The team

Maria Westerbos

Founder & Director

Maria Westerbos is educated in the social sciences, specialising in mass communication and psychology. She has worked in the media for the past 25 years, print and TV, and lately as change strategist and television programme developer. In Februari 2011 she founded the Plastic Soup Foundation and inn 2013 she finished 20th in the Dutch newspaper Trouw Sustainable Top 100. She has been in the Top 100 ever since.

Jeroen Dagevos

Head of Programs

Jeroen Dagevos is an environmental specialist working in the field of water for more than ten years now. He is specialized in water quality related issues and became involved in research and policy making objectives of marine litter. He participated in European Policy making and agenda setting of marine litter topics in relation to the development of the Marine Strategy Framework Directive and the evaluation of the Directive on Port Reception Facilities.

Richard van Os

Head of finances

Richard has experience in working as a financial software developer, a non-profit manager and as a teacher in business economics. As the head of finances he manages the finanaces at the Plastic Soup Foundation.

Annemarie Nederhoed


Annemarie helps the Plastic Soup Foundation with professionalizing fundraising and generating more income. She has a lot of experience as an account manager and the last 6 years she has been working for multiple foundations. She also rows a barge boat two times a week and wants to prevent plastic from entering the oceans.

Harmen Spek

Senior consultant

Harmen has a commercial background in media & design. With his experience in product design he developed a great passion for production and materials. These days, many products are made based on a 'short life cycle' where plastic, as the cheapest material, forms the most successful formula. Harmen’s is motivated to change these short cycli towards a more sustainable model where plastic is seen and used as a high-quality material. Also, Harmen is on a wordlwide search for finding the best technical solutions and innovations that can help solve the problems and pollution that plastic is causing in the environment.

Michiel Roscam Abbing

Research & blogs

Michiel Roscam Abbing is a political scientist and obtained his doctorate with a thesis on a historical topic. Since 2011 he has been active in the battle against plastic soup, including reviewing scientific news reports on the PSF website regarding the perils of plastic in the ocean.

Saskia Honcoop

Health / Plastic Soupermarket / Journalist

Saskia is a marine biologist and science communicator. At the Plastic Soup Foundation she is involved in the Health campaign and the Plastic Soupermarket project. She also writes news articles about the latest plastic soup news and scientific developments.

Laura Díaz Sánchez

Communication officer Ocean Clean Wash

Laura is a journalist with an MA degree in New Media & Digital Culture from the University of Utrecht. She helps with website management, online communication and social media for the Ocean Clean Wash campaign. She also has experience in radio, online journalism and corporate communication.

Yvette van den Brand

Education / campaigner

Yvette has done her graduation project for the Plastic Soup Foundation and is now working as a campaigner for several projects. She takes care of external communication for multiple campaigns and is managing the Twitter channels of PSF. She is involved in the Sustainable Horticulture and Education projects.

Frank Aldershof

Beat the Microbead App

Frank studied artificial intelligence and coordinates everything to do with the Beat the Microbead App. He lectures at the HAN University of Applied Sciences.

Janna Selier


Janna has studied history and was a volunteer educator at Artis Zoo and WFF. Janna heeft geschiedenis gestudeerd en was educatief vrijwilliger bij Artis Zoo en WNF. At the Plastic Soup Foundation she takes care of our fundraising actions acties like the plastic bags action, donation boxes and deposit system donations.

Woltera Niemeijer

Graphic designer (Freelance)

Woltera has developed the new corporate identity of the Plastic Soup Foundation and since then she, as a graphic designer, has been responsible and/or engaged in various PSF communications.

Nicola Chadwick

Translator (volunteer)

In November 2015, Nicola joined the Plastic Soup Foundation team as a translator. She picks up litter daily in her neighborhood. The more she learns about the effects of Plastic Soup the more motivated she is to work towards preventing it. But in the meantime, she organizes local clean ups and raises awareness about the problem of litter and plastic soup.

Joanna Bouma

Translator (volunteer)

Joanna is a professional writer/editor (native English speaker). She loves the ocean and supports a number of marine conservation organisations voluntarily with English language texts. After a few years at sea and as a diver, beach walker and nature lover, she knows first hand the negative effects of plastic on wildlife, the environment and humans. She supports PSF’s mission and is pleased to be part of the team.

Cindy Iseli

Plastic Soup-free events (volunteer)

Cindy has earned her stripes as a marketing and communications manager at festivals such as STRP and Dutch Design Week, recently she dove into the world of innovation at TNO. At the Plastic Soup Foundation she is working on concepts that lead to plastic-free events and conscious visitors.

Christian Bruno

Fundraising & Implementations (volunteer)

Christian is changing his career path from the Hedge Fund Industry to the environmental scene. He is helping the Plastic Soup Foundation in setting up and implementing new funds channels in order to ensure more financial stability. He is involved in different projects and helps where needed.

Anneke Wevers

Health Files (volunteer)

Anneke Wevers studied molecular sciences at WUR and there she took great interest in environmental and occupational toxicology issues. Her work in Mozambique in the early 80-ties deepened insights in this area. Back in Amsterdam she worked as a trainer, adviser and researcher in work place conditions and as an environmental expert and institutional adviser in export promotion at the Ministry of Foreign Affairs of the Netherlands.

Carla Mulder


Carla is a communication adviser who has a lot of experience with setting up and supervising changing processes in organizational, communicative and marketing areas. For the PSF she has developed an ambassador campaign for the public with the focus on funding and awareness.

Chayenne de Witte

AV producer (volunteer)

Outdoor and watersport lover Chayenne works as an advertising content producer, conference- and festival curator. Passionate about contributing her skills to media productions for the PSF to raise awareness around the (re-)use of plastic.

Petra Olgers

Volunteer / guestlecturer

Petra is very concerned about the plastic soup. She participated in "Gaat het zo mee?"; the anti-plastic bag campaign of the Bussum plastic-free movement. As a volunteer of the PSF she would is involved in education, giving lectures at schools. She is also chairman of the Bussum environmental council and an organizer of the Bussum Repair Café.

Yvonne Sjamaar


Yvonne has been interested in environmental matters for a while now. She shops at organic stores and buys fair-trade clothes. As a volunteer of the Plastic Soup Foundation, she wants to contribute to solutions for the problems marine litter causes in the environment. She helps the PSF with several administrative jobs and is always happy to help during events.

Marlies van Maarseveen

Research volunteer

Marlies has worked as analyst in training at the pesticides department of TNO. After that she studied agriculture in Wageningen. She initiated a organic mixed company in France and now she is going to do research plastic an agriculture at PSF.

Madhuri Prabhakar

Intern Beat the Microbead

Madhuri is a Research Masters Student in Gender Studies at Utrecht University. She is assisting with the communications and social media for the 'Beat the Micro Bead' campaign.

Ronja Jansz

Film director (volunteer)

Ronja Jansz is an award-winning filmmaker and journalist with a specialization in fiction and documentary film making. On top of her freelance work in Los Angeles and Amsterdam, she visually captures the Plastic Soup Foundation its events and projects to help raise awareness of the plastic problem in the world.

Tanja Chung

Translator (volunteer)

Tanja is a writer, editor and translator. From a young age she has been stimulating the people around her to recycle, be more aware of single-use plastic and carry their own bag to the supermarket. She is happy to contribute to the awareness of plastic soup by translating texts and articles for the Plastic Soup Foundation.

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