European research has found that a third of European seagrass was lost to disease, declining water quality and coastal development, chiefly during the 1970s and 1980s. However, since the late 20th century that decline has been gradually slowing and in some places seagrass meadows are recovering as a result of EU measures to improve water quality. The findings, made by European scientists including Marieke van Katwijk at Radboud University, have been published in Nature Communications.
source https://www.lifetechnology.com/blogs/life-technology-news-blog/after-years-of-decline-some-european-seagrass-meadows-show-signs-of-recovery