Trophic interactions between invertebrates and seaweeds in a changing world

Intertidal habitats provide an excellent system to investigate the impacts of climate change on species and their interactions. In this study, I investigated the effects of temperature on the physiological responses (growth, photosynthesis) of the two dominant brown seaweeds Ascophyllum nodosum and Fucus vesiculosus (North Sea). Thallus pieces of the algae were maintained at 15°C, 20°C and a third temperature treatment with an incubation period at 15°C followed by a simulated sudden heat wave of 20°C. For both species, biomass growth did not vary between 15°C and 20°C but was enhanced by a heat wave. Effective quantum yield of photosystem II declined at 20°C in A. nodosum but not in F. vesiculosus. Effects on herbivore-plant interactions were examined in choice feeding assays with the isopod Idotea emarginata and the amphipod Gammarus locusta as consumers. I. emarginata preferentially fed on F. vesiculosus of the 15°C treatment. For A. nodosum, no food preference was established. C:N ratio and tissue toughness, which are common determinants of algal tissue palatability, did not vary with temperature. This study provides evidence that temperature can affect trophic interactions in coastal marine ecosystem.

Promotor(s) & Supervisor: Lars Gutow

ISCED Categories

The highlighted icons, represent the fields of education (in compliance with ISCED Classification) engaged during this course/programme.

0511 - Biology", "0521 - Ecology