WP2 - EFFECTS OF KELP DETRITUS ON SHALLOW-WATER COMMUNITIES

Lead: Stein Fredriksen, UiO (Norway)

Objective 2.1. Is kelp detritus important for microbial diversity in sandy beaches? Kelp detritus often accumulates in shallow water areas like seagrass beds and sandy beaches (Krumhansl & Scheibling 2012), which constitute a wealth of life in the form of photosynthetic and heterotrophic microorganisms (Eikrem & Throndsen 2010). Here, we will investigate the ecological role kelp detritus in shaping the structure (abundance and biodiversity) of microbial communities to assess the importance of sandy beaches as retention areas for kelp-derived detritus. The results will be linked to the export data quantified in WP1.

Task 2.1. To determine and quantify the effect of kelp detritus on the abundance and diversity of microorganisms on sandy beaches.

Objective 2.2. Does kelp detritus affect the growth of key filter-feeder species? On littoral rocky shores, filter feeders may benefit from kelp detritus (Renaud et al., 2015). The blue mussel (Mytilus edulis) and common barnacle (Semibalanus balanoides) are common species along the entire Norwegian shore, in particular in exposed areas dominated by the kelp L. hyperborea. Here, we will address the potential for increased growth and survival of filter feeders fuelled by kelp detritus. Such benefit, if observed, could have important implications in the trophic chain, including top predators such as large crustaceans, birds and humans, particularly under the scenario of an expected recovery of kelp forests in the Arctic. The results will be analysed in the context of the data obtained by WP1 and will provide valuable data to WP4 (stable isotopes and biomass).

Task 2.2. Determine the effect of kelp detritus on growth of blue mussels and barnacles.

Sist oppdatert 09.03.2016