I an era of unprecedented environmental change, developing a suite of tools for ecosystem monitoring is critical. This need is particularly urgent in marine ecosystems, given the rapid, climatedriven changes in marine populations and communities (Poloczanska et al. 2013). Comprehensive monitoring in marine ecosystems presents a challenge due to difficulties inherent in observing the highly dynamic ocean environment at relevant timescales. Traditional shipbased surveys are expensive, autonomous floats and underwater vehicles are still sparsely distributed, and remote sensing fails to capture threedimensional ocean structure. Furthermore, ecological monitoring in the open ocean is largely extractive and often involves lethal sampling of animal communities. In the undersampled marine realm, innovative and costeffective tools that can rapidly assess ecosystem responses to environmental change are vital. “Sentinel” species have been proposed as a means to provide information about unobserved components of the ecosystem (Zacharias and Roff 2001). Classic examples of sentinels include a domesticated variety of the canary (Serinus canaria), which was formerly used to monitor air quality in coal mines, and invertebrates, whose diversity has been used as an indicator of aquatic ecosystem health (Wilhm and Dorris 1968; Barry 2013). More recent studies show that vertebrate species can serve as sentinels of human health and environmental pollution (Bossart 2006; Smits and Fernie 2013), as well as coupled climate–ecosystem processes (Moore 2008). Useful sentinel species should integrate broader processes into rapidly interpretable metrics that reflect underlying ecosystem processes. Marine top predators (including certain species of predatory fish, seabirds, sea turtles, and marine mammals) have been proposed as ecosystem sentinels based on their conspicuous nature and capacity to indicate or respond to changes in ecosystem structure and function that would otherwise be difficult to observe directly (Figure 1; Bossart 2006; Boersma 2008; Moore 2008). Many marine top predators possess key characteristics of sentinel species, including (1) exhibiting clear responses to environmental variability or change (Sydeman et al. 2015; Fleming et al. 2016), (2) playing important roles in shaping marine food webs (Estes et al. 2016), and (3) indicating anthropogenic impacts on ecosystems (Sergio et al. 2008). Given these characteristics, there is a strong argument for using marine predators as ecosystem sentinels. Despite the contemporary use of marine predators as sentinels (relevant examples are listed in WebTable 1), the absence of a standardized framework for identifying sentinel Marine top predators as climate and ecosystem sentinels

https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/fee.2125

Marine top predators as climate and ecosystem sentinels

The Antarctic Ice Sheet (AIS) is out of equilibrium with the current anthropogenic-enhanced climate forcing. Paleoenvironmental records and ice sheet models reveal that the AIS has been tightly coupled to the climate system during the past and indicate the potential for accelerated and sustained Antarctic ice mass loss into the future. Modern observations by contrast suggest that the AIS has only just started to respond to climate change in recent decades. The maximum projected sea level contribution from Antarctica to 2100 has increased significantly since the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report, although estimates continue to evolve with new observational and theoretical advances. This review brings together recent literature highlighting the progress made on the known processes and feedbacks that influence the stability of the AIS. Reducing the uncertainty in the magnitude and timing of the future sea level response to AIS change requires a multidisciplinary approach that integrates knowledge of the interactions between the ice sheet, solid Earth, atmosphere, and ocean systems and across time scales of days to millennia. We start by reviewing the processes affecting AIS mass change, from atmospheric and oceanic processes acting on short time scales (days to decades), through to ice processes acting on intermediate time scales (decades to centuries) and the response to solid Earth interactions over longer time scales (decades to millennia). We then review the evidence of AIS changes from the Pliocene to the present and consider the projections of global sea level rise and their consequences. We highlight priority research areas required to improve our understanding of the processes and feedbacks governing AIS change.

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The Sensitivity of the Antarctic Ice Sheet to a Changing Climate: Past, Present, and Future

The role that women play in fisheries around the world is receiving increasing international attention yet the contributions by women to fisheries catches continues to be overlooked by society, industry and policy makers. Here, we address this lack of visibility with a global estimation of small-scale fisheries catches by women. Our estimates reveal that women participate in small-scale fishing activities in all regions of the world, with approximately 2.1 million (± 86,000) women accounting for roughly 11% (± 4%) of participants in small-scale fishing activities, i.e., catching roughly 2.9 million (± 835,000) tonnes per year of marine fish and invertebrates. The landed value of the catch by women is estimated at USD 5.6 billion (± 1.5 billion), with an economic impact of USD 14.8 billion per year (± 4 billion), which is equivalent to 25.6 billion real 2010 dollars (± 7.2 billion). These catches are mostly taken along the shoreline, on foot, or from small, non-motorized vessels using low-technology, low-emission gears in coastal waters. Catches taken by women are often for home consumption, and thus considered part of the subsistence sub-sector. However, in many contexts, women also sell a portion of their catch, generating income for themselves and their families. These findings underscore the significant role of women as direct producers in small-scale fisheries value chains, making visible contributions by women to food and livelihood security, globally.

