Stickstoff-Fixierung in Küstengewässern der mittleren Ostsee

Hübel, Helmut; Hübel, Marianne

doi:10.1002/jobm.3630140709

Cited by 6 publications

(4 citation statements)

References 3 publications

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“…Assuming that 240 000 km 2 is a representative area of the Baltic Proper (Rolff et al 2007), we calculated an annual input of fixed nitrogen to new production in the order of 56 000 to 125 000 t (Table 3). This estimate is within the range of some of the earlier studies , Brattberg 1980, Niemistö et al 1989, Hübel & Hübel 1995, Rahm et al 2000, but significantly lower than most recent studies , Wasmund et al 2001, 2005, Rolff et al 2007). In a recent study, Rolff et al (2007) showed that the abundance of Aphanizomenon (one of the major contributors to N 2 fixation) was higher and lasted longer through the summer at all stations south of Stn BY31 in the Baltic Sea.…”

Section: Significance Of N 2 Fixation In the Baltic Seasupporting

confidence: 72%

“…This observation emphasizes the need for a sampling strategy with high spatial diversity and high temporal frequency in biogeochemical studies of the Baltic Sea (Ohlendieck et al 2007, Rolff et al 2007). Our estimates of N s fixation are a close third in rank behind riverine inputs (363 000 t N, Stålnacke et al 1999) Leppänen et al (1988) 167 Niemistö et al (1989) 100 a Hübel & Hübel (1995) 20-190 Rahm et al (2000 30-260 Larsson et al (2001) 180-430 Wasmund et al (2001) 370 Wasmund et al (2005) 434-792 Rolff et al (2007) 310 This study (BY31) 56 - ; Stns H4 and X1) was very variable and the estimates should be regarded with caution. Therefore, we are only considering here the 3 yr annual averages of 65 t N at Stn H4 and 89 t N at Stn X1 (calculated from Table 2).…”

Section: Significance Of N 2 Fixation In the Baltic Seamentioning

confidence: 60%

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Seasonal significance of N2 fixation in coastal and offshore waters of the northwestern Baltic Sea

Degerholm

Gundersen²,

Bergman³

et al. 2008

Mar. Ecol. Prog. Ser.

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Annual rates of N 2 fixation were measured over 3 yr (1998)(1999)(2000) at an open water station (BY31) and 2 coastal stations (H4 and X1) in the Baltic Sea. This is the first report on depthintegrated rates of N 2 fixation from more than one complete growth season in the Baltic Sea. Annual estimates of N 2 fixation ranged from 56 000 to 125 000 t N in the Baltic Proper, and 18 000 to 162 000 t N at the inshore stations (Himmerfjärden). Rates of N 2 fixation were measured in situ at 4 depths between 0 and 25 m using the 15 N tracer technique for size fractionated organisms larger and smaller than 20 μm. Maximum rates of N 2 fixation were found in surface waters (0 to 4 m depth), and a major part of this activity (80% in coastal and 89% in offshore waters) took place during daylight hours. Integrated rates of N 2 fixation in cells > 20 μm followed the average abundance of filamentous cyanobacteria (primarily Aphanizomenon sp.) in the water column. Molar C:N mass ratios in particles > 20 μm, i.e. filamentous cyanobacteria, suggest that this size fraction was N-sufficient during summer, whereas the molar C:P mass ratios indicated P-limitation during this period. A reduction in sewage discharge to the Himmerfjärden bay area during the study period appears not to have been compensated for by increased rates of N 2 fixation. The patchy distribution of cyanobacteria and the high seasonal variability in N 2 fixation rates emphasize the need for adequate spatial and temporal sampling strategies in studies of N 2 fixation in coastal and open waters of the Baltic Sea.KEY WORDS: Baltic Sea · Aphanizomenon · Nodularia · N 2 fixation · HimmerfjärdenResale or republication not permitted without written consent of the publisher

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Section: Significance Of N 2 Fixation In the Baltic Seasupporting

confidence: 72%

Section: Significance Of N 2 Fixation In the Baltic Seamentioning

confidence: 60%

Seasonal significance of N2 fixation in coastal and offshore waters of the northwestern Baltic Sea

Degerholm

Gundersen²,

Bergman³

et al. 2008

Mar. Ecol. Prog. Ser.

