Goliath Tigerfish

The Goliath Tigerfish, Hydrocynus goliath, is a ferocious predatory fish native to the Congo River Basin in Africa. It can grow up to 1.5 meters long and has be known to prey on small crocodiles and tearing large catfish into pieces! It occasionally attacks human since it is able to sense low frequency vibration in the water. It prefers to hunt in fast flowing water where smaller fish struggle to swim. Its massive teeth perfectly slide into distinct patches along its jaw. The Goliath Tigerfish is very rarely kept in any sort of aquarium although I did manage to spot a few at the Singapore River Safari the other day! See video below 🙂

Building with Nature

The Netherlands constantly has to battle against the threat of flooding from the ocean and rivers as a vast area of its land is below sea level. However, the last major flood was way back in 1953. The success of water management in Netherlands is largely rooted in careful spatial planning and ‘building with nature’ to achieve a resilient flood-proof landscape. The concept of Building with Nature was invented by the the Dutch water authority, Rijkswaterstaat, and several other research institutes and consultancy agencies. The concept basically develops waterworks by integrating infrastructure, nature and society for sustainable water management solutions. Working with nature, rather than against it, is seen as being more efficient and less costly. One such example is giving room to the river “ruimte voor de rivier“. During peak discharges, usually in winter and spring, the river has special designated areas along its banks where water can be stored and transported. These so called uiterwaarden or flood plains in English are of low commercial values with almost no buildings being built on them. In this way, the (financial) damage the river can cause is minimal. During normal water levels, these areas are normally used for recreation and cattle grazing.

In the picture and clip below you can see the river Waal near Nijmegen which has been fed large amounts of rain and meltwater from Switzerland and Germany in recent weeks. Despite it looking rather serious, the situation is very much under control as the flood plains are compensating for the high water level. It shows that Building with Nature is the way to go!


Panama Canal and City

One of the most remarkable man made infrastructure I have ever seen. The Panama Canal at 80 kilometers long uses a system of three locks where these massive ships get elevated from sea level to an impressive 26 meters! The canal cuts through the isthmus of Panama through some low mountains at the Culebra Cut and an reservoir called Gatun Lake. The whole trip takes only 8 to 10 hours which saves a lot of time compared to travelling around the continent of South America! Surrounding the canal are primary tropical rainforests that act as sponges for the canal in times of high rainfall…it shows that building with nature is the way to go! Panama City is a modern, largely Americanised metroplolis, with lively residents 😊 

Old town
Down town

Pictus Catfish

The Pictus Catfish, Pimelodus Pictus, is a small species of catfish with extreme long barbels. The barbels can even reach to the caudal fin! Pictus Catfish are active bottom feeders that are usually most active at night. They inhabit the Amazon and Orinoco river basins and are common in the aquarium trade. In captivity they are omnivorous and eat vegetables, blood worms and insects among others. They are relatively peaceful fish and can be kept with other fish of similar size. Larger Pictus Catfish, however, will have a go at smaller fish (small tetra’s for example). Pictus Catfish are non-territorial so a shoal of 5 or more will make this species of catfish feel more at home. Furthermore, it is important to provide plenty of plants, rock, caves and driftwood in soft water. A dimly lit aquarium encourages the fish to be more active.


Orange ASEAN, Jakarta

Last week I participated in the fifth edition of Orange ASEAN, this time in Jakarta! Orange ASEAN is an intensive 3-week consultancy project for young professionals, entrepreneurs and master students from the Netherlands and Southeast Asia designing innovative solutions for sustainability challenges in ASEAN countries. In interdisciplinary teams, participants work together in dedicated teams developing business cases for real-life issues. My team consisted of Tulus (Indonesia), Dawn (Singapore) and Sukumal (Thailand) with Royal HaskoningDHV as our client. They asked us to developed innovative solutions to Indonesia’s water challenges…very broad for a 3-week consultancy project! In the end we narrowed the scope down and came up with two products that were well received by our client: Smart Water ANalytics (SWAN) and a Technical Advive Platform (TAP). Massive thanks to the team for making the past 3 weeks so enjoyable! We really gelled and produced some interesting stuff 🙂

Uara Cichlid

The Uara Cichlid, uaru amphiacanthoides, is a large species of cichlid native to South America in Northern Brazil and parts of Guyana that can grown up to 30 centimeters in length. It inhabits clear water tributaries, particularly around submerged branches and tree roots. Uara Cichlids can be recognized by their large eyes and distinguishing large spot on the body. In the aquarium it is a surprisingly peaceful fish considering its size and the aggressive behavior of most other cichlid species. It can be housed together with tetras, angels and species of characins. Uara Cichlids do need be housed in large tanks of about two meters in length. These fish can be fed frozen foods such as blood worms or brine shrimp, but will also happily eat vegetables such as lettuce, peas and spinach. Dried foods will also be gladly accepted. Juveniles often feed on the slime coat of their parents, similar to what Discus do.

