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- Baden, Susanne Pihl, 1952, et al.
(author)
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Declining populations of mytilus spp. In north atlantic coastal waters-A swedish perspective
- 2021
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In: Journal of Shellfish Research. - : National Shellfisheries Association. - 0730-8000. ; 40:2, s. 269-96
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Research review (peer-reviewed)abstract
- During the past 2–3 decades, the spatiotemporal distribution of Mytilus spp. in coastal waters of the North Atlantic has changed considerably. In general, reduced abundances of Mytilus are observed, but there is a great degree of local variation, and some areas are also experiencing recovery after declining events. In this review, hypotheses regarding the causes behind the changes are presented with focus on a Swedish perspective. Excessive exploitation of mussel banks combined with direct and indirect effects of climate change are most probably the main drivers of Mytilus spp. decline in large parts of the North Atlantic. On the Swedish west coast, the wild stocks have disappeared despite no overfishing. Paradoxically, they thrive in mussel farms and on other non-demersal substrates. Changes in predation from, for example, increased wintering populations of eiders (Somateria molissima; 10-fold) and green crabs (Carcinus maenas; 3-fold), alteration of natural substrates elicited by eutrophica- tion, and exacerbated by climate change (increased sea surface temperature, precipitation and extreme weather events) are most likely the key factors for the decline. Most anthropogenic stressors may not be decisive by themselves, but combined effects can potentially be fatal to Mytilus spp. adults and larvae.
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| 2. |
- Collin, Betty, 1976-, et al.
(author)
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Experimental evaluation of survival of Vibrio parahaemolyticus in fertilized cold‐water sediment
- 2020
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In: Journal of Applied Microbiology. - 1364-5072 .- 1365-2672. ; 129:1, s. 75-84
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Journal article (peer-reviewed)abstract
- Aims: This experimental study focuses on survival and consistence of Vibrio parahaemolyticus in cold‐water sediments and how increasing temperature and nutritional availability can affect growth. Methods and Results: A pathogenic strain of V. parahaemolyticus was inoculated in seawater microcosms containing bottom sediment. Gradually, during 14 days, the temperature was upregulated from 8 to 21°C. Culturable V. parahaemolyticus was only found in the sediment but declined over time and did not recover even after another 2 days at 37°C. Numbers of culturable bacteria matched the amount found by q‐PCR indicating that they did not enter a dormant state, contrary to those in the water layer. After adding decaying phytoplankton as fertilizer to the microcosms of 8 and 21°C for 7 and 14 days, the culturability of the bacteria increased significantly in the sediments at both temperatures and durations of exposure. Conclusion: The study showed that V. parahaemolyticus can stay viable in cold‐water sediment and growth was stimulated by fertilizers rather than by temperature. Significance and Impact of the Study: Vibrio parahaemolyticus is a common cause of seafood‐borne gastroenteritis and is today recognized in connection to increasing ocean temperature. The results indicate that this pathogen should be considered a risk in well‐fertilized environments, such as aquacultures, even during cold periods.
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