A new paper published in the Proceedings of The Royal Society B

Community responses to seawater warming are conserved across diverse biological groupings and taxonomic resolutions

Scientific Abstract: Temperature variability is a major driver of ecological pattern, with recent changes in average and extreme temperatures having significant impacts on populations, communities and ecosystems. In the marine realm, very few experiments have manipulated temperature in situ, and current understanding of temperature effects on community dynamics is limited. We developed new technology for precise seawater temperature control to examine warming effects on communities of bacteria, microbial eukaryotes (protists) and metazoans. Despite highly contrasting phylogenies, size spectra and diversity levels, the 3 community types responded similarly to seawater warming treatments of +3 and +5°C, highlighting the critical and overarching importance of temperature in structuring communities. Temperature effects were detectable at coarse taxonomic resolutions and many taxa responded positively to warming, leading to increased abundances at the community-level. Novel field-based experimental approaches are essential to improve mechanistic understanding of how ocean warming will alter the structure and functioning of diverse marine communities.      

Read the paper here

Find out more about the work of the Smale group: Benthic Ecosystems and Environmental Change, and the Cunliffe group: Marine microbial biogeochemistry

Press release: Using a novel system to conduct warming experiments in real marine habitats, scientists in Plymouth have demonstrated that seawater warming of the magnitude already experienced during ‘marine heatwaves’ causes major changes in underwater communities of microbes and animals.

Understanding the responses of populations and communities to climate change is a major focus of contemporary ecology. Most studies on the effects of ocean warming are based on observations in the natural world or on experiments conducted in highly controlled laboratory conditions. A research team, led by scientists at the Marine Biological Association (MBA) in Plymouth, designed and developed a system that allows for precise control of seawater temperature in situ, in order to experimentally examine the effects of warming on a diverse range of marine organisms in their natural setting.

Heated panels were suspended in coastal water and were colonized by a range of marine life. The scientists looked in particular at marine microbes (bacteria and protists), and at larger attached invertebrates such as sea squirts and bryozoans. The ‘heated settlement panel system’ successfully controlled seawater temperature in a marine habitat for 40 days, and the responses of marine microbes and invertebrates was examined. Seawater warming of 3°C and 5°C caused major changes in the diversity and abundance of the marine organisms studied, showing that complex communities are potentially highly sensitive to increased temperature. 

Dr Dan Smale, Research Fellow at the MBA said “the surprising finding of the study was how very different groups of organisms, ranging from bacteria to sea squirts, responded similarly to the warming treatments. This shows how important temperature is in driving the structure of communities and suggests that temperatures experienced during extreme warming events alter biological diversity in coastal habitats.”  

Aug 23, 2017 By guba