Changes in physiological processes can reveal how individuals respond to environmental stressors. It can be difficult to link physiological responses to changes in vital rates such as growth, reproduction and survival. Here, bioenergetics modelling can aid in understanding non-intuitive outcomes from stressor combinations.
View Article and Find Full Text PDFEcosystem-based management requires understanding of food webs. Consequently, assessment of food web status is mandatory according to the European Union's Marine Strategy Framework Directive (MSFD) for EU Member States. However, how to best monitor and assess food webs in practise has proven a challenging question.
View Article and Find Full Text PDFInvestigating the factors regulating fish condition is crucial in ecology and the management of exploited fish populations. The body condition of cod () in the Baltic Sea has dramatically decreased during the past two decades, with large implications for the fishery relying on this resource. Here, we statistically investigated the potential drivers of the Baltic cod condition during the past 40 years using newly compiled fishery-independent biological data and hydrological observations.
View Article and Find Full Text PDFAccumulating research argues that migrants influence the functioning and productivity of local habitats and ecosystems along migration routes and potentially drive cross-system energy fluxes of considerable magnitude, yet empirical documentation of local ecological effects and descriptions of the underlying mechanisms are surprisingly rare. In this study, we discovered migrant-resident interactions and substantial cross-system lipid transportation in the transition zone between the Baltic Sea and the North Sea where a resident cod population (predators) was found to interact with a herring population (prey) on a seasonal basis. We traced the lipids, using fatty acid trophic markers (FATM), from the herring feeding grounds in the North Sea to the cod livers in the Western Baltic Sea.
View Article and Find Full Text PDFThe degree to which metapopulation processes influence fish stock dynamics is a largely unresolved issue in marine science and management, especially for highly mobile species such as Atlantic cod (Gadus morhua) and herring (Clupea harengus). The Baltic Sea comprises a heterogeneous oceanographic environment that structures the spatial and temporal distribution of the dominant species cod, herring, and sprat (Sprattus sprattus). Despite local differences, the stocks are traditionally managed as homogeneous units.
View Article and Find Full Text PDFNatural resource management requires approaches to understand and handle sources of uncertainty in future responses of complex systems to human activities. Here we present one such approach, the "biological ensemble modeling approach," using the Eastern Baltic cod (Gadus morhua callarias) as an example. The core of the approach is to expose an ensemble of models with different ecological assumptions to climate forcing, using multiple realizations of each climate scenario.
View Article and Find Full Text PDFThe application of data storage tags bears the potential for a quantum leap in the research on fish migrations, because not only first-capture and recapture positions are known, but at least theoretically, the migration path during the period at large can be reconstructed. Position, however, cannot be measured directly but has to be estimated using the available data on light, temperature, pressure and salinity. The reconstructed locations based on advanced estimation techniques have been termed geolocations.
View Article and Find Full Text PDFSome Atlantic cod in the Bornholm Basin undertake vertical foraging migrations into severely hypoxic bottom water. Hypoxic conditions can reduce the postprandial increase in gastrointestinal blood flow (GBF). This could subsequently postpone or reduce the postprandial increase in oxygen consumption (MO(2)), i.
View Article and Find Full Text PDFUnderstanding how climate change, exploitation and eutrophication will affect populations and ecosystems of the Baltic Sea can be facilitated with models which realistically combine these forcings into common frameworks. Here, we evaluate sensitivity of fish recruitment and population dynamics to past and future environmental forcings provided by three ocean-biogeochemical models of the Baltic Sea. Modeled temperature explained nearly as much variability in reproductive success of sprat (Sprattus sprattus; Clupeidae) as measured temperatures during 1973-2005, and both the spawner biomass and the temperature have influenced recruitment for at least 50 years.
View Article and Find Full Text PDFThe current study investigated how the gastric evacuation rate (GER) was affected after surgically introducing dummies of a blood flow biotelemetry system into the abdominal cavity of Atlantic cod, Gadus morhua. Gastric evacuation experiments were performed two and 10 days postsurgery on surgically implanted and control G. morhua force-fed sandeel, Ammodytes tobianus.
View Article and Find Full Text PDFIndividual behaviour of Atlantic cod Gadus morhua in the presence of hypoxic water was measured in situ in the vertically stratified Bornholm Basin of the Baltic Sea. Considering all recaptured individuals, the use of hypoxic habitat was comparable to data derived by traditional survey data, but some G. morhua had migrated towards the centre of the c.
View Article and Find Full Text PDFClimate and human influences on marine ecosystems are largely manifested by changes in predator-prey interactions. It follows that ecosystem-based management of the world's oceans requires a better understanding of food web relationships. An international workshop on predator-prey interactions in marine ecosystems was held at the Oregon State University, Corvallis, OR, USA on 16-18 March 2010.
View Article and Find Full Text PDFThe use of immunoisolation devices may allow transplantation without need for immunosuppression and could widen the indications for cell transplantation. In this study, we evaluated the survival of encapsulated parathyroid tissue in nonimmunosuppressed humans. Autologous parathyroid implants: Seven patients undergoing parathyroidectomy had devices containing small pieces of their own parathyroid tissue implanted SC.
View Article and Find Full Text PDFIn recent years, a number of cancer therapies have been developed based on the augmentation of the immune response in the tumor-bearing individual. We have developed a novel approach to such therapies, using a membrane-bound immunoisolation device containing tumor cells to enhance the immune response of mice to the adenocarcinoma, MCA-38. Use of an immunoisolation device for cancer immunotherapy has several advantages.
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