Search results for "North Pacific"
showing 10 items of 15 documents
Coralline alga reveals first marine record of subarctic North Pacific climate change
2007
[1] While recent changes in subarctic North Pacific climate had dramatic effects on ecosystems and fishery yields, past climate dynamics and teleconnection patterns are poorly understood due to the absence of century-long high-resolution marine records. We present the first 117-year long annually resolved marine climate history from the western Bering Sea/Aleutian Island region using information contained in the calcitic skeleton of the long-lived crustose coralline red alga Clathromorphum nereostratum, a previously unused climate archive. The skeletal δ18O-time series indicates significant warming and/or freshening of surface waters after the middle of the 20th century. Furthermore, the ti…
Calcifying phytoplankton standing stocks in the North Pacific from the R/V Kilo Moana cruise KM1712
2022
This dataset compiles the CaCO3 standing stocks of living coccolithophores (mg/m³), of detached coccoliths (mg/m³) and the integrated CaCO3 standing stocks of coccolithophores (mg/m²). The samples were collected in the North Pacific between Hawaii and the Gulf of Alaska during the R/V Kilo Moana cruise KM1712 in August 2017, with rosette Niskin bottles equiped with CTD (Sea-Bird SBE 9) at different depths throughout the photic zone including the deep chlorophyll maximum. To estimate the CaCO3 contribution by coccolithophore assemblages in each sample, we carried out the transformation of coccospheres in number of coccoliths, following the estimates by Yang and Wei (2003), and then we adopte…
Integrated annual calcium carbonate production of planktic calcifiers in the North Pacific from the R/V Kilo Moana cruise KM1712
2022
This dataset compiles the estimates of annual CaCO3 production, including the upper and lower limits of the estimates, for the 4 planktic calcifying groups considered in the study, the pteropods (mg/m²/yr), the heteropods (mg/m²/yr), the foraminifers (mg/m²/yr) and the coccolithophores (mg/m²/yr). The estimates derived from the living standing stocks of these 4 groups of organisms collected in the North Pacific between Hawaii and the Gulf of Alaska during the R/V Kilo Moana cruise KM1712 in August 2017. R code was used to calculate the integrated annual CaCO3 production for the different organisms, including the upper and lower limits (Gray, 2022).
Planktic calcifiers standing stocks and carbonate production in the North Pacific from the R/V Kilo Moana cruise KM1712
2022
The data collection consists of 3 datasets: - Zooplankton standing stocks: this dataset compiles the standing stocks (ind/m³), the integrated standing stocks (ind/m²) and the integrated CaCO3 standing stocks (mg/m²) for three groups of zooplanktonic calcifying organisms, pteropods, heteropods and foraminifers. The organisms were collected by oblique towing (Ø 0.5 m, 90 μm mesh size, SeaGear mechanical flowmeter) in the North Pacific between Hawaii and the Gulf of Alaska during the R/V Kilo Moana cruise KM1712 in August 2017. The sampling strategy was designed to capture an integrated sample of all foraminifers, pteropods and heteropods from juveniles to adults living throughout the upper wa…
Connections of the West Pacific subtropical high and some hydroclimatic regimes in China with Antarctic ice-snow indices
1987
On the basis of 10 years monthly and long-term annual data the importance of the antarctic ice-snow cover and correlated indices has been discussed. By computing time-lag correlation analyses of the ice-snow indices and different atmospheric indices of the northern hemisphere and some hydroclimatic regimes in China, it could be shown that a close relationship between sea-ice in the Antarctic and the intensity and area indices of the subtropical West Pacific high exists. It was also possible to prove a close relationship between antarctic ice-snow indices and the annual run-off of the Yellow River at Sanmenxia, and between rainfall over North China and the lower sections of the Yellow river.
Seawater carbonate chemistry and kelp densities and coral coverages at three study locations and photosynthesis and calcification of corals measured …
2021
Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed “tropicalization”. A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems…
Insights fromsodium into the impacts of elevated pCO2 and temperature on bivalve shell formation
2017
Ocean acidification and warming are predicted to affect the ability of marine bivalves to build their shells, but little is known about the underlying mechanisms. Shell formation is an extremely complex process requiring a detailed understanding of biomineralization processes. Sodium incorporation into the shells would increase if bivalves rely on the exchange of Na+/H+ to maintain homeostasis for shell formation, thereby shedding new light on the acid-base and ionic regulation at the calcifying front. Here, we investigated the combined effects of seawater pH (8.1, 7.7 and 7.4) and temperature (16 and 22 °C) on the growth and sodium composition of the shells of the blue mussel, Mytilus edul…
Sodium provides unique insights into transgenerational effects of ocean acidification on bivalve shell formation
2016
Ocean acidification is likely to have profound impacts on marine bivalves, especially on their early life stages. Therefore, it is imperative to know whether and to what extent bivalves will be able to acclimate or adapt to an acidifying ocean over multiple generations. Here, we show that reduced seawater pH projected for the end of this century (i.e., pH 7.7) led to a significant decrease of shell production of newly settled juvenile Manila clams, Ruditapes philippinarum. However, juveniles from parents exposed to low pH grew significantly faster than those from parents grown at ambient pH, exhibiting a rapid transgenerational acclimation to an acidic environment. The sodium composition of…
Seawater carbonate chemistry and composition of intertidal and subtidal communities
2018
Rising atmospheric concentrations of carbon dioxide are causing surface seawater pH and carbonate ion concentrations to fall in a process known as ocean acidification. To assess the likely ecological effects of ocean acidification we compared intertidal and subtidal marine communities at increasing levels of pCO2 at recently discovered volcanic seeps off the Pacific coast of Japan (34° N). This study region is of particular interest for ocean acidification research as it has naturally low levels of surface seawater pCO2 (280–320 µatm) and is located at a transition zone between temperate and sub-tropical communities. We provide the first assessment of ocean acidification effects at a biogeo…
Seawater carbonate chemistry and growth, physiological performance of the Manila clam Ruditapes philippinarum
2018
Ocean acidification may interfere with the calcifying physiology of marine bivalves. Therefore, understanding their capacity for acclimation and adaption to low pH over multiple generations is crucial to make predictions about the fate of this economically and ecologically important fauna in an acidifying ocean. Transgenerational exposure to an acidification scenario projected by the end of the century (i.e., pH 7.7) has been shown to confer resilience to juvenile offspring of the Manila clam, Ruditapes philippinarum. However, whether, and to what extent, this resilience can persist into adulthood are unknown and the mechanisms driving transgenerational acclimation remain poorly understood.…