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Medical shortages during the COVID-19 pandemic saw numerous efforts to 3D print personal protective equipment and treatment supplies. There is, however, little research on the potential biocompatibility of 3D-printed parts using typical polymeric resins as pertaining to volatile organic compounds (VOCs), which have specific relevance for respiratory circuit equipment. Here, we measured VOCs emitted from freshly printed stereolithography (SLA) replacement medical parts using proton transfer reaction mass spectrometry and infrared differential absorption spectroscopy, and particulates using a scanning mobility particle sizer. We observed emission factors for individual VOCs ranging from ∼0.001 to ∼10 ng cm–3 min–1. Emissions were heavily dependent on postprint curing and mildly dependent on the type of SLA resin. Curing reduced the emission of all observed chemicals, and no compounds exceeded the recommended dose of 360 μg/d. VOC emissions steadily decreased for all parts over time, with an average e-folding time scale (time to decrease to 1/e of the starting value) of 2.6 ± 0.9 h.

Deepstaria enigmatica (Semaeostomeae: Ulmaridae) is one of the largest and most mysterious invertebrate predators of the deep sea. Humans have encountered this jellyfish on only a few occasions and many questions related to its biology, distribution, diet, environmental tolerances, and behavior remain unanswered. In the 45 years since its formal description, there have been few recorded observations of D. enigmatica, due to the challenging nature of encountering these delicate soft-bodied organisms. Members of Deepstaria, which comprises two described species, D. enigmatica and D. reticulum, reside in the meso-bathypelagic region of the world's oceans, at depths ranging from ∼600 to 1750 m. Here we report observations of a large D. enigmatica (68.3 cm length × 55.7 cm diameter) using a custom color high-definition low-light imaging system mounted on a scientific remotely operated vehicle (ROV). Observations were made of a specimen capturing or “bagging” prey, and we report on the kinetics of the closing motion of its membranelike umbrella. In the same area, we also noted a Deepstaria “jelly-fall” carcass with a high density of crustaceans feeding on its tissue and surrounding the carcass. These observations provide direct evidence of singular Deepstaria carcasses acting as jelly falls, which only recently have been reported to be a significant food source in the deep sea.

Tethered deep-sea robots and instrument platforms, such as Remotely Operated Vehicles (ROVs) and vertical-profiling or towed instrument arrays, commonly rely on fiber optics for real-time data transmission. Fiber optic tethers used for these applications are either heavily reinforced load-bearing cables used to support lifting and pulling, or bare optical fibers used in non-load bearing applications. Load-bearing tethers directly scale operations for deep-sea robots as the cable diameter, mass, and length typically require heavy winches and large surface support vessels to operate, and also guide the design of the deep-sea robot itself. In an effort to dramatically reduce the physical scale and operational overhead of tethered live-telemetry deep-sea robots and sensors, we have developed the Fiber Optic Reel System (FOReelS). FOReelS utilizes a customized electric fishing reel outfitted with a proprietary hollow-core braided fiber optic fishing line and mechanical termination assembly (FOFL), which offers an extremely small diameter (750 μm) load-bearing (90 lb/400 N breaking strength) tether to support live high-bandwidth data transmission as well as fiber optic sensing applications. The system incorporates a novel epoxy potted data payload system (DPS) that includes high-definition video, integrated lighting, rechargeable battery power, and gigabit ethernet fiber optic telemetry. In this paper we present the complete FOReelS design and field demonstrations to depths exceeding 780 m using small coastal support vessels of opportunity. FOReelS is likely the smallest form factor live-telemetry deep-sea exploration tool currently in existence, with a broad range of future applications envisioned for oceanographic sensing and communication.

