Markku Viitasalo

Finnish Environment Institute | ymparisto · Marine Research Centre

Climate change has multiple effects on Baltic Sea species, communities and ecosystem functioning through changes in physical and biogeochemical environmental characteristics of the sea. Associated indirect and secondary effects on species interactions, trophic dynamics and ecosystem function are expected to be significant. We review studies investi...

The global demand for renewable energy is on the rise. Expansion of onshore wind energy is in many parts of the world limited by societal acceptance, and also ecological impacts are a concern. Here, pragmatic methods are developed for the integration of high-dimensional spatial data in offshore wind energy planning. Over 150 spatial data layers are...

Based on the Baltic Earth Assessment Reports of this thematic issue in Earth System Dynamics and recent peer-reviewed literature, current knowledge of the effects of global warming on past and future changes in climate of the Baltic Sea region is summarised and assessed. The study is an update of the Second Assessment of Climate Change (BACC II) pu...

Climate change has multiple direct and indirect potentially synergistic effects on Baltic Sea species, organism communities, and on ecosystem functioning, through physical and biogeochemical environmental characteristics of the sea. Associated indirect and secondary effects on species interactions, trophic dynamics and ecosystem function are expect...

Based on the Baltic Earth Assessment Reports of this thematic issue in Earth System Dynamics and recent peer-reviewed literature, current knowledge about the effects of global warming on past and future changes in climate of the Baltic Sea region is summarized and assessed. The study is an update of the Second Assessment of Climate Change (BACC II)...

Improving the health of coastal and open sea marine ecosystems represents a substantial challenge for sustainable marine resource management, since it requires balancing human benefits and impacts on the ocean. This challenge is often exacerbated by incomplete knowledge and lack of tools that measure ocean and coastal ecosystem health in a way that...

Tämä raportti vastaa merialuesuunnittelun tarpeisiin tarjoamalla olosuhteisiin räätälöidyn pohdinnan siitä, kuinka ekosysteemilähestymistapaa on hyvä soveltaa, jotta merialuesuunnitelmalle asetettu ympäristötavoite edistää meriympäristön hyvää tilaa saavutetaan. Merialuesuunnittelussa pyritään kokonaisvaltaisilla suunnitteluratkaisuilla tukemaan se...

Great cormorant Phalacrocorax carbo sinensis populations in the Baltic Sea have rapidly expanded since the 1990s, raising concerns about their ecosystem impacts. Nutrient runoff from colonies, as well as cormorant predation on fish, can affect surrounding producer communities. Past studies have found cormorant impacts on producers in the immediate...

ContextSpatial prioritization is an analytical approach that can be used to provide decision support in spatial conservation planning (SCP), and in tasks such as conservation area network design, zoning, planning for impact avoidance or targeting of habitat management or restoration.Methods Based on literature, we summarize the role of connectivity...

Hypoxia is an increasing problem in marine ecosystems around the world. While major advances have been made in our understanding of the drivers of hypoxia, challenges remain in describing oxygen dynamics in coastal regions. The complexity of many coastal areas and lack of detailed in situ data have hindered the development of models describing oxyg...

Hypoxia is an increasing problem in marine ecosystems around the world, and recent projections indicate that anoxic dead zones will be spreading in the forthcoming decades. While major advances have been made in our understanding of the drivers of hypoxia, it fundamentally hinges on patterns of water circulation that can be difficult to resolve in...

Predictive species distribution models are mostly based on statistical dependence between environmental and distributional data and therefore may fail to account for physiological limits and biological interactions that are fundamental when modelling species distributions under future climate conditions. Here, we developed a state-of-the-art method...

Marine Protected Areas (MPAs) are essential for safeguarding marine biodiversity. Various international and regional agreements require that nations designate sufficient marine areas under protection. Assessing the functionality and coherence of MPA networks is challenging, unless extensive data on species and habitats is available. We evaluated th...

Canopy-forming macroalgae living on rocky bottoms provide valuable ecosystem services but long-term eutrophication has narrowed their distribution and depth zonation in the Baltic Sea. The spatial distribution of macroalgae is shaped by many factors, such as light, salinity, nutrients and wave exposure. In addition, the lack of suitable hard substr...

Planning the use of marine areas requires support in allocating space to particular activities, assessing impacts and cumulative effects of activities, and generic decision making. The SmartSea project studies the Gulf of Bothnia, the northernmost arm of the Baltic Sea, as resource for sustainable growth. One objective of the project is to provide...

