Image Credit: Center for Environmental Visualizations at the University of Washington, Dr. Michael Wetz, Texas A&M University-Corpus Christi, Deep Sea Systems International, Schmidt Ocean Institute
Research Accomplished aboard the R/V Falkor
This morning the Fisheries Lab Team completed longline sampling and processing fish until noon. After all was complete the team headed to the dry lab on board to begin our summary of the cruise for the evening. The scientists ran statistics for the success of this cruise. Below is a summary.
At 6pm, crew and science teams gathered on the deck for the last BBQ at sea and for a presentation by Dr. Matt Ajemian. Afterward videos and pictures were shown on the projector and we enjoyed our last social aboard the R/V Falkor in the Gulf of Mexico. Tomorrow we will back in Corpus Christi!
With only two days left on this cruise the day's plan included the last CTD casts at site MU-828, and an ROV dive at Great Reef followed by longline sampling at A-7. The Coastal and Ecosystem Lab completed their collection from the last artificial reef site and started preparing to pack up. By early afternoon the seas were calm enough to deploy the ROV at Great Reef. However the visibility was poor due to the nepheloid layer which is the layer just above the seafloor containing lots of sediments. In the Gulf of Mexico this layer is generally significant and is created from a mixture of clay and a silty bottom . The ROV was retrieved after about an hour due to an incoming front. The weather quickly changed and white caps began to appear so the Fisheries Team prepared to ready the gear for fishing. The team deployed longlines at site A-7 in sets and fish were collected including red snapper, lane snapper, and almaco jacks. The weather is expected to be the same tomorrow so the fisheries team will have one last chance to collect fish.
Today began with 4 ft seas and 20 knot winds making it difficult to launch some of the equipment so we began preparing for a micro ROV dive. The plan was to dive two of the ships at MI-616. This time the fisheries team used the bow of the boat to launch the micro ROV and weighted the tether to the seafloor (100 ft). Each dive took about 45 minutes and we gathered great footage of the fish found at these sunken Liberty Ships. This micro ROV has been used at seven different artificial reef sites in the last year by the fisheries team and video will be analyzed to determine the fish abundance that inhabit these reefs and also a count of the total number of species seen. On the last dive we even came across a southern stingray. In the afternoon the fisheries team processed fish samples from the previous day as the CTD team collected samples around MU-A-16. Dr. Wetz and crew are looking to see if these artificial structures impact ocean currents and how that influences the base of the food web.
Megan and Stacey retrieve the ROV
Micro ROV
The team guides Megan
Dave and Judd tie the ROV cable to the ship
Dr. Ajemian and Megan operate the ROV and use a blanket to help shield the light
The first task for the day was a CTD cast at our deepest site on the cruise. As the CTD descended to 1100 meters (3600 feet), Dr. Wetz and crew collected water for plankton samples and to obtain "pure" water for in-lab filtering. Deploying the equipment and gathering the samples took about an hour just to get down to the bottom of the seafloor. Our next plan was to perform an ROV dive at BA-A-132 and longline sampling at the same location.
Lionfish at site BA-A-132
Ironically this morning an article appeared in a Scientific American blog on how busy we have been on this expedition counting fish. The article referenced the use of longlines, searching for lionfish, and exploring the liberty ships. As the ROV explored BA-A-132 we spotted numerous fish species previously seen, but we also observed a few new species including a soapfish and a blue tang. Visibility at this site was the best yet and the ROV was able to survey the entire structure all the way to the seabed with perfect water clarity. Toward the end of the dive the sub rounded the edge of the underwater rig near a pipe hole, and inside was another lionfish similar to the fisheries group's previous sighting (see below). The fish's back was turned facing into the structure when first spotted. These fish are an invasive species introduced into Florida waters and we first documented at the Flower Garden Banks in August 2011. Gradually lionfish are spreading further along the Texas Coast and with few predators and a voracious appetite, they can pose a threat to our natural ecosystems. Drs. Stunz and Ajemian will continue to monitor the abundance and distribution of lionfish as they monitor the artificial reefs off the Texas coast.
Below is a video taken by Dr. Ajemian and Megan Robillard from their latest survey using their micro ROV in September 2012 at Site MU-A-16 (toppled rig) 40 miles southeast of Port Aransas.