Submarine hydrothermal vent fields introduce buoyant plumes of chemically altered seawater to the deep-sea water column. Chemoautotrophic microbes exploit this energy source, facilitating seafloor-based primary production that evidence suggests may transfer to pelagic consumers. While most hydrothermal plumes have relatively small volumes, there are recent examples of large-scale plume events associated with periods of eruptive activity, which have had a pronounced effect on water-column biology. This correlation suggests that hydrothermal plumes may have influenced basin-scale ocean chemistry during periods of increased submarine volcanism during the Phanerozoic eon. This paper synthesizes a growing body of scientific evidence supporting the hypothesis that hydrothermal plumes are the energetic basis of unique deep-sea pelagic food webs. While many important questions remain concerning the biology of hydrothermal plumes, this discussion is not present in ongoing management efforts related to seafloor massive sulfide (SMS) mining. Increased research efforts, focused on high-resolution surveys of midwater biology relative to plume structures, are recommended to establish baseline conditions and monitor the impact of future mining-based disturbances to the pelagic biosphere.

Modern marine biologists seeking to study or interact with deep-sea organisms are confronted with few options beyond industrial robotic arms, claws, and suction samplers. This limits biological interactions to a subset of “rugged” and mostly immotile fauna. As the deep sea is one of the most biologically diverse and least studied ecosystems on the planet, there is much room for innovation in facilitating delicate interactions with a multitude of organisms. The biodiversity and physiology of shallow marine systems, such as coral reefs, are common study targets due to the easier nature of access; SCUBA diving allows for in situ delicate human interactions. Beyond the range of technical SCUBA (~150 m), the ability to achieve the same level of human dexterity using robotic systems becomes critically important. The deep ocean is navigated primarily by manned submersibles or remotely operated vehicles, which currently offer few options for delicate manipulation. Here we present results in developing a soft robotic manipulator for deep-sea biological sampling. This low-power glove-controlled soft robot was designed with the future marine biologist in mind, where science can be conducted at a comparable or better means than via a human diver and at depths well beyond the limits of SCUBA. The technology relies on compliant materials that are matched with the soft and fragile nature of marine organisms, and uses seawater as the working fluid. Actuators are driven by a custom proportional-control hydraulic engine that requires less than 50 W of electrical power, making it suitable for battery-powered operation. A wearable glove master allows for intuitive control of the arm. The manipulator system has been successfully operated in depths exceeding 2300 m (3500 psi) and has been field-tested onboard a manned submersible and unmanned remotely operated vehicles. The design, development, testing, and field trials of the soft manipulator is placed in context with existing systems and we offer suggestions for future work based on these findings.

Mesophotic coral reefs (~30–150 m) and deeper reefs (>150 m) represent some of the least explored and poorly documented habitats in our oceans. These deep ecosystems are both high in biodiversity and ecologically distinct from shallower reefs. They are also equally threatened by natural and anthropogenic factors. Thanks to advancements in remote undersea technologies, our access to and understanding of these poorly studied environments continues to expand. With current data now suggesting more stratified populations of reef fishes and a continuous yield of new species discovered in the mesophotic zone, now under global pressures of climate change and overfishing, the need to explore these ecosystems has never been greater. Most deep-sea (>200 m) biodiversity studies rely on dredging and trawling technologies that are not selective or targeted. Here we present on the design and field demonstration of a compact, low-cost, targeted reef fish sampling system intended for use on inspection-class ROVs in the mesophotic zone. During a research expedition to the Western Province of the Solomon Islands, the system successfully collected multiple novel fish species at depths ranging from 90 to 187 m. The results obtained during this expedition highlight the utility of ROV-based collecting systems, add to the growing knowledge of mesophotic reef communities, and inspire new techniques for sampling mobile faunas at depth.

Observing and measuring marine bioluminescence in situ presents unique challenges, characterized by the difficult task of approaching and imaging weakly illuminated bodies in a three-dimensional environment. To address this problem, a scientific complementary-metal-oxide-semiconductor (sCMOS) microscopy camera was outfitted for deep-sea imaging of marine bioluminescence. This system was deployed on multiple platforms (manned submersible, remotely operated vehicle, and towed body) in three oceanic regions (Western Tropical Pacific, Eastern Equatorial Pacific, and Northwestern Atlantic) to depths up to 2500 m. Using light stimulation, bioluminescent responses were recorded at high frame rates and in high resolution, offering unprecedented low-light imagery of deep-sea bioluminescence in situ . The kinematics of light production in several zooplankton groups was observed, and luminescent responses at different depths were quantified as intensity vs . time. These initial results signify a clear advancement in the bioluminescent imaging methods available for observation and experimentation in the deep-sea.

