A5000470608- Marine and fisheries research
- Fish Ecology and Management Studies
- Marine Bivalve and Aquaculture Studies
- Coral and Marine Ecosystems Studies
- Aquatic Ecosystems and Phytoplankton Dynamics
- Aquaculture Nutrition and Growth
- Food Industry and Aquatic Biology
- Isotope Analysis in Ecology
- Marine and environmental studies
- Evolutionary Game Theory and Cooperation
- Marine and coastal ecosystems
- Genetic diversity and population structure
- Fish Biology and Ecology Studies
- Arctic and Antarctic ice dynamics
- Agricultural Economics and Policy
- Marine animal studies overview
- Fish biology, ecology, and behavior
- Arctic and Russian Policy Studies
- Aquatic Invertebrate Ecology and Behavior
- Global Financial Crisis and Policies
- Geological and Geophysical Studies
- Methane Hydrates and Related Phenomena
- Aquatic Ecosystems and Biodiversity
- Freshwater macroinvertebrate diversity and ecology
- Science and Climate Studies
Swedish University of Agricultural Sciences
2013-2022
Swedish Agency for Marine and Water Management
2012
Swedish National Board of Fisheries
2003-2009
Umeå University
2000-2003
Fisheries can have a large impact on marine ecosystems, because the effects of removing predatory fish may cascade down food web. The implications these cascading processes system functioning and resilience remain source intense scientific debate. By using field data covering 30-year period, we show for Baltic Sea that underlying mechanisms trophic cascades produced shift in ecosystem after collapse top predator cod. We identified an ecological threshold, corresponding to planktivore...
Anthropogenic disturbances intertwined with climatic changes can have a large impact on the upper trophic levels of marine ecosystems, which may cascade down food web. So far it has been difficult to demonstrate multi-level cascades in pelagic environments. Using field data collected during 33-year period, we show for first time four-level community-wide open Baltic Sea. The dramatic reduction cod ( Gadus morhua ) population directly affected its main prey, zooplanktivorous sprat Sprattus...
Investigating the factors regulating fish condition is crucial in ecology and management of exploited populations. The body cod ( Gadus morhua ) Baltic Sea has dramatically decreased during past two decades, with large implications for fishery relying on this resource. Here, we statistically investigated potential drivers 40 years using newly compiled fishery-independent biological data hydrological observations. We evidenced a combination different operating before after ecological regime...
Abstract The eastern Baltic (EB) cod (Gadus morhua) stock was depleted and overexploited for decades until the mid-2000s, when fishing mortality rapidly declined biomass started to increase, as shown by assessments. These positive developments were partly assigned effective management measures, EB considered one of most successful recoveries in recent times. In contrast this optimistic view, analytical assessment failed 2014, leaving present status unclear. Deteriorated quality some basic...
The Baltic Sea ecosystem has undergone large changes during the last two decades, including a severe reduction in cod and herring biomass but, at same time, increase sprat abundance. lower trophic levels of also changed due to environmental fluctuations, variations salinity volume oxygenated water. In this apparently shifting environment, conditions have inter‐annual past 15–20 years. study, we explore how abiotic factors (i.e. temperature) biotic (biomass copepods Pseudocalanus elongatus ,...
Many marine ecosystems have undergone ‘regime shifts’, i.e. abrupt reorganizations across trophic levels. Establishing whether these constitute shifts between alternative stable states is of key importance for the prospects ecosystem recovery and management. We show how mechanisms underlying caused by predator–prey interactions can be revealed in field data, using analyses guided theory on size-structured community dynamics. This done combining data individual performance (such as growth...
The retreating ice cover of the Central Arctic Ocean (CAO) fuels speculations on future fisheries. However, very little is known about existence harvestable fish stocks in this 3.3 million–square kilometer ecosystem around North Pole. Crossing Eurasian Basin, we documented an uninterrupted 3170-kilometer-long deep scattering layer (DSL) with zooplankton and small Atlantic water at 100- to 500-meter depth. Diel vertical migration central DSL was lacking most year when daily light variation...
Individual morphology and performance are directly or indirectly under the influence of variation in resource levels. To study effects different conditions their on ontogenetic reaction norms young‐of‐the‐year (YOY) perch ( Perca fluviatilis ), we used three approaches. First, examined morphological trajectories over early ontogeny relation to lake‐specific resources a field study. Second, one lake that lacked recruitment was stocked with eggs from control whole‐lake experiment norms. Third,...
