Paul A. Tyler’s research while affiliated with University of Southampton and other places

The greater than 10 ⁹ km ³ volume of the deep-sea water column and greater than 300 × 10 ⁶ km ² area of the deep-sea floor represent a major natural capital asset. Global society has been utilising space in the deep ocean as a reservoir for solid, liquid, and hazardous waste produced by terrestrial-based societies, as a buffer that absorbs nonsolid, nonliquid industrial waste streams, specifically CO 2 from fossil fuel and biomass burning, heat from a warming atmosphere, and as freely available and convenient space. High-value uses such as the deployment of transoceanic telecommunications cables provide substantial, near-term economic and societal returns with minimal environmental impact. Low-value uses of this natural capital as empty space to absorb waste have arguably enabled industrialisation to continue further along an unsustainable trajectory than would have occurred had there been no such waste buffer available.

There has never been a time like the present when there is so much media, scientific, and economic interest in the deep waters of the world ocean and the animals that live there. It is increasingly important for students and new researchers, as well as experienced scientists, to understand how their research can help to address pressing societal challenges. It is beneficial for deep-sea scientists, social scientists, lawyers, authorities, conservationists, industry, and civil society to have broad knowledge of the issues surrounding exploitation in the deep ocean, which has gradually become an increasingly important research focus. The current and future work of deep-sea scientists in all disciplines provides rigorous scientific data and knowledge to support sound management of human activities in this highly complex and variable realm. In this volume, we have brought together internationally recognised scientists, economists, and legal experts to describe the processes by which humans can benefit from the natural capital of the deep sea in a sustainable framework. For this to happen, communication between all deep-sea stakeholders is essential, and this volume aims to facilitate future discussions between the many different sectors of society who may influence the global deep ocean for future generations.

Healthy oceans are essential to maintain a healthy planet, but the ocean is facing many challenges that need urgent attention. Robust scientific data and innovative technological, policy, and industrial solutions are essential to support sound management of the deep-ocean natural capital, both within and beyond national jurisdiction, to ensure future healthy and productive oceans. As with many systems on Earth, there is a delicate ecological balance in the deep ocean that must be maintained. Understanding the interactions of the different components of natural capital in the deep sea is complex, as many of the variables are interlinked and many have cumulative and synergistic effects on the ecosystem. Add to this the global and changing effects of climate change and ocean acidification, and legislators and managers have a tough job ahead to account for all of these issues when designing appropriate conservation measures. It is important that scientists work hand in hand with multiple stakeholders to identify issues and research needs that contribute to enhancing knowledge and the science needed for decision-making to help towards securing a healthy future for our deep-ocean ecosystems and their long-term natural capital.

The deep ocean is, by far, the planet’s largest biome and holds a wealth of potential natural assets. Most of the ocean lies beyond national jurisdiction and hence is the responsibility of us all. Human exploitation of the deep ocean is rapidly increasing, becoming more visible to many through the popular media. The scientific literature of deep-sea exploitation and its actual and potential effects has also rapidly expanded as a direct function of this increased national and global interest in deep-sea resources, both biological (e.g. fisheries, genetic resources) and non-biological (e.g. minerals, oil, gas, methane hydrate). At the same time there is a growing interest in deep-sea contamination (including plastics), with many such studies featured in high-profile scientific journals and covered by global media outlets. Finally, climate change is affecting even the deepest regions of our oceans and is a major priority for the international scientific and political agendas. However, there is currently no comprehensive integration of information about resource extraction, pollution and effects of climate change and these topics are only superficially covered in classic textbooks on deep-sea biology. The human race is at a pivotal point in potentially benefitting from the deep ocean’s natural resources and this concise and accessible work provides an account of past explorations and exploitations of the deep ocean, a present understanding of its natural capital and how this may be exploited sustainably for the benefit of humankind whilst maintaining its ecological integrity. The book gives a comprehensive account of geological and physical processes, ecology and biology, exploitation, management, and conservation.

Video and image data are regularly used in the field of benthic ecology to document biodiversity. However, their use is subject to a number of challenges, principally the identification of taxa within the images without associated physical specimens. The challenge of applying traditional taxonomic keys to the identification of fauna from images has led to the development of personal, group, or institution level reference image catalogues of operational taxonomic units (OTUs) or morphospecies. Lack of standardisation among these reference catalogues has led to problems with observer bias and the inability to combine datasets across studies. In addition, lack of a common reference standard is stifling efforts in the application of artificial intelligence to taxon identification. Using the North Atlantic deep sea as a case study, we propose a database structure to facilitate standardisation of morphospecies image catalogues between research groups and support future use in multiple front-end applications. We also propose a framework for coordination of international efforts to develop reference guides for the identification of marine species from images. The proposed structure maps to the Darwin Core standard to allow integration with existing databases. We suggest a management framework where high-level taxonomic groups are curated by a regional team, consisting of both end users and taxonomic experts. We identify a mechanism by which overall quality of data within a common reference guide could be raised over the next decade. Finally, we discuss the role of a common reference standard in advancing marine ecology and supporting sustainable use of this ecosystem.

