scholarly journals Importance of tropical tuna for seabird foraging over a marine productivity gradient

2018 ◽  
Vol 586 ◽  
pp. 233-249 ◽  
Author(s):  
MGR Miller ◽  
N Carlile ◽  
J Scutt Phillips ◽  
F McDuie ◽  
BC Congdon
Keyword(s):  
Productivity Gradient ◽  
Marine Productivity ◽  
Tropical Tuna

scholarly journals Foraging plasticity in a pelagic seabird species along a marine productivity gradient

2010 ◽  
Vol 398 ◽  
pp. 259-274 ◽  
Author(s):  
VH Paiva ◽  
P Geraldes ◽  
I Ramírez ◽  
A Meirinho ◽  
S Garthe ◽  
...  
Keyword(s):  
Seabird Species ◽  
Productivity Gradient ◽  
Marine Productivity ◽  
Pelagic Seabird

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 Quantifying the increase in fishing efficiency due to the use of drifting FADs equipped with echosounders in tropical tuna purse seine fisheries

2020 ◽  
Author(s):  
Gwenaëlle Wain ◽  
Loreleï Guéry ◽  
David Michael Kaplan ◽  
Daniel Gaertner
Keyword(s):  
New Technology ◽  
Recent Change ◽  
Purse Seine ◽  
Catch Per Unit Effort ◽  
Katsuwonus Pelamis ◽  
Thunnus Obesus ◽  
Efficiency Increase ◽  
Tropical Tuna ◽  
Floating Objects ◽  
The Impact

Abstract Numerous pelagic species are known to associate with floating objects (FOBs), including tropical tunas. Purse seiners use this behaviour to facilitate the capture of tropical tunas by deploying artificial drifting fish aggregating devices (dFADs). One major recent change has been the integration of echosounders in satellite-tracked GPS buoys attached to FOBs, allowing fishers to remotely estimate fishable biomass. Understanding the effects of this new technology on catch of the three main tuna species (yellowfin tuna, Thunnus albacares; bigeye tuna, Thunnus obesus; and skipjack tuna, Katsuwonus pelamis) is important to accurately correct for this change in catch-per-unit-effort (CPUE) indices used for stock assessments. We analysed catch data from the French purse seine fleet for the period 2010–2017 in the Indian Ocean to assess the impact of this fleet’s switch to echosounder buoys around 2012. Results indicate that echosounders do not increase the probability a set will be succesful, but they have a positive effect on catch per set, with catches on average increasing by ≈2−2.5 tonnes per set (≈10%) when made on the vessel's own dFADs equipped with an echosounder buoy. Increases were due to a decrease in sets below ≈25 tonnes and an increase in those greater than ≈25 tonnes, with a non-linear transition around this threshold. This increase explains the considerable investment of purse seiners in echosounder buoys, but also raises concerns about bias in stock size estimates based on CPUE if we do not correct for this fishing efficiency increase.

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

Effects of land-use changes on plant functional and taxonomic diversity along a productivity gradient in wet meadows

2013 ◽  
Vol 24 (5) ◽  
pp. 898-909 ◽  
Author(s):  
Š. Janeček ◽  
F. de Bello ◽  
J. Horník ◽  
M. Bartoš ◽  
T. Černý ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Taxonomic Diversity ◽  
Wet Meadows ◽  
Productivity Gradient ◽  
Effects Of Land Use
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