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Valuing invisible catches: Estimating the global contribution by women to small-scale marine capture fisheries production.

The massive number of seabirds (penguins and procellariiformes) and marine mammals (cetaceans and pinnipeds) - referred to here as top predators - is one of the most iconic components of the Antarctic and Southern Ocean. They play an important role as highly mobile consumers, structuring and connecting pelagic marine food webs and are widely studied relative to other taxa. Many birds and mammals establish dense breeding colonies or use haul-out sites, making them relatively easy to study. Cetaceans, however, spend their lives at sea and thus aspects of their life cycle are more complicated to monitor and study. Nevertheless, they all feed at sea and their reproductive success depends on the food availability in the marine environment, hence they are considered useful indicators of the state of the marine resources. In general, top predators have large body sizes that allow for instrumentation with miniature data-recording or transmitting devices to monitor their activities at sea. Development of scientific techniques to study reproduction and foraging of top predators has led to substantial scientific literature on their population trends, key biological parameters, migratory patterns, foraging and feeding ecology, and linkages with atmospheric or oceanographic dynamics, for a number of species and regions. We briefly summarize the vast literature on Southern Ocean top predators, focusing on the most recent syntheses. We also provide an overview on the key current and emerging pressures faced by these animals as a result of both natural and human causes. We recognize the overarching impact that environmental changes driven by climate change have on the ecology of these species. We also evaluate direct and indirect interactions between marine predators and other factors such as disease, pollution, land disturbance and the increasing pressure from global fisheries in the Southern Ocean. Where possible we consider the data availability for assessing the status and trends for each of these components, their capacity for resilience or recovery, effectiveness of management responses, risk likelihood of key impacts and future outlook.

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Marine ecosystem assessment for the Southern Ocean : Birds and marine mammals in a changing climate

Tracking data have led to evidence-based conservation of marine megafauna, but a disconnect remains between the many 1000s of individual animals that have been tracked and the use of these data in conservation and management actions. Furthermore, the focus of most conservation efforts is within Exclusive Economic Zones despite the ability of these species to move 1000s of kilometers across multiple national jurisdictions. To assist the goal of the United Nations General Assembly’s recent effort to negotiate a global treaty to conserve biodiversity on the high seas, we propose the development of a new frontier in dynamic marine spatial management. We argue that a global approach combining tracked movements of marine megafauna and human activities at-sea, and using existing and emerging technologies (e.g., through new tracking devices and big data approaches) can be applied to deliver near real-time diagnostics on existing risks and threats to mitigate global risks for marine megafauna. With technology developments over the next decade expected to catalyze the potential to survey marine animals and human activities in ever more detail and at global scales, the development of dynamic predictive tools based on near real-time tracking and environmental data will become crucial to address increasing risks. Such global tools for dynamic spatial and temporal management will, however, require extensive synoptic data updates and will be dependent on a shift to a culture of data sharing and open access. We propose a global mechanism to store and make such data available in near real-time, enabling a holistic view of space use by marine megafauna and humans that would significantly accelerate efforts to mitigate impacts and improve conservation and management of marine megafauna.

/pdf/overhauling-ocean-spatial-planning-to-improve-marine-aezgu8tzst.pdf

Overhauling Ocean Spatial Planning to Improve Marine Megafauna Conservation

Animal telemetry is a powerful tool for observing marine animals and the physical environments that they inhabit, from coastal and continental shelf ecosystems to polar seas and open oceans. Satellite-linked biologgers and networks of acoustic receivers allow animals to be reliably monitored over scales of tens of meters to thousands of kilometers, giving insight into their habitat use, home range size, the phenology of migratory patterns and the biotic and abiotic factors that drive their distributions. Furthermore, physical environmental variables can be collected using animals as autonomous sampling platforms, increasing spatial and temporal coverage of global oceanographic observation systems. The use of animal telemetry, therefore, has the capacity to provide measures from a suite of essential ocean variables (EOVs) for improved monitoring of Earth's oceans. Here we outline the design features of animal telemetry systems, describe current applications and their benefits and challenges, and discuss future directions. We describe new analytical techniques that improve our ability to not only quantify animal movements but to also provide a powerful framework for comparative studies across taxa. We discuss the application of animal telemetry and its capacity to collect biotic and abiotic data, how the data collected can be incorporated into ocean observing systems, and the role these data can play in improved ocean management.

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Mike Weise

Papers

Animal-borne telemetry: An integral component of the ocean observing toolkit