1. Environmental drivers and food web structure in the pelagic zone vary from south to north in the Baltic Sea. 2. While nitrogen is generally the limiting nutrient for primary production in the Baltic Sea, phosphorus is the limiting nutrient in the Bothnian Bay. 3. In the Gulf of Bothnia the food web is to a large extent driven by terrestrial allo...

Essential Biodiversity Variables (EBVs) have been suggested to harmonize biodiversity monitoring worldwide. Their aim is to provide a small but comprehensive set of monitoring variables that would give a balanced picture of the development of biodiversity and the reaching of international and national biodiversity targets. Globally, GEO BON (Group...

Biological invasions coupled with climate change drive changes in marine biodiversity. Warming climate and changes in hydrology may either enable or hinder the spread of non-indigenous species (NIS) and little is known about how climate change modifies the richness and impacts of NIS in specific sea areas. We calculated from climate change simulati...

This report is the final deliverable of the "Mapping and Assessment of marine ecosystem services and link to good environmental status (phase 1)" .This report was written as the final deliverable of a project from a service request under the agreement of the 'Framework contract for services related to development of methodological standards in rela...

The majority of studies in metacommunity ecology have focused on systems other than marine benthic ecosystems, thereby providing an impetus to broaden the focus of metacommunity research to comprise marine systems. These systems are more open than many other systems and may thus exhibit relatively less discrete patterns in community structure acros...

Increase in sea surface temperature is projected to change seasonal succession and induce dominance shifts in phytoplankton in spring and promote the growth of cyanobacteria in summer. In general, climate change is projected to worsen oxygen conditions and eutrophication in the Baltic Proper and the Gulf of Finland. In the Gulf of Bothnia, the incr...

Climate change is projected to increase air temperature, precipitation and river runoff in the Baltic Sea area. Consequently sea surface temperature will increase and salinity will gradually decline. Species' geographical ranges will shift and populations increase or decrease according to the temperature and salinity tolerances of each species. War...

Toxic cyanobacterial blooms, dominated by Nodularia spumigena, are a recurrent phenomenon in the Baltic Sea during late summer. Nodularin, a potent hepatotoxin, has been previously observed to accumulate on different trophic levels, in zooplankton, mysid shrimps, fish as well as benthic organisms, even in waterfowl. While the largest concentrations...

Feeding rate, growth and nutritional condition as well as nodularin concentration of juvenile three-spined sticklebacks Gasterosteus aculeatus were assessed in an experimental study where field-collected fish were given a diet of zooplankton fed with toxic Nodularia spumigena for 15 days. Food consumption was higher in N. spumigena bloom conditions...

We investigated the effects of two functionally different deposit feeders, the amphipod Monoporeia affinis and the bivalve Macoma balthica, on the benthic emergence of copepods (Acartia spp., Eurytemora affinis, Temora longicornis), cladocerans (Bosmina longispina maritima, Daphnia spp.), and rotifers (Synchaeta spp., Keratella spp., Notholca spp.)...

Eutrophication of the Baltic Sea has potentially increased the frequency and magnitude of cyanobacteria blooms. Eutrophication leads to increased sedimentation of organic material, increasing the extent of anoxic bottoms and subsequently increasing the internal phosphorus loading. In addition, the hypoxic water volume displays a negative relationsh...

Cyanobacteria of the Baltic Sea have multiple effects on organisms that influence the food chain dynamics on several trophic levels. Cyanobacteria contain several bioactive compounds, such as alkaloids, peptides, and lipopolysaccharides. A group of nonribosomally produced oligopeptides, namely microcystins and nodularin, are tumor promoters and cau...

Peltonen, H., Luoto, M., Pääkkönen, J.-P., Karjalainen, M., Tuomaala, A., Pönni, J., and Viitasalo, M. 2007. Pelagic fish abundance in relation to regional environmental variation in the Gulf of Finland, northern Baltic Sea. – ICES Journal of Marine Science, 64: 487–495. This study applies variation partitioning to analyse spatial patterns in hydro...

The prey selection of larvae of three common littoral fish species (pike, Esox lucius; roach,Rutilus rutilus; and three-spined stickleback, Gasterosteus aculeatus) was studied experimentally in the laboratory by using natural zooplankton assemblages. Zooplankton prey was offered at four different concentrations to study the functional responses of...