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“…In the following decades, occurrence of this cyanobacterium was rather rare [ 5 ]. Since the 1970s, as a consequence of human-induced eutrophication, the mass development of N. spumigena has become a regular phenomenon [ 5 , 6 ]. In the late 1980s, the production of nodularin (NOD) by the Baltic N. spumigena was reported for the first time [ 7 ].…”

Section: Introductionmentioning

confidence: 99%

Specific Chemical and Genetic Markers Revealed a Thousands-Year Presence of Toxic Nodularia spumigena in the Baltic Sea

et al. 2018

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In the Baltic Sea, diazotrophic cyanobacteria have been present for thousands of years, over the whole brackish water phase of the ecosystem. However, our knowledge about the species composition of the cyanobacterial community is limited to the last several decades. In the current study, the presence of species-specific chemical and genetic markers in deep sediments were analyzed to increase the existing knowledge on the history of toxic Nodularia spumigena blooms in the Baltic Sea. As chemical markers, three cyclic nonribosomal peptides were applied: the hepatotoxic nodularin, which in the sea was detected solely in N. spumigena, and two anabaenopeptins (AP827 and AP883a) characteristic of two different chemotypes of this species. From the same sediment samples, DNA was isolated and the gene involved in biosynthesis of nodularin, as well as the phycocyanin intergenic spacer region (PC-IGS), were amplified. The results of chemical and genetic analyses proved for the first time the thousands-year presence of toxic N. spumigena in the Baltic Sea. They also indicated that through all this time, the same two sub-populations of the species co-existed.

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“…Nodularia spumigena is a filamentous, heterocystous, diazotrophic cyanobacterial species found in the Baltic Sea which commonly blooms during the N -limited summer period. These extensive surface blooms have been reported as common occurrences since the 1970s (Hübel & Hübel 1974) and form an important annual source of new N . N. spumigena and other diazotrophic cyanobacteria assimilate the residual phosphate present after the spring bloom (Kononen et al 1996) and fix atmospheric N, thereby supplying the wider plankton community with bioavailable N .…”

Section: Introductionmentioning

confidence: 99%

Baltic Sea diazotrophic cyanobacterium is negatively affected by acidification and warming

Paul¹,

Sommer²,

Paul³

et al. 2018

Mar. Ecol. Prog. Ser.

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Nitrogen fixation is a key source of nitrogen in the Baltic Sea which counteracts nitrogen loss processes in the deep anoxic basins. Laboratory and field studies have indicated that single-strain nitrogen-fixing (diazotrophic) cyanobacteria from the Baltic Sea are sensitive to ocean acidification and warming, 2 drivers of marked future change in the marine environment. Here, we enclosed a natural plankton community in 12 indoor mesocosms (volume ~1400 l) and manipulated partial pressure of carbon dioxide (pCO 2) in seawater to yield 6 CO 2 treatments with 2 different temperature treatments (16.6°C and 22.4°C, pCO 2 range = 360−2030 µatm). We followed the filamentous, heterocystous diazotrophic cyanobacteria community (Nostocales, primarily Nodularia spumigena) over 4 wk. Our results indicate that heterocystous diazotrophic cyanobacteria may become less competitive in natural plankton communities under ocean acidification. Elevated CO 2 had a negative impact on Nodularia sp. biomass, which was exacerbated by warming. Our results imply that Nodularia sp. may contribute less to new nitrogen inputs in the Baltic Sea in the future.

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Stickstoff-Fixierung in Küstengewässern der mittleren Ostsee

Cited by 6 publications

References 3 publications

Seasonal significance of N2 fixation in coastal and offshore waters of the northwestern Baltic Sea

Seasonal significance of N2 fixation in coastal and offshore waters of the northwestern Baltic Sea

Specific Chemical and Genetic Markers Revealed a Thousands-Year Presence of Toxic Nodularia spumigena in the Baltic Sea

Baltic Sea diazotrophic cyanobacterium is negatively affected by acidification and warming

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