Goliath on the Reef aboard the R/V Falkor Artificial reef sites surveyed today in the Gulf of Mexico were abundant with life. Co-chief scientist, Matthew Ajemian sat in the control room with the ROV (remotely operated vehicle) operators, Toshi and Jamie, to direct the dive. As the ROV descended on our first site approximately 30 meters deep, Matt helped guide Jamie to the first designated transect. Before arriving at the reef the first glimpse of life appeared. A school of fish called lookdowns swam in front of the cameras. From the science control room, Megan Robillard and PhD student Judd Curtis began to identify the species and log the times the fish were spotted by viewing the video live on several large monitors from this room. They saw horse-eye jack, large schools of gray and red snapper, creole fish, hogfish, blue and rainbow runners, amberjack, butterfly fish, blue angelfish, barracuda, scamp (type of grouper), and spadefish.
At the end of the first dive the ROV came across a stairwell on the underwater rig and hiding behind it was a very large animal that was immediately identified by Judd. The science control room lit up as the goliath grouper slowly decided to show us a glimpse of his size. Using the built in lasers Dr. Matt Ajemian was able to estimate the size of this fish which was at least 4 feet! After visiting two other sites the fisheries team was able to capture the best video footage they have seen of these artificial reefs and the video will be analyzed further to get a good population count from all sites.
Tonight the crew and scientists gathered outside on the second deck to hear from PhD student, David Tupaj as he spoke about the socio-economics of the Rigs to Reefs Program along the Gulf Coast. After viewing the rigs today the topic of the economics of these structures fit well and after the talk we played video from the dive for the crew to see the massive grouper and all the life on the reef.
Our goals on this scientific research cruise have included mapping artificial reef sites off the Texas coast, surveying fish populations on the artificial reefs using the ROV and vertical longline gear, and examining phytoplankton by sampling the water column using the CTD along multiple transects. Using the map as reference here is what the team has accomplished this week.
CTD
Mapping -
On this leg the team has successfully processed and mapped the following sites:
BA-A-28, MI-616, BA-A-132, MI-A-7, MI-A-85 GR, MI-712, MU-802, MU-A-16, MU-828, MU-776, MU-770, MU-775, PN-A-58, PN-A-72, and PN-967.
CTD -
The Coastal and Ecosystem Lab has successfully gathered samples from the following sites: Transect 1 (4 sites), Transect 2 (3 sites), Transect 3 (3 sites), Transect 4 (4 sites) and Transect 5 (3 sites). ROV-
Micro ROV
The Fisheries and Ocean Health Lab has utilized the on board ROV at site BA-A-28 and gathered HD and 3D video from this site. At site MU-802 the micro ROV was tested off this vessel and captured HD video. Although there was limited visibility, the team gathered the best video from this site to date.
Longline sampling
Longline Sampling -
The Fisheries and Ocean Health Lab used a vertical longline sampling method to gather data from the following artificial reef sites:
BA-A-28, MI-616, and MI-712 and processed the fish collected to gather more information about the fish populations on these artificial reefs sites.
Today, we focused on getting two CTD transects complete. We visited seven sites today and deployed the CTD to gather the water samples and filtered them back in the wet lab for each site. This kept Dr. Wetz and his students, Lynn and Kelsey busy throughout the day and have only two transects left to complete. These data gathered will be instrumental for finding out more information on red tide and its harmful effects each season in the waters off the Texas coast.
Overnight the ship mapped one of the liberty ships at site MU-802. Megan Robillard and Dave Tupaj worked to process the map this morning with marine tech, Nathan. The shot on the left is of the Dwight L. Moody ship used in WWII. In the 1970s, twelve liberty ships used to carry supplies and oil in the war were sunk in the Gulf of Mexico at five different sites to be used as artificial reefs by Texas Parks and Wildlife's Artificial Reef Program. These reefs provide habitat for numerous fish species including reef fish and sport fish and we wanted to take an even closer look.
Late in the afternoon we gathered the equipment to launch the micro ROV (Video Ray Pro4). The challenge of doing this in particular was getting the sub over the side of the ship and into the water because of the rough seas and such a small ROV. Several precautions were taken and the ROV was successfully launched! The crew gathered to watch the feed on the laptop (pictured to the right). A GoPro was mounted on the ROV to capture better video quality. The ROV made it into the water and began recording. Dr. Ajemian maneuvered the ROV around the submerged ship and gathered good video for about twenty minutes. The visibility was not great, but the team was still very happy with the data gathered. The video was downloaded after the dive and the team will be able to determine fish species and abundance, as well as fish size using the lasers mounted on the front of the ROV.
Shortly after a few more CTD casts and ROV clean-up, the SOI team hosted a BBQ on the second deck and everyone got the opportunity to take a break and enjoy the company of all on board. This is an impressive ship but the crew are amazing and without their help in facilitating this research it would not be possible.
