Expedition goal: Our cruise off the central California coast has several objectives related to three research themes in deep-sea ecology: 1) study the sponge and coral communities at Sur Ridge, 2) revisit a corn stover sunk to 3,200 meters depth in 2009 and sample the colonizing communities, and 3) begin a wood-fall experiment to see how species colonize these ephemeral sources in the deep sea.

Expedition dates: April 19 – April 24, 2019

Ship: R/V Western Flyer

Research technology:  ROV Doc Ricketts, benthic respirometer system, deep particle image velocimetry (DeepPIV)

Expedition chief scientist: Jim Barry 

Our primary goals focus on studies of deep-sea coral and sponge communities at Sur Ridge, a seamount about 60 kilometers (40 miles) off the coast of Monterey which rises to within 800-1,400 meters (2,600-4,600 feet) of the sea surface. This rocky ridge is rich with beautiful coral and sponge gardens containing centuries-old corals towering two-to-three meters tall like small oak trees, sponges one-to-two meters wide that may be even older, as well as a suite of fishes, sea stars, and other species that call these gardens home. The corals and sponges consume suspended plankton and drifting organic particles from currents sweeping over the ridge and must avoid being consumed by predators such as sea slugs and sea stars.

Some of the questions we have about the Sur Ridge sponge and coral communities include: Why are corals and sponges thriving on some parts of the ridge but sparse in others? Is this difference attributed to food and feeding success, predators, and/or competition with their neighbors? How vulnerable are sponges and corals to human activities like climate change, which is now penetrating the depths of the ocean? To begin answering these questions, we plan various activities for each day, such as deploying current meters, sediment traps (funnel shaped traps that capture sinking debris), and other sensors to measure water flow and suspended material that influence the type and abundance of food sweeping over the ridge and past corals. We will also be measuring respiration rates of sponges and corals using novel sensors and instruments, tagging corals to monitor growth, and measuring rates of predation by sea stars—the deep-sea corals nemesis.

Our second goal is to revisit a large bale of corn stover (essentially a hay bale) that we sunk to a depth of 3,200 meters (10,500 feet) in 2009. We wanted to test one notion for deep-sea carbon sequestration that could mitigate climate warming by storing carbon in the deep-sea rather than allowing it to be emitted to the atmosphere. One idea for deep-sea carbon sequestration is to gather up crop residue (stalks, husks, and other plant material, package it, and sink it in the deep ocean where it will remain for many centuries, rather than allowing it to degrade in the soil and ultimately release CO2 into the atmosphere. This peculiar idea was suggested years ago and, in preparing for a cruise in 2009, we decided to sink one corn bale to test this notion. We’ll revisit the bale on this cruise to probe it with sensors to measure its rate of decay, giving us some idea of how long its carbon will remain in the deep sea before eventually making its way back to the atmosphere.

Our third goal for the cruise is to initiate an experiment measuring the diversity of animals that colonize wood falls in the deep sea. Logs and other woody debris are carried to the sea by rivers and eventually sink, some to great ocean depths. These wood falls can be a bonanza for some organisms living in the food-poor abyss. Wood-fall organisms—perhaps most notably wood-boring clams, are notorious for their damage to wooden ships, but several related species live in the deep ocean. Some are wood-fall specialists and are found nowhere else, while others are opportunists that use any food source they can find. Our experiment will place small wood falls, 10 x 10 x 45.5 centimeter wood blocks (4 x 4 x 18 inch wood blocks), on the seafloor across an area the size of 10 football fields to see if the assemblage of organisms (clams, snails, crustaceans, worms, etc.) that colonize each block are related to the distance between blocks. This will help us understand if larvae drifting over the seafloor may sense a wood fall or if the colonization process is more random. From this and similar experiments, we are building an understanding of how food limitation and the challenging conditions in the deep sea have shaped the evolution of species and their abilities to exploit ephemeral “food falls” (wood, whales, or anything in between).

About this expedition:

Eve Lundsten and Charlie Paull

A team of 11 from MBARI will be participating in an international research expedition on the Korean Polar Research Institute (KOPRI) icebreaker Araon from August 21 to September 17, 2022.  MBARI will be providing state-of-the-art autonomous underwater vehicles (AUVs) and a remotely operated vehicle (ROV) to study the seafloor under the Canadian Beaufort Sea along the southern edge of the Arctic Ocean. On this expedition we will investigate the effects of thawing submarine permafrost in this remote area of the Arctic Ocean.

