Towards incorporation of blue carbon in Falkland Islands marine spatial planning: a multi-tiered approach

Ecosystem-based conservation that includes carbon sinks, alongside a linked carbon credit system, as part of a nature-based solution to combating climate change, could help reduce greenhouse gas levels and therefore the impact of their emissions. Blue carbon habitats and pathways can also facilitate biodiversity retention, aiding sustainable fisheries and island economies. However, robust blue carbon research is often limited at the scale of regional governance and management, lacking both incentives and facilitation of policy-integration. The remote and highly biodiverse coastal ecosystems and surrounding continental shelf can be used to better inform long-term ecosystem-based management in the vast South Atlantic Ocean and sub-Antarctic, to synergistically protect both unique biodiversity and inform on the magnitude of nature-based benefits they provide. Understanding key ecosystem information such as their location, extent, and condition of habitat types, will be critical in understanding carbon pathways to sequestration, threats to this, and vulnerability. This paper considers the current status of blue carbon data and information available, and what is still required before blue carbon can be used as a conservation management tool integrated in national Marine Spatial Planning (MSP) initiatives. Our research indicates that the data and information gathered has enabled baselines for a number of different blue carbon ecosystems, and indicated potential threats and vulnerability that need to be managed. However, significant knowledge gaps remain across habitats, such as salt marsh, mudflats and the mesophotic zones, which hinders meaningful progress on the ground where it is needed most

Responses of Southern Ocean seafloor habitats and communities to global and local drivers of change

Knowledge of life on the Southern Ocean seafloor has substantially grown since the beginning of this century with increasing ship-based surveys and regular monitoring sites, new technologies and greatly enhanced data sharing. However, seafloor habitats and their communities exhibit high spatial variability and heterogeneity that challenges the way in which we assess the state of the Southern Ocean benthos on larger scales. The Antarctic shelf is rich in diversity compared with deeper water areas, important for storing carbon (“blue carbon”) and provides habitat for commercial fish species. In this paper, we focus on the seafloor habitats of the Antarctic shelf, which are vulnerable to drivers of change including increasing ocean temperatures, iceberg scour, sea ice melt, ocean acidification, fishing pressures, pollution and non-indigenous species. Some of the most vulnerable areas include the West Antarctic Peninsula, which is experiencing rapid regional warming and increased iceberg-scouring, subantarctic islands and tourist destinations where human activities and environmental conditions increase the potential for the establishment of non-indigenous species and active fishing areas around South Georgia, Heard and MacDonald Islands. Vulnerable species include those in areas of regional warming with low thermal tolerance, calcifying species susceptible to increasing ocean acidity as well as slow-growing habitat-forming species that can be damaged by fishing gears e.g., sponges, bryozoan, and coral species. Management regimes can protect seafloor habitats and key species from fishing activities; some areas will need more protection than others, accounting for specific traits that make species vulnerable, slow growing and long-lived species, restricted locations with optimum physiological conditions and available food, and restricted distributions of rare species. Ecosystem-based management practices and long-term, highly protected areas may be the most effective tools in the preservation of vulnerable seafloor habitats. Here, we focus on outlining seafloor responses to drivers of change observed to date and projections for the future. We discuss the need for action to preserve seafloor habitats under climate change, fishing pressures and other anthropogenic impacts

