Field Experiences in South Texas
The University of Texas Marine Science Institute

REUfest is a summer research program for undergraduates at the University of Texas Marine Science Institute. Student projects take advantage of the wide variety of coastal habitats near the Institute, including shallow bays, hypersaline lagoons, seagrass beds, estuaries, mangroves, and marshes.

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program photo

Starting Data Collection- Michele

July 3rd, 2014 Posted in Uncategorized | No Comments »

Hello, sorry for the very late blog update. I’ve been in lab for the past 13 hours and have just finished collecting my first set of data! In the past few weeks I have been trying various experimental setups and finally decided on  a 1.8 inner diameter siphon with a siphon flow of ~2.1 mL/s.Yesterday I incubated groups of 50 Acartia tonsa in various treatments, totaling 400 copepods total. I spent the entire morning picking them from our plankton tow and I think I am getting both faster at picking them and better at distinguishing between adults and late copepodite stages. I incubated the Acartia in a 5 µL/L concentration of crude oil, a 5 µL/L crude oil and 0.25 µL/L dispersant mixture (at a 20:1 ratio), at a 0.25 µL/L concentration of dispersant alone, and a control of filtered sea water. Each treatment was repeated twice and all were incubated for 24 hours. Unfortunately, I had to do the majority of the trials alone today and fumbled a bit with getting the siphon and pump to maintain a constant water level. It was also quite a challenge to start both the siphon and pump while immediately hitting the record button after. So far, I can only say that the treatments with either crude oil or dispersant had fairly similar and large mortality rates.  It is now 10:10 pm and I have not eaten since noon so I will be going now! Thanks for reading!

In order to quantify the shear values created by the siphon flow, tiny, hollow glass spheres are placed in the tank. A laser illuminates the tank and we use a program to analyze the video.


Halfway to somewhere.

July 3rd, 2014 Posted in Uncategorized | No Comments »

This week marks the midway point of the REU program here at UTMSI- and time has sure been flying. By the end of this week I will have finished all sampling from my first species of phytoplankton, Heterocapsa, and will have begun the culturing of my second species, Odontella. What this means is that from both the high and low light intensity groups for Heterocapsa I have sampled for cell count daily, as well as taken larger samples of the culture during both their growth phase and once after they had depleted nutrient resources for growth for fatty acids, cellular carbon and nutrient levels in the water column. These large samples will be analyzed for these constituent components while I am culturing the Odontella, whereas the cell counts were done daily during the culturing of the Heterocapsa. The cell growth counts seem to be on par with what was expected to be seen. This has me very excited to analyze the fatty acid, cellular carbon and nutrient levels because I am expecting to have great results. Preparing the Odontella culture requires cleaning and sanitizing the medium they will be growing in as well as applying a dosage of nutrients and vitamins, testing the water for salinity levels and measuring the light levels and temperature levels inside the incubator. These steps are taken to ensure that factors in all phases of the experiment are consistent. The sampling for the Odontella will be done in the same manner as what was done for the Heterocapsa. I am hoping that time will permit me to culture a third species of phytoplankton although there is a chance I will only be able to get through two species. I will however definitely have datasets on at least two species and will let you all know how the rest of the experiment goes in August upon completion of the program.

From Datum to Data

July 3rd, 2014 Posted in Uncategorized | No Comments »

Five weeks already? Time flies!

Hi all, Brett again. For my project I have taken freshwater-acclimated red drum and transferred them to saltwater so that I could record their osmoregulatory response, that is, how they remodel their gut and gill to compensate for the high salt content of marine water. Marine fishes have to drink sea-water and excrete the excess salt in order to keep their body hydrated. It follows that in doing this they will have a higher salt content in their blood plasma, more muscle water, increased protein expression in their gills and intestine, and a larger amount of intestinal fluid. So far, I have sampled all of my fish and am in the process of analyzing their fluids and tissues. I have analyzed muscle water and intestinal fluid, and I am partway through determining protein expression and plasma salt content. Preliminary results indicate a somewhat unexpected osmoregulatory response. Data from plasma osmolality, intestinal fluid, and muscle water indicate that red drum might up-regulate intestinal proteins so much that they over-compensate for the water transfer, becoming less salty than they were in freshwater.

I continue to have a good time in Port Aransas. Lots of fun to be had here, and I am learning some valuable scientific techniques in the lab.

4th of July in Port “A”? Fireworks on the beach.

Kemps-ridley sea turtle. One of the cool things to be found on the beach.

Blue Crab Megalopae Process

July 1st, 2014 Posted in Uncategorized | No Comments »

Every morning around 10am, I go out to the UTMSI pier and collect the megalopae. They are collected on hog’s hair collectors wrapped around PVC pipe with rubber bands. I replace each of the collectors that have been in the channel with clean collectors and put them back in the channel. I then wash out the collectors retrieved from the channel with fresh water into a bucket and pour the fresh water through a sieve to retrieve the organisms from the collectors. I then rinse the sieve with water into a plastic vial to store the organisms and label it with the date, time, and my initials. Sometimes I take note of the weather or if sargassum was caught on the collectors. I then take the vial into the wet lab to count megalopae. I have counted 24 samples off of the UTMSI pier and will continue to collect daily data. I do find the megalopae easy to spot when counting but I don’t always find megalopae in every sample.

One of my mentors and I have put out a current meter on the pier to collect data on the currents. It collects information on the currents every 30 seconds, and we go out and offload the data once a week. The data are transferred on a device like a flash drive and run through a computer to show the currents for the course of the week.  In the future, the currents and the number of megalopae collected will be analyzed to look for any correlations between the number of megalopae and the rate of the currents. They will be analyzed in R.  I am learning how to use R when analyzing a great deal of data; it’s a complex program that has a lot of math based functions, but it is good to use with all the data that is being collected. That’s all that is happening for now for the blue crab megalopae.          


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