New research at the revealed unexpectedly high growth rates for deep water photosynthetic corals. , led by Samuel Kahng, affiliate graduate faculty in the (SOEST), alters the assumption that deep corals living on the brink of darkness grow extremely slowly.

Leptoseris is a group of zooxanthellate (symbiotic microalgae) coral species which dominate the coral community near the deepest reaches of the sun’s light throughout the Indo-Pacific. Symbiotic microalgae live within the transparent tissues of some coral—giving corals their primary color and providing the machinery for photosynthesis, and in turn, energy.

Deeper in the ocean, less light is available. At the lower end of their depth range, the sunlight available to the Leptoseris species examined in the recent study is less than 0.2 percent of surface light levels. Less light dictates a general trend of slower growth among species that rely on light for photosynthesis.

Old assumptions

Previous studies suggested that photosynthetic corals at the bottom of the ocean’s sunlit layer grow extremely slowly—about 0.04 inch per year for one species of Leptoseris. Until recently, there were few data on growth rates of corals at depths greater than about 225 feet given the logistical challenges of performing traditional time series growth measurements at these depths.

Kahng, who is also an associate professor at �鶹��ý Pacific University, collaborated with SOEST’s (HURL), the , National Taiwan University and Hokkaido University to collect colonies of Leptoseris at depths between 225 and 360 feet in the Auʻau Channel, �鶹��ý using HURL’s Pisces IV/V submersibles. The research team used uranium-thorium radiometric dating to accurately determine the age of the coral skeletons at multiple points along its radial growth axis—much like one might determine the age of tree rings within a tree trunk.

“Considering the low light environment, the previous assumption was that large corals at these extreme depths should be very old due to extremely slow growth rates,” said Kahng. “Surprisingly, the corals were found to be relatively young with growth rates comparable to that of many non-branching shallow water corals. Growth rates were measured to be between nearly 1 inch per year at 225 feet depth and 0.3 inches per year at 360 feet depth.”

Maximizing light absorption

The research team found that these low light, deep water specialists employ an interesting strategy to dominate their preferred habitat. Their thin skeletons and plate-like shape allow for an efficient use of calcium carbonate to maximize surface area for light absorption while using minimal resources to form their skeleton. These thin corals only grow radially outward, not upward, and do not thicken over time like encrusting or massive corals.

“Additionally, the optical geometry of their thin, flat, white skeletons form fine parallel ridges that grow outward from a central origin,” said Kahng. “In some cases, these ridges form convex spaces between them which effectively trap light in reflective chambers and cause light to pass repeatedly through the coral tissue until it is absorbed by the photosynthetic machinery.”

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—By Marcie Grabowski

A reception was held on the research vessel Kaʻimikai-O-Kanalo (“Heavenly Searcher of the Seas of Kanaloa”) just before she was sold this fall. Affectionately known to many as the K-O-K, the ship joined the fleet of UH marine expeditionary research vessels on January 15, 1994. Since then, K-O-K has been used across the Pacific Ocean on a variety of missions that included submersible operations, deployment of deep-sea moorings, hydrographic surveys and studies of marine biology, chemistry and climate change.

The original vessel was built by Mangrove Shipbuilding Co., Houston, Texas, in 1979 and was used for more than a decade for oil and gas exploration. Starting in 1992, UH oceanographer and director of the (HURL), Alex Malahoff, worked tirelessly to acquire and reconfigure this 185-foot offshore supply vessel to serve as a support ship for HURL’s two human-occupied submersibles, Makaliʻi and Pisces V, the remotely-operated vehicle RC V-150. After the vessel Makaliʻi was retired, K-O-K also supported the submersible Pisces IV.

Attendees at the reception included Beverly Malahoff, who christened the reconfigured R/V Kaʻimikai-O-Kanaloa when she emerged from Bender Shipbuilding and Repair Co. as a versatile 223–foot oceanographic research vessel with a cruising speed of 10 knots, a 15,000 nautical mile range, 50–day endurance, and space for 14 crew members and 19 scientists. The approximately $5 million conversion was funded by the state of �鶹��ý and NOAA, with the state holding the ship’s title.