This article presents the development of an underwater gripper that utilizes soft robotics technology to delicately manipulate and sample fragile species on the deep reef. Existing solutions for deep sea robotic manipulation have historically been driven by the oil industry, resulting in destructive interactions with undersea life. Soft material robotics relies on compliant materials that are inherently impedance matched to natural environments and to soft or fragile organisms. We demonstrate design principles for soft robot end effectors, bench-top characterization of their grasping performance, and conclude by describing in situ testing at mesophotic depths. The result is the first use of soft robotics in the deep sea for the nondestructive sampling of benthic fauna.

In this paper we investigate the use of passive stabilization to support stereolithography (SLA) printing aboard a moving vessel at sea. 3D printing is a useful technology onboard a seagoing vessel to support engineering development, shipboard maintenance, and other applications when land-based manufacturing resources are unavailable. SLA printed material is particularly suited for underwater applications requiring sealed housings, since SLA printers are capable of producing high-resolution models that are fully solid and impervious to water. Hydrostatic pressure can quickly compromise parts created using standard fused filament fabrication (FFF) 3D printing. However, the dynamic environment onboard a moving vessel could impact the ability of an SLA printer to selectively cure voxels in a liquid resin bath as it undergoes constant motion, and can cause spilling over the walls of the resin tank. Using passive stabilization platforms onboard moving research vessels, we successfully printed a number of parts with no discernable differences from those produced in a traditional land-based laboratory. As a practical demonstration of this capability, we printed at sea underwater pressure housings that remained sealed to 200 m water depth with functional integrated internal electronics. No post-print machining was required to create the sealed housings. This work lays the foundation for lithographic 3D printing in seagoing oceanographic and naval applications, and additionally presents an economical approach for producing custom waterproof pressure housings in the field.

Cameras are essential components to almost every underwater vehicle including ROV’s, AUV’s, manned submersibles, ocean observatories, and baited remote underwater video systems (BRUVs). Deep-sea cameras are traditionally expensive components, and are almost exclusively fabricated as one-atmosphere pressure housings made of aluminum, stainless steel or titanium, combined with custom-made optical viewports. In autonomous recording systems such as BRUVs and biologging animal tags, camera size and form factor directly influences the physical design of the entire system and limits the operational endurance. In this paper, we describe a novel design for DEEPi, a deep-sea imaging and control system based on the Raspberry Pi family of single-board computers. The DEEPi camera is an extremely compact remote head unit (∼16 ml volume), can operate to depths of at least 5500m, and uses a photopolymer 3D-printed shell partially filled with epoxy as a pressure housing. A flat polished borosilicate glass disc serves as the optical viewport, and protects the lens assembly from pressure and water intrusion. The control computer is completely potted in epoxy, and is accessible through a wifi connection. The DEEPi system is described in detail, along with example imagery from deep-sea deployments to depths of up to 1096m.

This article presents the development of modular soft robotic wrist joint mechanisms for delicate and precise manipulation in the harsh deep-sea environment. The wrist consists of a rotary module and bending module, which can be combined with other actuators as part of a complete manipulator system. These mechanisms are part of a suite of soft robotic actuators being developed for deep-sea manipulation via submersibles and remotely operated vehicles, and are designed to be powered hydraulically with seawater. The wrist joint mechanisms can also be activated with pneumatic pressure for terrestrial-based applications, such as automated assembly and robotic locomotion. Here we report the development and characterization of a suite of rotary and bending modules by varying fiber number and silicone hardness. Performance of the complete soft robotic wrist is demonstrated in normal atmospheric conditions using both pneumatic and hydraulic pressures for actuation and under high ambient hydrostatic pressures equivalent to those found at least 2300 m deep in the ocean. This rugged modular wrist holds the potential to be utilized at full ocean depths (10,000 m) and is a step forward in the development of jointed underwater soft robotic arms.

