Editing Kattegat (section)

===Ecological collapse===
The Kattegat, characterised by widespread [[oceanic anoxic event|anoxia]],<ref name="DruonEtAl2004">{{cite journal |last1=Druon |first1=Jean-Noël |last2=Schrimpf |first2=Wolfram |last3=Dobricic |first3=Srdjan |last4=Stips |first4=Adolf |date=19 May 2004 |title=Comparative assessment of large-scale marine eutrophication: North Sea area and Adriatic Sea as case studies |url=https://www.int-res.com/articles/meps2004/272/m272p001.pdf |journal=Marine Ecology Progress Series |volume=272 |pages=1–23 |doi=10.3354/meps272001 |bibcode=2004MEPS..272....1D |access-date=10 August 2023}}</ref> was one of the first marine [[dead zone (ecology)|dead zone]]s to be noted in the 1970s, when scientists began to study the effects of heavy industry on the natural world.<ref>{{cite web|url=http://www.unep.org/Documents.Multilingual/Default.asp?DocumentID=486&ArticleID=5393&l=en|title=Further Rise in Number of Marine 'Dead Zones'|publisher=[[UNEP]]|date=19 October 2006|access-date=30 January 2016|archive-date=4 October 2009|archive-url=http://arquivo.pt/wayback/20091004170617/http%3A//www.unep.org/Documents.Multilingual/Default.asp?DocumentID%3D486%26ArticleID%3D5393%26l%3Den|url-status=dead}}</ref><ref>{{cite book|url=https://books.google.com/books?id=9fEKAAAAQBAJ&pg=PA4 |title=Introduction to Marine Biology |author=Karleskint, Turner and Small |publisher=Brooks/Cole |page=4|date=2013 |edition=4|isbn=978-1285402222 }}</ref> Since then,  research has leant much insight into processes like [[eutrophication]], and how to deal with it. Since the first Action Plan for the Aquatic Environment in 1985, Denmark and the EU have begun costly, far-reaching domestic projects  to stop, repair and prevent these environmentally destructive and economically damaging processes<ref>{{Cite book |doi=10.1029/CE052p0155|chapter = Benthic macrofauna and demersal fish|title = Eutrophication in Coastal Marine Ecosystems| volume=52| pages=155–178|series = Coastal and Estuarine Studies|year = 1996|last1 = Hagerman|first1 = Lars| last2=Josefson| first2=Alf B.| last3=Jensen| first3=Jørgen N.| isbn=978-0-87590-266-1}}</ref> and are now busy implementing the fourth Action Plan. The action plans sum up a broad range of initiatives and include the so-called Nitrate Directives.<ref>[http://www.mst.dk/English/Agriculture/nitrates_directive/implementation_in_denmark/ Implementation of the Nitrates directive in Denmark] {{Webarchive|url=https://web.archive.org/web/20131203112345/http://www.mst.dk/English/Agriculture/nitrates_directive/implementation_in_denmark/ |date=3 December 2013 }} Danish Ministry of the Environment</ref> The action plans have generally been viewed as a success, although the work is not finished and not all goals have been met yet.<ref>{{cite web|url=http://politiken.dk/debat/analyse/ECE1422611/vandmiljoeplaner-har-vaeret-en-succes/|title=Action Plans for the Aquatic Environment have been a success|newspaper=Politiken|author1=Jesper H. Andersen |author2=Jacob Carstensen |date=25 October 2011|language=da|access-date=24 November 2014}}</ref>