K-O-K’s greatest accomplishments

K-O-K facilitated research in Hawaiian waters and across the Pacific Ocean by scientists from UH and around the world. Some of K-O-K’s greatest accomplishments using the HURL submersibles include , long-term monitoring of the changes and growth of Loʻihi seamount off �鶹��ý Island and finding dozens of new species in the Papahānaumokuākea Marine National Monument.

“In addition to enabling important discoveries and ocean monitoring efforts, the local access of K-O-K made available UH’s UNOLSM (University-National Oceanographic Laboratory System) and AGOR (Auxiliary General Oceanographic Research) vessels (previously R/V Moana Wave and now R/V Kilo Moana) for extended circum-Pacific expeditions,” said Brian Taylor, dean of the UH ����ԴDz� .

One of the most consistent users of K-O-K was the (HOT) program. From July 1999 through July 2018, 93 separate HOT cruises to the open-ocean Station ALOHA were conducted aboard K-O-K. The vessel was also used in �鶹��ý for numerous expeditions by the UH and the UH , including the Life Aquatic in the Volcanic Aftermath expedition in July 2018 to explore the effects of the Kīlauea eruption on the marine environment.

After 25 years of scientific voyages for UH, K-O-K was retired following her final expedition in July 2018 on the 304th cruise of the HOT program. In December, K-O-K was towed to Mexico by an ocean tug where she will be recycled and repurposed.

—By Marcie Grabowski

New research reveals growth rates of deep-sea coral communities for the first time, and the pattern of colonization by various species. The study was a collaboration between researchers at the University of �鶹��ý at Mānoa (SOEST), and the .

The scientific team used the UH Mānoa submersible and remotely-operated vehicles to examine coral communities on submarine lava flows of various ages on the leeward flank of �鶹��ý Island. Utilizing the fact that the age of the lava flows—between 61 and 15,000 years—is the oldest possible age of the coral community growing there, they observed the deep-water coral community in �鶹��ý appears to undergo a pattern of ecological succession over time scales of centuries to millennia.

reported Coralliidae or pink coral, were the pioneering taxa, the first to colonize after lava flows were deposited. With enough time, the deep-water coral community showed a shift toward supporting a more diverse array of tall, slower growing taxa: Isididae, bamboo coral, and Antipatharia, black coral. The last to colonize was Kulamanamana haumeaae, gold coral, which grows over mature bamboo corals, and is the slowest growing taxa within the community.

“This study was the first to estimate the rate of growth of a deep-sea corals on a community scale,” said Meagan Putts, lead author of the study and research associate at SOEST’s . “This could help inform the management of the precious coral fishery in �鶹��ý. Furthermore, �鶹��ý is probably the only place in the world where such a study could have been performed due to its continuous and well known volcanology.”

“Prior to beginning this work, it was unclear if a pattern of colonization existed for deep-sea coral communities and in what time frame colonization would occur,” said Putts. “When put into context with what we do know about the life history of Hawaiian deep-water corals, the results of this work make sense.”

This study has important conservation and sustainability implications regarding these ecosystems that had never before been ecologically quantified. This research also provides insights about recovery of deep sea ecosystems that may be disturbed by activities such as fishing and mining.

“Further,” said Putts, “as the Island of �鶹��ý continues to have periodic eruptions producing very recent deep-water lava flows, the last in May 2018, there are opportunities to study initial settlement patterns and appraise the impact hot, turbid, mineral-rich water from new flows has on coral communities.”

—By Marcie Grabowski

Researchers from the University of �鶹��ý at ����ԴDz� have in the deep coral ecosystem in the ʻAuʻau channel off Maui, �鶹��ý. Mesophotic coral ecosystems (MCE) are generally found at depths between 130–500 feet and possess abundant plant (algal) life as well as new fish species. The mysteries of these reefs are only recently being revealed through technological advances in closed circuit rebreather diving. Previously overlooked—being too precarious for conventional SCUBA and too shallow to justify the cost of frequent submersible dives—mesophotic reefs continuously disclose breathtaking levels of biodiversity with each dive, yielding species and behavioral interactions new to science.

The UH ����ԴDz� (HURL) used the Pisces V submersible to collect native algae from the mesophotic reefs in the ʻAuʻau channel. Using the DNA sequencing facility at the UH ����ԴDz� , Benjamin Wainwright, lead author of the study and UH ����ԴDz� botany postdoctoral researcher, and colleagues determined which species of fungus were associated with the native algae.

