May 18, 2011

Throughout the past three weeks, the Khaled bin Sultan Living Oceans Foundation, Bahamian researchers, and other collaborators experienced a unique opportunity to study the shallow marine habitats of Cay Sal Bank, Bahamas.  Cay Sal Bank is a submerged platform that lies relatively close to the Florida Keys and Cuba, yet is remote, difficult to access and relatively un-impacted by man.  Over 99% of the bank is submerged, ranging in depths from 5-12 m, with a narrow fringe of emergent land, comprised of small sandy vegetated islands and lithified sand dunes, surrounding parts of the central lagoon.  Strong tidal currents, high winds and waves, frequent hurricanes and other forces of nature have created harsh conditions that have weeded out weak species. However, those organisms that survive under these harsh environmental conditions are flourishing.

While previous descriptions of the bank noted extensive seagrass bed communities and relatively depauperate and poorly developed reef systems, our extensive small-boat surveys using high-resolution satellite imagery to navigate, sophisticated acoustic measurements of the seafloor, and tethered underwater video and still images, revealed diverse geologic features and unique habitats shaped by these historic structures.  We identified numerous sink holes, blue holes that extended to over 100 m in depth, perfectly circular seagrass beds that formed on top of sediment-filled blue holes and around man-made objects such as ship wrecks, aircraft and abandoned oil exploration equipment, scoured hardground areas, oolitic sand shoals and moving sand waves.

Read the rest of “Quick-Look” Field Report from our Chief Scientist »

May 17, 2011

As the sun sets on Cay Sal Bank in the Bahamas tonight, our home for the last three weeks – the M/Y Golden Shadow – is steaming home toward Freeport. Our research team had one final dive this morning before closing up shop and putting away our gear until next time.

Read the rest of Mission Accomplished! »

May 15, 2011

Hi Sonia… what is your background and connection to the Living Oceans Foundation?

Hello! I am a Marine Biologist and I work under the supervision of professor Peter Mumby in the Marine Spatial Ecology Lab at the School of Biosciences at the University of Queensland in Brisbane, Australia. My appointment with the Living Oceans Foundation is as a Post-Doctoral Research Fellow.

Living Oceans Fellow Dr. Sonia Bejarano

Tell me about the research you’re conducting on the expedition as part of your Fellowship…

During the Global Reef Expedition, we’ll be visiting many different areas all over the world and I’ll be quantifying the amount of fish grazing that is occurring in each location. The reason why I am doing this is because fish grazing is a process that plays a very crucial role in the resilience of the reef ecosystem. The reef is constantly being hit by natural and human disturbances and there is always a chance that the reef is going to lose complexity and lose its main constructing organisms, which are the corals. In this particular situation, the algae have a bit of an advantage, so if a reef doesn’t have enough fish grazing activity, there is a risk that after a disturbance the reef would very quickly become an algae-dominated space rather than coral-dominated space. The reef may stand a better chance of remaining healthy if there is enough grazing pressure on it. So, if I can measure how much grazing pressure there is at each site, we will know how well each particular reef ecosystem can cope with a potential disturbance event and recover from it.

How do you measure the amount of fish grazing on a reef?

What we are measuring is the number of bites by each species of fish in a certain time over a certain area of reef. So, we are trying to quantify the grazing pressure as how often each square meter of reef gets grazed by the herbivorous fish community. We’ve tried in the past to do this measurement by following individual fish and counting its bites. That method is limited by the time an observer can spend underwater and we just felt we were not getting the full picture this way.

Read the rest of An Interview with Living Oceans Fellow Dr. Sonia Bejarano »

May 13, 2011

After 15 full days of research on Cay Sal Bank, our expedition team is still going strong. Our survey divers have completed transects and fish counts at 29 separate sites across the bank on nearly 40 dives. You can see each of these dive spots labeled below with red markers. The satellite groundtruthing team has covered hundreds of kilometers in the catamaran and surveyed nearly 400 sites with their drop camera. You can see their tracks as green markers on our map.

Yesterday afternoon the team had a chance to travel over to North Elbow Cay near where the M/Y Golden Shadow was anchored (see “Anchor 5″ above).

Read the rest of Odds & Ends »

MAY 11, 2011

Hi Jeremy… Can you tell us about your involvement in the Living Oceans Foundation Global Reef Expedition?

Sure, I’m a research assistant and a Ph.D. student in the National Coral Reef Institute housed at Nova Southeastern University’s Oceanographic Center and I work with Dr. Sam Purkis in the Remote Sensing Lab.  Dr. Purkis has been working with the Living Oceans Foundation for several years now, and I became a Living Oceans Fellow in 2010. Our research here on Cay Sal Bank focuses on the collection of ground-truth information for the creation of benthic habitat and bathymetric maps.  Essentially, we are trying to map the landscape of the bank using satellite imagery and the information we gather here in the field.