Soft robotics is an emerging technology that has shown considerable promise in deep-sea marine biological applications. It is particularly useful in facilitating delicate interactions with fragile marine organisms. This study describes the shipboard design, 3D printing and integration of custom soft robotic manipulators for investigating and interacting with deep-sea organisms. Soft robotics manipulators were tested down to 2224m via a Remotely-Operated Vehicle (ROV) in the Phoenix Islands Protected Area (PIPA) and facilitated the study of a diverse suite of soft-bodied and fragile marine life. Instantaneous feedback from the ROV pilots and biologists allowed for rapid re-design, such as adding "fingernails", and re-fabrication of soft manipulators at sea. These were then used to successfully grasp fragile deep-sea animals, such as goniasterids and holothurians, which have historically been difficult to collect undamaged via rigid mechanical arms and suction samplers. As scientific expeditions to remote parts of the world are costly and lengthy to plan, on-the-fly soft robot actuator printing offers a real-time solution to better understand and interact with delicate deep-sea environments, soft-bodied, brittle, and otherwise fragile organisms. This also offers a less invasive means of interacting with slow-growing deep marine organisms, some of which can be up to 18,000 years old.

Self-folding polyhedra have emerged as a viable design strategy for a wide range of applications, with advances largely made through modeling and experimentation at the micro- and millimeter scale. Translating these concepts to larger scales for practical purposes is an obvious next step; however, the size, weight, and method of actuation present a new set of problems to overcome. We have developed large-scale folding polyhedra to rapidly and noninvasively enclose marine organisms in the water column. The design is based on an axisymmetric dodecahedron net that is folded by an external assembly linkage. Requiring only a single rotary actuator to fold, the device is suited for remote operation onboard underwater vehicles and has been field-tested to encapsulate a variety of delicate deep-sea organisms. Our work validates the use of self-folding polyhedra for marine biological applications that require minimal actuation to achieve complex motion. The device was tested to 700 m, but the system was designed to withstand full ocean depth (11 km) pressures. We envision broader terrestrial applications of rotary-actuated folding polyhedra, ranging from large-scale deployable habitats and satellite solar arrays to small-scale functional origami microelectromechanical systems.

The discovery of deep-sea hydrothermal vents in 1977 challenged our views of ecosystem functioning and yet, the research conducted at these extreme and logistically challenging environments still continues to reveal unique biological processes. Here, we report for the first time, a unique behavior where the deep-sea skate, Bathyraja spinosissima, appears to be actively using the elevated temperature of a hydrothermal vent environment to naturally “incubate” developing egg-cases. We hypothesize that this behavior is directly targeted to accelerate embryo development time given that deep-sea skates have some of the longest egg incubation times reported for the animal kingdom. Similar egg incubating behavior, where eggs are incubated in volcanically heated nesting grounds, have been recorded in Cretaceous sauropod dinosaurs and the rare avian megapode. To our knowledge, this is the first time incubating behavior using a volcanic source is recorded for the marine environment.