Thriving in extremely diverse habitats

Fungi have been documented in almost all habitats on Earth, although marine fungi are less studied in comparison to their terrestrial counterparts. Scientists have found fungi in deep and shallow water corals, marine sponges and other invertebrates. The recently discovered fungi, however, were found living in association with algae.

“To the best of our knowledge, this is the first documented evidence confirming fungi in MCEs,” said Wainwright.

Additionally, the research team discovered that 27 percent of the species detected in these deep dark environments are also found on terrestrial rainforest plants in �鶹��ý.

“Finding such high overlap of fungal diversity on terrestrial plants was surprising. Mesophotic reefs are as dark as it gets where photosynthesis is still possible, so to find the same species of fungi on forest plants illustrates the remarkable ability of some fungi to tolerate, and thrive, in extremely different habitats,” said , senior author of the study and UH ����ԴDz� associate professor of botany. “This ecological breadth is something that seemingly sets fungi apart from other organisms.”

Potential benefits to society

Plant-associated fungi provide many benefits to society. For example, Taxol, a chemotherapy medication used to treat cancers, is produced by a fungus found inside tree bark and leaves. Additionally, research has shown that fungi are useful in bioremediation efforts (for example, oil spill and industrial waste treatment) and capable of breaking down plastic waste.

It is currently not known whether the newly discovered fungal species are pathogens, helpful symbionts or unimportant to their algae hosts.

“Further, we don’t currently know what metabolic capabilities they have that may prove to have medical or environmental applications,” said Wainwright. “We know other undiscovered species are present in these ecosystems. Unfortunately, if we do not look now we may miss our opportunity to benefit from them and conserve them.”

Deep reefs, like those in the ʻAuʻau channel, may act as a refuge as Earth’s climate changes, providing habitat for any marine creatures that can take advantage of this deeper habitat. If this is indeed the case, understanding how this habitat functions and how the corals, algae and fungi interact with one another will be vital to preserving the refuge in the deep.

—By Marcie Grabowski

The deep sea is a dark, cold, remote place—yet many Earth processes, and likely the origin of life itself, occur uniquely there. Few have been able to study its wonders in person. The (HURL) based at the University of �鶹��ý at Mānoa (SOEST) maintains two of the last manned submersibles in the world, the and the . Even during tight budgetary times, the subs have enabled incredible research, discovery, and exploration—not just for researchers but for students, as well.

“We have just completed a banner year,” said , director of facilities and submersible operations at HURL. “It is hard to believe all that happened in 2016.”

During test dives in March, HURL was fortuitously able to recover the , a World War II-era Imperial Japanese Navy mega-submarine, lost since 1946 when it was intentionally sunk by U.S. forces after its capture.

Following that, HURL secured a contract with the Navy to train U.S. Navy Special Operations Command divers how to pilot the Launch, Recovery and Transport platform.

“This was what allowed us to keep our excellent crew intact for a few more months and gave me time to put together more Pisces dives,” said Kerby.

Capturing video of deep coral bioluminescence

HURL originally had on its September schedule two dives focused on NOAA’s study of deep sea corals with Frank Parrish, a research marine biologist, at the Pacific Islands Fisheries Science Center. Then four more dives were supported by National Geographic for Sylvia Earle to bring new lowlight camera technology down and capture the first video images of deep coral bioluminescence on bamboo and gold coral. As these were coral species that Parrish was working on Earle invited him collaborate on the dives. During the dives, Kerby, who is an expert submersible pilot and artist, used the sub’s robotic arm to hold a paint brush to stimulate the bioluminescent response in deep sea corals.

“It was as if Terry was painting the bioluminescence on a coral colony like it was a canvas,” said Parrish. “It was a stunning effect!”

Exploring seamounts and the Monument

HURL got help once again. This time from Conservation International (CI). In September, with support from —two of which have never been explored by human-occupied submersibles. Cook and McCall seamounts—part of the Geologists Seamounts, located 100 miles southwest of the Big Island of �鶹��ý—and Loʻihi were the destinations for this three-day series of dives using the Pisces IV and Pisces V, HURL’s two submersibles. Among the impressive volcanic formations, the team spotted such wonders as a rare with large fins that look like Dumbo’s ears at Cook Seamount, and a potentially new species of violet-hued coral they dubbed Purple Haze. At McCall Seamount, which is home to a large number of small deep-sea sharks, the team saw a .

