Delfland Water Board launches crackdown on crayfish to protect aquatic nature

Delfland Water Board launches crackdown on crayfish to protect aquatic nature

The Delfland Water Board has started trapping American crayfish at ten locations. This invasive alien species poses a growing threat to aquatic ecosystems and water quality. The approach will be significantly expanded in the coming years: by 2027, it will involve 170 trapping locations along a total of 59 kilometers of riverbank.

By 2027 at the latest, water quality and ecology must meet the requirements of the European Water Framework Directive (WFD). Delfland works every day on clean and healthy water. To achieve the WFD goals, the water board invests specifically in wet ecological zones (NEZs), such as nature-friendly banks, fish spawning grounds, and aquatic plant zones. Crayfish also cause significant damage in these areas.

Harmful invasive species

According to ecologist Wilco de Bruijne, intervention is necessary: ​​’The crayfish first appeared in our area in the 1980s. Conditions here are favorable and they reproduce rapidly. By now, we are talking about tens of millions of animals. If we do nothing, the impact on aquatic nature and water quality will be incalculable.’

American crayfish cause damage in various ways. They dig deep burrows, which can cause banks to subside and damage dikes. This increases the risk of flooding. Additionally, they eat aquatic plants and churn up the bottom, leading to turbid water. As a result, biodiversity declines and water quality deteriorates.

Lierwetering, 16-04-2026, Het HoogHeemraadschap Delfland presenteert het Project beschermen ecologische zones. Delfland vangt rivierkreeften die lokale inheemse flora bedreigt.

Targeted approach in vulnerable areas

The catch initially focuses on locations where NEZs have recently been constructed and on watercourses with young submerged aquatic plants. Project leader Ad Valkenburg: ‘This is a large-scale operation for us. Ultimately, we will deploy thousands of catch containers that need to be emptied weekly. That is why we are working in phases and learning as we go. In doing so, we are also measuring the effects on water quality.’

First results show the extent of the problem

To empty the traps, Delfland employs two professional fishermen via a contractor. The traps are designed to be as animal-friendly as possible, with minimal risk of bycatch. The caught lobsters go to Craw Fish Farm, a Dutch company focused on sustainable food production.

The first catches show that the lobster population is large in many locations. The number of catches is expected to increase further as it gets warmer and the lobsters become more active.

Lierwetering, 16-04-2026, Het HoogHeemraadschap Delfland presenteert het Project beschermen ecologische zones. Delfland vangt rivierkreeften die lokale inheemse flora bedreigt.

A hefty price tag

The approach requires a substantial investment. The Delfland board has made 7 million euros available for 2026 and 2027. The goal is to reduce the crayfish population per location by approximately 80 percent, so that aquatic nature can recover.

The total costs for the protection of all wet ecological zones are estimated at 13 million euros in the first year and 7.3 million euros per year thereafter. This concerns only the control of crayfish. Restoration of banks and dikes is in addition to this.

Delfland wants a national approach

Although Delfland is now taking measures itself, the responsibility for combating American crayfish lies with the central government. Water Board Member Stijn van Boxmeer: ​​’We are now taking responsibility for the artificial aquatic nature in our area, but according to the Invasive Alien Species Ordinance, the control of this invasive alien species lies with the Ministry of Agriculture, Fisheries, Food Security and Nature (LVVN). Furthermore, Delfland is not the only one suffering from American crayfish. They occur throughout the low-lying Netherlands, in all peat meadow areas. The scale of the problem therefore also calls for a national approach.’

Text & Images: Delfland Water Board

Translation to English: The Hague Online

The Netherlands and water are inextricably linked. However, strong dikes, clean ditches, and pure water are essential requirements for a safe environment. At the Delfland Water Board, we take care of the water. So that you, together with all the residents of our area, can enjoy living, working, and relaxing in this beautiful, water-rich environment.

The Ultimate Kings Day Guide for The Hague (27 April 2026)

The Ultimate Kings Day Guide for The Hague (27 April 2026)

The tradition of celebrating the Dutch monarch’s birthday dates back to 1885, when Princess Wilhelmina’s fifth birthday was marked with national festivities. It was originally called Prinsessedag, then became Koninginnedag (Queen’s Day) as the Netherlands was ruled by queens for much of the 20th century — first Wilhelmina, then Juliana, then Beatrix. Queen’s Day was famously celebrated on 30 April. When King Willem-Alexander took the throne in 2013, the holiday was renamed Koningsdag and the date shifted to his actual birthday: 27 April. The House of Orange-Nassau connection also explains the sea of orange — the colour has long been a symbol of the Dutch royal family.

