Seagrasses

This page is dedicated to Dr. Susan Williams, whose passions for seagrasses, physiology, ecosystem ecology, and conservation continue to inspire generations of scientists. She was a guiding light for me from the day I started my PhD at UC Davis and Bodega Marine Lab.

 

Eelgrass – Zostera marina

My past and current research explores questions about biogeography and food web interactions in eelgrass (Zostera marina) communities. Eelgrass is the most widespread seagrass in the temperate Northern Hemisphere, and like all seagrasses it is a vascular plant that lives and reproduces entirely underwater. Seagrass systems are highly productive and support complex food webs by creating dynamic three dimensional structure that acts as habitat for many other organisms. Seagrasses are also cool because they arguably represent the most extreme evolutionary transition of plants from land back to the sea (other examples include mangroves and salt marsh grasses).

 

 

Having fun in the field. Akkeshi-Ko, Hokkaido, Japan

 

Surfgrass (Phyllospadix spp.) on Calvert Island

Hakai_20170726_Phyllospadix

Surfgrass habitat on Calvert Island, 5th Beach. Emmett Duffy (foreground) and Gustav Paulay (background) pictured.

Antarctonemertes_phyllospadicola_B0402_d01268.JPG

Antarctonemertes phyllospadicola, a species of nemertean (ribbon worm) only known from the inflorescences of surfgrasses (Phyllospadix spp.), which the species name reflects. Photo credit: Gustav Paulay.

In this habitat we find lots of the organisms typically found on the surrounding rocky shore, sometimes in different relative abundance, but we also find a few unique taxa. Check their flowers for a deeper understanding of seagrass biology and ecology!

The beauty of seagrass leaves

Seagrasses provide hard, albeit temporary, surfaces for all sorts of ocean life to attach to and grow, in addition to all the swimming and crawling critters that move about in seagrass meadows. These attached organisms include everything from mussels to seaweeds, and many of these are organisms would not be found in surrounding unvegetated sediments. For me, the following photo captures the beauty of the intimate associations that seagrasses can have with sessile life stages. In some cases, species are only found in association with seagrasses, like the red algae in the photo. In other cases, seagrasses may offer a “stepping-stone” habitat for species that can be found in multiple habitats (assuming they can reproduce during the lifespan of the leaf) like the bryozoan.

species of the day_seagrass_day 3-9503_bryozoan on seagrass_gustav paulay

Zostera marina leaf with attached red algae and a bryozoan. The algae are all individuals of Smithora naiadum which grows almost exclusively on seagrass, and most typically on the edges of leaves. The bryozoan is Membranipora sp. (I’ll update the species designation soon), which can also be found growing on the large kelps typical of British Columbia’s outer coast. If you zoom in a bit you can see the individual zooids emerging from the bryozoan. Photo credit: Gustav Paulay.

This photo was a “Species of the Day” winner during the 2018 Seagrass BioBlitz on Calvert Island, British Columbia, Canada.

 

 

Advertisements