Extracts of Aphanizomenon flos-aquae and Nodularia spumigena , the two most common cyanobacteria forming recurrent blooms in the Baltic Sea, decrease the abundance of some phytoplankton species via the release of allelopathic substances. We investigated how cell-free filtrates of the two cyanobacteria, as well as purified hepatotoxin nodularin, pro...

We studied the effect of cyanobacteria on foraging and refuge use in small fish. We measured pike larval feeding in the presence of cyanobacteria by counting leftover prey. Our results showed that feeding by pike larvae on zooplankton prey decreased significantly in the presence of non-toxic cyanobacteria. The behaviour can be due to lowered vision...

Toxic cyanobacteria can have harmful or fatal impacts on aquatic organisms. In the archipelagos of the northern Baltic Sea, the open sea blooms often drift into littoral areas, where they decompose and release toxins and other chemical compounds in the water. However, the effects of cyanobacteria on the littoral organisms have not previously been i...

Cyanobacterial blooms are a common phenomenon in the Baltic Sea, and the hepatotoxin nodularin has been frequently detected in certain Baltic Sea fishes and mussels. However, there is no knowledge about the naturally occurring concentrations of nodularin in Baltic Sea zooplankton. The aim of this study was to survey the concentrations of nodularin...

Engström-Öst J, Lehtiniemi M, Jónasdóttir SH, Viitasalo M. Growth of pike larvae (Esox lucius) under different conditions of food quality and salinity. Ecology of Freshwater Fish 2005. © Blackwell Munksgaard, 2005 Abstract – We measured growth of pike larvae (Esox lucius) fed with freshwater and brackish-water zooplankton by monitoring larval wet w...

The aim of this study was to evaluate the potentially harmful effects of zooplankton preexposed to cyanobacteria on two planktivorous animals: a fish larva (pike, Esox lucius) and a mysid shrimp (Neomysis integer). The planktivores were fed zooplankton from a natural community that had been preexposed to cell-free extract or to purified toxin (nodu...

We tested how algal turbidity and light conditions influence anti-predator behaviour of first-feeding pike. Results showed that pike larvae were able to detect the predator by both chemical and visual signals in turbid water. However, the anti-predator behaviour was reduced in turbid water compared with clear water. Larvae hid in the vegetation in...

The abundance of Bosmina longispina maritima (Cladocera), the most common water flea in the Baltic Sea, shows considerable interannual fluctuations. The number of Bosmina resting eggs (ephippia) in the sediment also fluctuates from year to year. Biotic as well as abiotic factors have been suggested to contribute to these fluctuations, but the impac...

We used the longest available weight-at-age (WAA) time series (from 1950 to 1999) for Baltic herring (Clupea harengus membras L.) in the Gulf of Finland to investigate which environmental factors affect Baltic herring growth. The relationships among WAAs, annual weight increments, and growth rates for different herring year classes, water salinity,...

The predator avoidance behaviours of two littoral mysid species, Neomysis integer (Leach) and Praunus flexuosus (Mller), were studied experimentally. In ingestion experiments, mysids responded to a combination of chemical and visual signals of perch (Perca fluviatilis), but not to each stimulus alone. In the presence of the combined visual and chem...

It has been suggested that larval survival determines the year-class strength in most marine fish species. During their growth and development, the ability of the larvae to catch prey and avoid predation will increase. However, the factors affecting short-term changes in the growth of Baltic Sea herring have been little studied in the field. We col...

Proceedings of the Estonian Academy of Sciences. Biology Ecology, 1406-0914, vol. 52, nr. 1, 1-16 In 1928, Sven G. Segerstråle made detailed analyses of benthic communities in Tvärminne region (SW coast of Finland). In addition to traditional presentation, he included illustrative photographs where the collected macro-invertebrates were laid on bla...

Toxic cyanobacterial blooms are a common phenomenon in the Baltic Sea. The fate of the toxin in the food web is largely unknown. We studied the effect of algal diets on production of pellets and toxin content of the calanoid copepod Eurytemora affinis in the northern Baltic Sea. Field-collected copepods were fed with (1) cultured toxic cyanobacteri...

It has been suggested that pelagic planktivores may receive cyanobacterial toxins indirectly, i.e., by preying on organisms that have ingested cyanobacteria. We tested this hypothesis in laboratory conditions by providing mysid shrimps, Mysis relicta, and three-spined sticklebacks, Gasterosteus aculeatus, with cyanobacteria-fed copepods. The aim of...

