Marine Productivity

2007 ◽  
pp. 350-369 ◽  
Author(s):  
Victor Smetacek ◽  
Marina Montresor ◽  
Peter Verity
Keyword(s):  
Marine Productivity

RECOVERY OF MARINE PRODUCTIVITY AFTER THE SNOWBALL EARTH: EVIDENCE FROM PYRITE IRON ISOTOPES

2020 ◽  
Author(s):  
Ruimin Wang ◽  
◽  
Xianguo Lang ◽  
Tianzheng Huang ◽  
Bing Shen
Keyword(s):  
Snowball Earth ◽  
Iron Isotopes ◽  
Marine Productivity

scholarly journals Anatomy of an extinction revealed by molecular fossils spanning OAE2

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. M. Forkner ◽  
J. Dahl ◽  
A. Fildani ◽  
S. M. Barbanti ◽  
I. A. Yurchenko ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Cumulative Effect ◽  
Environmental Stresses ◽  
Ecological Change ◽  
Western Interior Seaway ◽  
Oceanic Anoxic Event ◽  
Greenhorn Formation ◽  
Productivity Decline ◽  
Marine Productivity ◽  
New Evidence

AbstractThe Cenomanian–Turonian mass extinction (Oceanic Anoxic Event 2-OAE2) was a period of profound ecological change that is recorded in the sedimentary record in many locations around the globe. In this study, we provide a new and detailed account of repetitive changes in water column ecology by analyzing the organic geochemical record preserved within the OAE2 section of the Greenhorn Formation, Western Interior Seaway (WIS) of North America. Results from this study provide evidence that OAE2 in the WIS was the result of the cumulative effect of reoccurring environmental stresses rather than a single massive event. During OAE2, extreme variations in biotic composition occurred erratically over periods of several thousands of years as revealed by molecular fossil (biomarker) abundances and distributions calibrated to sedimentation rates. These cycles of marine productivity decline almost certainly had follow-on effects through the ecosystem and likely contributed to the Cenomanian–Turonian mass extinction. While the causes behind organic productivity cycling are yet unproven, we postulate that they may have been linked to repeated episodes of volcanic activity. Catastrophic volcanism and related CO2 outgassing have been interpreted as main drivers for OAE2, though this study provides new evidence that repetitive, punctuated environmental stresses were also important episodes within the anatomy of OAE2. Following OAE2, these cycles of productivity decline disappeared, and the WIS returned to conditions comparable to pre-OAE2 levels.

Rapid Resurgence of Marine Productivity After the Cretaceous-Paleogene Mass Extinction

Science ◽  
2009 ◽  
Vol 326 (5949) ◽  
pp. 129-132 ◽  
Author(s):  
J. Sepulveda ◽  
J. E. Wendler ◽  
R. E. Summons ◽  
K.-U. Hinrichs
Keyword(s):  
Mass Extinction ◽  
Marine Productivity

Late Holocene Sea Temperatures along the Central California Coast

1999 ◽  
Vol 51 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Terry L. Jones ◽  
Douglas J. Kennett
Keyword(s):  
Late Holocene ◽  
Fish Bone ◽  
Archaeological Sites ◽  
Central California ◽  
The Past ◽  
Past 2000 Years ◽  
Terrestrial Productivity ◽  
Continued Use ◽  
Mussel Shells ◽  
Marine Productivity

AbstractMussel shells from central California coastal archaeological sites record changes in sea surface temperatures in the past 2000 years. Water temperatures, inferred from oxygen isotopes in the shells, were about 1°C cooler than present and stable between 2000 and 700 yr ago. Between about 700 and 500 yr ago, seasonal variation was greater than present, with extremes above and below historic levels. Water temperatures were 2–3°C cooler than today 500–300 yr ago. The interval of variable sea temperatures 700–500 yr ago partially coincided with an interval of drought throughout central California. A coincident disruption in human settlement along the coast suggests movements of people related to declining water sources. Quantities of fish bone in central coast middens dating to this same period are high relative to other periods, and the remains of northern anchovies, a species sensitive to changing oceanographic conditions, are also abundant. The continued use of local fisheries suggests that changes in settlement and diet were influenced more by drought than by a decrease in marine productivity, as fish provided a staple during an interval of low terrestrial productivity.

