Saturday, August 14, 2010

Sam - Reflection on my experience

The flats teem with living organisms that interact with one another and collectively serve our ecosystem. In a somewhat different way, scientists such as the ones at Hatfield are pooling their expertise from an extensive range of fields to examine the what and the how of things aquatic. I enjoyed living, working and playing with members of such a vibrant, dynamic community.

It was great to get a behind the scenes tour of the Oregon Coast Aquarium. After the tour, I had the chance to watch the sea otters (Enhydra lutris) during feeding time.

Though I still tend to feel a bit anxious when I'm up to my shins in mud, I believe the worry will lessen over time with practice. I'm glad I've had this opportunity to work on the Oregon Coast, meet lots of interesting people, and hone skills I hope to use in the future. While at Oregon State, I want to learn more about estuarine habitats.

Laury - My final post

This summer has been an incredible experience and one I will remember later on in life. I am still in awe with how much I have accomplished in the last 8 weeks! The first few weeks seemed long as I was becoming adjusted to lab and field work, but the last 6 weeks have flown by. I started out primarily doing field work so we could collect the samples I would later process in lab. The last two weeks I spent all of my time in lab calculating out the energetic content of the individual species so it would be ready to present at our presentation at the end. I would highly recommend this internship to anyone who is interested in marine sciences. Not only will you be surrounded by people who are just as passionate about marine science as you are, but they will guide you and help you grow as a future scientist.

Friday, August 13, 2010

Sam - Gaper Clam Burrowing Rates and Reburial Capabilities

I measured the changes in each clam's burrow depth for 1-2 weeks. The data suggests that there is a moderately negative association between shell length and average burrowing rate. In other words, the larger clams tended to dig slower than the smaller clams, but there was no evidence of a cause-effect relationship.

 After softening the mud, we collected and tagged more clams to use in our final experiment I divided the clams into 3 size classes based on their shell length and let them acclimate overnight. The next morning, I placed 29 clams in the buckets and let them go at it for 24 hours before photoing them and giving them a score from 1 (no evidence of burrowing) to 5 (shell completely below surface). The results show that the largest class had a wide range of scores, and nearly all of the smallest class rated 5, but a cracked one only got a 2. It was clearly unable to stand up and squirt water below its foot, and died a few days later. The fragility of the young clams' shells may be one reason ODFW wants us to keep them if we catch them.

Laury - Smooth Bay Shrimp (Lissocrangon stylirostris)

After a month of sampling and “bombing” my samples I learned how to input all of the data collected into excel so we could calculate out the energetic content in joules. A joule is a measurement of heat, as are calories. Because smooth bay shrimp (Lissocrangon stylirostris) were so easy to catch in our samplings we had a lot of data collected on them. We were finding three categories of smooth bay shrimp, we would find ones that were brooding (had eggs), some that had been parasitized, and what I inaccurately called “regular” meaning they were neither brooding nor parasitized. From the beginning we separated out all the shrimp we caught from seining into the three categories and I bombed them accordingly. I started to notice some trends once I had calculated out their energetic content. The brooding shrimp had a higher caloric value than the other two shrimp categories. This was not a surprise because eggs naturally have more energy, and supply more nutrition. However what I found interesting was that the shrimp with parasites seemed to have the same caloric content (aka energetic content) as the shrimp that were deemed regular. Why this was so surprising to me was because the shrimp that had parasites were around the same large size as the shrimp that were brooding. The regular shrimp were small in size so that might have had an effect of their caloric content as well. So I started to research the relationship between the parasite (Argeia pugettensis) and it’s host the smooth bay shrimp. What I had discovered by reading some science journals that Jose (my mentor) had recommended to me was that there wasn’t a lot known about the shrimp and the relationship between the parasites.

Jose had asked me earlier if there was anything I wanted to research independently, well I had found my topic. How are the parasites effecting the shrimp? Because I have been working so much with the Bomb Calorimeter I formed my question to ask: “Are the shrimp effecting the caloric content of the shrimp?” I hypothesized that if I were to remove the parasites from the shrimp I would find that the shrimp would have a lower caloric content.

Dr. Jessica Miller, Jose and I came up with an experiment design on how I would go about asking this question. We decided to have a total of 30 shrimp that I would bomb, and collect 15 from each of our two sampling locations. So 15 shrimp from Alsea Bay and 15 Shrimp from Coos Bay. Within the 15 I would collect from each site I would have 5 brooding shrimp, 5 parasitized shrimp, and 5 “regular” shrimp. So that’s what we did! I removed all of the eggs and parasites off the shrimp so I would put them back to their “regular” state.

(This is what the shrimp infected with parasites look like, the one on the very right had a parasite missing, I think it may have fallen off when we caught the shrimp). The parasite live on the gills under the shrimp just under the exoskeletons.

(This is what the parasite looks like after being removed from the shrimp).
(this shrimp is around 5.5cm long, the point of this picture is to show just how big the parasites are compared to the size of the shimp).

After entering and graphing the data, I found that parasites do not seem to effect the caloric content of the shrimp. This isn’t the result I expected, but it was still a surprising discovery!