REVIEW OF THE CENTRAL AND SOUTH ATLANTIC SHELF AND DEEP-SEA BENTHOS: SCIENCE, POLICY, AND MANAGEMENT

The Central and South Atlantic represents a vast ocean area and is home to a diverse range of ecosystems and species. Nevertheless, and similar to the rest of the global south, the area is comparatively understudied yet exposed to increasing levels of multisectoral pressures. To counteract this, the level of scientific exploration in the Central and South Atlantic has increased in recent years and will likely continue to do so within the context of the United Nations (UN) Decade of Ocean Science for Sustainable Development. Here, we compile the literature to investigate the distribution of previous scientific exploration of offshore (30 m+) ecosystems in the Central and South Atlantic, both within and beyond national jurisdiction, allowing us to synthesise overall patterns of biodiversity. Furthermore, through the lens of sustainable management, we have reviewed the existing anthropogenic activities and associated management measures relevant to the region. Through this exercise, we have identified key knowledge gaps and undersampled regions that represent priority areas for future research and commented on how these may be best incorporated into, or enhanced through, future management measures such as those in discussion at the UN Biodiversity Beyond National Jurisdiction negotiations. This review represents a comprehensive summary for scientists and managers alike looking to understand the key topographical, biological, and legislative features of the Central and South Atlantic.This paper is an output of the UN Ocean Decade endorsed Challenger 150 Programme (#57). Challenger 150 is supported by the Deep Ocean Stewardship Initiative (DOSI) and the Scientific Committee on Oceanic Research’s (SCOR) working group 159 (NSF Grant OCE-1840868) for which KLH is co-chair. AEHB, KLH, KAM, SBu, and KS are supported by the UKRI funded One Ocean Hub NE/S008950/1. TA is supported by the BiodivRestore ERA-NET Cofund (GA N°101003777) with the EU and the following funding organisations: FCT, RFCT, AEI, DFG, and ANR. TA also acknowledges financial support to CESAM by FCT/MCTES (UIDP/50017/2 020+UIDB/50017/2020+ LA/P/0094/2020) through national funds. NB is supported by the John Ellerman Foundation. AB is supported by the German Research Foundation. DH, CO, AFB, LA, SBr, and KS received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 818123 (iAtlantic); this output reflects only the author’s view and the European Union cannot be held responsible for any use that may be made of the information contained therein. DH, AF, JT, and CW were additionally supported through the Cluster of Excellence “The Ocean Floor – Earth’s Uncharted Interface” (EXC-2077 – 390741603 by Deutsche Forschungsgemeinschaft). CO also extends thanks to the HWK – Institute for Advanced Study, and PM to Dr. Alberto Martín, retired professor of Universidad Simón Bolívar in Caracas, Venezuela for facilitating references used in the Venezuela section.Peer reviewe

"Antarctica just has this hero factor ... ": gendered barriers to Australian Antarctic research and remote fieldwork

Antarctica is often associated with images of masculine figures battling against the blizzard. The pervasiveness of heroic white masculine leadership and exploration in Antarctica and, more broadly, in Science, Technology, Engineering, Mathematics, and Medicine (STEMM) research cultures, has meant women have had lesser access to Antarctic research and fieldwork opportunities, with a marked increase since the 1980s. This article presents findings from an exploratory online survey examining how 95 women experienced research and remote Antarctic fieldwork with the Australian Antarctic Program. Although women are entering polar science in greater numbers, a key theme of the qualitative findings of this survey is that gendered barriers to participation in research and fieldwork persist. We discuss five key gendered barriers including: 1) Physical barriers, 2) Caring responsibilities/unpaid work, 3) Cultural sexism/gender bias, 4) Lack of opportunities/recognition, and 5) Unwanted male attention/sexual harassment. We argue that the lack of attention paid to gender and sexuality in polar fieldwork contributes to the invisibility and exclusion of women and other marginalized identities broadly. To conclude, we point to the importance of targeted inclusivity, diversity and equity initiatives through Antarctic research globally and specifically by National Antarctic Programs

How important is carbon storage by southern polar benthos as a negative feedback on climate change?

Carbon capture and storage by southern polar benthos is potentially the largest negative feedback on climate change. Most feedbacks on global climate change are positive; they exacerbate physical change. The few known strong negative feedbacks, those which reduce physical change, are polar, and include i) broadening existing sinks with sea-ice losses over polar continental shelves, ii) subarctic vegetation growth increases and iii) formation of new sinks where ice shelves collapse. To date, carbon sequestration gains have been recorded around the Antarctic coastal shallows where they are likely to be offset by fjordic losses associated with sedimentation, and open coast losses through increased iceberg scouring. These feedbacks are complicated by additional positive forcing associated with greater heat absorption from albedo change. In contrast there is no albedo change (negligible sea ice losses) over sub-Antarctic shelves, where rising sea temperatures are likely to increase carbon storage by animals. The continental shelves along polar continent margins and archipelagos are wide, deep and rich in life. Most species known from polar waters live on these shallower shelf regions and it has been observed that they play an increasingly important role in the carbon cycle. Carbon is transported through the system by being fixed in photosynthesis by algae, which are eaten by benthic invertebrates, and then buried when the animal dies. We aim to measure how much carbon is held per unit area of the seabed per year and how this varies in time and space. Teasing apart biological processes in these important geographic regions is vital to our understanding of global carbon capture. One of the biggest sources of error in this regard is understanding the extent to which these feedbacks are effects of climate forcing on sub-Antarctic and Arctic shelf benthos performance. This type of carbon sequestration, termed blue carbon (associated with natural processes), is likely to increase, so long as sea ice and ice shelf losses continue to be sustained. Our research project, titled Antarctic Seabed Carbon Capture Change (ASCCC) has participated in the Antarctic Circumnavigation Expedition (ACE) in 2016 and 2017 to address the question ‘How will regional warming influence how much carbon is captured and stored by life on the seabed around Antarctica and the sub-Antarctic?’, from which we plan to estimate increased benthic carbon stored across the southern polar region due to recent ice shelf losses, sea ice losses and temperature increases

Carbon storage by Kerguelen zoobenthos as a negative feedback on climate change.

