1. Local Adaptation

To test for local adaptation in the eelgrass growing in Bodega Harbor I set up a couple of different reciprocal transplant experiments, one between sites in the intertidal and one between subtidal and intertidal plants growing at one site. The two intertidal sites I used were Campbell Cove (CC) and Westside Park (see map of Bodega Harbor). I collected plants with at least two shoots from each site or tidal height and planted one shoot of each plant back to its home site and the other shoot to the foreign site. This allows be to see how well shoots grow in there home location compared to a foreign location.

This program was pretty fun and basically involved a lot of eelgrass gardening!

My subtidal vs. intertidal transplants were also fun because I got to scuba dive to collect and plant shoots in the subtidal!

Below you can see a picture of my intertidal plots (with the poles and orange flags) and the tiny dot out in the water that is circled in red in a buoy marking my subtidal plot.

Setting up an experiment underwater was a new challenge for me and I enjoyed it quite a bit. The conditions weren’t always ideal and sometimes I could barely see what i was doing, but with the help of many of the other experienced divers at the Bodega Bay Marine Lab, I was able to make it work!

Below are some underwater shots of my sutidal plot. You can tell the water can be pretty murky and a lot of algae grows down there!

And one last shot of my fabulous dive buddy and labmate, Olivia!

Eelgrass is marine angiosperm that grows in soft sediment in bays and estuaries in North America, Europe, and Asia. It is the most abundant seagrass species in the northern hemisphere, and it plays a critical role in forming the structural foundation for many costal communities. Eelgrass also provides ecosystem functions, including increased primary productivity, sediment stabilization, and nutrient cycling, making it of ecological and economic value.

Eelgrass is clonal species that reproduces both sexually through seeds and asexually through vegetative propagation. Eelgrass is flowering plant that produces and pollinates seeds underwater. Eelgrass can also produce new shoots off of a rhizome (a horizontal stem) that grows just below the sediment surface and allows for a single genotype or clone to spread. As a result, eelgrass populations can differ substantially in their genotypic richness, or the number of different genotypes found in a given area. Indeed, richness can range from areas in populations with many genotypes ( >10) per square meter to populations that are dominated by a single genotype that can cover hundreds of square meters. Eelgrass genotypes can be long lived with some clones that are likely 1000 years old or more.

Eelgrass typically grows in large stands where it is the dominant plant species. Because there is little species diversity at the primary producer level in eelgrass communities, genetic diversity may be particularly influential in determining population and communities properties, such as productivity, stability, and transfer of resources between trophic levels. Indeed, studies have found that eelgrass population with higher genetic diversity (measured as number of genotypes in a given area) are better able to withstand disturbances like grazing by geese, algal blooms, and heat waves.

Eelgrass community

Eelgrass beds support a wide variety of marine life. Few animals feed on the eelgrass itself because of its high cellulose content. However, some animals, including water fowl (e.g geese and ducks), sea turtles, and some invertebrates (e.g. isopods and snails), do feed directly on eelgrass, although it is not usually the their sole or even primary food source. Eelgrass also provides a substantial source of nutrients to consumers after the leaves fall of and begin to decay. This decaying material, or detritus, is broken down by bacteria and fungi into more accessible organic matter that infuanal (sediment dwelling) species, including worms and crustaceans, feed on. Clams are another important infaunal species and that live in eelgrass beds. They are suspension feeder (filtering organic matter out of the water), and are often harvested for human consumption.

Eelgrass leaves also usually host a number of epiphytes, including algal species, bacteria, fungi, sponges, bryozoans, etc. Many species of invertebrates preferentially graze the epiphtyes growing on the eelgrass.

More information coming soon!

I also worked on IGERT stuff this afternoon and then skyped in with my group (minus Carmen).  We all gave an update of what we have done. I must admit that I really haven’t put as much work into the IGERT project as I would like lately.  In my defense I’ve been super busy setting up field projects and getting things going at BML. However, I also do find it hard transitioning back and forth between field work mode and sit in front of the computer and focus mode.  It is a different frame of mind and usually when I have field work in the morning I’m pretty tired by the afternoon/evening and find it hard to focus.  I also feel like I need larger chunks of time to devote to working on things like IGERT work, or contacting people about internships/ updating my CV. I’m not sure what to do about the transitioning problem, but at least I think I will have a couple days without much field work coming up.

I dropped the weights with buoy attached this morning. I added two stakes to drive into ground to help secure the line, I also think I will add a concrete flowerpot to be sure. That buoy is not going anywhere!  I will pound in the stake and attach the pot this afternoon when dive.

This morning we also counted missing shoots from my intertidal plots (9 and 3) and measured the shoot density of surrounding eelgrass. I wanted to do 10m transects directly north and south of the plots, but the disturbance from clam diggers was so bad on the north side that I had to run the transect parallel to the northern plot (just east of the plot).

I’m a little concerned about the clam diggers. They cause so much destruction and I would be so sad if they dug in my plot. So far they have been respectful (I have PVC poles lining the plots and pin flags at each shoot), but today we saw a guy out there that said he had thought that the plot was there because little kids were playing in the mud! I put lamented labels on my plots at Westside Park today, but I’m not sure they are big enough, and I actually think many of the people who go clam digging most often may not be able to read English (they often don’t speak English).

I think I might make a no digging sign with a picture!

Elaine was helping me today (yes I convince techs to dig in the mud at 6am on holiday weekends!), which was great. After survey the intertidal reciprocal transplant plots we continued clearing my plots for the relatedness experiment.  Five 1 by 11 m  plots to be cleared and we had almost 3 done when we came in today (2 days of work).

Highlight of the morning: Elaine found an octopus in on the mud flat!! Sea gulls had caught it and were trying to eat it. Elaine rescued it and we got to check it out for a while and return it to deeper water. It was missing a tentacle but I think other than that it was OK.  I looked it up and I’m pretty sure it was a pacific red octopus (Octopus rubescens), which apparently like kelp beds but can be found in both rocky and sandy/muddy bottomed intertidal habitat. Cool!

In the afternoon I dove with Sonya at my subtidal plot

Agenda:

1. Anchor buoy with stakes and cement filled flowerpot. – Completed with no problems.

2. Hammer in pole with light/temp logger. – Completed with no problems.

3. Check plot and record which shoots are missing. – Completed with no problems (only 3 missing shoots!).

4. Do two 10m transects measuring eelgrass shoot density every meter (one transect to the north and one to the south). – Completed the the transect to the north but not the south.

Everything went smoothly. Gorgeous day, decent visibility, good dive buddy!  Counting shoots in quadrats was harder than expected. The visibility at the bottom is bad and gets worse as soon as I touch anything. I ended up counting shoots but touch, but it was a bit hard with gloves on (even thin ones).  I’m how accurate it was. I think it worked OK though.  I’m not sure if I could tell if the shoots were reproductive or not in some quadrats.

I saw a bunch of crabs this time and big ones too. Not sure what kind they are, but will look it up.

All in all an excellent day!