Estuarine dam water discharge enhances summertime primary productivity near the southwestern Korean coast.

The gate opening of estuarine dams discharge a large amount of freshwater into coastal zones during the summer monsoon in northeast Asia. We investigated seasonal and spatial variations in primary productivity (PP) and community structures of phytoplankton on a downstream macrotidal flat and examined the dam discharge effects. Our harmonic analysis of the PP revealed a clear seasonality with a unimodal peak in summer, possibly driven by high ammonium loading through internal recycling.

Sea ice predicts long-term trends in Adélie penguin population growth, but not annual fluctuations: Results from a range-wide multiscale analysis.

Understanding the scales at which environmental variability affects populations is critical for projecting population dynamics and species distributions in rapidly changing environments. Here we used a multilevel Bayesian analysis of range-wide survey data for Adélie penguins to characterize multidecadal and annual effects of sea ice on population growth. We found that mean sea ice concentration at breeding colonies (i.

Pan-Arctic Depth Distribution of Diapausing Copepods.

Diapause at depth is considered an integral part of the life cycle of copepods, but few studies have focused on the Arctic species and . By analyzing a large set of pan-arctic observational data compiled from multiple sources, we show that Arctic has a broad depth distribution in winter, indicating that diapause at depth is a facultative strategy. Both species' vertical distributions tend to deepen in winter and to be deeper and broader with increasing bottom depth, while individuals are aggregated closer to the sea floor in shallow areas.

The Paris Agreement objectives will likely halt future declines of emperor penguins.

The Paris Agreement is a multinational initiative to combat climate change by keeping a global temperature increase in this century to 2°C above preindustrial levels while pursuing efforts to limit the increase to 1.5°C. Until recently, ensembles of coupled climate simulations producing temporal dynamics of climate en route to stable global mean temperature at 1.

It's about time: A synthesis of changing phenology in the Gulf of Maine ecosystem.

The timing of recurring biological and seasonal environmental events is changing on a global scale relative to temperature and other climate drivers. This study considers the Gulf of Maine ecosystem, a region of high social and ecological importance in the Northwest Atlantic Ocean and synthesizes current knowledge of (a) key seasonal processes, patterns, and events; (b) direct evidence for shifts in timing; (c) implications of phenological responses for linked ecological-human systems; and (d) potential phenology-focused adaptation strategies and actions. Twenty studies demonstrated shifts in timing of regional marine organisms and seasonal environmental events.

Population genetic structure of the deep-sea mussel s (Bivalvia: Mytilidae) in the Northwest Pacific.

Studying population genetics of deep-sea animals helps us understand their history of habitat colonization and population divergence. Here, we report a population genetic study of the deep-sea mussel (Bivalvia: Mytilidae) widely distributed in chemosynthesis-based ecosystems in the Northwest Pacific. Three mitochondrial genes (i.

Pushing the limit: Resilience of an Arctic copepod to environmental fluctuations.

Life history strategies such as multiyear life cycles, resting stages, and capital breeding allow species to inhabit regions with extreme and fluctuating environmental conditions. One example is the zooplankton species Calanus hyperboreus, whose life history is considered an adaptation to the short and unpredictable growth season in the central Arctic Ocean. This copepod is commonly described as a true Arctic endemic; however, by statistically analyzing compiled observational data, we show that abundances are relatively low and later stages and adults dominate in the central Arctic Ocean basins, indicating expatriation.

Pan-Antarctic analysis aggregating spatial estimates of Adélie penguin abundance reveals robust dynamics despite stochastic noise.

Colonially-breeding seabirds have long served as indicator species for the health of the oceans on which they depend. Abundance and breeding data are repeatedly collected at fixed study sites in the hopes that changes in abundance and productivity may be useful for adaptive management of marine resources, but their suitability for this purpose is often unknown. To address this, we fit a Bayesian population dynamics model that includes process and observation error to all known Adélie penguin abundance data (1982-2015) in the Antarctic, covering >95% of their population globally.

Biogeographic responses of the copepod Calanus glacialis to a changing Arctic marine environment.

Dramatic changes have occurred in the Arctic Ocean over the past few decades, especially in terms of sea ice loss and ocean warming. Those environmental changes may modify the planktonic ecosystem with changes from lower to upper trophic levels. This study aimed to understand how the biogeographic distribution of a crucial endemic copepod species, Calanus glacialis, may respond to both abiotic (ocean temperature) and biotic (phytoplankton prey) drivers.

Circumpolar analysis of the Adélie Penguin reveals the importance of environmental variability in phenological mismatch.

Evidence of climate-change-driven shifts in plant and animal phenology have raised concerns that certain trophic interactions may be increasingly mismatched in time, resulting in declines in reproductive success. Given the constraints imposed by extreme seasonality at high latitudes and the rapid shifts in phenology seen in the Arctic, we would also expect Antarctic species to be highly vulnerable to climate-change-driven phenological mismatches with their environment. However, few studies have assessed the impacts of phenological change in Antarctica.

Decadal changes in zooplankton of the Northeast U.S. continental shelf.

The abundance of the subarctic copepod, Calanus finmarchicus, and temperate, shelf copepod, Centropages typicus, was estimated from samples collected bi-monthly over the Northeast U.S. continental shelf (NEUS) from 1977-2010.

Sea ice phenology and timing of primary production pulses in the Arctic Ocean.

Arctic organisms are adapted to the strong seasonality of environmental forcing. A small timing mismatch between biological processes and the environment could potentially have significant consequences for the entire food web. Climate warming causes shrinking ice coverage and earlier ice retreat in the Arctic, which is likely to change the timing of primary production.

Marine plankton phenology and life history in a changing climate: current research and future directions.

Increasing availability and extent of biological ocean time series (from both in situ and satellite data) have helped reveal significant phenological variability of marine plankton. The extent to which the range of this variability is modified as a result of climate change is of obvious importance. Here we summarize recent research results on phenology of both phytoplankton and zooplankton.