Annual Review of Marine Science最新文献

Climatic extremes are becoming increasingly common against a background trend of global warming. In the oceans, marine heatwaves (MHWs)-discrete periods of anomalously warm water-have intensified and become more frequent over the past century, impacting the integrity of marine ecosystems globally. We review and synthesize current understanding of MHW impacts at the individual, population, and community levels. We then examine how these impacts affect broader ecosystem services and discuss the current state of research on biological impacts of MHWs. Finally, we explore current and emergent approaches to predicting the occurrence andimpacts of future events, along with adaptation and management approaches. With further increases in intensity and frequency projected for coming decades, MHWs are emerging as pervasive stressors to marine ecosystems globally. A deeper mechanistic understanding of their biological impacts is needed to better predict and adapt to increased MHW activity in the Anthropocene.

Gender equity, providing for full participation of people of all genders in the oceanographic workforce, is an important goal for the continued success of the oceanographic enterprise. Here, we describe historical obstructions to gender equity; assess recent progress and the current status of gender equity in oceanography by examining quantitative measures of participation, achievement, and recognition; and review activities to improve gender equity. We find that women receive approximately half the oceanography PhDs in many parts of the world and are increasing in parity in earlier levels of academic employment. However, continued progress toward gender parity is needed, as reflected by metrics such as first-authored publications, funded grants, honors, and conference speaker invitations. Finally we make recommendations for the whole oceanographic community to continue to work together to create a culture where oceanographers of all genders can thrive, including eliminating harassment, reexamining selection and evaluation procedures, and removing structural inequities.

Constraining rates of marine carbonate burial through geologic time is critical for interpreting reconstructed changes in ocean chemistry and understanding feedbacks and interactions between Earth's carbon cycle and climate. The Quaternary Period (the past 2.6 million years) is of particular interest due to dramatic variations in sea level that periodically exposed and flooded areas of carbonate accumulation on the continental shelf, likely impacting the global carbonate budget and atmospheric carbon dioxide. These important effects remain poorly quantified. Here, we summarize the importance of carbonate burial in the ocean-climate system, review methods for quantifying carbonate burial across depositional environments, discuss advances in reconstructing Quaternary carbonate burial over the past three decades, and identify gaps and challenges in reconciling the existing records. Emerging paleoceanographic proxies such as the stable strontium and calcium isotope systems, as well as innovative modeling approaches, are highlighted as new opportunities to produce continuous records of global carbonate burial.

The oceanic waters below a depth of 200 m represent, in terms of volume, the largest habitat of the biosphere, harboring approximately 70% of the prokaryotic biomass in the oceanic water column. These waters are characterized by low temperature, increasing hydrostatic pressure, and decreasing organic matter supply with depth. Recent methodological advances in microbial oceanography have refined our view of the ecology of prokaryotes in the dark ocean. Here, we review the ecology of prokaryotes of the dark ocean, present data on the biomass distribution and heterotrophic and chemolithoautotrophic prokaryotic production in the major oceanic basins, and highlight the phylogenetic and functional diversity of this part of the ocean. We describe the connectivity of surface and deep-water prokaryotes and the molecular adaptations of piezophilic prokaryotes to high hydrostatic pressure. We also highlight knowledge gaps in the ecology of the dark ocean's prokaryotes and their role in the biogeochemical cycles in the largest habitat of the biosphere.

Releases of anthropogenic radionuclides from European nuclear fuel reprocessing plants enter the surface circulation of the high-latitude North Atlantic and are transported northward into the Arctic Ocean and southward from the Nordic Seas into the deep North Atlantic, thereby providing tracers of water circulation, mixing, ventilation, and deep-water formation. Early tracer studies focused on ¹³⁷Cs, which revealed some of the first significant insights into the Arctic Ocean circulation, while more recent work has benefited from advances in accelerator mass spectrometry to enable the measurement of the conservative, long-lived radionuclide tracers ¹²⁹I and ²³⁶U. The latest studies of these tracers, supported by simulations using the North Atlantic-Arctic Ocean-Sea Ice Model (NAOSIM) and enhanced by the use of transit time distributions to more precisely accommodate mixing, have provided a rich inventory of transport data for circulation in the Arctic and North Atlantic Oceans that are of great importance to global thermohaline circulation and climate.

