The scent of home

We decided to divide and conquere the west coast of North America in search of more populations of Gracilaria vermiculophylla, as if we didn’t already have enough by Midsummer’s Eve!
I headed to my home state – California. I was able to sneak in 24 hours without the tang of seaweed and mud hanging about my person before three sites in less than 40 hours and a flight to the European leg. Thanks to my field assistants Brent Hughes and Nicole Kollars for braving the mud and taking notes. And, also to my mom who spent time in the car headed north on the 101 so we could see more of each other …

Erik headed to his home state of Oregon and then northward to sample in Washington and British Columbia.


In Vancouver, he caught up with Patrick Martone at the University of British Columbia.
Dr. Martone and his post-doc Katy Hind have been busy resolving the taxonomy of coralline algae.
Coralline (i.e., coral-like) red algae have calcareous deposits contained in their cell walls. They play an important role in the ecology of coral reefs and I remember my phycology professor calling them “coral fly paper.” But, it turns out they are as important on rocky shores.
Kelp zoospores may be aided by corallines living on the rocky intertidal and subtidal. In other words, they may use corallines as a “scent of home.”

Kelp forests are integral to the ecology and economy of near-shore ecosystems. Recent work, particularly molecular, has shed light on kelp biodiversity (see this post here), but if corallines are lost, what will happen to the kelps?
Corallines may not be able to deposit as much calcium carbonate as the ocean become more acidic. This will put kelp forests at risk if zoospores can’t find a home. The disappearance of corallines may also impact the invertebrates that may cue in on their homey vibes.
Corallines are also what’s left behind when sea otters disappear from kelp forest ecosystems and invertebrates (particularly sea urchins) gobble up all the kelps.

Future research directions were recently highlighted by an article on UBC’s Dept. of Botany’s website:

The species diversity of coralline algae that persist and flourish under such intense herbivory is completely unknown, but may be higher than previously thought. 

In order to understand more about corallines, we also need to understand more about their diversity. This is generally true about algae in which genetic studies tend to lag behind other taxa.
Drs. Hind and Martone, along with co-authors including Paul Gabrielson and Kathy Ann Miller, have resolved some of the taxonomy of corallines in a new paper out in the American Journal of Botany.
Traditional taxonomy relied on morphological and anatomical features, but intraspecific variation in morphology may be due to phenotypic plasticity. Alternatively, similar morphologies may be the result of convergent evolution due to inhabiting similar environmental pressures (e.g., wave swept shores).
The corallines are well suited to integrative studies combining herbarium and natural population samples with DNA sequencing. They have relatively simple morphologies and these may be due to convergence.
Hind et al. (2015) sampled specimens from Alaska to Baja California and have added new species in the coralline genus Bossiella in the NE Pacific where previously only one species was recognized.
For example, B. hakaiensis and B. reptans may have been lumped together based on morphology, but after using the genetic boundary between these two species, they found subtle differences in reproductive structures and thallus morphology. In general, the corallines have been grouped into taxonomic units based on their reproductive structures.
Their study demonstrates

the process of delineating species, including considerations of habitat, distribution, morphological variation, and possible species names, requires sequencing both contemporary and type specimens.

Thanks to Patrick for hosting Erik’s BC leg of the Gracilaria globe-trotting and for sharing some of his research with The Molecular Ecologist.
References
Hind, KR, KA Miller, M Young, C Jensen, PW Gabrielson, PT Martone. 2015. Resolving cryptic species of Bossiella (Corallinales, Rhodophyta) using contemporary and historical DNA. Am J Bot 102 (11): 1-19. doi: 10.3732/ajb.1500308.
Hind, KR, S Lindstrom, PT Martone. 2015. Seaweed diversity on Calvert Island, British Columbia. Story Highlights from the Department of Botany, UBC.
Thomson, J. 2015. How does kelp pick its home? Hakai Science on the Coastal Margin.