King’s Day in The Hague

The Hague has a particularly special relationship with the day, given its status as the royal city.

The vrijmarkt (free market) is the heart of it all — markets scatter across the city, with everyone from kids to grandparents selling old treasures, performing, or just soaking up the atmosphere.

Find bargains at the free market

Some of the best spots:

Belgisch Park

Belgisch Plein & Stevinstraat — neighbourhood charm, good mix of sellers

Frederik Hendriklaan

Statenkwartier — lively, popular with families and young crowds

Noordeinde

Near the palace — a bit of royal atmosphere alongside the stalls

Keizerstraat, Scheveningen

Beach vibes, more relaxed pace — good if you want sea air with your bargain hunting

The Life I Live Festival

King’s Night takes place the night before, on 26 April. The centre will once again be transformed into one huge festival site. This free city festival brings together local pride and top national acts for a night full of energy and musical discovery. This year, Lange Voorhout will feature two stages with energetic and moving performances, with a Silent Disco (in collaboration with PAARD) at the centre, whilst Kerkplein (in collaboration with PIP) is the place for electronic beats. At the Hofvijver and at Popdistrict on the Grote Markt (Sniesterstage), the party kicks off with live music in all styles — from hypnotic soundscapes to raw guitars.

King’s Fair

Currently on until 27 April, Malieveld will once again be transformed into a grand Royal Fair with attractions for young and old — something for everyone at an affordable price.

Hollands Live Festival

Billed as the largest Dutch-language festival in South Holland, Hollands Live is held at Zuiderpark. The vibe is distinctly Dutch — think sing-along pop and schlager music with a very orange, very gezellig crowd. The line-up features artists like Gerard Joling, Mart Hoogkamer, Monique Smit, and Django Wagner — all big names in mainstream Dutch pop and Nederlandstalige (Dutch-language) music.

Visit hollandslive.nl/koningsnacht2026 for more information and to purchase tickets.

King’s Day boat trips through The Hague’s canals

Fancy a unique King’s Night? Come aboard the Willemsvaart and celebrate on The Hague’s canals. You can book a boat trip for up to 23 people — for more information or to book, email info@willemsvaart.nl.

So what do you need to make the most of the celebrations?

  1. Dress in orange. Stores like Hema will have everything you need to get kitted out — including accessories for your furry friend too.
  2. Bring cash to the vrijmarkt if you plan on shopping, and get there early to find the good stuff.
  3. King’s Night is one of the rare occasions when you are allowed to walk the streets with your own drinks, so grab a cooler or backpack if you’re looking for a more affordable option. Food and drinks will also be available for purchase throughout the night.
  4. Eat a tompouce. Several bakeries make them orange to mark the occasion, and no King’s Day is complete without one.

There’s your King’s Day survival guide — enjoy it. Living in The Hague for this one is genuinely special. 🧡

Images: Sherika Rooplal-Clappers and Pixaby

Behind The Menu: De Filosoof – The Winebar That Brings the World Together

Behind The Menu: De Filosoof – The Winebar That Brings the World Together

Venue provided complimentary drinks during Sherika’s visit for this feature. The Hague Online retained editorial control, and the views expressed are the writer’s own

As a wine lover, the first countries that come to mind when thinking about wine are the classics: France, Italy, South Africa, Chile. But after sitting with Ofran Badakhshani, the owner of De Filosoof wine bar, I learned about the true history of wine.

Wine is a story. Nowhere is that truer than in Persia, the civilisation we now know as Iran, where wine was not simply consumed but revered. Long before it reached Europe, it was woven into the very fabric of Persian life — into its religion, its rituals, and most enduringly, its poetry. The great Sufi poet Rumi used wine as a metaphor for the soul’s journey toward God, describing spiritual ecstasy as being drunk on something far beyond the earthly. Omar Khayyam filled his celebrated Rubaiyat with it, using each glass as a quiet argument for living fully in the present. And Hafez, perhaps the most beloved poet in the Persian tradition, wrote about wine with a provocation that was as much political as it was spiritual — raising a cup, in many ways, against rigidity itself. It is one of history’s more poignant ironies that the country which gave the world its oldest confirmed traces of winemaking — clay jars from the Zagros Mountains dating back over seven thousand years — is today one where wine cannot be legally produced or consumed. Before the Islamic Revolution of 1979, Iran had close to 300 wineries. Now it has none. The culture remains, pressed into the pages of its literature.

