New study shows that appendicularian zooplankton thrive under warmer and more acidic ocean conditions and consequently alter carbon cycling

Oikopleura

Oikopleura dioica, animal and house. Source: Genoscope.cns.fr

This study provides to our knowledge the first experiment that contains multiple trophic levels and climate stressors (warming and ocean acidification) to investigate how gelatinous zooplankton (appendicularians) affect carbon cycling of marine food webs. Our novel results reveal that appendicularians thrive under climate warming and benefit from low pH levels, which alters the direction of carbon flow. An increase in the dominance of gelatinous zooplankton removes particles from the water column that might otherwise nourish copepods and fish by increasing carbon transport to depth. This helps to remove CO2 from the atmosphere, but may also have significant fisheries implications.

Winder, M., Bouquet, J.-M., Rafael Bermúdez, J., Berger, S. A., Hansen, T., Brandes, J., Sazhin, A. F., Nejstgaard, J. C., Båmstedt, U., Jakobsen, H. H., Dutz, J., Frischer, M. E., Troedsson, C. and Thompson, E. M. (2017) Increased appendicularian zooplankton alter carbon cycling under warmer more acidified ocean conditions. Limnol. Oceanogr. doi:10.1002/lno.10516

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Mesocosm setup at the Marine Biology Station Espegrend,Bergen, Norway

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Presentations at ASLO 2017, Honolulu Hawaii

Konrad Karlsson and Monika Winder attended the ASLO conference and presented their research.

Konrad presented results from this project on the adaptation potential of Baltic Sea copepod species to climate change. The study shows that warm adapted populations could be better prepared for future elevated temperatures, but food quality and lower salinity could hamper their relative benefits.

Monika presented research on phytoplankton diversity across the land-sea interface and it’s importance for secondary production. This study combines long-term phytoplankton observations and food quality of phytoplankton taxa, showing that the type of food quality produced in estuarine-coastal ecosystems is likely another factor contributing to their high productivity.

Photo: left: Konrad Karlsson, right: Konrad Karlsson, Andrea Caputo, Monika Winder

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New article on ‘The importance of benthic–pelagic coupling for marine ecosystem functioning in a changing world’ in Global Change Biology

This synthesis article is based on a collaborative effort highlighting the importance of benthic-pelagic coupling under changing environmental conditions using the Baltic Sea as a case study.

We illustrate the varied nature of physical and biological benthicpelagic coupling processes and their potential sensitivity to three anthropogenic pressures climate change,nutrient loading, and fishing and summarize current knowledge on the exchange of inorganic nutrients and organic material between habitats. We emphasize how improved empirical and experimental understanding of benthicpelagic coupling processes and their variability are necessary to inform models that can quantify the feedbacks among processes and ecosystem responses to a changing world, and give recommendation for future research.

Griffiths, J. R., Kadin, M., Nascimento, F. J. A., Tamelander, T., Törnroos, A., Bonaglia, S., Bonsdorff, E., Brüchert, V., Gårdmark, A., Järnström, M., Kotta, J., Lindegren, M., Nordström, M. C., Norkko, A., Olsson, J., Weigel, B., Žydelis, R., Blenckner, T., Niiranen, S. and Winder, M. (2017) The importance of benthic–pelagic coupling for marine ecosystem functioning in a changing world. Glob Change Biol. doi:10.1111/gcb.13642

 

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NEW: PhD position in Marine Ecology

We have an open PhD position in our group with focus on benthic-pelagic coupling.

Closing date: 20 September 2016

This position will be associated with the FORMAS project ‘Responses of pelagic-benthic coupling to environmental change in the Baltic Sea’. The goal of this project is to disentangle how shifts in pelagic and benthic species composition can affect the flux of organic matter and nutritional quality of settling material. The student will study relationships between planktonic and benthic dynamics using monitoring data, reciprocal fluxes of particulate organic matter and potentially experiments using experiments, and use this information to project functional species traits under future climate and nutrient scenarios. The project involves statistical analysis, experiments and modelling to assess effects of human pressure on benthic-pelagic coupling processes.

Please visit the University website for more information at:

http://www.su.se/english/about/vacancies/vacancies-new-list

 

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Alfred Burian defended his PhD thesis well

… in an interesting discussion with the opponent Prof. Kevin Flynn and the evaluation committee.

Alfred defense

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Jens Nielsen successfully defended his PhD thesis

Jens defended his thesis entitled ‘Species interactions and energy transfer in aquatic food webs’ with the opponent Prof. Michael Brett and the evaluation committee Jan 26th. Congratulations!

Jens defense Jan 26 2016

Jens defense 2 Jan 26 2016

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New publication on ‘Amino acid stable nitrogen isotope ratios for estimating trophic position’

A continuous challenge in ecology is to estimate and predict trophic structures in complex food webs. Knowledge on trophic interactions is crucial for our understanding of energy pathways, predations and feeding patterns in ecosystems.

Analysis of amino acid  stable nitrogen isotope ratios is a relatively new and powerful technique for estimating trophic position of organisms.  One of the primary advantages of this method, compared to common bulk stable isotopes, is that the stable nitrogen isotope ratios of some amino acids measured in a consumer’s tissue are very similar to the primary producers at the base of the food web, while the stable nitrogen isotope ratios of other amino acids increase with each trophic position.

In this paper we present the first meta-analysis of stable nitrogen isotope ratios of amino acids from measurements of 359 marine species covering four trophic levels for predicting species trophic position. This study clarifies the advantages and limitations of using stable nitrogen isotope ratios of amino acids as a tool in trophic ecology and provides a guideline for future application of this technique in food web studies.

The full study can be found here:

Nielsen, J. M., B. N. Popp, and M. Winder. 2015. Meta‐analysis of amino acid stable nitrogen isotope ratios for estimating trophic position in marine organisms. Oecologia: DOI:10.1007/s00442-015-3305-7.

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