“I’m proud to say that we went out in September and pulled of 18 dives in 10 days and accomplished every scheduled dive,” said Kerby. “On top of that, we’ve built a partnership with Conservation International—they’re asking for more dives in 2017! We are all excited about doing these exploration dives of seamounts in 2017.”

In October 2016, with National Science Foundation-funded researchers, the Pisces crew explored the Marine National Monument, a monument recently expanded by President Barack Obama to cover three times its previous area. During this month-long trip, the team explored deep corals and collected important samples and images of seamounts that had been ravaged by coral dredging activities—area that will now be protected in the new expanded monument. Next fall, the subs will go out to Papahānaumokuākea again with the same NSF group.

Submersibles provide unique access and exploration capability

In a world that seems to be moving towards remotely operated vehicles for deep sea exploration, “There is no substitute for being down in the environment, for being able to react to the environment in real time. These are things only humans can do,” said , UH Mānoa vice chancellor for research. “I hope we never see the day that we replace, rather than supplement, manned submersibles.”

“There is so much more to explore in the deep sea,” said Brian Taylor, SOEST dean. “We want to be able to provide our researchers with eyes and hands-on access to these inaccessible marine environments for as long as we can.”

The opportunities afforded by the Pisces subs enable greater exploration and innovation—a cornerstone of SOEST’s and UH Mānoa’s academic and research vision.

“A lab like HURL is always innovative, in equipment and in bringing research to the public,” said Kerby. “The great thing about a university is you get students, faculty, and industry coming together to advance our understanding and progress, and HURL is a great example of what that can look like for the marine environment.”

Read more on the .

—By Marcie Grabowski

A team of 16 researchers, including several from the University of �鶹��ý at Mānoa, has completed a comprehensive investigation of deep coral reef environments, known as mesophotic coral ecosystems, throughout the Hawaiian Archipelago. The , published in the open-access journal spanned more than two decades and involved a combination of submersibles operated by the UH Mānoa (HURL), remotely operated vehicles, drop-cameras, data recorders and advanced mixed-gas diving to study these difficult-to-reach environments.

The researchers documented vast areas of 100 percent coral-cover and extensive algal communities at depths of 50-90 meters (165-300 feet) extending for tens of square kilometers, and found that the deep-reef habitats are home to many unique and distinct species not found on shallow reefs. The findings of the study have important implications for the protection and management of coral reefs in �鶹��ý and elsewhere.

“This is one of the largest and most comprehensive studies of its kind,” said Richard Pyle, researcher and lead author of the publication. “It involved scientists in many different disciplines and from multiple federal, state and private organizations working together with a range of different technologies across the entire Hawaiian Archipelago.”

Documenting the “Twilight Zone”

The primary objective of the study was to characterize deep coral reef habitat, known as mesophotic coral ecosystems or the coral-reef “Twilight Zone.” Coral reefs at depths of 30 to 150 meters (100 to 500 feet) are among the most poorly explored of all marine ecosystems on Earth. Deeper than conventional scuba divers can safely venture, and shallower than most submersible-based exploration, these reefs represent a new frontier for coral reef research.

To document these elusive deep coral reefs, the team used a wide range of advanced technology, including multibeam bathymetry mapping, mixed-gas closed-circuit rebreather diving, towed and remotely operated camera systems, a variety of environmental sensors for recording light, temperature, water movement and other parameters, and two research submersibles operated by HURL. One of the novel approaches taken during the project was to combine rebreather divers and submersibles together on coordinated dives.

“Free-swimming divers and submersibles don’t often work side-by-side on scientific research projects,” said Pyle. “Submersibles can go much deeper and stay much longer, but divers can perform more complex tasks to conduct experiments and collect specimens. Combining both together on the same dives allowed us to achieve tasks that could not have been performed by either technology alone.”

