title: Hypoxia is increasing in the coastal zone of the Baltic Sea.
abstract: Hypoxia is a well-described phenomenon in the offshore waters of the Baltic Sea with both the spatial extent and intensity of hypoxia known to have increased due to anthropogenic eutrophication, however, an unknown amount of hypoxia is present in the coastal zone. Here we report on the widespread unprecedented occurrence of hypoxia across the coastal zone of the Baltic Sea. We have identified 115 sites that have experienced hypoxia during the period 1955-2009 increasing the global total to ca. 500 sites, with the Baltic Sea coastal zone containing over 20% of all known sites worldwide. Most sites experienced episodic hypoxia, which is a precursor to development of seasonal hypoxia. The Baltic Sea coastal zone displays an alarming trend with hypoxia steadily increasing with time since the 1950s effecting nutrient biogeochemical processes, ecosystem services, and coastal habitat.
authors.affiliation: Department of Earth and Ecosystem Sciences, Lund University , SE-223 62 Lund, Sweden. daniel.conley@geol.lu.se
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Conley
authors.forename: Jacob
authors.initials: J
authors.lastname: Carstensen
authors.forename: Juris
authors.initials: J
authors.lastname: Aigars
authors.forename: Philip
authors.initials: P
authors.lastname: Axe
authors.forename: Erik
authors.initials: E
authors.lastname: Bonsdorff
authors.forename: Tatjana
authors.initials: T
authors.lastname: Eremina
authors.forename: Britt-Marie
authors.initials: BM
authors.lastname: Haahti
authors.forename: Christoph
authors.initials: C
authors.lastname: Humborg
authors.forename: Per
authors.initials: P
authors.lastname: Jonsson
authors.forename: Jonne
authors.initials: J
authors.lastname: Kotta
authors.forename: Christer
authors.initials: C
authors.lastname: Lännegren
authors.forename: Ulf
authors.initials: U
authors.lastname: Larsson
authors.forename: Alexey
authors.initials: A
authors.lastname: Maximov
authors.forename: Miguel Rodriguez
authors.initials: MR
authors.lastname: Medina
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Lysiak-Pastuszak
authors.forename: Nijolé
authors.initials: N
authors.lastname: Remeikaité-Nikiené
authors.forename: Jakob
authors.initials: J
authors.lastname: Walve
authors.forename: Sunhild
authors.initials: S
authors.lastname: Wilhelms
authors.forename: Lovisa
authors.initials: L
authors.lastname: Zillén
mesh_terms: D000693:Anaerobiosis; D004784:Environmental Monitoring; D005843:Geography; D009792:Oceans and Seas; D010100:Oxygen / Q000032:analysis*; D012623:Seawater / Q000737:chemistry*; D013997:Time Factors
chemical_list: D010100:Oxygen