Friday, September 20, 2019

News from the Beach: The “GIVE A FISH A HOME!” Virundu Edition

Summer is coming again here on Lake Malawi and we are excited for the warm weather and calm lake conditions it brings.  Our winter season with Operation Wallacea was amazing with great students and great research accomplished!  Back at Kande we have some exciting plans for the next few months that we need your help on!  Info on the first plan is below! (more to come)

Let’s Build Artificial Reefs a.k.a. “Virundu” in Lake Malawi!

The people of Malawi get most of the little meat-protein that they consume from the Lake’s amazing fish species.  For centuries one of the ways that fishermen here have worked with the Lake to provide them with more fish is by building underwater “reef” structures, locally known as Virundu, which create more fish habitats particularly for breeding.  Traditionally these Virundu were built by cutting down hardwood trees, once plentiful, and sinking them.  Such structures were durable and provided an inviting lattice work of branches upon which algae could grow and in which fish could make temporary homes.  After the breeding season, the fishermen would return and harvest a portion of the fish around the Virundu to feed their families.  Unfortunately, these days hardwood trees are difficult to come by and fishermen are finding that inshore waters no longer have the fish they used to.  This forces them to go deeper and deeper into the lake to catch the fish they need to feed their families.  
We first learned about Virundu by speaking with fishermen at Masakhahunju fishing village where we do our Fisheries Monitoring Surveys and started brainstorming with them how we might re-create them in the Lake in a way that was as equally as durable as hardwood, could be made from locally available materials, was scalable, and perhaps even more attractive to the lake’s fish.  What we came up with last year were structures inspired by the baskets that Malawians use to transport their fish to market.  After getting a local weaver to make some of these structures from readily available bamboo we sunk 10 of them near Kande Island as a trial and began waiting to see if fish might find them attractive.


To our astonishment within two months fish had made our Virundu their homes!  Look at the video below! (ignore the wrong timestamp) This was taken earlier this year.

 So by February of this year we knew that our structures were locally feasible, scalable, and attractive to the fish!  So far so good!  What we didn’t know was how durable they were.  For this we would have to wait and see if they could last through the annual winter windy season when strong winds create strong underwater currents that could potentially uproot our Virundu from the lake floor. Unfortunately, with this year’s windy season now at a close we now know our answer.  Our beautiful trial Virundu that we anchored to lake floor last year have all been blown away!


While very sad this is the nature of research.  There is trial and there is error.  But there is also progress and learning!  So this new summer season we need YOUR HELP! 

We KNOW that our reef structures WORK at attracting fish.

We KNOW that we can make them with LOCAL materials.

We also KNOW that we can SCALE them up to create potentially VAST underwater fish habitats.

All that we need to do is make them STRONGER to last through the annual winter windy season.
To do that we are going use IRON! The bamboo lattice work baskets were an ideal material on which algae could go and an attractive structure to the fish, they just weren’t strong enough to withstand the currents.  BUT if we reinforce our bamboo virundu baskets with IRON rebar we believe that they stand a good chance of making it through the Lake’s next winter windy season. 


While easily available, iron rebar, unlike wild growing bamboo, is not free.  How much is it you ask?  Well we have calculated that the rebar needed to reinforce one 2-meter-long by 1-meter-round virundu basket and provide strong anchors to attach it to the lake floor will cost JUST $25 USD!


Click the link above to donate any amount you can to help buy rebar to GIVE A FISH A HOME and we will send you a picture of the virundu basket that your donation helped to build and send you regular updates on the fish that have made it their home! 




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