Stace E. Beaulieu

The abundance of seafloor massive sulfide deposits

The possibility of mining seafl oor massive sulfide deposits has stirred debate about the sustainable use of this new resource and whether commercial development is worth the risk. Among the outstanding questions is how many deposits might be accessible to deep-sea mining. More than 300 sites of high-temperature hydrothermal venting have been identifi ed since the discovery of black smokers, but signifi cant massive sulfide accumulation has been found at only 165 of these sites. Estimates of the total number of vent fields and associated mineral deposits, based on plume studies and deposit occurrence models, range from 500 to 5000. We have used new deposit occurrence data from 10,000 km of ridge, arc, and backarc spreading centers to estimate the amount of massive sulfide in the easily accessible neovolcanic zones of the global oceans. The total accumulation in these areas is estimated to be on the order of 6 × 108 tonnes, containing ~3 × 107 tonnes of copper and zinc. This is similar to the total discovered copper and zinc in Cenozoic massive sulfi de deposits mined on land but is insuffi cient to satisfy a growing global demand for these metals.

Larvae from afar colonize deep-sea hydrothermal vents after a catastrophic eruption

The planktonic larval stage is a critical component of life history in marine benthic species because it confers the ability to disperse, potentially connecting remote populations and leading to colonization of new sites. Larval-mediated connectivity is particularly intriguing in deep-sea hydrothermal vent communities, where the habitat is patchy, transient, and often separated by tens or hundreds of kilometers. A recent catastrophic eruption at vents near 9°50′N on the East Pacific Rise created a natural clearance experiment and provided an opportunity to study larval supply in the absence of local source populations. Previous field observations have suggested that established vent populations may retain larvae and be largely self-sustaining. If this hypothesis is correct, the removal of local populations should result in a dramatic change in the flux, and possibly species composition, of settling larvae. Fortuitously, monitoring of larval supply and colonization at the site had been established before the eruption and resumed shortly afterward. We detected a striking change in species composition of larvae and colonists after the eruption, most notably the appearance of the gastropod Ctenopelta porifera, an immigrant from possibly more than 300 km away, and the disappearance of a suite of species that formerly had been prominent. This switch demonstrates that larval supply can change markedly after removal of local source populations, enabling recolonization via immigrants from distant sites with different species composition. Population connectivity at this site appears to be temporally variable, depending not only on stochasticity in larval supply, but also on the presence of resident populations.

Deep-sea Geo-referenced Video Mosaics

Seafloor imagery is an important tool for scientists engaged in quantifying geological and biological processes operating on the deep-ocean floor. Large-scale mosaics of seafloor imagery have significant advantages over individual still photographs and video footage as they are able to capture large areas while retaining sufficient resolution to identify small-scale features. However, the process of constructing a mosaic is usually limited to a single panorama or transects from still imagery, and often requires manual control by the user. The goal of this paper is to describe a methodology that allows for utilization of navigation data for robust automatic construction and geo-referencing of video mosaics. This methodology is designed specifically for the submersible Alvin, but our methodology may be modified for use with other underwater vehicles and is broadly applicable to the creation of mosaics in a variety of seafloor settings

Photographic identification guide to larvae at hydrothermal vents

Funding provided by NSF grants OCE-9619605, OCE-9712233, OCE-0424593 and ATM-0428122 and ChEss Grant #WHOI 1334800.

Bacterial diversity and successional patterns during biofilm formation on freshly exposed basalt surfaces at diffuse-flow deep-sea vents.

