Growth and morphology of Saccharina latissima in response to varying exposure to hydrodynamic conditions: A ripple effect

Abstract

Kelps (Order Laminariales) exhibit high morphological plasticity across the range of habitats in which they are found. Saccharina latissima, or sugar kelp, found commonly in the Pacific Northwest’s rocky intertidal and subtidal, exhibits this variation. Prior studies have linked Saccharina latissima’s morphological variability to the surrounding physical environment. In order to better understand this relationship, we gathered morphological, growth, and environmental data from three different field sites on San Juan Island, Washington at Friday Harbor Labs, Cattle Point, and Deadman Bay. We found significant differences in variation between our sites in growth rate (p < 0.01), bullation pattern and prevalence (p < 0.05), and wave exposure (p < 0.01). However, we were unable to conclusively link the kelp’s growth and morphology to wave exposure. Our results appear to conflict with the outcomes of previous studies. Despite its drawbacks, this experiment still has implications for S. latissima’s climate resilience and further understanding of coastal ecology. As climate change is expected to increase the frequency and severity of extreme weather events, documenting S. latissima’s morphology and reaction to increased wave action and disturbance is critical to detecting and understanding changing patterns.