This history is personal at De Filosoof. Ofran, who grew up in Amsterdam, originally studied philosophy and was later offered a role at Delft University — unpaid, as it turned out, which prompted him to think seriously about his next move. Beyond philosophy, what did he know deeply? Wine. And so he began to explore how the two might come together. In 2014, he started hosting art history and philosophy discussions shared over a glass, bringing together a small community of intellectuals that grew steadily over time. Of Persian descent himself, Ofran introduced this community not to French or Chilean pours, but to wines from Bulgaria, Moldova, and Greece. There was hesitation at first — these were unfamiliar regions, unfamiliar grapes — but over time, Ofran earned their trust, and the wines spoke for themselves. Restaurants in The Hague couldn’t fully tell the stories behind bottles like these; most owners know France and Italy and little else. And so what had begun as a gathering became a destination. De Filosoof wine bar opened in 2019.

Built from the ground up by Ofran, his girlfriend, and his mother — the three of them doing much of the work with their own hands — the bar had barely found its feet when Covid arrived. When the world eventually quietened down, they opened their doors fully, and something quietly remarkable happened: different cultures began to flock in. Brazilians, Turkish, Dutch — strangers sitting side by side over a shared glass, the noise of the outside world briefly held at bay. What Ofran has built is not simply a beautiful bar that serves delicious wine and food. It is a space where background becomes secondary, where the common ground is a well-chosen bottle and the willingness to be curious. At a time when many world leaders are pushing division, De Filosoof makes a gentle case for the opposite — that we can sit with our fellow humans, talk, and remember that at the end of the day, we all carry the same hopes for ourselves and the people we love.

With over 500 wines available by the glass — many sourced from conflict zones including Lebanon — there is something quietly radical about the place. It almost makes you wonder what could be resolved if more of the world’s decision-makers sat down together over a good bottle.

De Filosoof hosts regular events each month: new wine launches, performances by Persian musicians, tastings, and evenings centred on literature and art. I attended the launch of Château Heritage’s new Brut — the first sparkling wine from Lebanon from a house currently ranked 33rd best in the world. Bursting with crisp green apple, juicy pear, and zesty citrus, it is exactly the kind of wine you reach for when there is something worth celebrating.

Food is very much part of the experience too. Small bites are on offer, and I tried Ofran’s mother’s famous aubergine dish, Burani — fresh tomatoes served with yoghurt and coriander. It was fragrant, light, and completely at home here. The Kufta followed: spiced meatballs with ginger, paprika, and warm spices, slow-cooked in a fresh tomato sauce. With my eyes closed, I could have been somewhere else entirely — somewhere much warmer, and further away from the Dutch cold.

So, can world peace be achieved over a glass of wine? That may be a loaded question and one we cannot answer simply. But after seeing so many different people come together to enjoy brilliant food, wine and art, it does make you think.

Check out De Filosoof’s website and Instagram for information on future events. De Filosoof can be found on Molenstraat 16.

Images: Sherika Rooplal-Clappers and De Filosoof

Do you have a story about your own café, restaurant or bar in the city? Reach out to sherika@thehagueonline.com to possibly be featured.

Sherika Rooplal-Clappers is a contributing writer for The Hague Online, covering culture, lifestyle, and local events. With a passion for storytelling and international perspectives, she highlights the people, places, and experiences that make The Hague a dynamic city. 

Youngsters explore science and technology at EPO’s Girls’ Day in Rijswijk

Youngsters explore science and technology at EPO’s Girls’ Day in Rijswijk

In international cities such as The Hague, and across many parts of Europe, Girls’ Day has become an established part of the education and innovation calendar, inviting girls to explore science, technology, engineering, and mathematics (STEM) through hands‑on activities and encounters with professionals. This week, 100 girls aged 11 to 14 from seven schools across The Hague region visited the European Patent Office’s (EPO) facilities in Rijswijk, taking part in workshops and demonstrations for a glimpse into the real‑world applications of science and innovation. The mayor of Rijswijk also joined the event, accompanied by young ambassadors from the Children’s Rights Group, promoting inclusion and empowerment in STEM education.

