Nature Conservation

Today there are many threats to animals and nature. That is why it is important that people become aware of the protection of nature. The Dolfinarium makes people aware of how we can preserve the animals and nature. But what does that actually mean? Millions of Dutch people visit one or more zoos every year and get to know the most special animals there. The Dolfinarium is home to bottlenose dolphins, Steller and California sea lions, walruses, gray and common seals, porpoises (also known as the Dutch dolphin) and thousands of fish. Our guests really get to know these animals in a fun, accessible, but also substantive way. You want to protect something that you know and have a feeling for. Not only the animals in the zoos, but also the animals in nature.

Cooperation with parties

The Dolfinarium is actively committed to preserving animal species and their natural habitat. Together we are strong and we can reduce the threats to animals and nature. These are our conservation projects and partnerships:

Collaboration with international organizations

The Dolfinarium is affiliated with the European Association for Aquatic Mammals (E.A.A.M.)

Thanks to our international collaboration with E.A.A.M. we have achieved many great things. For example, the risk of extinction of Europe’s most endangered marine mammal, the Mediterranean monk seal, has been reduced.

How did we achieve this together?

The international advocacy organization for marine mammals, European Association for Aquatic Mammals (EAAM), has strengthened its commitment to Europe’s most endangered marine mammal. The Dolfinarium is an active member of this international organisation.

The Mediterranean monk seal, the most endangered marine mammal in Europe, was once a common marine mammal species in all Mediterranean countries and along the African coast. This species is almost extinct in its native range and the population has been reduced to less than 700, which are divided into three or four subpopulations. The Mediterranean monk seal is the most endangered seal species in the wild. Unwanted bycatch in fisheries and disturbance of their habitat, especially the beaches where they breed, are the main threats.

Thanks to various international organizations and important conservation and awareness campaigns, the chance of survival is now increasing.

In 2019, EAAM doubled its contribution to help this endangered species. Among other things, she provides financial support to the Greek organization MOM, which takes in rescued monk seal pups and then releases them back into the wild. While the efforts are bearing fruit, much work remains to be done to be truly optimistic about the full recovery of the species.

Since 2009, EAAM has spent more than €50,000 on the rehabilitation and rehabilitation of this unique species. As a result, dozens of monk seals could be captured and released back into the wild. In the coming summer months, EAAM will also fund a scholarship for a European student. This student can help MOM with the rescue and rehabilitation of Mediterranean Monk Seal pups.

In the coming years, to be optimistic about the recovery of this species, we will have to evaluate annually whether the number of Mediterranean monk seals will continue to increase. Therefore, the International Union for Conservation of Nature (IUCN) will map the level of threat to this species throughout 2020. These types of counts are especially important in the context of global climate change, the effects of which could lead to the extinction of critically endangered species.

Save the Vaquita!!

The vaquita must not disappear!

The most endangered whale species in the world urgently needs our help. The population has declined drastically in recent years, mainly due to illegal gillnet fishing. Now there are only 30 animals left! Support this campaign to prevent the extinction of the vaquita.

The vaquita is a porpoise species

Vaquita, California harbor porpoise (Phocoena sinus)

Order: Whales

Suborder: Toothed whales

Family: Porpoises

Length: 1.2 – 1.5 meters (at birth 70 – 80 cm)

Weight: 30-55 kg

Gestation period: 10 – 11 months

Generation time: About 10 years

Habitat: Shallow coastal waters

Distribution: Mexico, northern Gulf of California

Global population: 30 animals

IUCN red list classification: ENDANGERED

The vaquita is one of the smallest whale species with a small distribution area of ​​4000 km2 (about the same size as the province of North Holland). Vaquitas live exclusively in the northernmost part of the Gulf of California in shallow coastal waters. In this nutrient-rich area they feed on smaller fish, squid and crustaceans.


The vaquita is one of the smallest whale species with a small distribution area of ​​4000 km2 (about the same size as the province of North Holland). Vaquitas live exclusively in the northernmost part of the Gulf of California in shallow coastal waters. In this nutrient-rich area they feed on smaller fish, squid and crustaceans.

