| 1. |
- Kautsky, Hans, et al.
(författare)
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The phytobenthic zone
- 2017
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Ingår i: Biological Oceanography of the Baltic Sea. - Dordrecht : Springer. - 9789400706675 - 9789400706682 ; , s. 387-455
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Bokkapitel (refereegranskat)abstract
- 1. Phytobenthic communities consist of macrophytes (macroalgae, vascular plants andmosses) with their accompanying fauna and microorganisms.2. The phytobenthic communities occur in the photic zone, which in the Baltic Sea extendsfrom the water surface down to a*20 m water depth, but in turbid coastal waters onlydown to*5m.3. The type of vegetation is determined by the available substrate, which is a result ofgeography and geology in combination with currents. Most macroalgae grow attachedto hard substrates whereas vascular plants and charophytes grow on sandy or soft (siltand mud) substrates.4. Generally, the coastal areas of the Baltic Sea consist of mixed substrates with anintermingled vegetation of vascular plants and algae. In the northern Baltic Sea hardsubstrates dominate in the outer archipelagos, and in the southeastern Baltic Sea sandyand muddy substrates dominate.5. Luxuriant stands of macrophytes provide food, shelter and spawning habitats for theassociated sessile and mobile micro-, meio- and macrofauna, includingfish.6. On an ecosystem-wide scale, the phytobenthic communities vary along the large-scaleBaltic Sea gradient. Biomass decreases with lower salinity and colder climate, while theproportion of freshwater species increases.7. On a local scale, the phytobenthic communities are mainly, directly or indirectly, shapedby water movement (e.g.by the occurrence of sandy beaches and rocky shores) andwinter ice cover. Light and substrate availability give rise to typical depth zonationpatterns, ending with soft-substrate communities deepest down.8. On a small scale (patches), phytobenthic community structure and composition isinfluenced by microhabitat structure and biotic interactions.9. The phytobenthic communities in the brackish Baltic Sea are more sensitive to dis-turbance than their marine counterparts due to low diversity, physiological stress and theloss of sexual reproduction when species approach their salinity limit.
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| 2. |
- Kijewski, Tomasz, et al.
(författare)
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Random forest assessment of correlation between environmental factors and genetic differentiation of populations : Case of marine mussels Mytilus
- 2019
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Ingår i: Oceanologia. - : Elsevier BV. - 0078-3234. ; 61:1, s. 131-142
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Tidskriftsartikel (refereegranskat)abstract
- The novel machine learning technique Random Forest (RF) was used to test if the genetic differentiation of populations of marine species may be related to any of the key environmental variables known to shape species distributions. The study was performed in North and Baltic Sea characterized by strong gradients of environmental factors and almost continuous distributions of Mytilus mussel populations. Assessment of the species identity was performed using four nuclear DNA markers, and previously published single nucleotide polymorphism (SNP) data. A general pattern of cline variation was observed with increasing Mytilus trossulus share towards the eastern Baltic Sea. Average allele share rose to 61% in Hoga Kusten, Gulf of Bothnia. All Baltic Sea samples revealed a strong introgression of Mytilus edulis and a limited introgression of M. trossulus through the Danish Straits. The studied environmental variables described 67 and 68% of the variability in the allele frequencies of M. edulis and M. trossulus. Salinity defined over 50% of the variability in the gene frequencies of the studied Mytilus spp. populations. Changes along this environmental gradient were not gradual but instead a significant shift from gene dominance was found at a salinity of 12 PSU. Water temperature and the trophic status of the sea area had only moderate association with the gene frequencies. The obtained results showed that the novel machine learning technique can be successfully used for finding correlations between genetic differentiation of populations and environmental variables and for defining the functional form of these linkages.
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| 3. |
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| 4. |
- Strandmark, Alma, et al.
(författare)
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Climate change effects on the Baltic Sea borderland between land and sea
- 2015
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 44, s. s28-S38
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Tidskriftsartikel (refereegranskat)abstract
- Coastal habitats are situated on the border between land and sea, and ecosystem structure and functioning is influenced by both marine and terrestrial processes. Despite this, most scientific studies and monitoring are conducted either with a terrestrial or an aquatic focus. To address issues concerning climate change impacts in coastal areas, a cross-ecosystem approach is necessary. Since habitats along the Baltic coastlines vary in hydrology, natural geography, and ecology, climate change projections for Baltic shore ecosystems are bound to be highly speculative. Societal responses to climate change in the Baltic coastal ecosystems should have an ecosystem approach and match the biophysical realities of the Baltic Sea area. Knowledge about ecosystem processes and their responses to a changing climate should be integrated within the decision process, both locally and nationally, in order to increase the awareness of, and to prepare for climate change impacts in coastal areas of the Baltic Sea.
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| 5. |
- Svensson, Filip, 1980-
(författare)
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Effects of warming on the ecology of algal-dominated phytobenthic communities in the Baltic Sea
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Through climate change, the global average air and surface water temperature has risen 0.85°C during the last 100 years. The Baltic Sea experienced one of the most rapid increase in temperature recorded of marine ecosystems. During the last two decades of the 20th century, the surface water temperature of the Baltic Sea has increased seven times faster than the global average.This thesis is an investigation of how community traits, trophic interactions and ecophysiological processes in the filamentous algal belt in the northern Baltic Sea are affected by warming. The majority of the studies were conducted in or in the vicinity of the Forsmark Biotest basin, an artificial heated enclosure of the southern Bothnian Sea (northern Baltic Sea). One study also included sampling along a natural salinity gradient - the Swedish east coast.In the benthic diatom community, we found that cell size decreases with decreasing seasonal temperature, and increased with warming during the cold season. Warming also selected for motile and colonial traits. Along the salinity gradient, cell size decreased with decreasing salinity, apparently mediated by changes in the nitrogen to phosphorus ratio.In the filamentous algal community, warming increased algal cover and photosynthetic capacity, and affected the ratio of carotene to chlorophyll a ratio. Warming also desensitized the photosynthetic response and growth of algal communities exposed to anthropogenic stressors: increased nitrogen and phosphor concentrations as well as copper additions. In connection to one of the field studies, the first finding of the non-native bivalve Mytilopsis leucophaeata in Sweden was also done.Using a fish exclusion experiment in heated and non-heated areas, we found that warming decreases the number of trophic levels in the lower parts of the food web, which in turn lead to increased top-down control and higher algal biomass at heated than unheated sites.In summary, warming has here been shown to have major impacts on the phytobenthic community due to a combination of direct effects on physiological processes, as well as indirect effects mediated by interactions among species and trophic levels.
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