An international initiative with strong roots in The Hague region

Inspired by what she had seen and done during the workshops at the EPO in Rijswijk, one girl left determined to become a Formula 1 racecar mechanic, fascinated by the precision, teamwork and engineering behind high-performance racing. Another participant said the experience helped her imagine a future as a heart surgeon, combining technology, biology, and problem-solving to save lives. These moments of inspiration capture what Girls’ Day aims to achieve, while also highlighting how rare such clear career ambitions remain for many girls.

The stories of aspiring Formula 1 mechanics and future heart surgeons remain promising exceptions rather than the norm, as structural barriers persist. In an EPO report about women in STEM recently published, the EPO highlighted the persistent gender gap in technology-related fields: only 17.8% of technology researchers are women. While the number of women inventors is increasing, very few go on to launch technology startups. 

“The choice of a STEM degree often sets the trajectory, and it is shaped long before university by experiences that build or challenge confidence and identity in STEM,” said EPO spokesperson Roberta Romano-Götsch. “Even today, women make up only about 30% of STEM tertiary graduates in Europe and with this event we want to inspire girls to embrace STEM and reverse this trend.”

With 39 member states and staff from 35 member states, the EPO is the largest international organisation in the Netherlands and is committed to inspiring future generations to engage with science and innovation. Through initiatives like Girls’ Day, the EPO aims to offer direct insight into real world STEM environments. 


Women remain strongly underrepresented in deep tech entrepreneurship

The EPO report on women in STEM shows that girls perform as well as  mathematics and science during compulsory education, yet this parity is not reflected later in their careers. The lower continuation rate of girls in STEM subjects is often described as a confidence gap rather than an ability gap, shaped by social expectations, stereotypes, and a lack of visible role models.

According to the same study, the gender gap is particularly pronounced in patenting startups. Only 13.5% of startups with patents include a woman founder. Differences across Europe are substantial: Portugal, Spain, and Ireland show the highest participation rates, while the Netherlands, Austria and Germany record the lowest. These findings come just as the EU’s Industrial Strategy and European Innovation Council (EIC) stress the importance of inclusive innovation ecosystems to reinforce Europe’s competitiveness in strategic technologies.

Newer startups show higher shares of women founders, suggesting that newly created startups are becoming more diverse. However, companies co-founded by women appear to face greater challenges in scaling.

Ready to Engage Youth Programme for Climate Change @ The Hague Humanity Hub – Apply before 19 April 2026

Ready to Engage Youth Programme for Climate Change @ The Hague Humanity Hub – Apply before 19 April 2026

Are you between 15 and 30 and ready to move beyond awareness into real impact?

Ready to Engage is a two-month youth programme in The Hague that helps young people transform their concern about climate change into practical initiatives for a more just and sustainable future.

Through workshops, coaching, and collaboration with experts and peers, you will develop your ideas into a concrete action plan – and take your first steps as a climate changemaker.

Are you interested? Keep reading for more information and how to apply!

Applications are open and will close on April 19

https://www.humanityhub.org/project/ready-to-engage

New Entrepreneurship Launchpad Course for Internationals and Expats

New Entrepreneurship Launchpad Course for Internationals and Expats

The Webster Leiden Campus is offering a new Entrepreneurship Launchpad course which will run for 4 weeks in June. Taught in English, the course is designed for internationals and expats who want to start or expand a business in the Netherlands.  Participants will learn how to build and grow a sustainable business in the Netherlands. At the same time, they will develop practical entrepreneurial skills, including industry engagement, networking and local business connections, leadership, peer interaction, and much more. The course is taught by experienced professionals.

 Webster Leiden is an international campus of Webster University, which has over a century of experience providing accredited education worldwide. Established in 1983, the Leiden campus has been delivering a globally minded education in the Netherlands for four decades, bringing together a highly international student community in small, discussion-based classes with close faculty engagement.

Key Facts

• Part of Webster University’s global campus network

• Location: Leiden – 10- minute walk from Leiden Central Station

• Accredited undergraduate and graduate programs

• English-language instruction

• Highly international student body

Contact Information:

Dr. Sheetal Shah

Academic Director

Webster Leiden Campus

Shah@webster.nl

Tel.: +31 (0)71 516 8000

Andreia Couto

Head of Admissions and Marketing

Webster Leiden Campus

Couto@webster.nl

Tel.: +31 (0)71 516 8000