Migrating reefs, unprecedented species assemblages, neophytes, toxicities, pollutants, aquatic ruins – The future of coral reefs in the Anthropocene is likely to look different from anything we have experienced so far. While the classic conservation debate on coral reef restoration still treats these ecosystems as “sick patients,” a radically different view of convivial conservation is beginning to challenge exclusive human control over these endangered habitats. Putting aside notions of natural “purity” and adopting a much more humble and highly interconnected perspective on marine habitats, we can begin to see reefs as transformative, sympoïetic and blasted seascapes for a convivial future. The discipline of biodesign has been primarily focussed on researching ecological relationships with regard to new materials and products. The emerging interest in shaping the multi-layered ecological relationships of habitats for other-than-human lives, however, is steering design practice towards terraforming or, in the case of marine environments, “aquaforming.” This paper argues for taking convivial conservation practices in marine environments as a starting point for the development of a new design methodology that focuses on the design of living systems in open environments: a proposed methodology called Sympoïetic Design.

In sediments, clay minerals are mainly detrital. Formed by continental weathering, they are carried by surface transport predominantly by rivers, glaciers and, to a lesser extent, winds to the adjacent sedimentary basins and then are redistributed by oceanic currents. In a sedimentary core, the variability in the clay mineral assemblages reflects either variable physical and chemical weathering conditions in the watershed, typically with a significant link to climatic conditions, or changes in the mineral source, the latter being associated with various transport agents. When different sources are involved, a combination of mineralogical and geochemical proxies allows us to trace the detrital provenance, but they also indirectly provide valuable information on transport pathways and palaeocurrents. This manuscript reviews several examples from the literature and ongoing research on clay mineral variability in marine or lacustrine sedimentary records and interprets them in terms of: (1) climate control at different timescales, from the Neogene to the Quaternary; and (2) transport paths. Examples are selected to review the various clay-derived proxies in existence.

To inform water quality monitoring techniques and modeling at coastal research sites, this study investigated seasonality and trends in coastal lagoons on the eastern shore of Virginia, USA. Seasonality was quantified with harmonic analysis of low-frequency time-series, approximately 30 years of quarterly sampled data at thirteen mainland, lagoon, and ocean inlet sites, along with 4–6 years of high-frequency, 15-min resolution sonde data at two mainland sites. Temperature, dissolved oxygen, and apparent oxygen utilization (AOU) seasonality were dominated by annual harmonics, while salinity and chlorophyll-a exhibited mixed annual and semi-annual harmonics. Mainland sites had larger seasonal amplitudes and higher peak summer values for temperature, chlorophyll-a and AOU, likely from longer water residence times, shallower waters, and proximity to marshes and uplands. Based on the statistical subsampling of high-frequency data, one to several decades of low-frequency data (at quarterly sampling) were needed to quantify the climatological seasonal cycle within specified confidence intervals. Statistically significant decadal warming and increasing chlorophyll-a concentrations were found at a sub-set of mainland sites, with no distinct geographic patterns for other water quality trends. The analysis highlighted challenges in detecting long-term trends in coastal water quality at sites sampled at low frequency with large seasonal and interannual variability.

This introduction briefly discusses the global constitutional issues raised by ocean governance and introduces the three pieces from our Agora contributors.

The Anthropocene epoch, characterized by human-caused planetary-scale transformations like climate change and ocean acidification, today is usually associated with the period beginning in the mid-twentieth century. Taking an oceanic perspective on the Anthropocene in Asia, the article argues that oceanic and terrestrial energy regimes synchronized since the 1950s when, for the first time in history, oceanic ghost acres turned marine spaces into a major fuel source. Despite global connections between offshore oil regions located in North America, Asia, and other places going back to the late nineteenth century, Asia’s contingent offshore oil field locations and their physical geographies, combined with political factors, inhibited large-scale offshore drilling before the 1950s. These characteristics of marine spaces meant that Asian political elites and their developmentalist agendas became the guiding force in exploring offshore fields, a process that was hardly dominated by corporate capitalism or structural choice limitations due to the legacies of colonialism.

When conducting accident analysis, the assessment of risk is one of the important links. Moreover, with regards to crew training, risk cognition is also an important training subject. However, most of the existing researches only rely on a single or a few data sources. It is necessary to fuse the collected multi-source data to obtain a more comprehensive risk evaluation model. There are few studies on the three-dimensional (3D) multi-modal data-fusion-based trajectory risk cognition. In this paper, a fuzzy logic-based trajectory risk cognition method is proposed based on multi-model spatial data fusion and accident data mining. First, the necessity of multi-model spatial data fusion is analysed and a data-fusion-based scene map is constructed. Second, a risk cognition model fused by multiple factors, multi-dimensional spatial calculations as well as data mining results is proposed, including a novel ship boundary calculation approach and newly constructed factors. Finally, a radar chart is used to illustrate the risk, and a risk cognition system is developed. Experiment results confirm the effectiveness of the method. It can be applied to train human operators of unmanned ship systems.

Modern-day ocean circulation behaves as a complex forced convective system that is characterized by the decrease in water temperature but increase in water density with depth. The dissolved oxygen content – which initially decreases due to biological oxygen demand – also increases with depth. In contrast to the present-day scenario, we propose that during the Archaean and Proterozoic eons inverted profiles could have developed such that, with depth, ocean water temperature increased and density and dissolved oxygen decreased. These inverted temperature and density profiles resulted in palaeo-ocean circulation behaving as a free convective system. It is proposed that this free convection, which may have been stable, or chaotic and subject to secondary instabilities, hindered the deep oxygenation of the palaeo-ocean. It may not be coincidental that the great oxygenation event (GOE) and Huronian glaciations are contemporaneous, in a similar way that the Neoproterozoic oxygenation event (NOE) is known to have been associated with glaciations. The global-scale external forcing required to switch the natural convective system to its present-day configuration is suggested to have been associated with Neoproterozoic glaciations and the subsequent lowering of ocean water salinity that accompanied them. We propose that this inverted the ocean water density gradient, allowing the oxygenation of the oceans for the first time. It is beyond the scope of this work to model the complex natural convection system, but we hope that geophysicists and numerical modellers will quantitatively evaluate the hypothesis proposed here to validate or refute our proposition.

Under the influence of a rapidly warming climate, abrupt changes have been observed along the coast of Greenland. This commentary is based on a Japanese research project initiated in 2012, in which we examined the recent changes in the coastal environment and their impacts on human society in Qaanaaq, a village in northwestern Greenland. Initially, our research sought to quantify the mass loss of glaciers and its interaction with the ocean in the Qaanaaq region. Over the course of the project in collaboration with local communities, we soon realised that the changes in glaciers and the ocean directly impacted the ~600 residents of Qaanaaq. We observed natural disasters triggered by climate change. Environmental changes are also important for local economy and industry because loss of sea ice may lead to growth in transportation, tourism and mineral resource exploration. In order to share the results of our study with the Qaanaaq community, and to gain understanding of local and traditional knowledge, we organised an annual meeting in the village every summer since 2016. Our experience demonstrates the critical importance of performing a long-term multidisciplinary study, including participation of the local communities to understand the changing environment, and to contribute to a sustainable future in Qaanaaq.