Extensive deep sea corals

A major focus of the study was to document extensive areas of 100 percent coral cover at depths of 90 meters (300 feet) or more off the islands of Maui and Kauaʻi. In particular, vast expanses of continuous coral cover, extending for tens of square kilometers, exist in many sites in the ʻAuʻau channel off the southwest side of Maui. The reefs are dominated by stony, reef-building corals in the genus Leptoseris, a plate-like coral specialized for deep reef environments.

“These are some of the most extensive and densely populated coral reefs in �鶹��ý,” said Anthony Montgomery, a co-author of the study who represented the �鶹��ý State Department of Land and Natural Resources during most of the project. “It’s amazing to find such rich coral communities down so deep.”

Healthy algae meadows

In addition to the corals, the area is also home to extensive algae meadows that support unique communities of fishes and invertebrates. More than seventy species of macroalgae inhabiting the deep reefs were identified during the study, and several more new species have not yet been assigned formal scientific names. Both corals and algae depend on sunlight to drive photosynthesis, and the study attributed the existence of many of the deep reef habitats to exceptionally clear water.

“We found that the diversity of macroalgal species actually peaked at around 90 meters (300 feet) deep,” said Heather Spalding of the UH Mānoa and a co-author of the study. “These extensive algae meadows represent a major component of the deep-reef communities, and play a fundamentally important role in the overall ecology.”

Species found nowhere else on Earth

Another interesting finding of the study is that the rate of endemism—species found nowhere else on Earth—increases substantially on the deep reefs. Whereas only 17 percent of the fishes surveyed at depths less than 30 meters (100 feet) are species endemic to the Hawaiian Islands, more than half of the species below 70 meters (230 feet) are Hawaiian endemics. The rate of endemism increases even more in the Northwestern Hawaiian Islands, where 100 percent of the fishes inhabiting some of the deep reefs are found only in �鶹��ý.

“The extent of fish endemism on these deep coral reefs, particularly in the Northwestern Hawaiian Islands, is astonishing,” said Randall Kosaki, NOAA’s Deputy Superintendent of the and a co-author of the study. “We were able to document the highest rates of endemism of any marine environment on Earth.”

Food web studies

The food web supporting the fishes on deep reefs was studied using advanced stable isotope methods, which revealed small but important differences in the ecology of fish living on deep and shallow reefs.

“We used these methods because more traditional approaches require large numbers of specimens,” said Brian N. Popp, professor of Geology and Geophysics in the UH Mānoa “Our results are helping us better understand the relationship between the ecology of deep and shallow coral reef fish communities.”

Implications for conservation

The results of the study have important implications for conservation management. In addition to the rich and unique biodiversity inhabiting these environments, deep coral reefs may serve as a refuge for certain species that are more heavily impacted on shallow coral reefs.

“With coral reefs facing a myriad of threats,” said Kimberly Puglise, an oceanographer with NOAA’s “The finding of extensive reefs off Maui provides managers with a unique opportunity to ensure that future activities in the region, such as cable laying, dredging dump sites, and deep sewer outfalls, do not irreparably damage these reefs.”

Research sponsors

The research, which spanned more than two decades and encompassed the entire 2,590- kilometer (1,600-mile) extend of the Hawaiian Archipelago, was primarily supported by NOAA’s and the as well as, HURL and the State of �鶹��ý.

“We dedicate this work to our friend, colleague and co-author John Rooney, whose commitment to documenting mesophotic coral ecosystems in �鶹��ý was inspirational to us all,” stated the authors. Rooney received a master of science degree in oceanography in 1995 and his doctorate in geology and geophysics in 2002, both from the UH Mānoa School of Ocean and Earth Science and Technology. Rooney passed away in a recreational diving accident in �鶹��ý on January 16, 2016.

—By Marcie Grabowski

The Pacific Ocean has by far the largest number of seamounts, distinct features of volcanic origin that rise off the seafloor but do not break the surface, of any ocean on the planet. Earlier this month, the (HURL) teamed up with the non-profit group (CI) to dive on seamounts near �鶹��ý—two of which have never been explored by human-occupied submersibles. Cook and McCall seamounts—part of the Geologists Seamounts, located 100 miles southwest of the Big Island of �鶹��ý—and ��ōʻ���� were the destinations for this three-day series of dives using the Pisces IV and Pisces V, HURL’s two submersibles.

