Combining fish and benthic communities into multiple regimes reveals complex reef dynamics

Abstract Coral reefs worldwide face an uncertain future with many reefs reported to transition from being dominated by corals to macroalgae. However, given the complexity and diversity of the ecosystem, research on how regimes vary spatially and temporally is needed. Reef regimes are most often characterised by their benthic components; however, complex dynamics are associated with losses and gains in both fish and benthic assemblages. To capture this complexity, we synthesised 3,345 surveys from Hawai‘i to define reef regimes in terms of both fish and benthic assemblages. Model-based clustering revealed five distinct regimes that varied ecologically, and were spatially heterogeneous by island, depth and exposure. We identified a regime characteristic of a degraded state with low coral cover and fish biomass, one that had low coral but high fish biomass, as well as three other regimes that varied significantly in their ecology but were previously considered a single coral dominated regime. Analyses of time series data reflected complex system dynamics, with multiple transitions among regimes that were a function of both local and global stressors. Coupling fish and benthic communities into reef regimes to capture complex dynamics holds promise for monitoring reef change and guiding ecosystem-based management of coral reefs

27 years of benthic and coral community dynamics on turbid, highly urbanised reefs off Singapore

Coral cover on reefs is declining globally due to coastal development, overfishing and climate change. Reefs isolated from direct human influence can recover from natural acute disturbances, but little is known about long term recovery of reefs experiencing chronic human disturbances. Here we investigate responses to acute bleaching disturbances on turbid reefs off Singapore, at two depths over a period of 27 years. Coral cover declined and there were marked changes in coral and benthic community structure during the first decade of monitoring at both depths. At shallower reef crest sites (3–4 m), benthic community structure recovered towards pre-disturbance states within a decade. In contrast, there was a net decline in coral cover and continuing shifts in community structure at deeper reef slope sites (6–7 m). There was no evidence of phase shifts to macroalgal dominance but coral habitats at deeper sites were replaced by unstable substrata such as fine sediments and rubble. The persistence of coral dominance at chronically disturbed shallow sites is likely due to an abundance of coral taxa which are tolerant to environmental stress. In addition, high turbidity may interact antagonistically with other disturbances to reduce the impact of thermal stress and limit macroalgal growth rates

Shaping nature outcomes in corporate settings

Transnational companies have substantive impacts on nature: a hallmark of living in the Anthropocene. Understanding these impacts through company provision of information is a precursor to holding them accountable for nature outcomes. The effect of increasing disclosures (of varying quality) is predicated on ‘information governance’, an approach that uses disclosure requirements to drive company behaviour. However, its efficacy is not guaranteed. We argue that three conditions are required before disclosures have the possibility to shape nature outcomes, namely: (1) radical traceability that links company actions to outcomes in particular settings; (2) developing organizational routines, tools and approaches that translate strategic intent to on-the-ground behaviour; and (3) mobilizing and aligning financial actors with corporate nature ambitions. While disclosure is key to each of these conditions, its limits must be taken into account and it must be nested in governance approaches that shape action, not just reporting. This article is part of the theme issue ‘Bringing nature into decision-making’. © 2024 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License

The Ocean 100 : Transnational corporations in the ocean economy

The ocean economy is growing as commercial use of the ocean accelerates, while progress toward achieving international goals for ocean conservation and sustainability is lagging. In this context, the private sector is increasingly recognized as having the capacity to hamper efforts to achieve aspirations of sustainable ocean-based development or alternatively to bend current trajectories of ocean use by taking on the mantle of corporate biosphere stewardship. Here, we identify levels of industry concentration to assess where this capacity rests. We show that the 10 largest companies in eight core ocean economy industries generate, on average, 45% of each industry's total revenues. Aggregating across all eight industries, the 100 largest corporations (the "Ocean 100") account for 60% of total revenues. This level of concentration in the ocean economy presents both risks and opportunities for ensuring sustainability and equity of global ocean use

Sharing the seas:A review and analysis of ocean sector interactions

Ocean activities are rapidly expanding as Blue Economy discussions gain traction, creating new potential synergies and conflicts between sectors. To better manage ocean sectors and their development, we need to understand how they interact and the respective outcomes of these interactions. To provide a first comprehensive picture of the situation, we review 3187 articles to map and analyze interactions between economically important ocean sectors and find 93 unique direct and 61 indirect interactions, often mediated via the ocean ecosystem. Analysis of interaction outcomes reveals that some sectors coexist synergistically (e.g. renewable energy, tourism), but many interactions are antagonistic, and negative effects on other sectors are often incurred via degradation of marine ecosystems. The analysis also shows that ocean ecosystems are fundamental for supporting many ocean sectors, yet 13 out of 14 ocean sectors have interactions resulting in unidirectional negative ecosystem impact. Fishing, drilling, and shipping are hubs in the network of ocean sector interactions, and are involved in many of the antagonistic interactions. Antagonistic interactions signal trade-offs between sectors. Qualitative analysis of the literature shows that these tradeoffs relate to the cumulative nature of many ecosystem impacts incurred by some sectors, and the differential power of ocean sectors to exert their rights or demands in the development of the ocean domain. There are also often time lags in how impacts manifest. The ocean governance landscape is not currently well-equipped to deal with the full range of trade-offs, and opportunities, likely to arise in the pursuit of a Blue Economy in a rapidly changing ocean context. Based on our analysis, we therefore propose a set principles that can begin to guide strategic decision-making, by identifying both tradeoffs and opportunities for sustainable and equitable development of ocean sectors. © 2021 The Author(s). Published by IOP Publishing Lt

