The Road to Restoration

On August 24th and 25th, (7 weeks after the first set of clams were deployed and 5 weeks after the second set were deployed) we went out to remove the plots from the study sites in Lynnhaven and to collect samples to determine the results of the study. Suction sampling was used to collect the infaunal organisms within the plots including (hopefully) the Mya that we planted. In addition to suction sampling we too sediment cores to determine the grain size of the sediment to observe the effects of sediment type on the plots.

For suction sampling we used a pump to effectively vacuum up the sediment within the 1/4 square meter plot into a 1mm mesh bag. We then used a 1mm box sieve to sieve out all of the organisms and debris smaller than 1mm, removing unnecessary large rocks or dead shell as well. After the samples were sieved, any crabs were measured and released. The remaining sediment and bivalves were placed in gallon ziploc bags and put in a cooler to bring back to the lab for processing.

Sediment cores were taken using plastic syringes to take first ~2inches of the surface sediment. The sediment was then placed in whirl packs and added to the cooler to analyze grain size in the lab.

Both collection days went very well. Pleasure House Creek was sampled on the 24th and Broad bay was sampled on the 25th. Now all that remains is to process the samples, and then the analysis can begin.

After the disappointment of the cages being moved at the Linkhorn location, new plots were deployed at the other two locations (Pleasure House Creek and Broadbay) to replace the ones lost. This brought the study to a total of 36 cages at two locations (18 at each), instead of 36 cages at three locations (12 at each).

Monitoring of the cages ocurred weekly. We checked the cages to make sure they were still intact and examined the uncaged plots to look for any broken shell that might indicated that a clam had been eaten. Visibility was too low to see anything on the first day of monitoring, therefore we limited the monitoring to ensuring cages, frames, and markers were still in place.

On August 3rd, we went to conduct predator surveys at 4 locations in Lynnhaven. Two locations corresponded with the final locations of my survey: Pleasure House Creek and Broad Bay. The two remaining locations corresponded to the location that was removed from my study and a graduate student’s scallop study: Chalmer’s and Linkhorn. At each location we used a trawl net to determine benthic predator densities. The benthic predators included blue crabs and small fish. Crabs are known predators of clams, consuming the entire organism, but small fish engage in a predatory behavoir called siphon nipping. When siphon nipping, fish bite off the part of the clam siphon above the surface of the sediment. This shortens the clam’s siphon temporarily forcing the clams closer to the surface where crabs can get at them more easily, but eventually the siphons can grow back allowing the clam to seek refuge further in the sediment. We did 2 trawls at each location (one with the current and one against the current) for 2 minutes each at 15rpm. We sorted through the trawl right on the boat, counting, measuring, and releasing all relevant predators.

With the problem of the ruined location solved and the predator surveys done, the study is really starting to come together and I can see what the final results are going to look like. It’s nice to have everything working out again. Probably the most important thing I’ve learned from this research is to be flexible and not panic when things don’t go perfectly according to plan. There is always a solution – you just need to be patient and creative to figure it out.

Good news!! On July 7 & 8th, the experiment officially started. We set up the cages and frames at all locations and put the substrate and clams in on the 7th with no problems – YAY! I put cages on all of the plots on the 7th to allow the clams time to acclimate to the substrate, and then on the 8th we went back and removed the acclimation cages from the plots that are receiving an “uncaged” treatment. Both days went really well and we had no problems getting everything done. . . . . .

and unfortunately, now the bad news. Last week, I checked on the cages and the cages at Linkhorn have been tampered with. We had taken extra caution making sure that the cages were well marked as a VIMS experiment, including a phone number to contact with any problems, but unfortunately it seems like it wasn’t enough. Two of the cages seem to be undisturbed, but the remaining cages have been removed. I’m not entirely sure what I’m going to do about this yet, but obviously I won’t be using the location at Linkhorn any longer.

On the bright side, hopefully everything is continuiing to go well at the other locations and the experiment will be fine for those places. I’ll be taking care of the the Linkhorn problem this week and figuring out what to do with everything, but for now – check out the photo album again because I added pictures from July 7th & 8th. Until the next post, fingers crossed that this works out.

Here’s a slideshow of the photo album that I’ll be using to post all of the pictures from my research. There are a few up already. Check it out!!

Caitlin’s Clam Photo Album

My first blog post! This has been a great summer so far, and I should really just get caught up on what I’m doing and what my super, exciting research is all about.

This summer I’m working on research for my honors thesis with Professor Swaddle (biology) and Professor Seitz (VIMS). I’ve been researching the soft shell clam Mya arenaria — also known as steamers or longneck clams. The project that I’m working on is focused on a field experiment in the Lynnhaven River System in the Chesapeake Bay (near Virginia Beach). The clams used to be found in that area, but haven’t been there in large numbers since the 1970′s, so we are doing an experiment to determine whether or not the clams can survive there now. The two main things I’ll be examining are general survival – do the soft shell clams survive in the conditions in Lynnhaven? and predation – Is predation the reason the clams do not thrive in Lynnhaven?

Up until now the summer has been full of building cages, planning the experiment, and looking for clams to use in the experiment. The good news is that we finally found clams!! After searching almost everywhere we could think of, we found about 300 clams in a flow tank that we were cleaning out at the lab. It’s crazy how you find things when you aren’t really looking for them.

This week we’re finally putting the cages in the water and starting the experiment. Tuesday will be the day we go to Lynnhaven and deploy the cages. Hopefully we can get it all done in one day, but we have a boat ready for Wednesday too if we don’t finish it all in one day. I’m really looking forward to getting out in the field and starting this study. I’m going to try to post some pictures of the clams up here, so I’ll see how that goes. The next post will probably be after everything is in the water, until then. Hope everyone had a great 4th of July!