Prior to the recent expedition, limited surveys on Cook using remotely operated vehicles showed tall fan corals, a variety of deep sea hard corals, and other invertebrates. Very little was known about McCall.

To examine geological features and the rich variety of marine life, the team conducted video surveys and collected sediment, rock and water samples on each dive. They also used bait stations to draw close fish and especially deep sea sharks. Among the impressive volcanic formations, the team spotted such wonders as a rare Dumbo octopus with large fins that look like Dumbo’s ears at Cook Seamount, and a potentially new species of violet-hued coral they dubbed Purple Haze. At McCall Seamount, which is home to a large number of small deep-sea sharks, the team saw a purple chimaera.

During the last dive of the three-day expedition, HURL’s submersibles went into ��ōʻ����’s pit crater for the first time since 2011. The submersible crews were able to survey familiar territory and make an updated assessment of the ever changing conditions in the bottom of the pit. They saw incredible basalt formations, rugged terrain and a very active vent system. The bait station set in the pit crater lured out a large, elusive Pacific sleeper shark.

Dive video highlights

A dumbo octopus (Grimpoteuthis sp.) swims on the Cook Seamount (filmed from UH HURL’s submersible). (credit: CI and HURL)

A purple chimaera swims near McCall Seamount (filmed from UH HURL’s submersible). (credit: CI and HURL)

A Pacific sleeper shark swims near ��ōʻ���� Seamount (filmed from UH HURL’s submersible). (credit: CI and HURL)

A special issue of the academic journal , published recently, is devoted to expanding understanding of the global issue of chemical munitions dumped at sea. The publication was edited by , interim director of the University of �鶹��ý at Mānoa’s , and Jacek Beldowski, Science for Peace and Security MODUM (Towards the Monitoring of Dumped Munitions Threat) project director at the —two international leaders in the assessment of sea-dumped military munitions and chemical warfare; and the effects on the ocean environment and those who use it.

“The overarching objective of the special issue of Deep Sea Research II is to collate and compare results from two of the most comprehensive studies of sea-dumped chemical munitions to promote data sharing and constrain the factors that influence where and how to mitigate the damage,” said Edwards.

International practice and treaty

Whereas today chemical warfare agents (CWA) are destroyed via chemical neutralization processes or high-temperature incineration, the internationally accepted practice in the early to middle 20th century was sea disposal of excess, obsolete or unserviceable munitions, including chemical warfare materiel.

In 1970, the U.S. Department of Defense discontinued this practice and in 1972 an international treaty, the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, was developed to protect the marine environment. By the time this treaty, referred to as the London Convention, was signed by a majority of nations, millions of tons of munitions were known to have been disposed throughout the world’s oceans.

�鶹��ý munitions assessment

Since 2007, the (HUMMA) has been assessing sea-disposed military munitions in a region south of the island of Oʻahu. Scientists at UH Mānoa and Environet and members of the U.S. Army collaborated to assess the condition of munitions casings, effects on seafloor ecosystems and the presence of metals and CWA in sediments and shrimp.

The results of those studies, published in the current issue of Deep Sea Research II, document that the 40 munitions examined in detail in the HUMMA field area pose little, if any, risk to human health while simultaneously recognizing that these 40 are only a subset of the hundreds of likely chemical munitions in the area.

Illustrative of the mystery of the vast ocean, the HUMMA project enabled , Brisingenes margoae nov. sp.—named in honor of Edwards. This unique species and other sea stars were collected using the ’s submersibles.

Baltic Sea munitions assessment

The (CHEMSEA) was conducted in the Baltic Sea from 2011 until 2014. In combination, the studies from CHEMSEA published in Deep Sea Research II recognize sea-dumped munitions as a point source of pollution in the Baltic Sea, although its contribution appears to be low and limited to deep, anoxic basins. Acute toxicity to humans from CWA (e.g., mustard, Adamsite) is unlikely given recorded concentrations, although adverse effects of chronic exposure on fish populations cannot be excluded.

The collected articles from the CHEMSEA and HUMMA projects projects in the special issue of Deep Sea Research II present a number of techniques that are useful for the complex in-depth investigation of munitions dumpsites. Results show that sea-dumped munitions in both project areas do not represent direct risk for humans except in cases of exposure due to recovery, although in the more confined Baltic Sea with limited water exchange, munitions can have adverse impact on the ecosystem.

