scholarly journals Enrichment of novel Verrucomicrobia , Bacteroidetes , and Krumholzibacteria in an oxygen‐limited methane‐ and iron‐fed bioreactor inoculated with Bothnian Sea sediments

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Paula Dalcin Martins ◽  
Anniek Jong ◽  
Wytze K. Lenstra ◽  
Niels A. G. M. Helmond ◽  
Caroline P. Slomp ◽  
...  
Keyword(s):  
Bothnian Sea

scholarly journals Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates?

2012 ◽  
Vol 69 (8) ◽  
pp. 1448-1456 ◽  
Author(s):  
Anna Gårdmark ◽  
Örjan Östman ◽  
Anders Nielsen ◽  
Karl Lundström ◽  
Olle Karlsson ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Older Individuals ◽  
Standard Assessment ◽  
Abundance Estimates ◽  
Stock Biomass ◽  
Key Species ◽  
Spawning Stock ◽  
Bothnian Sea

Abstract Gårdmark, A., Östman, Ö., Nielsen, A., Lundström K., Karlsson O., Pönni, J., and Aho, T. 2012. Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates? – ICES Journal of Marine Science, 69: . Mortality of small pelagic fish due to marine mammals is generally considered to be low compared with other sources of mortality. With recent recoveries of marine mammal predators worldwide, this may no longer hold. The grey seal (Halichoerus grypus) population in the Bothnian Sea has increased fivefold since 1985. Its main prey, herring (Clupea harrengus), is a key species for fisheries in the region. Yet, current stock assessments assume constant natural mortality, leading to a risk of biased stock estimates with increasing predation and misleading analyses of herring population dynamics. We estimated grey seal predation from diet data and reanalysed herring spawning stock biomass (SSB) during 1973–2009. Accounting for predation increased the herring SSB 16% (maximum 19%), but this was within the confidence intervals when ignoring predation. Although mortality in older individuals was inflated when accounting for seal predation, this did not change the conclusions about drivers of herring dynamics. Accounting for grey seal predation is important for abundance estimates of old herring, but currently not for SSB estimates, given the great uncertainties in the standard assessment. The grey seal impact on Bothnian Sea herring will need to be reassessed if stock age composition, grey seal feeding preferences, or total stock development change.

scholarly journals Enrichment of novel Verrucomicrobia, Bacteroidetes and Krumholzibacteria in an oxygen-limited, methane- and iron-fed bioreactor inoculated with Bothnian Sea sediments

2020 ◽  
Author(s):  
Paula Dalcin Martins ◽  
Anniek de Jong ◽  
Wytze K. Lenstra ◽  
Niels A. G. M. van Helmond ◽  
Caroline P. Slomp ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Coastal Sediments ◽  
Ecosystem Functions ◽  
Marker Genes ◽  
Iron Cycling ◽  
Low Oxygen ◽  
Coastal Marine ◽  
Metabolic Versatility ◽  
Comprehensive Knowledge ◽  
Bothnian Sea

AbstractMicrobial methane oxidation is a major biofilter preventing larger emissions of this powerful greenhouse gas from marine coastal areas into the atmosphere. In these zones, various electron acceptors such as sulfate, metal oxides, nitrate or oxygen can be utilized. However, the key microbial players and mechanisms of methane oxidation are poorly understood. In this study, we inoculated a bioreactor with methane- and iron-rich sediments from the Bothnian Sea in order to investigate microbial methane and iron cycling under low oxygen concentrations. Using metagenomics, we observed shifts in the microbial community over approximately 2.5 years of bioreactor operation. Marker genes for methane and iron cycling, as well as respiratory and fermentative metabolism, were investigated. Metagenome-assembled genomes representing novel Verrucomicrobia, Bacteroidetes and Krumholzibacteria were recovered and revealed potential for methane oxidation, organic matter degradation, and iron cycling, respectively. This work brings new insights into the identity and metabolic versatility of microorganisms that may be members of such functional guilds in coastal marine sediments and highlights that the methane biofilter in these sediments may be more diverse than previously appreciated.ImportanceDespite the essential role of microorganisms in preventing most methane in the ocean floor to reach the atmosphere, comprehensive knowledge on the identity and the mechanisms employed by these microorganisms is still lacking. This is problematic because such information is needed to understand how the ecosystem functions in the present and how microorganisms may respond to climate change in the future. Here, we enriched and identified novel taxa potentially involved in methane and iron cycling in an oxygen-limited bioreactor inoculated with methane- and iron-rich coastal sediments. Metagenomic analyses provided hypotheses about the mechanisms they may employ, such as the use of oxygen at very low concentrations. The implication of our results is that in more shallow sediments, where oxygen-limited conditions are present, the methane biofilter is potentially composed of novel, metabolically versatile Verrucomicrobia that could contribute to mitigating methane emissions from coastal marine zones.

scholarly journals Both predation and feeding opportunities may explain changes in survival of Baltic salmon post-smolts

2012 ◽  
Vol 69 (9) ◽  
pp. 1574-1579 ◽  
Author(s):  
Samu Mäntyniemi ◽  
Atso Romakkaniemi ◽  
Johan Dannewitz ◽  
Stefan Palm ◽  
Tapani Pakarinen ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Clupea Harengus ◽  
Coefficient Of Determination ◽  
Migration Route ◽  
Grey Seal ◽  
Explanatory Variables ◽  
Direct Observations ◽  
The Baltic ◽  
Bothnian Bay ◽  
Bothnian Sea

