“Dear captain, could you kindly take on some seawater on your voyage to Rotterdam?” – When this email from Mirsada Mutapcic of the Diergaarde Blijdorp lands in Mark Langer’s email inbox, the captain knows that the zoo in Rotterdam needs some fresh water for its Oceanium. And that means it’s time to make an unusual “refuelling stop” on the open sea!
About every two weeks, his “Cap San Nicolas” or one of the other Hamburg Süd Cap San-class vessels that sail back and forth between Europe and South America take turns supplying the zoo in this Dutch port city with water from the Atlantic Ocean. This regular task is necessary because sharks in particular, but also other sensitive sea creatures, such as seals and fish, need water of a very specific quality and salinity – just like the water found in the Bay of Biscay, where our ships take some in. “We bring the animals their ‘living room’ right into the zoo,” is how Captain Langer aptly puts it.
“Refuelling stop” in the Bay of Biscay
To transport the water, the ships use their ballast tanks. An empty ballast tank is flooded in the central part of the Bay of Biscay – a large gulf off the north coast of Spain and the south-west coast of France – and then serves as the transport container until the ship arrives in Rotterdam.
One such “load” contains around 400 cubic metres of seawater – or enough to fill a small indoor public swimming pool. After the bunkering process has been completed, the “Cap San Nicolas” sits about four centimetres lower in the water.
“Last mile” delivery by barge
A few days later in the Port of Rotterdam, a barge takes on the valuable water and transports it via rivers and canals directly to the zoo. There, the water from the Bay of Biscay is pumped into a storage tank and used as needed to replace seawater in aquariums. Mirsada Mutapcic closely monitors the quality of the water. “We are extremely grateful for this gift, as our marine animals are very sensitive and feel most comfortable when they have fresh water from their natural habitat,” the chemist explains.
Visiting the zoo will have to wait
Captain Langer still hasn’t had a chance to pay a personal visit to “his” sharks, rays and penguins. “There usually isn’t any time for shore leave,” he notes with regret. Nevertheless, he stresses that it makes him feel good “that we can contribute to helping the zoo – and especially the sharks there – with minimal effort”, adding: “It’s a pleasure to do it!”
22 February 2021