared to the aquaponic systems. Nutrient deficiency in hydroponics can easily be corrected by adding fertilizer. In an aquaponic system on the other hand, the dependency on the right conditions for the ﬁsh and the bacteria makes an increase of the nitrate concentration much more complicated.
The use of insect-based ﬁsh food revealed the advantages of the conventional ﬁsh food based on ﬁshmeal. Ever since ﬁsh have been cultivated the composition of the ﬁsh food has been investigated to optimize ﬁsh growth. Achieving the same optimization with ﬁsh food based on insect meal will require years of research. However, since fishmeal is unsustainable and can’t be produced locally, the search for alternatives has to be promoted.
Aquaponics was found to be a promising technique to increase food security in Palestine. By cultivating climate-adapted vegetables and ﬁsh species, large amounts of food can be produced locally. To also produce ﬁsh food locally, research of alternative protein sources should be expanded.
To increase awareness and acceptance of aquaponics in the West Bank, research at the PMNH in Bethlehem will continue. The research site is open to the public and is visited frequently by pupils, students and people interested in this new agricultural technique.
During my research, I helped building another small-scale aquaponic system on a rooftop in Bethlehem. George Handal, a local shop owner heard of the idea, visited the research site several times and started to build his own unit. I supported the building process, gave further training and also helped purchasing measuring tools. This private aquaponic unit was visited by several friends of George who are now also planning to build a system on their own.
In the last years, several small-scale farmers in the region were equipped with aquaponic systems by non-government organizations. Visiting these projects showed that most systems failed already after several months. The farmers stated that ﬁsh did not grow fast enough to be harvested before winter and that extension service was insufficient. By providing support and advice for owners of small-scale aquaponics over a long period of time and by promoting privately financed and maintained systems, aquaponics might become a widely used technique in the West Bank.
Palestinian National Authority (2016) Palestinian national information center.
Sealey WM, Gaylord T, Barrows F, Tomberlin J, McGuire M, Ross C, St-Hilaire S (2011) Sensory analysis of rainbow trout, Oncorhynchus mykiss, fed enriched black soldier fly prepupae, Hermetia illucens.
Somerville C, Cohen M, Pantanella E, Stankus A, Lovatelli A (2014) Small- scale aquaponic food production.
Viladomat L, Jones P (2012) Aquaponics Training Manual.
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ABOUT THE AUTHOR
Samuel Kessens started his studies in Environmental Sciences at ETH Zurich in 2009. The work on an organic farm alongside his studies aroused his interest in agriculture. After a six-month internship on a permaculture farm in Bethlehem (Palestine), he decided to focus on Crop Science in his master studies. The acquired knowledge on growing crops, own research on fish farming and the fascination for Palestine brought him back to Bethlehem in 2016 to write his master thesis on aquaponics.