Many deep-sea hydrothermal vent systems are regularly impacted by volcanic eruptions, leaving fresh basalt where abundant animal and microbial communities once thrived. After an eruption, microbial biofilms are often the first visible evidence of biotic re-colonization. The present study is the first to investigate microbial colonization of newly exposed basalt surfaces in the context of vent fluid chemistry over an extended period of time (4–293 days) by deploying basalt blocks within an established diffuse-flow vent at the 9°50′ N vent field on the East Pacific Rise. Additionally, samples obtained after a recent eruption at the same vent field allowed for comparison between experimental results and those from natural microbial re-colonization. Over 9 months, the community changed from being composed almost exclusively of Epsilonproteobacteria to a more diverse assemblage, corresponding with a potential expansion of metabolic capabilities. The process of biofilm formation appears to generate similar surface-associated communities within and across sites by selecting for a subset of fluid-associated microbes, via species sorting. Furthermore, the high incidence of shared operational taxonomic units over time and across different vent sites suggests that the microbial communities colonizing new surfaces at diffuse-flow vent sites might follow a predictable successional pattern.

Toward cyberinfrastructure to facilitate collaboration and reproducibility for marine integrated ecosystem assessments

There is a growing need for cyberinfrastructure to support science-based decision making in management of natural resources. In particular, our motivation was to aid the development of cyberinfrastructure for Integrated Ecosystem Assessments (IEAs) for marine ecosystems. The IEA process involves analysis of natural and socio-economic information based on diverse and disparate sources of data, requiring collaboration among scientists of many disciplines and communication with other stakeholders. Here we describe our bottom-up approach to developing cyberinfrastructure through a collaborative process engaging a small group of domain and computer scientists and software engineers. We report on a use case evaluated for an Ecosystem Status Report, a multi-disciplinary report inclusive of Earth, life, and social sciences, for the Northeast U.S. Continental Shelf Large Marine Ecosystem. Ultimately, we focused on sharing workflows as a component of the cyberinfrastructure to facilitate collaboration and reproducibility. We developed and deployed a software environment to generate a portion of the Report, retaining traceability of derived datasets including indicators of climate forcing, physical pressures, and ecosystem states. Our solution for sharing workflows and delivering reproducible documents includes IPython (now Jupyter) Notebooks. We describe technical and social challenges that we encountered in the use case and the importance of training to aid the adoption of best practices and new technologies by domain scientists. We consider the larger challenges for developing end-to-end cyberinfrastructure that engages other participants and stakeholders in the IEA process.

International study of larval dispersal and population connectivity at hydrothermal vents in the U.S. Marianas Trench Marine National Monument

Deep-sea, chemosynthesis-based ecosystems, such as hydrothermal vents, have received increasing attention in the past decade for protection of biodiversity and ecosystem function. For these spatially discrete habitats, dispersal of larvae in the plankton, settlement to the seafloor, and recruitment are processes that connect populations of benthic fauna. Knowledge of these processes is vital to understanding the resilience of vent ecosystems to disturbance or removal of sources of propagules. In particular, hydrothermal vents may be impacted by human activities including scientific research, eco-tourism, bioprospecting, and polymetallic sulfide mining. In 2009 the first Marine Protected Area (MPA) for vents in the U.S. EEZ was established as part of the Marianas Trench Marine National Monument (MTMNM). The vents in this region are located along the Mariana back-arc spreading center (BASC) and volcanic arc.

Global viewport to deep-sea vents : dataset for spherical display systems

This zipped file, “vents_sphere_package_ver1.zip”, contains datasets, movies, and educational materials produced as the Global Viewport to Deep-Sea Vents: Dataset for Spherical Display Systems. The zipped file contains 15 main folders, 14 of which contain files prepared for NOAA’s Science on a Sphere® (SOS; http://sos.noaa.gov/), and the remaining folder contains the two compilation movies formatted for Magic Planet (http://globalimagination.com). The unzipped contents are ~8 GB, with a total of 118 files in 24 folders.

Should we mine the deep seafloor

As land-based mineral resources become increasingly difficult and expensive to acquire, the potential for mining resources from the deep seafloor has become widely discussed and debated. Exploration leases are being granted, and technologies are under development. However, the quantity and quality of the resources are uncertain, and many worry about risks to vulnerable deep-sea ecosystems. Deep-sea mining has become part of the discussion of the United Nations Sustainable Development Goals. In this article we provide a summary of benefits, costs, and uncertainties that surround this potentially attractive but contentious topic.