Periodic Reporting for period 2 - EdgeStress (On the edge: The influence of multiple stressors on thermal tolerance inpoleward edge populations in a climate change era)
Periodo di rendicontazione: 2022-02-01 al 2023-01-31
Specifically, the overall objectives of the project are:
O1. Investigate if high summer temperatures lead to lethal heat stress in populations at their poleward limits.
O2. Investigate if the combination of several interacting stressors in a natural environment decreases the thermal tolerance of habitat-forming species, hereby changing ecosystem structure.
O3. Investigate if freshening and increased warming allow the expanding blue mussel Mytilus edulis to outcompete a native sister species in the Arctic
My results show a remarkable resilience in blue mussels to global warming. Physiological measurements have been done on all biological levels from genes, protein expression, to whole-animal responses. Furthermore, have I been exploring the effects of multiple stressors on sensitivity to warming. For instance have I looked at how parasites affects thermal tolerance, and the preliminary results clearly show that parasite infections interfere with thermal tolerance of the host organisms. I have also investigated the interaction of ocean acidification and thermal stress on several blue mussel species
In West Greenland, two species on blue mussels are present - the southern Mytilus edulis and the northern Mytilsu trossulus. In North Greenland, there is a hybrid zone in which the two species overlap, and to increase knowledge on how the two series response to climate change, laboratory experiments have been conducted on thermal tolerance. The Northern species seems to struggle compared to the southern species under warmer conditions, indicating a potential shift in species dominance and distribution.
When conducting experiments on Mytilus mussels, a key challenge is to identify the species. Mytilus are cryptic species making it impossible to distinquish them by visual inspection. The classic approach to this issue has been to confirm the species ID after the experiment, using of DNA extraction. However, for laboratory experiment, knowing the ID before the experiment would optimise the experimental design and reduce the number of animals needed. I have worked on a designed a code in the R program that via machine learning use Elliptic Fourier analyses of shells outliners to distinguish individual Mytilus species. For now, the results indicate that this method can distinguish the species with a 73% success rate, but I am continuously finetuning the method, and the hope is to reach an 85-90% rate.
Results from EdgeStress includes:
- Public presentations at science events
- Presentations at scientific conferences
- Supervision and talent development of students at all level
- 8 published peer-reviewed papers, with multiple more in preparation
- outreach at social media
I have described how intertidal communities are controlled by local- rather than large-scale environmental drivers, and the Greenlands intertidal ecosystems seems resilient to climate change. This indicates that no major changes in community structure is expected in a near future. These results on the resilience of species and ecosystems at high latitude are novel, and the papers produced so far has moved beyond the current state of the art. Therefore they are receiving significant attention and is already being widely cited. The intraspecific dynamics among M. edulis and M. trossulus in North Greenland has never been studied before, and these data will pave for way for our understanding of how climate change affects closely related species.
The results obtained in EdgeStress are important for scientists and societies as improved knowledge and perspectives on the effects of multiple climate stressors on individuals to ecosystems is crucial for understanding the effects on species survival, biodiversity changes and ecosystem stability. New information on multiple climate stressors on coastal systems is important worldwide. Coastal systems provide nursery grounds for commercially important fish and shellfish species, and ecosystem services such as, carbon sequestration and shoreline protection with an estimated value in the trillons of euro. The results from this project will therefore have implications for global and local communities and economies as it will be used to inform stakeholders, organisations, researchers, and the public about the future effects of climate change on one of the most sensitive ecosystems on earth.