| 11. |
- Svedäng, Henrik, et al.
(author)
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Compensatory Feeding in Eastern Baltic Cod (Gadus morhua) : Recent Shifts in Otolith Growth and Nitrogen Content Suggest Unprecedented Metabolic Changes
- 2020
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In: Frontiers in Marine Science. - : FRONTIERS MEDIA SA. - 2296-7745. ; 7
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Journal article (peer-reviewed)abstract
- The productivity of the Eastern Baltic cod (EBC) has been severely reduced over the last 25 years, for reasons that remain unclear. The size distribution of EBC has become increasingly truncated, condition and health status have deteriorated, and sexual maturation has started to occur at increasingly smaller sizes. Despite an increasing trend in recruitment during this period, reduced growth or increased mortality rates after the recruitment phase have resulted in decreasing landing levels and low profitability in the cod fishery, whereas the scientific community has difficulties in disentangling the causes of the decline of EBC. We studied changes in metabolic status in EBC between the capture years of 1995 and 2015, by investigating two aspects of fish metabolism that can be extracted retrospectively from otolith (earstone) morphometry and nitrogen content. Changes in relative otolith size to fish size are related to the metabolic history of the individual fish, and the otolith nitrogen content reveals the level of protein synthesis and feeding rate. Because otoliths accrue continuously on their surface and are biological stable (inert), the chemical content of the otolith trajectory reflects the timeline of the fish. We measured the N/Ca ratio as a proxy for protein content in EBC otolith along distal radius traverses from the core to the edge of the otolith by using secondary ion mass spectrometry (SIMS). Here we show that the otoliths have become smaller at a given fish size, and the ratio of N/Ca has increased over the studied period. These proxies reveal significant metabolic changes during the same period as the condition, and stock productivity has declined. We discuss potential mechanisms behind the metabolic changes, including elevated temperature and compensatory feeding due to nutrient deficiencies. Such changes in food quality may, in turn, relate to still unrecognized but on-going ecosystem shifts, where climate change could be the ultimate driver.
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| 12. |
- Svedäng, Henrik, et al.
(author)
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Re-thinking the “ecological envelope” of Eastern Baltic cod (Gadus morhua) : conditions for productivity, reproduction, and feeding over time
- 2022
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In: ICES Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 79:3, s. 689-708
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Journal article (peer-reviewed)abstract
- Hypoxia is presently seen as the principal driver behind the decline of the former dominating Eastern Baltic cod stock (EBC; Gadus morhua). It has been proposed that both worsening conditions for reproduction and lower individual growth, condition, and survival are linked to hypoxia. Here, we elucidate the ecological envelope of EBC in terms of salinity stratification, oxygen content, and benthic animal biomasses, and how it has affected EBC productivity over time. The spawning conditions started deteriorating in the Gotland Deep in the 1950s due to oxygen depletion. In contrast, in the Bornholm Basin, hydrographic conditions have remained unchanged over the last 60 years. Indeed, the current extent of both well-oxygenated areas and the frequency of hypoxia events do not differ substantially from periods with high EBC productivity in the 1970s–1980s. Furthermore, oxygenated and therefore potentially suitable feeding areas are abundant in all parts of the Baltic Sea, and our novel analysis provides no evidence of a reduction in benthic food sources for EBC over the last 30 years. We find that while reproduction failure is intricately linked to hydrographic dynamics, a relationship between the spread of hypoxia and the decline in EBC productivity during the last decades cannot be substantiated.
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| 13. |
- Weinberger, Florian, et al.