I am a child of Sputnik, the satellite launched by the Soviet Union in 1957. That event created opportunities for me to escape the horrors of apartheid by emigrating from South Africa to the United States. There, fortuitously, I was given excellent opportunities to explore how an interplay between the waves and currents influences climate variability, from interannual El Niño events to millennial ice ages. During my career, I also witnessed intriguing facets of the interactions between the profoundly different worlds of science and of human affairs. Up to 1957, El Niño was welcomed as a blessing, but by 1982 it had become a curse-not because it changed, but because our human activities are making us vulnerable to natural climate variability. We have learned to cope admirably with the occasional failures of the Indian monsoons; the resultant famines are not as calamitous as they once were. What guidance does that limited success provide for a response to global warming, a climate change we humans are inducing? This article briefly summarizes how my career as a geoscientist brought me to the conclusion that a strategy to promote responsible stewardship of planet Earth should be based on love rather than fear. We can only love what we know, so warnings of imminent gloom and doom should be complemented with efforts to make everyone aware of the wonders of our amazing planet-the only one in the universe known to be habitable.

The world's eastern boundary upwelling systems (EBUSs) contribute disproportionately to global ocean productivity and provide critical ecosystem services to human society. The impact of climate change on EBUSs and the ecosystems they support is thus a subject of considerable interest. Here, we review hypotheses of climate-driven change in the physics, biogeochemistry, and ecology of EBUSs; describe observed changes over recent decades; and present projected changes over the twenty-first century. Similarities in historical and projected change among EBUSs include a trend toward upwelling intensification in poleward regions, mitigatedwarming in near-coastal regions where upwelling intensifies, and enhanced water-column stratification and a shoaling mixed layer. However, there remains significant uncertainty in how EBUSs will evolve with climate change, particularly in how the sometimes competing changes in upwelling intensity, source-water chemistry, and stratification will affect productivity and ecosystem structure. We summarize the commonalities and differences in historical and projected change in EBUSs and conclude with an assessment of key remaining uncertainties and questions. Future studies will need to address these questions to better understand, project, and adapt to climate-driven changes in EBUSs.

The regular movements of waves and tides are obvious representations of the oceans' rhythmicity. But the rhythms of marine life span across ecological niches and timescales, including short (in the range of hours) and long (in the range of days and months) periods. These rhythms regulate the physiology and behavior of individuals, as well as their interactions with each other and with the environment. This review highlights examples of rhythmicity in marine animals and algae that represent important groups of marine life across different habitats. The examples cover ecologically highly relevant species and a growing number of laboratory model systems that are used to disentangle key mechanistic principles. The review introduces fundamental concepts of chronobiology, such as the distinction between rhythmic and endogenous oscillator-driven processes. It also addresses the relevance of studying diverse rhythms and oscillators, as well as their interconnection, for making better predictions of how species will respond to environmental perturbations, including climate change. As the review aims to address scientists from the diverse fields of marine biology, ecology, and molecular chronobiology, all of which have their own scientific terms, we provide definitions of key terms throughout the article.

Ocean carbon dioxide removal (OCDR) is rapidly attracting interest, as climate change is putting ecosystems at risk and endangering human communities globally. Due to the centrality of the ocean in the global carbon cycle, augmenting the carbon sequestration capacity of the ocean could be a powerful mechanism for the removal of legacy excess emissions. However, OCDR requires careful assessment due to the unique biophysical characteristics of the ocean and its centrality in the Earth system and many social systems. Using a sociotechnical system lens, this review identifies the sets of considerations that need to be included within robust assessments for OCDR decision-making. Specifically, it lays out the state of technical assessments of OCDR approaches along with key financial concerns, social issues (including public perceptions), and the underlying ethical debates and concerns that would need to be addressed if OCDR were to be deployed as a carbon dioxide removal strategy.

The Arctic Ocean's Beaufort Gyre is a dominant feature of the Arctic system, a prominent indicator of climate change, and possibly a control factor for high-latitude climate. The state of knowledge of the wind-driven Beaufort Gyre is reviewed here, including its forcing, relationship to sea-ice cover, source waters, circulation, and energetics. Recent decades have seen pronounced change in all elements of the Beaufort Gyre system. Sea-ice losses have accompanied an intensification of the gyre circulation and increasing heat and freshwater content. Present understanding of these changes is evaluated, and time series of heat and freshwater content are updated to include the most recent observations.