Read the rest of An Interview with Living Oceans Fellow Jeremy Kerr »

May 9, 2011

The weather has been beautiful the last few days. The sea is calm enough we can look over the railings of the Golden Shadow and see the bottom clearly, 20 meters below. We were treated to a gorgeous sunset this evening with quietly lapping waves and glassy waters.

Read the rest of Clear Skies, Calm Seas »

May 8, 2011

Throughout the weekend, our Global Reef Expedition research team continued to crank out dives and surveys in the far northeast corner of Cay Sal Bank.  Tomorrow afternoon, following our team’s morning dives, the M/Y Golden Shadow will leave its current anchorage at Dog Rocks to move westward on to new survey territory.

Early yesterday evening, Executive Director Phil Renaud brought out the foundation’s Remotely Operated Vehicle (ROV) for a test run off the stern of the Shadow. Along with NCRI’s Dr. Sam Purkis and the Shadow’s Electronics Officer Brian Meskell, Phil prepped the ROV for its first deployment of the expedition. Slowly, but surely, the entire expedition team made its way to the aft deck to watch the activities as Phil drove the ROV along the reef.

The ROV is a very useful addition to our expedition toolkit. The Seabotix LBV-150 ROV has a maximum operating depth of 150 meters, or roughly 500 feet, so it can survey the area below diver depth and it also allows our team to continue exploring the reef in the evenings when our SCUBA diving is finished for the day.

Read the rest of A Busy Weekend »

May 7, 2011

After arriving at our new anchorage point around noon, the expedition team was quickly underway again on the M/Y Golden Osprey for more research dives on Cay Sal Bank. During the transit, I caught up with coral reef scientist Dr. Judy Lang to find out more about her work and the AGRRA surveys that the expedition team is conducting here in Cay Sal.

Judy Lang gets ready in the dive locker.

Hi Judy… Can you tell me a little bit about your background and what your role is on this mission of the Global Reef Expedition?

I’m a coral reef biologist and for the last 12 years I’ve been involved with the AGRRA project. AGRRA is the Atlantic and Gulf Reef Rapid Assessment program. It was started by Robert Ginsberg in the mid-1990s following a large gathering of coral reef scientists from all around the world. Ginsberg wanted to know what was the status of reefs across the tropical Western Atlantic, so the program was designed to try and answer that question. We assess some important structural and functional attributes of reefs using a standardized protocol so the data can be broadly comparable. That means we’re mainly focused on the stony corals that are the primary constructors of the reef habitat, the herbivores that help to control the growth of the algae there, and the predators of both. And we’re trying to rapidly acquire information that’s representative not just of a few reefs, but the region as a whole and that means we have to get a little bit of information from a large number of sites throughout any given area of interest, such as Cay Sal.

Read the rest of An Interview with Coral Reef Expert Dr. Judy Lang »

May 6, 2011

Our time in Cay Sal Bank is going fast – we’ve already reached our halfway point, marked by a short trip back to Freeport today. We’ve covered a lot of ground on the East side of the bank in a short time. The AGRRA coral and fish teams have completed 22 total dives on 18 survey sites, and the groundtruthing team has traveled over 240 miles collecting video of the seafloor at nearly 200 separate survey sites.

On this map, the M/Y Golden Shadow's two anchorage points are labeled with anchors and our dive survey sites appear as red squares. The yellow dots represent our ADCP current profiler sites, and the green dots represent the groundtruthing team’s tracks.

  Read the rest of Comings and Goings »

May 4, 2011

During the last four days at our first anchorage site near Anguilla Cay, the expedition team covered a large amount of ground, including nine research dives. You can see the various research sites on the map below labeled as red dive flags. The yellow dots also represent where the groundtruthing team took measurements during their research runs.

 

Before pulling anchor to head North to our next research area on Sunday, the team picked up the Acoustic Doppler Current Profiler, or ADCP, from the seafloor with help from the Golden Shadow’s crew and the ship’s stern elevator.

Crew from the Golden Shadow use the ship’s elevator to bring the ADCP and its stabilizer to the surface.

Chief Scientist Andy Bruckner and Director Phil Renaud were happy with the results from this first trial and plan to leave the ADCP down longer on its next deployment. The ADCP provides us with measurements of temperature, oxygen levels, conductivity and turbidity over time. Most importantly, the sensor records current measurements that add to our understanding of life on the bank, such as the types and sizes of the corals that grow in this area.

Read the rest of A Change of Scene »