The body of the vaquita is grey, with the clear dark gray to black markings around the mouth and the dark circles around the eyes distinguishing the vaquita from other porpoise species. Also, for harbor porpoises, the vaquita has an unusually large dorsal fin. This helps the vaquita to give off copious body heat so as not to overheat.

Totoaba vs. Vaquita

Why is the smallest whale species almost extinct?

Within 20 years, the population of the vaquitas has shrunk from about 560 individuals to about 30. The main cause of this is the gillnet fishery, which kills the vaquita as bycatch year after year. Despite a ban on gillnets by the Mexican government, the vaquita population has continued to decline.

The body of the vaquita is grey, with the clear dark gray to black markings around the mouth and the dark circles around the eyes distinguishing the vaquita from other porpoise species. Also, for harbor porpoises, the vaquita has an unusually large dorsal fin. This helps the vaquita to give off copious body heat so as not to overheat.

The fishermen’s nets are not actually cast for the vaquita, but for the totoaba. The totoaba is fished for its swim bladder. In Chinese culture, this is considered a delicacy and a sign of wealth and prosperity. It is also used in Chinese medicines. On the black market, a kilogram of totoaba swim bladder can fetch up to 20,000 US dollars. This makes it even more expensive than cocaine!

Unfortunately, the vaquitas get entangled in the loopholes of the illegal nets and can no longer swim to the surface to breathe. It is feared that this whale species will soon disappear if drastic measures are not taken soon. The Mexican government is ready to do everything to protect the last vaquitas. The last and only option to prevent the extinction of the vaquita is a controlled breeding program with the remaining animals in a professionally managed, cordoned off and protected marine area.

Dolfinarium and the vaquita

There are only 7 porpoise species worldwide, of which the vaquita is one. The porpoises you see at the Dolfinarium are a different species – the common porpoise (Phocoena phocoena) – which fortunately is not threatened with extinction. However, these porpoises can contribute to the conservation of the vaquita, as they are genetically closest to the vaquita. The Dolfinarium has the most worldwide experience in keeping porpoises and shares this valuable knowledge with a partnership of several organizations (Vaquita CPR) that stands for the conservation of the vaquita.

More information about the vaquita? Then take a look here of here!


Partnership with Plastic Soup Foundation

No plastic in the sea, that is our mission

During performances, through communication on park signs and on social media, we make visitors aware of the dangers in the sea. In the Dolfinarium you can discover how dolphins live in nature, but nowadays nature also entails great dangers: the animals eat plastic and regularly get entangled in plastic and fishing nets.

Charities such as the Plastic Soup Foundation do important work to reduce plastic in the sea and to raise consumer awareness about it. To this end, they hold talks with industry and government and education in schools is a spearhead. The Dolfinarium has a knowledge partnership with the Plastic Soup Foundation. From this partnership, the Dolfinarium brings knowledge to its visitors about the adverse consequences of plastic for humans, animals and the environment.

The collaboration between the Plastic Soup Foundation and the Dolfinarium is aimed at conveying information about plastic soup to the visitor. The Plastic Soup Foundation supports the Dolfinarium in conveying the insights to the public in the best possible way

The consequences of plastic soup for marine mammals:


Some animal species are more vulnerable than others to ingesting plastic. All that plastic can lead to them eating less because they no longer feel hungry. Or their stomach gets blocked. It is usually impossible to find out where the swallowed plastic originally came from, but sometimes it is clear. In 2012, a dead male sperm whale was found on a beach in Spain in a region where many fruits and vegetables are grown. This region also exports to our supermarkets. Of all the plastic in the cadaver, 26 pieces could be directly related to those agricultural activities. These included plastic plant pots and 30 m2 of plastic cover.