Laury - Surf Zone Sampling!

Hello fellow bloggers! As promised I am going to talk to you a little bit about how we collect all of our samples. The primary focus of these outdoor adventures is to catch salmon out in the surf, but we also want to collect the prey that salmon eat. How do I know what salmon eat? Well Jose (my mentor) has been doing this study for 5 years now, and part of what he does when he catches salmon is conduct a stomach analysis. Basically he looks at all of the stomachs of the salmon that’s been caught and identifies what they’ve been eating. So far the main prey species seem to be mysids, amphipods, megalopae and other juvenile fish, or their fish larvae.
How do we sample? Well there are a couple different ways that we collect our samples. First is the “seining method” which is a 15 meter long mesh net. Three people carry the net from the shore to the surf and then once we reach a deep enough spot the middle person stakes the middle pole into the ground and the other two people with poles stretch out the net to form a “V” shape. Once we know the net is not tangled up we drag the net across the sea floor and back to shore. We are literally scooping up all of the inhabitants of the surf in the net and bringing them back to shore.
Once the net is dragged up on shore, we extend out the net and collect everything that we’ve caught. We count everything we found and record that in a little handy dandy notebook, and everything is returned back to the water with the exception of salmon or shrimp, or other species of prey that the salmon eat for “bombing” later. Some of the cool things we have found by doing this are: starry flounders, staghorn sculpins (grumpy little guys), English sole, pike fish (look similar to a seahorses), gooseberries, jellyfish, and lots of smooth bay shrimp! Of course when we find salmon they are the real trophy prizes.

In this picture above are some of the CSC crew members (highschool kids working their summer jobs at The Natural Resource Crew of Community Service Consortium located in Newport, Oregon), and Jose who is at the very right of the photo. In this picture they are dragging back a tow to shore, we do about 6 tows per sampling day.

This picture above shows Jose preparing the sledge or commonly known as a “sled”. The sled works by having two very fine mesh nets that catches all of the smaller invertebrates that salmon eat. We carry out the sled into the surf, and lower it to wear it’s just surface deep, and drag it around a total of 400 meters, and all of the prey get scooped up into the net and end up in the codends at the end of the net. A couple of times we’ve accidently caught an English sculpin in the net, and an anchovy. We released the sculpin and kept the anchovy to bomb since they are also prey for the salmon.

This is a picture of a juvenile Chinook salmon that we caught while we were seining out in Alsea Bay. So far we have around 90 salmon that we’ve caught in the last 8 weeks.

Wednesday, August 11, 2010

Dave - Ulva bioassay using oyster larvae

Having determined that the Ulva was capable of affecting the pH, I moved on to using the three sources of water to do a bioassay with oyster larvae.  I took four 10 liter samples each from the three tank system, the large tank system and from the incoming filtered HMSC water. I stocked each 10 liter sample with 50,000 larvae. I did periodic water changes, using water from the corresponding sources, and feed each sample with a calculated amount of micro algae. After 6 days I sieved the larvae out and restocked the samples with 10,000 larvae each to remove any excess dead to avoid fouling the water. After 10 days I again sieved the larvae out of the samples. I used a 60 micrometre sieve and put each sample into 800 ml of water, from that I took three 20 ml from each 800 ml sample.  I then took photos, did counts and took measurements form each 20 ml sample.

In the samples taken from the filtered HMSC water, 48% of those found survived, and of those alive the average length was 116 micrometers across.

In the Three Tank System, 57% of those found survived, and of those alive the average length was 120 micrometres across.

There doesn't appear to be a significant difference between the filtered HMSC water and the Three tank system treatments. But...

In the Large Tank System, 83% of those found survived, and of those alive the average length was 150 micrometres across. This is a significant difference between the filtered HMSC water and the large tank system.

This bioassay is the conclusion to my research. it shows that there is a potential for Ulva to be used as a biofilter to improve the health and survival of oyster larvae.
~David L. Hubert

Dave - Large tank system

This is the large tank system.

This tank was storing the Ulva but was not getting a desirable growth rate. The basic setup is a round tank that is 4 feet tall and 10 feet across, with an inverted lawn sprinkler suspended above the tank to keep the Ulva from drying out. The drain is on the bottom of the tank and enables the water level to be adjusted by raising or lowering the exit point. This is where I would take my samples to test.
When I took over this tank the water depth was about 7 inches, the single sprinkler was reaching about half of the surface of the water, there was a ring with light aeration around the edge of the tank, and the bottom was filled with various types of debris intended to be an anchor for the Ulva to grow on.


The first thing I did was raise the water level to about 16 inches, I removed all of the debris and I increased the amount of aeration. This resulted in an increase in the growth but still not what we were looking for.

The next set of adjustments I made was to raise the water level to about 23 inches. I tripled the water flow, added a second sprinkler resulting in full coverage of the surface of the water. I removed all of the aeration from the tank, creating a calmer surface allowing the Ulva to spread, and I placed a small submersible pump into the tank to create some movement under the water. This combination seemed to do the trick and resulted in approximately 95% coverage within a few days.

~David L. Hubert