Abstract Mäntyniemi, S., Romakkaniemi, A., Dannewitz, J., Palm, S., Pakarinen, T., Pulkkinen, H., Gårdmark, A., and Karlsson, O. 2012. Both predation and feeding opportunities may explain changes in survival of Baltic salmon post-smolts. – ICES Journal of Marine Science, 69: 1574–1579. The survival of wild and hatchery-reared post-smolts of salmon (Salmo salar) in the Baltic Sea has declined since the 1990s. Direct observations of the processes affecting survival are, however, lacking. Here, the importance of food availability and predation in regulating post-smolt survival is analysed. Based on previous studies, the following explanatory variables were selected: (i) availability of herring (Clupea harengus membras) recruits in the Gulf of Bothnia (Bothnian Sea, Bothnian Bay) in the northern Baltic Sea; (ii) sprat (Sprattus sprattus balticus) and herring abundance in the southern Baltic Sea; and (iii) abundance of grey seal (Halichoerus grypus) along the post-smolt migration route. Bayesian analysis was used to estimate the relative probability of each of the 32 combinations of these variables and revealed that the model including grey seal abundance and herring recruits per post-smolt had the highest posterior probability and a high coefficient of determination. The results suggest that the declining trend in post-smolt survival is explained by the increased number of grey seals, whereas the annual variation in survival coincides with variation in the recruitment of Bothnian Sea herring. However, it remains uncertain whether the observed correlations arise from direct causalities or other mechanisms.

scholarly journals Nitrogen fixation estimates for the Baltic Sea indicate high rates for the previously overlooked Bothnian Sea

AMBIO ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 203-214 ◽  
Author(s):  
Malin Olofsson ◽  
Isabell Klawonn ◽  
Bengt Karlson
Keyword(s):  
Nitrogen Fixation ◽  
Baltic Sea ◽  
Nutrient Loading ◽  
External Input ◽  
Nitrogen Loading ◽  
External Loading ◽  
The Baltic Sea ◽  
Positive Effects ◽  
The Baltic ◽  
Bothnian Sea

AbstractDense blooms of diazotrophic filamentous cyanobacteria are formed every summer in the Baltic Sea. We estimated their contribution to nitrogen fixation by combining two decades of cyanobacterial biovolume monitoring data with recently measured genera-specific nitrogen fixation rates. In the Bothnian Sea, estimated nitrogen fixation rates were 80 kt N year−1, which has doubled during recent decades and now exceeds external loading from rivers and atmospheric deposition of 69 kt year−1. The estimated contribution to the Baltic Proper was 399 kt N year−1, which agrees well with previous estimates using other approaches and is greater than the external input of 374 kt N year−1. Our approach can potentially be applied to continuously estimate nitrogen loads via nitrogen fixation. Those estimates are crucial for ecosystem adaptive management since internal nitrogen loading may counteract the positive effects of decreased external nutrient loading.

The first large-scale assessment of three-spined stickleback (Gasterosteus aculeatus) biomass and spatial distribution in the Baltic Sea

2019 ◽  
Vol 76 (6) ◽  
pp. 1653-1665 ◽  
Author(s):  
Jens Olsson ◽  
Eglė Jakubavičiūtė ◽  
Olavi Kaljuste ◽  
Niklas Larsson ◽  
Ulf Bergström ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Baltic Sea ◽  
Gasterosteus Aculeatus ◽  
Population Characteristics ◽  
Alternative Methods ◽  
The Baltic Sea ◽  
Baltic Proper ◽  
The Baltic ◽  
The Impact ◽  
Bothnian Sea

Abstract Declines in predatory fish in combination with the impact of climate change and eutrophication have caused planktivores, including three-spined stickleback (Gasterosteus aculeatus), to increase dramatically in parts of the Baltic Sea. Resulting impacts of stickleback on coastal and offshore foodwebs have been observed, highlighting the need for increased knowledge on its population characteristics. In this article, we quantify abundance, biomass, size structure, and spatial distribution of stickleback using data from the Swedish and Finnish parts of the Baltic International Acoustic Survey (BIAS) during 2001–2014. Two alternative methods for biomass estimation suggest an increase in biomass of stickleback in the Baltic Proper, stable or increasing mean size over time, and larger individuals toward the north. The highest abundance was found in the central parts of the Baltic Proper and Bothnian Sea. The proportion of stickleback biomass in the total planktivore biomass increased from 4 to 10% in the Baltic Proper and averaged 6% of the total planktivore biomass in the Bothnian Sea. In some years, however, stickleback biomass has ranged from half to almost twice that of sprat (Sprattus sprattus) in both basins. Given the recent population expansion of stickleback and its potential role in the ecosystem, we recommend that stickleback should be considered in future monitoring programmes and in fisheries and environmental management of the Baltic Sea.

The dependence of organohalogen compound concentrations on herring age and size in the Bothnian Sea, northern Baltic

2006 ◽  
Vol 52 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Raimo Parmanne ◽  
Anja Hallikainen ◽  
Pirjo Isosaari ◽  
Hannu Kiviranta ◽  
Jaana Koistinen ◽  
...  
Keyword(s):  
Organohalogen Compound ◽  
Bothnian Sea

Long-term changes in the sublittoral zonation of brown algae in the southern Bothnian Sea

1998 ◽  
Vol 33 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Britas Klemens Eriksson ◽  
Gustav Johansson ◽  
Pauli Snoeijs
Keyword(s):  
Brown Algae ◽  
Long Term Changes ◽  
Bothnian Sea
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