Faunal assemblages at hydrothermal vents associated with island-arc volcanism are less well known than those at vents on mid-ocean ridges and back-arc spreading centres. This study characterizes chemosynthetic biotopes at active hydrothermal vents discovered at the Kemp Caldera in the South Sandwich Arc. The caldera hosts sulfur and anhydrite vent chimneys in 1375–1487 m depth, which emit sulfide-rich fluids with temperatures up to 212°C, and the microbial community of water samples in the buoyant plume rising from the vents was dominated by sulfur-oxidizing Gammaproteobacteria. A total of 12 macro- and megafaunal taxa depending on hydrothermal activity were collected in these biotopes, of which seven species were known from the East Scotia Ridge (ESR) vents and three species from vents outside the Southern Ocean. Faunal assemblages were dominated by large vesicomyid clams, actinostolid anemones, Sericosura sea spiders and lepetodrilid and cocculinid limpets, but several taxa abundant at nearby ESR hydrothermal vents were rare such as the stalked barnacle Neolepas scotiaensis. Multivariate analysis of fauna at Kemp Caldera and vents in neighbouring areas indicated that the Kemp Caldera is most similar to vent fields in the previously established Southern Ocean vent biogeographic province, showing that the species composition at island-arc hydrothermal vents can be distinct from nearby seafloor-spreading systems. δ13C and δ15N isotope values of megafaunal species analysed from the Kemp Caldera were similar to those of the same or related species at other vent fields, but none of the fauna sampled at Kemp Caldera had δ13C values, indicating nutritional dependence on Epsilonproteobacteria, unlike fauna at other island-arc hydrothermal vents.

Video and image data are regularly used in the field of benthic ecology to document biodiversity. However, their use is subject to a number of challenges, principally the identification of taxa within the images without associated physical specimens. The challenge of applying traditional taxonomic keys to the identification of fauna from images has led to the development of personal, group, or institution level reference image catalogues of operational taxonomic units (OTUs) or morphospecies. Lack of standardisation among these reference catalogues has led to problems with observer bias and the inability to combine datasets across studies. In addition, lack of a common reference standard is stifling efforts in the application of artificial intelligence to taxon identification. Using the North Atlantic deep sea as a case study, we propose a database structure to facilitate standardisation of morphospecies image catalogues between research groups and support future use in multiple front-end applications. We also propose a framework for coordination of international efforts to develop reference guides for the identification of marine species from images. The proposed structure follows the Darwin Core standard to allow integration with existing databases. We suggest a management framework where high-level taxonomic groups are curated by a regional team, consisting of both end users and taxonomic experts. We identify a mechanism by which overall quality of data within a common reference guide could be raised over the next decade. Finally, we discuss the role of a common reference standard in advancing marine ecology and supporting sustainable use of this ecosystem.

The oceans were observed to be deep during the great age of exploration in the early to mid-nineteenth century. Subsequent exploration demonstrated that the ocean was bisected by underwater mountain ranges and dotted with abyssal hills. With the advent of the echosounder and latterly multichannel swath bathymetry, we now know that the deep ocean has topography as diverse as found on land. In the last 30 years, with an increase in deep-sea scientific activity and the use of underwater vehicles, we have learned that the deep sea consists of a series of habitats and ecosystems interconnected by hydrography and topography. The more recent challenges have been how to sample and analyse these separate habitats and ecosystems. This chapter describes the different environments and briefly outlines the main methods of sampling for each habitat or ecosystem. More detailed aspects of these sampling methods are found in subsequent chapters.

The deep-sea squat lobster Kiwa tyleri (also known as yeti crab) is the dominant macroinvertebrate inhabiting hydrothermal vents on the northern and southern segments of the East Scotia Ridge in the Southern Ocean. Here, we describe the first zoeal stage of the species—which is morphologically advanced—and provide evidence for its lecithotrophy in development. This morphologically advanced stage at hatching suggests that dispersal potential during early ontogeny may be limited. Adults of K. tyleri typically inhabit a warm-eurythermal, and spatially defined, temperature envelope of vent chimneys. In contrast, ovigerous females with late embryos are found away from these temperatures, off the vent site. This implies that at least part of embryogenesis takes place away from the chemosynthetic environment. Larvae are released into the cold waters of the Southern Ocean that are known to pose physiological limits on the survival of reptant decapods. Larval lecithotrophy may aid long developmental periods under these conditions and facilitate development independent of pronounced seasonality in primary production. It remains uncertain, however, how population connectivity between distant vent sites may be achieved.