 

Korea icebreaker Araon

Permafrost is ground that remains frozen throughout the year. Global warming has focused considerable attention on the decomposition of permafrost on land and its impact on shaping the landscape. In contrast, almost nothing is known about the decomposition of relict permafrost under the sea. The Arctic Ocean is rimmed by vast shallow areas, such as the continental shelf in the Beaufort Sea. During periods of low sea level associated with glaciation, these shallow areas have been periodically exposed to the frigid air temperatures suitable for permafrost formation. Because of the lack of moisture in the Arctic, this area was not blanketed in glaciers and therefore experienced mean annual air temperatures that were often -15°C (5° F) or colder. These cold air temperatures caused the development of thick permafrost. In contrast, when sea level rises during interglacial periods, as happened about 12,000 years ago, the permafrost is flooded by the relatively warm seawater. Because the permafrost here was so thick and the diffusion of heat was so slow, ancient Pleistocene permafrost bodies that are still 100’s of meters thick remain beneath the continental shelf of the Beaufort Sea, even after 12,000 years.

The first systematic high-tech mapping along the edge of the continental shelf of the Canadian Beaufort Sea was conducted in 2010. These maps revealed a band of unusually rough seafloor terrain along a 95-kilometer (59-mile) stretch of the shelf, roughly 180 kilometers (110 miles) offshore. This rough topography coincided with what was once the seaward edge of that relict Pleistocene permafrost. Sections of this topography were subsequently remapped multiple times using MBARI AUVs. These repeated surveys show that multiple new sinkholes have formed in this area over just a few years. The volume of the largest new sinkhole, developed in less than 9 years, is equivalent in size to a city block of 6-story apartment buildings. The rate of morphologic change associated with the decomposing relict permafrost seen here is among the most rapid seen anywhere on Earth.

Route that the Araon will take during the 2022 Arctic expedition. MBARI will be participating in the second leg (in red), from Utqiagvik to Nome.

Route that the Araon will take during the 2022 Arctic expedition. MBARI will be participating in the second leg (in red), from Utqiagvik to Nome.

On this upcoming expedition in August 2022, the MBARI science party will be boarding the Araon in Utqiagvik, Alaska (formerly Barrow), along with other researchers from Korea, Canada, and the US. From Utqiagvik, the Araon will transit east passing along the entire north shore of Alaska before entering into the study areas in Canadian waters.

MBARI is contributing to the expedition two AUVs that are designed to map the seafloor. These untethered, free-swimming robots will descend to and independently navigate over the bottom terrain to map the seafloor along pre-programmed routes. The AUVs carry multi-beam mapping sonars that collect data at a resolution that exceeds what can be collected with a ship mounted system. These highly-detailed maps help illuminate the processes that shape the seafloor and, when conducted at repeated intervals, reveal how dynamic areas like these change over time.

MBARI’s MiniROV will be used to explore and sample the freshly altered seafloor. This ROV was designed to be small and robust so that it could be easily shipped to remote ports, providing access to study areas beyond the west coast of North America. The MiniROV utilizes an articulated arm to collect water samples, sediment samples, and animals, while recordings from a high-resolution video camera provide insight about the precise context of their locations.

Pre-cruise preparations

Expeditions like this take years to plan and require an enormous amount of work from numerous people from all of MBARI’s divisions. Engineering efforts, permitting acquisition, funding agreements, and safety training all begin years before we can set foot on the boat. It is only with considerable organization, and a little bit of good luck, that it all comes together to allow us conduct the research of interest to our team.

Physical preparations for this expedition began at MBARI in the fall of 2021 with the building of new ROV control room specifically designed for this expedition. The space was fabricated within a 20-foot shipping container with just enough floor space reserved to house the two mapping AUVs during shipping.

Tests of the new ROV control room were conducted at sea in Monterey Bay through early 2022 to ensure everything worked prior to packing, which commenced in March 2021. Two additional shipping containers were needed to hold the MiniROV, the ROV winch, and other assorted equipment needed for the expedition.

Our three shipping containers had to make an arduous journey from Oakland, California to Korea before heading up to the Arctic. Transpacific shipping delays and backlogs left some of our gear behind­–fortunately, it caught the last possible ship, arriving in Busan, Korea, just in the nick of time. To our knowledge all the MBARI gear is safely stowed onboard the Araon, awaiting our arrival in Utqiagvik.

The two container ships which carried MBARI’s equipment to Korea.
 

Maritime safety training

MBARI staff enjoyed a unique experience completing a required 5-day safety training and survival class that included the basics of fighting fires, CPR, first aid, and at-sea survival. Far outside our normal routines as scientists and engineers, it had us in full fire fighter gear, donning a self-contained breathing apparatus to put out a fire in a confined space, and we had to practice jumping off a mock ship (a high dive) and flipping an overturned life raft. It was a wonderful experience that we hope to never have to use in real life.

Learning how to work as a team to advance on a fire during firefighting training.
Life raft flipping test.

Expedition Logs

Team

Directory

Collaborators

Jong Kuk Hong (Korean Polar Research Institute), Young Keun Jin (Korean Polar Research Institute), Tae Siek Rhee (Korean Polar Research Institute), Scott Dallimore (Geological Survey of Canada). Mathieu Duchesne (Geological Survey of Canada)

Technologies

All Technologies