scholarly journals Marine productivity response to Heinrich events: a model-data comparison

2012 ◽  
Vol 8 (5) ◽  
pp. 1581-1598 ◽  
Author(s):  
V. Mariotti ◽  
L. Bopp ◽  
A. Tagliabue ◽  
M. Kageyama ◽  
D. Swingedouw
Keyword(s):  
North Atlantic ◽  
General Circulation ◽  
Circulation Model ◽  
Global Ocean ◽  
Biogeochemical Model ◽  
Heinrich Events ◽  
The North ◽  
Heinrich Event ◽  
The North Atlantic ◽  
Marine Productivity

Abstract. Marine sediments records suggest large changes in marine productivity during glacial periods, with abrupt variations especially during the Heinrich events. Here, we study the response of marine biogeochemistry to such an event by using a biogeochemical model of the global ocean (PISCES) coupled to an ocean-atmosphere general circulation model (IPSL-CM4). We conduct a 400-yr-long transient simulation under glacial climate conditions with a freshwater forcing of 0.1 Sv applied to the North Atlantic to mimic a Heinrich event, alongside a glacial control simulation. To evaluate our numerical results, we have compiled the available marine productivity records covering Heinrich events. We find that simulated primary productivity and organic carbon export decrease globally (by 16% for both) during a Heinrich event, albeit with large regional variations. In our experiments, the North Atlantic displays a significant decrease, whereas the Southern Ocean shows an increase, in agreement with paleo-productivity reconstructions. In the Equatorial Pacific, the model simulates an increase in organic matter export production but decreased biogenic silica export. This antagonistic behaviour results from changes in relative uptake of carbon and silicic acid by diatoms. Reasonable agreement between model and data for the large-scale response to Heinrich events gives confidence in models used to predict future centennial changes in marine production. In addition, our model allows us to investigate the mechanisms behind the observed changes in the response to Heinrich events.

scholarly journals Erratum: Corrigendum: Enhanced Southern Ocean marine productivity due to fertilization by giant icebergs

2016 ◽  
Vol 9 (9) ◽  
pp. 728-728
Author(s):  
Luis P. A. M. Duprat ◽  
Grant R. Bigg ◽  
David J. Wilton
Keyword(s):  
Southern Ocean ◽  
Marine Productivity

scholarly journals Seasonal and interannual variations in the propagation of photosynthetically available radiation through the Arctic atmosphere

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
J. Laliberté ◽  
S. Bélanger ◽  
M. Babin
Keyword(s):  
Large Data ◽  
The Arctic ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
The Sun ◽  
Photosynthetically Available Radiation ◽  
Data Set ◽  
Melt Ponds ◽  
Arctic Atmosphere ◽  
Marine Productivity

The Arctic atmosphere–surface system transmits visible light from the Sun to the ocean, determining the annual cycle of light available to microalgae. This light is referred to as photosynthetically available radiation (PAR). A known consequence of Arctic warming is the change at the atmosphere–ocean interface (longer ice-free season, younger ice), implying an increase in the percentage of PAR being transferred to the water. However, much less is known about the recent changes in how much PAR is being transferred by the overlaying atmosphere. We studied the transfer of PAR through the atmosphere between May 21 and July 23 at a pan-Arctic scale for the period ranging from 2000 to 2016. By combining a large data set of atmospheric and surface conditions into a radiative transfer model, we computed the percentage of PAR transferred to the surface. We found that typical Arctic atmospheres convey between 60% and 70% of the incident PAR received from the Sun, meaning the Arctic atmosphere typically transmits more light than most sea ice surfaces, with the exception of mature melt ponds. We also found that the transfer of PAR through the atmosphere decreased at a rate of 2.3% per decade over the studied period, due to the increase in cloudiness and the weaker radiative interaction between the atmosphere and the surface. Further investigation is required to address how, in the warmer Arctic climate, this negative trend would compensate for the increased surface transmittance and its consequences on marine productivity.

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