Aquaponics in the West Bank
During our stay at Bustan Qaraaqa in Palestine, we have been lucky enough to volunteer one day a week with Phil and Lorena from Byspokes on aquaponic systems (their website is where the following information comes from). Aquaponics is a combination of aquaculture, which is growing fish in water, with hydroponics, which is growing plants in a liquid. Since they arrived in the West Bank in July 2010 they have been researching, developing and trialing the FIRST EVER aquaponic system constructed behind the Wall!
They have been developing integrated aquaculture/irrigation systems and aquaponic systems to enhance food security in rural areas of Palestine, where as much as 44% of the population are chronically food insecure. In general, water and space for agriculture here are in short supply, and this is nowhere more apparent than in high density urban areas such as refugee camps. For the last 60 years, the 27 refugee camps in the Palestine have become increasingly densely populated – now over 673,000 people live in these camps in the West Bank and Gaza. Unemployment can reach up to 80% in the camps, and with no land for agriculture or gardening it is almost impossible for residents to produce any food domestically, creating a massive dependence on external aid.
Two of the biggest problems facing the Palestinian agricultural sector are water availability and space available for cultivation. Palestinians have been denied access to the Jordan River and its water since the start of the occupation in 1967, and although the West Bank sits on top of (and is the recharge area for) the mountain aquifer, 80% of the water in this resource is utilized by Israel. Palestinian abstraction is strictly controlled, and as a consequence the only way that Palestinians can meet their water needs is to buy water back from the Israeli water company Mekorot (for example, this accounted for 39% of Palestinian water consumption in 2005).
Aquaponics removes the need for fertile ground as they can be constructed pretty much anywhere – even on a rooftop - which is why Phil and Lorena saw that these systems could be so useful here in Palestine. Due to its recirculating nature, an aquaponics system is extremely water efficient and also a very space efficient means of fresh food production. Here is a simple diagram showing how aquaponics works...
Aquaponics at Bustan Qaraaqa
Phil and Lorena have been exploring lots of different construction and operation methods to develop an aquaponic system that works well, and is appropriate for, the West Bank. The systems they have implemented:
- Uses cheap, locally available materials – mainly re-claimed or re-cycled, in line with the philosophy of everything else here at Bustan Qaraaqa
- Works with the extremely high alkalinity and high pH of the groundwater in the West Bank
- Grows plants which thrive in the local conditions, and are already part of the local diet
- Enables production of plants with high water requirements even during the driest times of the year
- Offers the opportunity to grow “exotic” plant species that are not consumed locally at present, such as basil, lemongrass and butternut squash.
- Recently, as the winter gradually moves in, and overnight temperatures begin to fall, they have been very busy trying to “winter-proof” the aquaponic system at Bustan Qaraaqa. This system is located on an exposed terrace close to the house, and gets the full brunt of the prevailing wind. For most of the year this is not too problematic as air movement helps keep plants strong, healthy and pollinated. However, now the wind simply blows away the warmth that the system managed to accumulate during the day.Although the carp in the system will tolerate pretty much any temperature, the tilapia will all die off if temperatures dip much below 15
°
C for an extended period. To winter-proof the system, they are constructing a simple greenhouse from transparent plastic sheeting to envelop the whole terrace for the winter months and a solar water heater to try to warm up the water during the daytime. To make the solar water heater they decided to reuse all those Tetra-Paks that were cluttering up the recycling area at the farm. They wrapped them up tightly in black plastic bags (thus finding a use for another ubiquitous waste stream) and painting them with a home-made paint, see the recipe on their website. The heater, in the photo to the left, has been plumbed in and now they are monitoring its performance.- Aquaponics in the community
Recently they added some Australian redclaw crayfish, Cherax quadricarinatus, in to the aquaponic systems. They have been interested to experiment with other crops and this seemed like a good start. Adding them to the sump tanks and/or raft tanks provides another crop without needing any additional resources. By introducing a crustacean they are increasing the diversity and hence stabilising and strengthening the aquaponic ecosystem. Also, it just seemed like a good opportunity as they could acquire some for free! Last but not least, shrimps are very expensive here in Palestine and these bad boys taste even nicer than shrimps! Check out how beautiful they are... this is one that escaped:
Another technique is the Nutrient Film Technique where a thin film of nutrient rich water flows along the bottom of pipes with holes cut in them for plants in baskets to sit in with their roots reaching the water. This technique doesn't offer the same root support as a medium filled growbed, but the pipes are lightweight and can be stacked one on top of the other, creating green walls.
With the Floating Raft technique the growbeds are filled with aerated, slowly flowing, nutrient rich water. Styrofoam sheets are floated on the water surface, and the plants are planted in baskets through holes in the styrofoam. The plant roots are always immersed in the oxygenated, nutrient laden water. This growing technique does not offer as much root support as a medium filled growbed, and has an equivalent sized footprint. However, it could be very useful on rooftops, for example, as there is no need to transport hundreds of kilograms of growing medium. Also, the increased overall water volume compared to a similar sized flood and drain system gives increased thermal stability to the system. In addition, the aerated water under the plant roots provides a great habitat for other aquatic animals such as crayfish or freshwater mussels.
Here is a sketch I did of an aquaponics system they have recently designed that combines the Flood and Drain Technique with the Nutrient Film Technique (NFT):
Aquaculture
In addition to aquaponics, Phil and Lorena have been promoting sustainable aquaculture. One method to enhance resource use efficiency is to practice this in existing irrigation cisterns. Unlike modern, high intensity aquaculture, sustainable aquaculture is not heavily reliant on technology, power, and fishmeal based fish food. Instead, the aquaculture systems they advocate rely on fairly low stocking densities and enhancing natural pond productivity through fertilisation of the water with manures and/or supplemental feeding with domestic and agricultural vegetable and cereal wastes.
This low-tech option has a couple of limitations in terms of the types and amount of fish that can be farmed because of the lack of aeration and filtration. However, for true sustainability, less fish actually means better water quality, less fish stress and less disease and parasite outbreaks. Fertilising the water costs nothing and promotes planktonic and microbial growth, leading to healthy and diverse pond ecosystems. This means that the fish live off an entirely natural diet of aquatic vegetation and pond organisms. Without air pumps, water pumps and filters, they don't consume power either which makes it cheaper, greener and worry-free – especially in a region with frequent power cuts! There are so many advantages too - production of an additional crop (food fish) from already existing resources; fresh fish to eat instead of imported, expensive frozen fish; the nutrient rich water can be used as a natural, free fertiliser for crops.
In summary
Delicious fish, edible plants, nutrient rich natural fertiliser, space efficiency, water efficiency... Aquaculture systems are amongst the most productive on earth! As part of my permaculture journey, I hope to use everything Phil and Lorena have shared with us to create our own system one day. In the mean time I will keep following their website to learn as much as I can from these energetic and beautiful people. We also want to take this opportunity to encourage you helping them... they are about to start several other pilot projects in the West Bank, and in the medium-long term, they are hoping to do similar projects in other parts of the world, including Africa. If you know of potential places or partnerships please let us/them know. Last but not least, you can support their initiative by donating here - any little helps!
As for us, sadly, we are leaving Palestine this weekend... so long, and thanks for all the fish!
2 comments:
Yes, it was a very helpful thing that rainwater tank can be a part of your aquaponics water system.
underground water tanks
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