Blog Post: Salty and Soggy: Understanding the role of crabs in California salt marshes

Blake searching through the salt marsh in Bodega Bay for the lined shore crab (Pachygrapsus crassipes). PC: Jan Walker
Blake searching through the salt marsh in Bodega Bay for the lined shore crab (Pachygrapsus crassipes). PC: Jan Walker

By Blake Nogleberg

My name is Blake Nogleberg and I am a fourth year SRJC student looking to pursue a career in the marine sciences. I worked alongside Graduate Student Jan Walker this summer.

As a kid I grew up only a short drive away from the Bodega Marine Lab (BML), and I was always intensely interested in what kind of work went on in this facility. So when the opportunity arose this summer to intern here, I did not hesitate to apply. My time at BML has been an amazing experience. I was able to work with and learn from some extremely talented scientists, help maintain field experiments in the salt marshes of Bolinas Lagoon, Tomales Bay, and Bodega Bay, as well as help conduct several laboratory experiments at BML. My mentor was Jan Walker, a PhD student from the Grosholz lab, and we examined the impact of the lined shore crab (Pachygrapsus crassipes) on the salt marsh plant community. Understanding the role of crabs in determining plant community composition is important when considering management strategies of foundational marsh species, such as cordgrass. Cordgrass has been targeted for management and restoration due to its amplitude of ecosystem services, such as sediment accretion, flood attenuation, and habitat for endangered species. We hypothesize that these crabs could impact the plant community by consuming dominant salt marsh plants (cordgrass and pickleweed), and by creating burrows in the marsh sediment, thereby changing sediment properties crucial for plant health (salinity, oxygen concentrations, etc.). Crabs may play a critical role in meditating stress for plants and, by understanding their role, we can better inform and bolster management and restoration in our northern California wetlands.

The field work portion was quite enjoyable. I spent most of the time chasing our crab friends and attempting to catch them without being pinched, their feisty attitude continually surprising me. There was a learning curve when it came to walking through the salt marsh, however I became proficient in navigating the spongy, quick sand-like landscape without swamping my boots or falling too many times. We woke up before the sun to catch the low tide, and we worked efficiently to collect data (and crabs) to make it back out of the marsh before high tide.

The lab work we did was interesting and engaging. I helped Jan setup two different feeding experiments to determine exactly what plants, and what part of the plant (roots or leaves), the crabs preferred. This portion of the internship allowed me to ask countless questions about our experiment, and the setup and execution of lab experiments in general. Additionally, I was able to get professional advice on how to navigate the unfamiliar territory of academia. It was infinitely valuable to be a part of Jan’s work, and the skills and knowledge I acquired over the summer have set me up to succeed in the next stages of academic life. I hope to use my experience here to further pursue a career in marine science.




Blake field site


Blake at BML



Blog Post: Into the Velvet Jungle

Tyler and Suzanne
Tyler and Suzanne

By Tyler Schatto

Tyler Schatto is a student at Santa Rosa Junior College. He was mentored this summer by Luis Morales and Suzanne Olyarnik.

TylerIn 2019, Bodega Marine Reserve was my summer hangout spot. With my mentor, Luis A. Morales, Steward for BMR, I conducted field surveys, implemented and updated signage, and  utilized a selection of plant management techniques to reduce invasive species populations. Along the way, I learned several identification markers for coastal prairie plant and bird species, I learned how to work safely in rugged environments and now, I have a better understanding of land management techniques to restore native habitat and implement ecological enhancement projects.    

At BMR, conservation of native flora biodiversity is a primary focus. Velvet Grass (Holcus lanatus) is the greatest threat to native plant species here, wholly overtaking great swaths of native coastal prairie. Luis and the team at BMR are testing a method to reduce Velvet Grass populations by mowing two times per year instead of just once. The BMR team hypothesizes that the grass puts a large portion of its energy into growing its flowers, and that a second annual mow occuring after flowers have regrown and matured will lead to greater percentages of Velvet Grass dieoff. I was able to participate in the experiment by both mowing and observing test plots. Additionally hoeing and hand pulling in areas where the Velvet grass has the potential to spread quickly. 

thistle removalOther plant populations we managed included Bull Thistle (Cirsium vulgare) by the bluffs, Rabbits Foot (Lagurus ovatum) and Rattlesnake Grass (Briza Maxima) in the coastal prairie, and spurge (Euphorbia lathyris) in the dunes and marshes, which each require their own specialized approach and adaptive land management technique.

From a wider perspective, my time was focused on learning many of the themes and overarching approaches used in natural land management. BMR uses adaptive management, a concept focused on the reactive reworking and adjusting of land management plans to cater to changes in the local environment.     

As such, the BMR Team and I met frequently, evaluating the state of the reserve and adjusting priorities. For example, after one land survey, we found a choke point where Velvet Grass was likely to spread rapidly into an area of pristine native coastal prairie. We were able to adapt our plans to focus on that area, hand pulling several of the most dangerous plants and spreading mulch to create a barrier beyond which the Velvet Grass will not spread.

Tyler and snakeAnother amazing opportunity I experienced was a nature hike through the saltwater marsh, led by former BMR director Peter. He showed a group of us almost every single plant, native or otherwise, that lives in the saltwater marsh along Bodega Bay. He has been leading these nature hikes for several years, and he and the BMR crew are able to talk about fluctuations in plant populations. There were several native plant populations that have rebounded surprisingly well - in one case, a plant population had increased from less than 10 individuals the previous year to well over 100 individuals at the time of our hike. Peter was able to show me the anatomical markers botanists utilize most often to identify and distinguish different plant species, which I was able to use directly in the field during surveys. My observations in the saltwater marsh helped me to think about the reserve as several smaller ecosystems, interconnected with complex relationships.

The SRJC-BML mentorship/internship program is valuable to anyone who is interested in life sciences, land management, or the sciences in general. It provides networking opportunities, career path guidance, and a very valuable perspective into the professional and academic sciences that is hard to acquire in a classroom, especially at a non-research-based community college. The people I met were unique and amazing individuals who showed a real interest in me, and the experiences I had, I will cherish forever. Few people are privileged with an opportunity to immerse themselves in a career before starting it, and this internship provided that for me.