How does macroalgal cover change between intertidal habitats differentially affected by rising temperatures on Svalbard?

The abundance and diversity of macroalgae in Svalbard in expected to increase due to warming temperatures and a reduction of sea ice. As macroalgae provide shelter and food to many invertebrate and fish species, changing macroalgal communities have the potential to greatly impact Svalbard’s rocky beach ecosystems. There is a rich history of macroalgal research in Kongsfjorden, but studies are more sparse in the East of Svalbard where ice scouring keeps macroalgal cover low. Surveying the macrofaunal community in rocky beaches in Edgeøya and Kongsfjorden will help provide a baseline for future research, as well as an opportunity to better understand how environmental conditions affect regional differences in macroalgal cover.

 Goals:

1. Quantify the macroalgal cover over the inundation zone in East Svalbard rocky beaches using transects (to establish a baseline for future studies), and, if possible, in West Svalbard (to use as a comparison). Hypothesis: We expect to see less macroalgal cover in East Svalbard than West Svalbard.
2. Sample macroalgal community to describe species diversity and abundance at rocky beaches in East Svalbard. If possible, we would also like to describe epiphyte abundance and diversity. Hypothesis: We expect to see different species and less diversity in macroalgae, as well as associated epiphytes, in East Svalbard than West Svalbard.
3. Evaluate presence of stressful growing conditions by measuring morphological characteristics (e.g. frond length can be a proxy for ice scour, or discoloration can be evidence for UV damage). Hypothesis: We expect to see greater evidence of stressful growing conditions in East Svalbard than West Svalbard.
4. Look for evidence of the kelp-barnacle (fucus-balanus) associations in East Svalbard, which have been mostly absent in this area due to ice scouring.

Methods: We will conduct quadrat transects over the inundation zone in rocky beaches with photographs to be analyzed for macroalgal percent cover and species composition. We would collect select macroalgal samples to be analyzed for species composition and diversity, morphological characteristics (like frond length) and, possibly, epiphytes.

Collaboration: Cruise participants can help with data collection since sample collection methods, as well as measuring macroalgal morphological characteristics, can be easily taught. This sampling can be done in conjunction with other researchers studying the intertidal area, like Sophie Brasseur, Martine van den Heuvel-Greve, and Paul Renard. Collaboration with macroalgal experts for species identification will be necessary after the cruise.