Zonation and spatial distribution of littoral fish communities from the southwestern Finnish coast (Archipelago and Bothnian Sea, Northern Baltic 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.

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Vertical and spatial distribution of biogenic silica in the sediment of the gulf of Riga, Baltic Sea

Toxicological and Environmental Chemistry ◽

10.1080/02772249709358468 ◽

1997 ◽

Vol 60 (1-4) ◽

pp. 245-259 ◽

Cited By ~ 6

Author(s):

Rolf Carman ◽

Juris Aigars

Keyword(s):

Spatial Distribution ◽

Baltic Sea ◽

Biogenic Silica ◽

Gulf Of Riga

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A three-dimensional view on biodiversity changes: spatial, temporal, and functional perspectives on fish communities in the Baltic Sea

ICES Journal of Marine Science ◽

10.1093/icesjms/fsy027 ◽

2018 ◽

Vol 75 (7) ◽

pp. 2463-2475 ◽

Cited By ~ 3

Author(s):

Romain Frelat ◽

Alessandro Orio ◽

Michele Casini ◽

Andreas Lehmann ◽

Bastien Mérigot ◽

...

Keyword(s):

Baltic Sea ◽

Environmental Conditions ◽

Environmental Changes ◽

Temporal Dynamics ◽

Marine Ecosystem ◽

Fish Communities ◽

The Baltic Sea ◽

Functional Richness ◽

Holistic Understanding ◽

The Baltic

Abstract Fisheries and marine ecosystem-based management requires a holistic understanding of the dynamics of fish communities and their responses to changes in environmental conditions. Environmental conditions can simultaneously shape the spatial distribution and the temporal dynamics of a population, which together can trigger changes in the functional structure of communities. Here, we developed a comprehensive framework based on complementary multivariate statistical methodologies to simultaneously investigate the effects of environmental conditions on the spatial, temporal and functional dynamics of species assemblages. The framework is tested using survey data collected during more than 4000 fisheries hauls over the Baltic Sea between 2001 and 2016. The approach revealed the Baltic fish community to be structured into three sub-assemblages along a strong and temporally stable salinity gradient decreasing from West to the East. Additionally, we highlight a mismatch between species and functional richness associated with a lower functional redundancy in the Baltic Proper compared with other sub-areas, suggesting an ecosystem more susceptible to external pressures. Based on a large dataset of community data analysed in an innovative and comprehensive way, we could disentangle the effects of environmental changes on the structure of biotic communities—key information for the management and conservation of ecosystems.

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

ICES Journal of Marine Science ◽

10.1093/icesjms/fss088 ◽

2012 ◽

Vol 69 (9) ◽

pp. 1574-1579 ◽

Cited By ~ 16

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.

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Understanding the spatial distribution of subtidal reef assemblages in the southern Baltic Sea using towed camera platform imagery

Estuarine Coastal and Shelf Science ◽

10.1016/j.ecss.2018.04.006 ◽

2018 ◽

Vol 207 ◽

pp. 82-92 ◽

Cited By ~ 7

Author(s):

Kolja Beisiegel ◽

Alexander Darr ◽

Michael L. Zettler ◽

René Friedland ◽

Ulf Gräwe ◽

...

Keyword(s):

Spatial Distribution ◽

Baltic Sea ◽

Southern Baltic Sea ◽

Southern Baltic

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Seasonal variation and drivers of zooplankton, macroinvertebrate and littoral fish communities from irrigation ponds in a semi-arid region in the Eastern Cape (South Africa)

African Journal of Aquatic Science ◽

10.2989/16085914.2021.1924608 ◽

2021 ◽

pp. 1-12

Author(s):

L Mofu ◽

T Dalu ◽

RJ Wasserman ◽

DJ Woodford ◽

D Khosa ◽

...

Keyword(s):

South Africa ◽

Seasonal Variation ◽

Arid Region ◽

Fish Communities ◽

Eastern Cape ◽

Littoral Fish ◽

Semi Arid Region ◽

Semi Arid

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

AMBIO ◽

10.1007/s13280-020-01331-x ◽

2020 ◽

Vol 50 (1) ◽

pp. 203-214 ◽

Cited By ~ 1

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.

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