—By Marcie Grabowski

During a test dive last week, the recovered a bronze bell from the I-400—a World War II-era Imperial Japanese Navy mega-submarine, lost since 1946 when it was intentionally sunk by U.S. forces after its capture.

Longer than a football field at 400 feet, the I-400 was known as a “Sen-Toku” class submarine—the largest submarine ever built until the introduction of nuclear-powered subs in the 1960s. The I-400 is now protected under the Sunken Military Craft Act and managed by the Department of the Navy.

Teamwork and partnership

The recovery was led by veteran undersea explorer , HURL operations director and chief submarine pilot. Kerby was joined by Scott Reed, Chris Kelley and Max Cremer (all with HURL) on the dive. The team used both of HURL’s human-occupied submersibles, Pisces IV and Pisces V. Teamwork between the two subs was instrumental in recovering the bell.

Since 1992, HURL has used its submersibles to search for historic wreck sites and other submerged cultural resources as part of the maritime heritage research effort. Heritage properties like historic wreck sites are non-renewable resources possessing unique information about the past. This recovery effort was possible because of a collaboration between the University of �鶹��ý , , Naval History and Heritage Command and the .

“It was an exciting day for the submersible operations crews of Pisces IV and Pisces V. Just prior to our test dive, Dr. [archaeologist at CSU-C] had received the underwater archaeological research permit from the Naval History and Heritage Command. We had only one chance to relocate and recover the bell,” said Kerby.

A symbol of the past and the future

At the end of WWII, the U.S. Navy captured five Japanese subs, including the I-400, and brought them to Pearl Harbor for inspection. When the Soviet Union demanded access to the submarines in 1946 under the terms of the treaty that ended the war, the U.S. Navy sank the subs off the coast of Oʻahu. The goal was to keep their advanced technology out of Soviet hands during the opening chapters of the Cold War. HURL has successfully located four of these five lost submarines and now recovered a piece of that history.

“These historic properties in the Hawaiian Islands recall the events and innovations of World War II, a period which greatly affected both Japan and the United States and re-shaped the Pacific region,” said Hans Van Tilburg, maritime heritage coordinator for NOAA in the Pacific Islands region. “Wreck sites like the I-400 are reminders of a different time and markers of our progress from animosity to reconciliation.”

A historic maritime treasure

Fox developed a conservation treatment plan for the bell. Following a year-long stabilization process, the bronze bell will be on display at the USS Bowfin Submarine Museum, where it will join binoculars and other artifacts from the I-400.

“The recovery of the bronze bell from the I-400, and its eventual display at the USS Bowfin Submarine Museum gives us a chance to share this history with more than three hundred thousand annual visitors, many from the Pacific Region. What was once an artifact on the seafloor will now be a national historic maritime treasure for all to see,” said Jerry Hofwolt, executive director of the USS Bowfin Submarine Museum.

—By Marcie Grabowski

Starting this month, NOAA Ship began two months of dives using unmanned remotely operated vehicles, or ROVs, to explore marine protected areas in the central Pacific Ocean. Anyone with an internet connection can the deep sea with scientists and researchers from their computer or mobile device. is available during each and every dive.

“Given the unexplored nature of these areas, their remoteness and their known status as biodiversity hotspots, I’d be very surprised if we didn’t see many animals and phenomena that are new to science,” said expedition science team lead Christopher Kelley, associate professor of biology and program biologist at the at the .

The ship and its crew will investigate deeper waters in and around in the Northwestern Hawaiian Islands, Johnston Atoll in the , and the .

Exploration Command Center on UH Mānoa campus

In the �鶹��ý Institute of Geophysics Building at UH Mānoa, NOAA and UH Mānoa’s established an Exploration Command Center—a location where live video feeds from the ship and ROVs are displayed and scientists on land can communicate with the ship-board team, enabling tele-presence collaboration.

This is the first expedition of a major three-year effort to systematically collect information to support science and management needs within and around the U.S. marine national monuments and NOAA’s national marine sanctuaries in the Pacific.

Read more about the current expedition in the .

—By Marcie Grabowski