(author)
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Seaweed resources of the Baltic Sea, Kattegat and German and Danish North Sea coasts
- 2020
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In: Botanica Marina. - : Walter de Gruyter GmbH. - 0006-8055 .- 1437-4323. ; 63:1, s. 61-72
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Research review (peer-reviewed)abstract
- Due to low salinity and lack of hard substrata, the Baltic Sea and Kattegat area and German and Danish North Sea coasts are characterized by a relatively low diversity of seaweeds. At the same time the areas are severely eutrophicated, which has caused extensive shifts in macroalgal communities toward opportunistic species. Unattached seaweed communities dominated by Furcellaria lumbricalis, which have been a resource for hydrocolloid production since the 1940s, have been severely reduced due to eutrophication and unsustainable harvesting and are nowadays only exploited commercially in Estonia. On the other hand, the biomass of opportunistic seaweeds of various red, green and brown algal genera has increased. They cause ecological problems, are a nuisance on many tourist beaches and constitute at the same time a potential bioresource that is so far only exploited to a limited extent for production of energy and fertilizer. Commercial seaweed cultivation is largely focused on Saccharina latissima and still very limited, but is currently being expanded as a compensation measure for sea-based fish aquaculture. Also land-based seaweed cultivation is primarily employed for recycling of nutrients in tank animal aquaculture, but in most cases so far only on an experimental scale.
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| 14. |
- Wikström, Sofia A., et al.
(author)
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Ekosystemansatsen – praktiska erfarenheter från svensk havs- och vattenförvaltning
- 2020
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Reports (other academic/artistic)abstract
- Rapporten sammanfattar resultaten från forskningsprojektet ”Ekosystemansatsen – praktiska erfarenheter och nästa steg”. Projektet har undersökt erfarenheter av det praktiska införandet av ekosystembaserad havs-, vattenoch fiskförvaltning i Sverige, utifrån publicerad litteratur och intervjuer med nyckelpersoner i Sverige, Tyskland, Norge och USA. Sammanställningen visar att Sverige tagit flera steg mot en mer ekosystembaserad förvaltning, men pekar också på svårigheter. En viktig erfarenhet är att ekosystembaserad förvaltning ställer höga krav på samverkan och kommunikation mellan aktörer och att en stabil och tillräcklig finansiering är en viktig förutsättning. Det finns behov av en tydligare styrning och uppföljning från centrala myndigheter, en mer långsiktig finansiering och tydligare processer för kunskapsutbyte mellan olika aktörer. Det finns även ett behov av att kartlägga bristande överensstämmelse mellan olika sektorslagstiftningar och olika samhällsmål och att diskutera målkonflikter på nationell nivå. Implementeringen av åtgärdsprogram och planer behöver stärkas genom att berörda aktörer ges ett tydligt ansvar för att förvaltningsmål uppfylls och för en ambitiös uppföljning av framsteg mot målen. Det vore också önskvärt att vidareutveckla indikatorer för ekosystembaserad förvaltning som kvantitativt mäter framstegen mot dess principer.
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| 15. |
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| 16. |
- Åberg, Anna-Maja, et al.
(author)
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High monocyte count and expression of s100a9 and s100a12 in peripheral blood mononuclear cells are associated with poor outcome in patients with metastatic prostate cancer
- 2021
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In: Cancers. - : MDPI. - 2072-6694. ; 13:10
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Journal article (peer-reviewed)abstract
- Increasing evidence indicates calcium-binding S100 protein involvement in inflammation and tumor progression. In this prospective study, we evaluated the mRNA levels of two members of this family, S100A9 and S100A12, in peripheral blood mononuclear cells (PBMCs) in a cohort of 121 prostate cancer patients using RT-PCR. Furthermore, monocyte count was determined by flow cytometry. By stratifying patients into different risk groups, according to TNM stage, Gleason score and PSA concentration at diagnosis, expression of S100A9 and S100A12 was found to be significantly higher in patients with metastases compared to patients without clinically detectable metastases. In line with this, we observed that the protein levels of S100A9 and S100A12 in plasma were higher in patients with advanced disease. Importantly, in patients with metastases at diagnosis, high monocyte count and high levels of S100A9 and S100A12 were significantly associated with short progression free survival (PFS) after androgen deprivation therapy (ADT). High monocyte count and S100A9 levels were also associated with short cancer-specific survival, with monocyte count providing independent prognostic information. These findings indicate that circulating levels of monocytes, as well as S100A9 and S100A12, could be biomarkers for metastatic prostate cancer associated with particularly poor prognosis.
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