Abstract Declines in predatory fish combination with the impact of climate change and eutrophication have caused planktivores, including three-spined stickleback (Gasterosteus aculeatus), to increase dramatically parts Baltic Sea. Resulting impacts on coastal offshore foodwebs been observed, highlighting need for increased knowledge its population characteristics. In this article, we quantify abundance, biomass, size structure, spatial distribution using data from Swedish Finnish...
Catastrophic collapses of top predators have revealed trophic cascades and community structuring by top-down control. When populations fail to recover after a collapse, this may indicate alternative stable states in the system. Overfishing has caused several most compelling cases these dynamics, particular Atlantic cod stocks exemplify such lack recovery. Often, competition between prey species juvenile is hypothesized explain recovery predator populations. The then considered compete with...
This study explores how feeding performance (size-dependent attack rate) and the diet shift from zooplankton to benthic macroinvertebrates in fish species roach (Rutilus rutilus L.) is related changes functional morphology over ontogeny. The morphological included overall body shape structures of apparatus. foraging on zooplankton, as a function size, was hump-shaped with maximum ~160 mm, took place around 150 mm. Over ontogeny, gradually changed fusiform into high-bodied. second principal...
Two size‐dependent processes, metabolic requirements and foraging capacity, heavily influence the competitive ability of organisms. We studied roach ( Rutilus rutilus ) in a laboratory experiment to determine attack rate as function zooplankton sizes. The estimated rates, demands handling capacities were subsequently used interpret outcome competition between two size classes roach. Furthermore, rates implemented an optimal model predict consumption selection reveal mechanisms behind...
Interactions in size-structured populations are characterized by a mixture of predatory and competitive interactions dependent on the size individual organism. We analyzed this for species constellation consisting perch (Perca fluviatilis) roach (Rutilus rutilus) replicated whole lake experiment over 4 yr. Roach preyed upon large perch, but at same time compete with small zooplankton. Predictions regarding effects performance resource dynamics whole-lake were based results from previous pond...
Abstract Vainikka, A., Gårdmark, Bland, B., and Hjelm, J. 2009. Two- three-dimensional maturation reaction norms for the eastern Baltic cod, Gadus morhua. – ICES Journal of Marine Science, 66: 248–257. Industrial fisheries have caused decreases in size age at several stocks cod (Gadus morhua). Although earlier can be a phenotypic response to improved growth conditions, estimation probabilistic (PMRNs) remove most impacts demography from schedules has often revealed residual, potentially...
Abstract Over the past century, advances in technology and historical events such as climate change have resulted significant changes exploitation pattern, population sizes potential yield of fish stocks. These variations provide contrast data that improves our knowledge on dynamics ability to develop management strategies for long‐term sustainable exploitation. In this study, we use a standardized scientific trawl survey obtain time series (1901–2007) relative abundance, recruitment size...
Stocks of Atlantic cod (Gadus morhua) in the Baltic Sea, Kattegat and Skagerrak (N. Europe) have been strongly exploited for decades bringing them into an enduringly depleted status. Scientific stock related advice targeted mixed fisheries is provided on annual basis by International Council Exploration Sea. This forms a ministerial decisions on, e.g., total allowable catch management plans. Despite measures to reduce fishing-induced mortality cod, such as effort restrictions, increased gear...
Abstract We explored the trends in ln-transformed catch per unit effort, defined as average weight (kg) 1 h trawling, and spatial distribution of 32 demersal fish species Kattegat Skagerrak using International Bottom Trawl Survey data collected between 1981 2003. As other areas, biomass roundfish such cod, pollack, hake, ling drastically decreased during this period most likely owing to fishing pressure. However, commercially important species, e.g. haddock, whiting, some flatfish, showed a...
Abstract To supplement catch and effort regulations with the purpose to rebuild cod (Gadus morhua) stock in Kattegat, Sweden Denmark established a large (426 km2) year-round no-take zone (NTZ) surrounded by partially protected areas (PPAs) 2009. The of these spatial was prohibit fishing on spawning grounds displace fisheries bycatch from where mature aggregate Kattegat. aim this study is evaluate effects NTZ PPAs local fish assemblage, including cod. Based spatially high-resolution bottom...