If dolphins, or other marine mammals such as seals and whales, get caught in the sharp nylon threads of fishing nets, they risk losing their fins or tails. That’s how deep those wires can cut into the flesh! Entanglement can have all kinds of other horrific consequences, such as starvation and the development of inflammation or deformities. In all these cases, an animal becomes less vital. This means that the animal has less energy, can find less good food or has fewer offspring. And then there is the chance that due to weakening they become victims of predators looking for easy prey…

Micro and nanoplastics

The smaller the plastic particles in water, the greater the chance that multiple species of marine life will ingest or ingest them. Molluscs, such as mussels and oysters, filter seawater and ingest microplastics in the process. Shellfish are regularly on the menu of humans. If you eat fish, the chance of ingesting microplastics is small. The organs they can be in are always removed. This is not the case with shellfish. For example, eating mussels always ingests microplastics. The vast majority of this leaves the body through your faeces, but the smallest particles may still spread through the body. The possible effect of this is still largely unknown.


Organic toxins adhere to plastic like a magnet attracts iron. With the plastic that an animal ingests, these toxins also end up in that animal’s body. These substances can accumulate in the tissue. Pathogenic bacteria can also attach to plastic. This poses yet another danger. The germs can spread over great distances via floating plastic. As a result, animals that would otherwise never have come into contact with the germs can still become infected.

The consequences of plastic soup for human health

What effect do microplastics really have on our bodies? How dangerous are they exactly? What are the long-term consequences of the chemical additives in plastic production for our health? The first studies for this have started in recent years.


Partnership with the Arctic Marine Litter Project of Wageningen University & Research

Important research on the waste on the beaches in the Arctic

Researchers from Wageningen University & Research are conducting research in the Arctic Marine Litter Project in the Arctic into the origin, causes and consequences of the waste produced in the Arctic.

Plastics from the Netherlands and other European countries float to the Arctic via ocean currents, where they cause problems for animals of the same kind in the Dolfinarium: porpoises, seals, walruses, whales and other animals. With that knowledge, governments and companies can much more easily determine what needs to be done to solve this problem.

Local clean-up activities of plastic and partnership with Beestenbende

No plastic in the sea = no plastic in the street!

If the plastic is not on the street, it cannot blow into the rivers, lakes or seas. That is why the Dolfinarium also organizes a few plastic soup activities in our own neighbourhood. In this way we prevent – from very close by – plastic soup pollution of the sea.

The Dolfinarium organizes a special plastic soup day every year. Every year, the Dolfinarium participates in World Cleanup Day and waste clean-up activities are organized together with volunteers. In recent years, researchers from the Arctic Marine Litter project of Wageningen University & Research have supervised this activity and explained their working methods in the Arctic.

  • The collection of waste in the vicinity of the Dolfinarium in Harderwijk
  • Their analysis method of the waste washed up on the Harderwijk streets
  • A presentation about the Arctic Marine Litter project.

In addition, the Dolfinarium tries to involve young people and visitors in raising awareness of plastic waste on the street. The Dolfinarium together with Beestenbende. Nearly 2000 Dutch children are affiliated with Beestenbende who are committed to a clean and pleasant neighbourhood. Every year, as a reward, the children can go to the Dolfinarium for free for a day.

The cooperation with these parties contributes to the Dolfinarium’s mission to make its visitors and the environment aware of the threats of plastic in the sea. On to clean seas where the animals in the ocean can live a healthy life. And that also starts with you! Let’s become aware of all that plastic we use and together make the change possible. Because the plastic soup is not something from very far away or only in the middle of the sea. No, the plastic soup already starts on the sidewalk.

Partnership with MSC

Choose responsible fish

You can help by choosing nature-friendly what’s on your plate. Of course we can all eat less fish together. And if you eat fish, make sure it’s caught in a sustainable way! You can see this by the MSC or ASC label.


Marine Stewardship Council (MSC) certified fisheries ensure that there is enough fish available in the future, that marine habitats are preserved and that endangered fish species are protected.


The Aquaculture Stewardship Council (ASC) ensures that the nursery takes place in a responsible manner, with as little natural habitat and biodiversity as possible being affected. Almost half of the fish we eat today comes from farm ponds. However, this often happens with a method or on such a large scale that it is harmful to nature.

By buying fish with the MSC or ASC label, you can be sure that this fish comes from a sustainable fishery that does not contribute to overfishing and that minimizes damage to the sea. Good management of fish populations has already been shown to be possible. Plaice, mackerel and herring are doing very well again. Even the North Sea cod is doing better and better! Let’s continue that positive trend!


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