MEPS 396:13-25 (2009)  -  DOI:

Effects of warming and shifts of pelagic food web structure on benthic productivity in a coastal marine system

A.-K. Eriksson Wiklund1,*, K. Dahlgren2,3, B. Sundelin1, A. Andersson2,3

1Department of Applied Environmental Science, ITM, Stockholm University, 106 91 Stockholm, Sweden
2Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden
3Umeå Marine Sciences Centre, 910 20 Hörnefors, Sweden

ABSTRACT: It has been predicted that climate change will lead to increased temperature and precipitation in northern latitudes, which in turn may lead to brownification of coastal sea areas. This will increase the importance of the heterotrophic microbial food web in areas like the northern Baltic Sea. Such a structural change in the pelagic food web would hamper benthic productivity, since microheterotrophs have lower settling rates than phytoplankton. We tested how variation in temperature and alteration of the pelagic food web structure affected the productivity of a key benthic species, the amphipod Monoporeia affinis, and the pelagic-benthic food web efficiency (FWE). Using water from the northern Baltic Sea, a mesocosm experiment was performed in which the temperature was altered by 5°C. The structure of the pelagic food web changed from one based on algae to one based on bacteria. Amphipod productivity was 3 times higher and FWE was 25 times higher in the algae than in the bacteria-based food web, showing that an altered pelagic food web will have severe effects on benthic productivity. Temperature variation, on the other hand, did not cause any changes in either growth of M. affinis or FWE. Our data indicate that indirect effects of climate change, leading to structural changes in the pelagic food web, will have much more severe effects on benthic productivity than the direct effect of increased temperature.

KEY WORDS: Climate change · Altered pelagic food web structure · Decreased benthic productivity · Pelagic-benthic coupling · Monoporeia affinis

Full text in pdf format 
Cite this article as: Eriksson Wiklund AK, Dahlgren K, Sundelin B, Andersson A (2009) Effects of warming and shifts of pelagic food web structure on benthic productivity in a coastal marine system. Mar Ecol Prog Ser 396:13-25.

Export citation
Mail this link - Contents Mailing Lists - RSS
- -