Remotely operated vehicle (ROV) exploration at the distal margins of a debris avalanche deposit from Kick’em Jenny submarine volcano in Grenada has revealed areas of cold seeps with chemosynthetic-based ecosystems. The seeps occur on steep slopes of deformed, unconsolidated hemipelagic sediments in water depths between 1952 and 2042 m. Two main areas consist of anastomosing systems of fluid flow that have incised local sediments by several tens of centimeters. No temperature anomalies were observed in the vent areas and no active flow was visually observed, suggesting that the venting may be waning. An Eh sensor deployed on a miniature autonomous plume recorder (MAPR) recorded a positive signal and the presence of live organisms indicates at least some venting is still occurring. The chemosynthetic-based ecosystem included giant mussels ( Bathymodiolus sp.) with commensal polychaetes ( Branchipolynoe sp.) and cocculinid epibionts, other bivalves, Siboglinida (vestimentiferan) tubeworms, other polychaetes, and shrimp, as well as associated heterotrophs, including gastropods, anemones, crabs, fish, octopods, brittle stars, and holothurians. The origin of the seeps may be related to fluid overpressure generated during the collapse of an ancestral Kick’em Jenny volcano. We suggest that deformation and burial of hemipelagic sediment at the front and base of the advancing debris avalanche led to fluid venting at the distal margin. Such deformation may be a common feature of marine avalanches in a variety of geological environments especially along continental margins, raising the possibility of creating large numbers of ephemeral seep-based ecosystems.

Schooling fishes, like flocking birds and swarming insects, display remarkable behavioral coordination. While over 25% of fish species exhibit schooling behavior, nighttime schooling has rarely been observed or reported. This is due to vision being the primary modality for schooling, which is corroborated by the fact that most fish schools disperse at critically low light levels. Here we report on a large aggregation of the bioluminescent flashlight fish Anomalops katoptron that exhibited nighttime schooling behavior during multiple moon phases, including the new moon. Data were recorded with a suite of low-light imaging devices, including a high-speed, high-resolution scientific complementary metal-oxide-semiconductor (sCMOS) camera. Image analysis revealed nighttime schooling using synchronized bioluminescent flashing displays, and demonstrated that school motion synchrony exhibits correlation with relative swim speed. A computer model of flashlight fish schooling behavior shows that only a small percentage of individuals need to exhibit bioluminescence in order for school cohesion to be maintained. Flashlight fish schooling is unique among fishes, in that bioluminescence enables schooling in conditions of no ambient light. In addition, some members can still partake in the school while not actively exhibiting their bioluminescence. Image analysis of our field data and model demonstrate that if a small percentage of fish become motivated to change direction, the rest of the school follows. The use of bioluminescence by flashlight fish to enable schooling in shallow water adds an additional ecological application to bioluminescence and suggests that schooling behavior in mesopelagic bioluminescent fishes may be also mediated by luminescent displays.

Measurements of the defecation rate of Salpa thompsoni were made at several stations during two cruises west of the Antarctic Peninsula in 2004 and 2006. Rates were quantified in terms of number of pellets, pigment, carbon and nitrogen for a wide size range of both aggregate and solitary salps. Measured defecation rates were constant over several hours when salps were held at near-surface conditions from which they had been collected. The defecation rate per salp increased with both salp size and the ambient level of particulate organic matter (POM) in the upper water column. The weight-specific defecation rate ranged between 0.5 and 6% day−1 of salp body carbon, depending on the concentration of available particulate matter in the water. Carbon defecation rates were applied to biomass estimates of S. thompsoni to calculate daily carbon defecation rates for the populations sampled during the two cruises. Dense salp populations of over 400 mg C m−2 were calculated to produce about 20 mg C m−2 day−1, comparable to other major sources of vertical flux of organic material in the Southern Ocean. Measured sinking rates for salp fecal pellets indicated that the majority of this organic material could reach deep sediments within a few days, providing a fast and direct pathway for carbon to the deep ocean.

Mid-Cayman Rise objectives were built on exciting results from a flurry of recent expeditions that investigated hydrothermal sites in the region (German et al., 2010, 2012). The 2013 E/V Nautilus cruise explored oceanic core complexes (OCCs), tall, smooth-sided hills that rise from the seafloor on the flanks of some mid-ocean ridges. Dives (Figure 1) explored the full extent and nature of life around the Von Damm hydrothermal field, previously discovered there, as well as the geology to further understanding of the vents’ origins, and to survey the OCC summits that had never before been investigated by a deep diving vehicle. This 2013 study was the first Nautilus cruise to have more scientists participating in the expedition from locations on shore than from the ship, tripling the size of the science party.