We studied the development of the plankton community in an artificially created toxic Nodularia spumigena bloom during a 2 wk enclosure study at the SW coast of Finland in the Baltic Sea. We measured bacterial abundance, dominant phytoplankton groups and ciliates, as well as concentrations of phytoplankton pigments, fatty acids, nodularin, protein...

Feeding and fecundity of two calanoid copepod species (Acartia bifilosa and Eurytemora affinis) were studied in a food assemblage dominated by toxic cyanobacteria, to reveal whether mesozooplankton are able to obtain sufficient good quality food in different phases of a cyanobacteria bloom. Bloom conditions were simulated in a mesocosm by adding a...

The Baltic Sea is a very suitable site for stoichiometric studies, since its subbasins differ in their concentration of elemental components, and primary production can therefore be either nitrogen or phosphorus limited. To reveal if the nutrient limitation of mesozooplankton mirrors that of the primary producers, carbon, nitrogen and phosphorus co...

We studied the growth, feeding, and elemental composition of Mysis mixta from June to September 1997 in the northern Baltic Sea. In June the juvenile population had a unimodal size distribution (mean length ∼6 mm), but in July-August, the population was divided into two cohorts. A stomach content analysis showed that the mysids in the larger and fa...

It has been shown that freshwater pelagic mysid shrimps capture zooplankton at a higher rate in light than in darkness. This has been suggested to be due to facilitation of visual predation on evasive zooplankton prey. To test this hypothesis with Baltic mysid shrimps, and to see whether pelagic (migrating) and littoral (non-migrating) mysids diffe...

Predation rates and prey selection of the pelagic mysid shrimp, Mysis mixta, were studied experimentally in the northern Baltic Sea in 1998 during their most intensive growth period, from June to October. Functional responses during 5 months were determined by providing the mysids with a natural zooplankton assemblage, diluted to several different...

We measured the effect of toxic and non-toxic cyanobacteria strains on grazing, predation rates and survival of the mysid shrimp Mysis mixta by means of laboratory experiments. Juvenile and adult M. mixta fed most actively on the non-toxic strains Aphanizomenon flos-aquae and Nodularia sphaerocarpa as on high quality food, the green flagellate Brac...

We investigated prey selection by the 2 most important planktivores in the northern Baltic, the Baltic herring Clupea harengus membras L. and the mysid shrimp Mysis mixta Lilljeborg. We hypothesised that the intensity of prey selection by herring is positively related to prey size and that deviations from this relationship can be explained by prey...

We measured ingestion and clearance rates of two Baltic Sea calanoid copepods, Eurytemora affinis and Acartia bifilosa, on toxic and non-toxic cyanobacteria Nodularia sp. using the isotope technique. Eurytemora affinis fed actively on the non-toxic strain and moderately actively on the toxic strain, whereas A.bifilosa totally avoided feeding on bot...

We measured ingestion and clearance rates of two Baltic Sea calanoid copepods, Euryremora affinis and Acartia bifilosa, on toxic and non-toxic cyanobacteria Nodularia sp. using the isotope technique. Eurytemora affinis fed actively on the non-toxic strain and moderately actively on the toxic strain, whereas A.bifilosa totally avoided feeding on bot...

The dietary habits of the pelagic mysid Mysismixta were studied during its growing season at an open sea location in the Gulf of Finland, the northern Baltic Sea. Stomach samples were taken twice a month from June to September 1997. The most abundant phytoplankton taxa in the stomachs were diatoms and dinoflagellates, and copepods and cladocerans w...

Reproduction (egg production and hatching success) and maintenance (mortality and carbon and nitrogen content) of the calanoid copepod Eurytemora affinis were measured at 5 concentrations (ca 50, 100, 200, 400 and 600 μg Cl-1) of toxic and non-toxic strains of the cyanobacterium Nodularia sp. and the green alga Brachiomonas submarina, and in 3 diff...

We investigated the sedimentation of copepod fecal pellets in three different sea areas representing a sheltered bay, an archipelago area, and the open sea on the southwestern coast of Finland in the northern Baltic Sea. Fecal carbon sedimentation was always ,0.05% of the total sedimentation of particulate organic carbon, whereas the fecal carbon p...

Seasonal development of mesozooplankton abundance, biomass and production were studied on the SW coast of Finland in three hydrographically distinct areas with different phytoplankton dynamics. In addition, the present species composition was compared to that at the beginning of the century, using a multidimensional scaling analysis. Mesozooplankto...