Profitability in Aquaponics

To grow vegetables in water from a fish pond full of nutrients might sound like a brilliant idea, but is it really profitable? A study by reaearchers from the Wageningen Univesity showed that more than half of the 1000 commercial aquaponic farms worldwide make a loss. This was mainly the result of low market value for the produced vegetables and fish that were farmed. Before starting an aquaponics farm it is important to look at the market prospects. A niche in the market needs to be found that could make aquaponics more profitable. Tilapia and catfish usually won’t make it because they sell for far to cheap. Perch, burbot and pike could be interesting alternatives for the European market as their market value is much higher.

Schematic overview of a aquaponic system. Illustration retrieved from Baliga Lab, Institute for Systems Biology


The Anammox process was developed by the Technical University of Delft and is an innovative treatment process for the removal of ammonium from wastewater. It is a shortcut in the nitrogen cycle in which ammonium is directly converted into nitrogen gas. The Anammox process occurs within one of the many granules present in the reactor. Half of the ammonium is oxidized into nitrite by nitration bacteria. Subsequently, Anammox bacteria convert the nitrite and the rest of the ammonium into nitrogen gas. The whole process takes place in one reactor which makes the Annamox process very compact. In conventional methods, at least two reactors are needed for the nitrification and denitrification steps. Another advantage of the Annamox process is that far less oxygen is required to drive the conversion of the ammonium, which substantially reduces the overall treatment cost. Anammox treatment is particularly suited for industrial wastewater high in ammonium content 🙂


Illustration retrieved from: https://www.zeolite-anammox.com/faq on the 27th of August 2017

Åndalsnes, Norway

Spent several days in the awesome Norwegian fjords with hundreds of waterfalls and peaceful surroundings. The magnificent scenery was shaped by past glaciers that have eroded the rock to form steep U-shaped valleys. When the glaciers retreated, some of the valleys became filled by the ocean, creating the sublime fjords of Norway. Some of the fjords are over 1300 meters deep! Thousands of waterfalls dot this pristine and rugged landscape making it a heaven for outdoor sports such as hiking, skiing and fishing. The train ride from Dombås to Åndalsnes was one of the most scenic train rides I have ever experienced. Particularly towards the end when the train descends to sea level towards the foot of the fjord at Åndalsnes. The nearby Trollstigen and Trollveggen and are the two main highlights of the region. Trollstigen is a 20km breathtaking zigzagging road that crawls up over a mountain pass crossing many waterfalls along the way. Tourists from all over the world come to Trollstigen during the summer to witness it for themselves. Trollveggen is in the adjacent valley and is Europe’s highest vertical cliff at over 1000 meters high. At the top of the of the cliff several sharp rocks can be seen which are referred to as the “trolls teeth”:P. Base jumping was popular here, but after several fatal accidents this has now been banned.

Romsdalseggen is a 10km hike that is definitely worth doing. From Åndalsnes, take a bus to the other side of the nearby mountain and walk the entire path back to Åndalsnes. It takes approximately 6 to 8 hours and passes through pristine landscape and very steep mountain cliffs. At some point the cliff almost go vertically down left and right of the path. You should not have fear of heights when attempting this walk!

Norway is one of the most expensive countries in the world, so in order to save a bit of money you can opt to camp in the many campgrounds for about 14 euro’s for two persons and make use of the facilities. We stayed at the Åndalsnes camping ground which was a pleasant place to stay 🙂

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Blackline Penguinfish

The Blackline Penguinfish, Thayeria boehlkei, also known as the hockey-stick tetra is a species of tetra native to the upper Amazon River basin in Peru and Araguaia River in Brazil. It has a distinguishing black line across its body which hooks downwards at its tail. It is highly recommended to cover the aquarium as these small fish have been seen jumping 2 meters out of the aquarium! Keep this fish in schools of at least 6 individuals (preferably more). The blackline penguinfish does not grow very large (max 7 centimeters long), so one does not need a very large aquarium to house a school of these fish. These fish are not too fussy concerning water parameters as long as the tank is cleaned periodically. This is a very peaceful fish excellent for a community tank. Goes well with other species of schooling tetra’s 🙂

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