In 2013, a team of marine scientists established the global citizen science Secchi Disk programme for seafarers to study the marine phytoplankton. This ongoing citizen science Secchi Disk study combines the traditional plain white, 30 cm diameter marine Secchi Disk with mobile technology to upload Secchi depth data collected from the sea to a central database. The study's first scientific results were published in 2017. The Secchi Disk study was begun in response to a controversial scientific report that suggested the phytoplankton that influence water transparency had declined by 40% in the oceans between the years 1950 and 2008.