A synthesis book has been published on the eutrophication of rivers and water in coastal areas (in France and with many examples from other countries): see the synthesis document (free of charge, in French) https://inra-dam-front-resources-cdn.wedia-group.com/ressources/afile/412485-044a1-resource-expertise-eutrophisation-synthese-148-p.pdf
On the economic aspects of this pollution, see (free of charge, in English; also available on Researchgate): Terreaux J.Ph, J.M. Lescot, 2019, Economic instruments to combat eutrophication: a survey, in P.T. Chandrasekaran Ed., Water and Sustainability, IntechOpen, 18 p.
You are lucky (and forgive me for not mentioning it directly), the book also exists now in an English version (free of charge) : https://inra-dam-front-resources-cdn.brainsonic.com/ressources/afile/421182-29a62-resource-eutrophication-english-synthesis-november-2017.pdf