At the beginning of their stay, we give the seals a kind of puree made from ground salmon. It contains many important fats, minerals and other nutrients. Severely weakened seals can digest the fish porridge a lot more easily than solid food. Fish porridge is mixed with water if the seals need extra fluid.
Did you know...
Seals' breast milk cannot be imitated? That is why we feed seal pups fish porridge.
To feed the fish porridge to the seals, we have to force-feed them. We insert a flexible, soft tube into the esophagus with a funnel at the end. We pour in the porridge there. This is a quick way to feed the seals. Speed is important in order to cause as little stress as possible for the animal.
When the seals switch to solid food, we always give them herring. Herring is a nutritious and firm fish, with a good shape for forcefeeding. By sticking to a single species of fish, we know how many nutrients the seals are getting per kilo of fish.
Our herring comes from Norway and is of high quality: in principle it is good enough for human consumption. We buy all the fish ourselves, it is not donated. This way we know that all fish is of good quality.
The fish is dead when we give to the seals. The two main reasons for it:
- It is extremely expensive to keep enough live fish for seals. Sometimes we need hundreds of kilos a day!
- It is ethically irresponsible to give live animals to captive predators. There are rules in the Netherlands about which animals can and cannot be fed live to predators. Animals with a backbone (including fish) may only be used as food when they are dead.
The herring is already frozen when we get it. We keep it in a special freezer where only food for the seals is allowed. Freezing it keeps it fresh for longer and reduces the chance that it will still contain live parasites. Enough herring is thawed daily to feed that day, but it never stays longer than a day.
You must be thinking: hunting should be easy! But seals are not used to eating dead fish because they hunt live animals in the wild. That is why they often have to learn to eat the dead herring themselves. This process usually involves three steps:
Forcefeeding – handfeeding – selfeating
Did you know...
That a seal doesn't drink water? They get all the water they need from the fish they eat. It's a good thing: seawater is much too salty to drink!