Like a fish out of water

Visitors can’t normally go here but let me take you behind the scenes of the enormous aquarium at Rotterdam’s famous zoo.

Written by Michael Turtle

Michael Turtle is the founder of Time Travel Turtle. A journalist for more than 20 years, he's been travelling the world since 2011.

Michael Turtle is the founder of Time Travel Turtle and has been travelling full time for a decade.


Oceanium, Rotterdam Zoo, The Netherlands

All around is blue. There’s water above, there’s water either side, and there’s water ahead. Like a fish out of water, I’m surrounded by ocean.

Sharks glide past on one side and then a large turtle appears, swimming overhead. Schools of fish dart around and a stingray patrols the sandy ground.

This is what it must feel like to be in the sea… yet here I am in the middle of Rotterdam in The Netherlands.

Oceanium, Rotterdam Zoo, The Netherlands
Oceanium, Rotterdam Zoo, The Netherlands

But if you think being in the tunnel of Rotterdam Zoo’s Oceanium is interesting enough, let me take you outside it to a truly fish out of water experience: behind the scenes of the aquarium.

Visitors are not normally allowed back here and this is a special access opportunity just so I can show you what goes on to keep the Oceanium running.

Oceanium, Rotterdam Zoo, The Netherlands

“We have a public lab where visitors can also have a look and get an impression of what we’re doing behind the scenes,” the zoo’s Constance Alderlieste tells me. “But what you’re seeing – that is real.”

Constance leads me through a nondescript door, up a flight of internal stairs and down a corridor of offices. In one room, models of sharks hang from the ceiling and a cloth stingray is strewn over a set of shelves.

Oceanium, Rotterdam Zoo, The Netherlands

We turn right at the end of the corridor and walk down a metal gangway. Suddenly we arrive at a massive pool.

I go to peer over the edge and Constance warns me to make sure nothing I’m carrying might fall into it. I see why when I look down and watch a turtle go past, followed by a shark and some fish.

Beneath me is the huge aquarium with the tunnel going right through the middle of it.

“We have 7 million litres of water in the oceanium and in the shark area 3 million litres,” Constance explains as I stare around in awe.

From above it looks massive on a scale that was hard to judge from below.

Oceanium, Rotterdam Zoo, The Netherlands
Oceanium, Rotterdam Zoo, The Netherlands
Oceanium, Rotterdam Zoo, The Netherlands

There are pipes everywhere connected to big tanks. There’s a whirring sound in contrast to the silence of the tunnel we had just come from. It’s all part of the elaborate filtration system that keeps the animals alive.

“It consists of several kinds of filters, sand filters, biological filters, UV filters,” Constance tells me, “and all the water is purified within one and a half hours and we have a system in different layers.”

“The most pure water first goes to the animals which are very vulnerable then it goes to the sharks and the other fishes and at last to the sea lion – they are less vulnerable to illnesses than some of the specialised fish we have.”

Oceanium, Rotterdam Zoo, The Netherlands
Oceanium, Rotterdam Zoo, The Netherlands

I’m led back along the gangway, down the corridor and through another door at the other end. Again there’s a large room with a pool in the middle, although this one is covered with much more scaffolding and equipment.

A woman, whose name turns out to be Dayenne, emerges from the water in a scuba outfit. She had been underwater cleaning the windows and feeding the coral. She holds up an empty box where the food had been.

Oceanium, Rotterdam Zoo, The Netherlands

There’s also some lab equipment with plastic trays of samples. Like many zoos, there’s a lot of scientific work going on behind the scenes.

“They are breeding several kinds of fishes and corals also,” Constance explains.

Oceanium, Rotterdam Zoo, The Netherlands
Oceanium, Rotterdam Zoo, The Netherlands

Visiting Rotterdam Zoo

Rotterdam Zoo is one of the most popular attractions in the Netherlands with more than 1.4 million visitors each year. This Oceanium is just a drop in the ocean.

There’s also an arctic section with polar bears, an Asian area with elephants, and Africa area with crocodiles, a savannah with hyenas and zebras, and a new butterfly section where cocoons are sent each week from Costa Rica.

You could spend all day wandering around the different zones but unfortunately I don’t have that kind of time today. Luckily there are plenty more fish in the sea.


As you would expect in Rotterdam, there are some very cool and interesting accommodation options in the city.


For one of the best backpacker options in the whole country, check out King Kong Hostel.


Hotel Bazar has some really funky rooms and with the huge breakfast, it’s great value.


For a bit of history, you can stay in the beautifully-designed Hotel New York.


And I think the best modern luxury in the city is the stunning Mainport Design Hotel on the water.

Time Travel Turtle was a guest of Rotterdam Marketing but the opinions, over-written descriptions and bad jokes are his own.

11 thoughts on “Like a fish out of water”

  1. Ok, this is one of the grooviest posts you’ve done in awhile 🙂 Oceanariums are always so amazing, and this one looks awesome! I haven’t been to a good one in a long time…nothing down here in Cancun, even though they have an aquarium and the underwater submarine here…that can compare.

    Great stuff!

    • I guess most aquariums are similar in the sense that they have water and fish… but I love the ones that go out of their way to make the experience a little bit more special for the visitors.

  2. I would have loved this! I once upon a time wanted to be a marine biologist and spent my first year of college working toward that goal. Life happened, but my interest in sea creatures lives on. It would have been incredible for me to get a behind the scenes look at the aquarium!


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