As oceans warm, reducing the extent of sea-ice and-ice shelves, increased carbon capture by phytoplankton and storage by southern polar benthos (sea bed organisms), is potentially the largest negative feedback on climate change. Teasing apart biological processes within and between geographic regions is vital to our understanding of global carbon capture. One of the biggest sources of error in this regard is understanding the extent to which this feedback is the direct and indirect effect of recent climate forcing on sub-Antarctic benthos performance (growth, metabolism, reproduction etc). This type of carbon sequestration, termed blue carbon, is hypothesised to increase, so long as sea-ice and iceshelf losses continue to be sustained in the Antarctic. The sub-Antarctic may differ, due to reduced, or in some cases, no sea-ice duration. Our research project, titled Antarctic Seabed Carbon Capture Change (ASCCC, www.asccc.co.uk) aims to understand the temporal and spatial complexity of polar benthic blue carbon sinks, and the marine ice-free Kerguelen Plateau provides a unique geographic testing ground for this

The Growing Potential of Antarctic Blue Carbon

The removal of carbon from the atmosphere for a long period (sequestration) is an increasingly pressing societal need in order to mitigate the negative effects of climate change. Investment and technology solutions are moving in the direction of industrial carbon capture and storage. To date, this technology is inefficient, expensive, and in some cases, not even net carbon zero. Optimistic estimates suggesting huge investment in infrastructure, which requires resources that include land and fresh water, will only marginally contribute toward the reductions in atmospheric CO2 required to minimize the impact of climate change over the next 50 years (Hankin et al., 2019)

Towards estimation of blue carbon sink potential of sub-Antarctic continental shelf benthos

Continental shelves around Antarctica are a globally important carbon sink, due to both oceanographic CO2 absorption and biological fixation and trophic cascading. Most carbon passing through the foodweb is pelagic and is recycled through microbial loops. However significant masses are accumulated and immobilized (within calcareous skeletons of benthos), accounting for sequestration potential of 106 tonnes per year. Burial potential is enhanced by being largely untrawled by human harvesting and too deep for iceberg scouring. Yet these are also true for subAntarctic island shelves where there are considerable phytoplankton blooms, little or no sea ice and warmer sea temperatures (enabling faster meal processing time by benthos) – yet their potential as a carbon sink has been largely ignored. We report on the Antarctic Seabed Carbon Capture Change (ASCCC) project which sampled most of the high southern latitude continental shelves during the 2016/17 Antarctic Circumnavigation Expedition (ACE). Video and photo- equipped trawls collected imagery and benthos samples allowing us to estimate changes in intra and inter-shelf variability in benthos density and biomass. Growth models constructed from age structure of sampled species with growth check lines (e.g. bryozoans, bivalves, brachiopods etc) enable annual carbon accumulation to be estimated. Preliminary data and analyses suggest that continental shelves of 40-55°S may be globally significant, both in terms of absolute carbon storage but also in trying to reduce error in climate models. See www.asccc.co.u

A review and meta-analysis of potential impacts of ocean acidification on marine calcifiers from the Southern Ocean

Understanding the vulnerability of marine calcifiers to ocean acidification is a critical issue, especially in the Southern Ocean (SO), which is likely to be the one of the first, and most severely affected regions. Since the industrial revolution, ~30% of anthropogenic CO2 has been absorbed by the global oceans. Average surface seawater pH levels have already decreased by 0.1 and are projected to decline by ~0.3 by the year 2100. This process, known as ocean acidification (OA), is shallowing the saturation horizon, which is the depth below which calcium carbonate (CaCO3) dissolves, likely increasing the vulnerability of many resident marine calcifiers to dissolution. The negative impact of OA may be seen first in species depositing more soluble CaCO3 mineral phases such as aragonite and high-Mg calcite (HMC). Ocean warming could further exacerbate the effects of OA in these particular species. Here we combine a review and a quantitative meta-analysis to provide an overview of the current state of knowledge about skeletal mineralogy of major taxonomic groups of SO marine calcifiers and to make projections about how OA might affect a broad range of SO taxa. We consider a species' geographic range, skeletal mineralogy, biological traits, and potential strategies to overcome OA. The meta-analysis of studies investigating the effects of the OA on a range of biological responses such as shell state, development and growth rate illustrates that the response variation is largely dependent on mineralogical composition. Species-specific responses due to mineralogical composition indicate that taxa with calcitic, aragonitic, and HMC skeletons, could be at greater risk to expected future carbonate chemistry alterations, and low-Mg calcite (LMC) species could be mostly resilient to these changes. Environmental and biological control on the calcification process and/or Mg content in calcite, biological traits, and physiological processes are also expected to influence species-specific responses