Evolving Perspectives of Stewardship in the Seafood Industry

Humanity has never benefited more from the ocean as a source of food, livelihoods, and well-being, yet on a global scale this has been accompanied by trajectories of degradation and persistent inequity. Awareness of this has spurred policymakers to develop an expanding network of ocean governance instruments, catalyzed civil society pressure on the public and private sector, and motivated engagement by the general public as consumers and constituents. Among local communities, diverse examples of stewardship have rested on the foundation of care, knowledge and agency. But does an analog for stewardship exist in the context of globally active multinational corporations? Here, we consider the seafood industry and its efforts to navigate this new reality through private governance. We examine paradigmatic events in the history of the sustainable seafood movement, from seafood boycotts in the 1970s through to the emergence of certification measures, benchmarks, and diverse voluntary environmental programs. We note four dimensions of stewardship in which efforts by actors within the seafood industry have aligned with theoretical concepts of stewardship, which we describe as (1) moving beyond compliance, (2) taking a systems perspective, (3) living with uncertainty, and (4) understanding humans as embedded elements of the biosphere. In conclusion, we identify emerging stewardship challenges for the seafood industry and suggest the urgent need to embrace a broader notion of ocean stewardship that extends beyond seafood

Combining fish and benthic communities into multiple regimes reveals complex reef dynamics

Coral reefs worldwide face an uncertain future with many reefs reported to transition from being dominated by corals to macroalgae. However, given the complexity and diversity of the ecosystem, research on how regimes vary spatially and temporally is needed. Reef regimes are most often characterised by their benthic components; however, complex dynamics are associated with losses and gains in both fish and benthic assemblages. To capture this complexity, we synthesised 3,345 surveys from Hawai‘i to define reef regimes in terms of both fish and benthic assemblages. Model-based clustering revealed five distinct regimes that varied ecologically, and were spatially heterogeneous by island, depth and exposure. We identified a regime characteristic of a degraded state with low coral cover and fish biomass, one that had low coral but high fish biomass, as well as three other regimes that varied significantly in their ecology but were previously considered a single coral dominated regime. Analyses of time series data reflected complex system dynamics, with multiple transitions among regimes that were a function of both local and global stressors. Coupling fish and benthic communities into reef regimes to capture complex dynamics holds promise for monitoring reef change and guiding ecosystem-based management of coral reefs. © 2018, The Author(s)

We may not know much about the deep sea, but do we care about mining it?

1. The way we value the environment affects how we treat it. While public awareness of human impacts on the ocean is increasing, industrial activities in the deep sea are accelerating rapidly and out of sight. 2. The underlying values we hold for the environment were increasingly recognised as an important factor in environmental decision-making, and it was thus important to evaluate public values towards deep-sea environments. 3. Here, we explored people's care for the deep sea and related this to the perceived risks of seafloor mining by comparing the deep sea to three other remote environments: Antarctica, remote terrestrial environments and the Moon. 4. We conducted an online survey to investigate symbolic values, which we define as the emotions, moods and meanings an environment evokes, as an element affecting people's care for the environment. In addition, we investigated the respondent's knowledge, worldviews and the perceived environmental and societal risk of mining in these four environments. 5. We found that symbolic values shape people's environmental care and that the overall symbolic value attributed to each of the environments differs. 6. People perceived it likely that mining will take place in the deep sea, and the majority of respondents (81%) stated to care a lot or very much about human activities harming the deep sea. 7. In comparison to the other remote environments, in a general sense people cared less about the deep sea, and their self-assessed knowledge of the deep sea was lower. 8. These results suggest that it was fundamental to account for the underlying values and emotions towards the environment when evaluating the risks of human activities in remote settings. 9. Our results further highlighted the need to improve public understanding and connection with the deep sea and its role within wider society to engender deep-sea stewardship.Peer reviewe

Hawaii_regime_drivers

Hawaii_regime_drivers.csv is a comma-separated file containing data used to understand relationships between regime transitions and local and global drivers. The file includes data on human population density and degree heating weeks for each replicate found in Hawaii_regime_timeseries.csv. Details of the analysis can be found in the accompanying publication. Parties interested in using this data for other purposes are asked to contact Mary Donovan ([email protected])

Hawaii_regimes

Hawaii_regimes.csv is a comma-separated file containing data used to define reef regimes for the Hawaii Islands. The file includes metadata for 1027 replicates, 10 reef community metrics used to define regimes in a cluster analysis, and the resulting reef regime. Reef community metrics are averages of individual replicates grouped based on spatial proximity. Details of the analysis can be found in the accompanying publication. Parties interested in using this data for other purposes are asked to contact Mary Donovan ([email protected])