The Wels catfish, Silurus glanis, is one of the largest fresh water fish in the world. Accurate measurements over the last couple of decades have shown several specimens of over two metres in length, the longest and heaviest being 2.78m (144kg). It’s a not the most attractive fish you will ever see as it has a long snake-like body, with slimy skin and a huge mouth. Using its long barbels, it tracks its prey by hearing and smelling. The eyesight of a Wels catfish is fairly poor, but it enjoys a tapetum lucidum which gives it reasonable vision at night. They eat insects, crustaceans and other fish. The larger ones go after small mammals and aquatic birds. It is rarely kept in the aquarium due to its sheer size.
This giant fish has been introduced in several European rivers, including the Seine and Po rivers in France and Italy respectively. In some areas, they are known to lunge out of the water to grab pigeons on land. Check youtube for video’s on this! Also the 6th season “cities” of the BBC’s Planet Earth II series spends time covering this phenomena.
Photo from the Watershed Council Petoskey
On Thursday the 16th of February 2017, I held my colloquium at Wageningen University of my master thesis covering the sanitation issue in Ciwalengke, Majalaya, Indonesia.
This master thesis research examined the important issues that play a role for successful implementation of domestic sanitation treatment facilities and the potential for nutrient harvesting in Ciwalengke. Based on field observation, water sample analysis, questionnaires and interviews a new sanitation design was proposed specifically for the case of Ciwalengke. It incorporated both a technical and institutional design. The technical design concluded that storage of urine and the treatment of the remaining wastewater through septic tanks were the most feasible technologies. The institutional design concluded that a solid platform would be necessary that incorporates community involvement in the maintenance and operation of the sanitation system. Governmental guidance coupled with a financial structure should be in place to facilitate this process.
It was great to see many students of my year and others attending this 🙂 Thank you all for coming!
In October 2016 I was invited to visit the only centralised domestic wastewater treatment plant in Bandung located in Bojongsoang. It was a very interesting day where I saw the many processes that take place within such a treatment plant. In this case, a series of stabilisation ponds were used to treat the incoming wastewater. Check out my short documentary of the processes below!