Introduction:
http://itamerenoppimispolku.fi/itameren-rehevoityminen-vakava-ongelma/
https://www.environment.fi/en-US/Sea/What_is_the_state_of_the_Baltic_Sea
http://www.coastalwiki.org/wiki/Trophic_level_-_a_marine_example
https://en.wikipedia.org/wiki/Trophic_level
http://ec.europa.eu/environment/marine/good-environmental-status/descriptor-4/index_en.htm
http://c14.dhigroup.com/productdescriptions/primaryproduction#TotalProd
Study1:
https://fi.wikipedia.org/wiki/Happamuus_(limnologia)
http://www.luontoportti.com/suomi/fi/itameri/hankajalkaiset
https://en.wikipedia.org/wiki/Ocean_acidification
http://www.cosee.net/files/coseenet/plankton_guide_final_2.pdf
http://marinebio.org/oceans/zooplankton
Study2:
http://www.pelastajarvi.fi/typen_kierto
http://www.luontoportti.com/suomi/fi/itameri/marenzelleria-monisukasmadot
https://www.jarviwiki.fi/wiki/Marenzelleria
http://www03.edu.fi/oppimateriaalit/laboratorio/ymparistoanalyysit_veteen_liuennut_happi.html
https://spektrofotometria.wordpress.com/2016/04/11/spektrofotometriasta/
https://www.youtube.com/watch?v=oVW5LAzd7Ec
http://www.whoi.edu/oceanus/feature/tracking-nitrogens-elusive-trail-in-the-ocean
https://en.wikipedia.org/wiki/Carbon_sequestration
https://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/Spectrpy/UV-Vis/spectrum.htm
http://omp.gso.uri.edu/ompweb/doee/science/physical/choxy1.htm
http://www.whoi.edu/page.do?pid=110417&cid=46925&cl=32332&article=53946&tid=5782
Study3:
https://wwf.fi/alueet/itameri/rehevoityminen/https://suomenkuvalehti.fi/jutut/ulkomaat/lisaako-hiilidioksidi-sinilevan-maaraa/
https://fi.wikipedia.org/wiki/Korkean_erotuskyvyn_nestekromatografia
https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?SpeciesID=178
https://en.wikipedia.org/wiki/High-performance_liquid_chromatography
https://en.wikipedia.org/wiki/Scintillation_counter
http://departments.agri.huji.ac.il/zabam/beta.html
https://en.wikipedia.org/wiki/Liquid_scintillation_counting
https://sciencing.com/sonication-work-5171302.html
http://www.radioactivity.eu.com/site/pages/RadioCarbon.htm