scholarly journals Madrepora oculata forms large frameworks in hypoxic waters off Angola (SE Atlantic)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Covadonga Orejas ◽  
Claudia Wienberg ◽  
Jürgen Titschack ◽  
Leonardo Tamborrino ◽  
André Freiwald ◽  
...  
Keyword(s):  
North Atlantic ◽  
Environmental Conditions ◽  
Coral Community ◽  
Hypoxic Conditions ◽  
The North ◽  
Minimum Zone ◽  
The North Atlantic ◽  
Age Range ◽  
Local Oxygen ◽  
Oxygen Minimum

AbstractThis study aims to map the occurrence and distribution of Madrepora oculata and to quantify density and colony sizes across recently discovered coral mounds off Angola. Despite the fact that the Angolan populations of M. oculata thrive under extreme hypoxic conditions within the local oxygen minimum zone, they reveal colonies with remarkable heights of up to 1250 mm—which are the tallest colonies ever recorded for this species—and average densities of 0.53 ± 0.37 (SD) colonies m−2. This is particularly noteworthy as these values are comparable to those documented in areas without any oxygen constraints. The results of this study show that the distribution pattern documented for M. oculata appear to be linked to the specific regional environmental conditions off Angola, which have been recorded in the direct vicinity of the thriving coral community. Additionally, an estimated average colony age of 95 ± 76 (SD) years (total estimated age range: 16–369 years) indicates relatively old M. oculata populations colonizing the Angolan coral mounds. Finally, the characteristics of the Angolan populations are benchmarked and discussed in the light of the existing knowledge on M. oculata gained from the North Atlantic and Mediterranean Sea.

scholarly journals Oxygen minimum zone in the North Atlantic south and east of the Cape Verde Islands

2008 ◽  
Vol 113 (C4) ◽  
Author(s):  
Lothar Stramma ◽  
Peter Brandt ◽  
Jens Schafstall ◽  
Friedrich Schott ◽  
Jürgen Fischer ◽  
...  
Keyword(s):  
North Atlantic ◽  
Oxygen Minimum Zone ◽  
Cape Verde ◽  
Cape Verde Islands ◽  
The North ◽  
Minimum Zone ◽  
The North Atlantic ◽  
Oxygen Minimum

scholarly journals Isopycnal Mixing in the North Atlantic Oxygen Minimum Zone Revealed by RAFOS Floats

2019 ◽  
Vol 124 (9) ◽  
pp. 6478-6497 ◽  
Author(s):  
Donald Rudnickas ◽  
Jaime Palter ◽  
David Hebert ◽  
H. Thomas Rossby
Keyword(s):  
North Atlantic ◽  
Oxygen Minimum Zone ◽  
The North ◽  
Minimum Zone ◽  
The North Atlantic ◽  
Oxygen Minimum ◽  
Isopycnal Mixing

scholarly journals Water mass pathways to the North Atlantic oxygen minimum zone

2015 ◽  
Vol 120 (5) ◽  
pp. 3350-3372 ◽  
Author(s):  
Jesús Peña-Izquierdo ◽  
Erik van Sebille ◽  
Josep L. Pelegrí ◽  
Janet Sprintall ◽  
Evan Mason ◽  
...  
Keyword(s):  
North Atlantic ◽  
Water Mass ◽  
Oxygen Minimum Zone ◽  
The North ◽  
Minimum Zone ◽  
The North Atlantic ◽  
Oxygen Minimum

scholarly journals Environmental variability in the North Atlantic and Iberian waters and its influence on horse mackerel (Trachurus trachurus) and albacore (Thunnus alalunga) dynamics

2007 ◽  
Vol 64 (3) ◽  
pp. 425-438 ◽  
Author(s):  
Alicia Lavín ◽  
Xabier Moreno-Ventas ◽  
Victoria Ortiz de Zárate ◽  
Pablo Abaunza ◽  
José Manuel Cabanas
Keyword(s):  
North Atlantic ◽  
Environmental Conditions ◽  
Environmental Variability ◽  
Horse Mackerel ◽  
Wind Component ◽  
Trachurus Trachurus ◽  
The Third ◽  
The North ◽  
Thunnus Alalunga ◽  
The North Atlantic

Abstract Lavín, A., Moreno-Ventas, X., Ortiz de Zárate, V., Abaunza, P., and Cabanas, J. M. 2007. Environmental variability in the North Atlantic and Iberian waters and its influence on horse mackerel (Trachurus trachurus) and albacore (Thunnus alalunga) dynamics. – ICES Journal of Marine Science, 64: 425–438. We explore the potential impact of climatic and oceanic variables on the dynamics of horse mackerel Trachurus trachurus (coastal distribution) and albacore Thunnus alalunga (oceanic distribution). Principal components analysis of a set of environmental parameters for the years 1966–2000 allowed us to characterize the system by three components. The first consisted mainly of sea surface temperature (SST; 18.5% of variability), the second was determined by the oceanic transport indices, potential energy anomaly (PEA), and the Gulf Stream Index (15.6%), and the third by the meridional wind component and Ekman transport (11.5%). Horse mackerel recruitment was negatively correlated mainly with the first thermal component, whereas albacore age 3 catches were negatively correlated with the second oceanic component and positively with the third wind component. Multiple linear regression confirmed that environmental conditions [SST, PEA, and the zonal (east–west) wind component] explained the availability of age 3 albacore to the surface fisheries for the period 1975–1999. In contrast, cross-validation analysis showed that environmental conditions did not consistently explain horse mackerel recruitment, probably because of the short time-series available (15 y).

scholarly journals Can Environmental Conditions at North Atlantic Deep-Sea Habitats Be Predicted Several Years Ahead? ——Taking Sponge Habitats as an Example

2021 ◽  
Vol 8 ◽  
Author(s):  
Feifei Liu ◽  
Ute Daewel ◽  
Annette Samuelsen ◽  
Sebastian Brune ◽  
Ulrike Hanz ◽  
...  
Keyword(s):  
Climate Variability ◽  
North Atlantic ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Large Scale ◽  
Benthic Habitats ◽  
The North ◽  
Environmental Properties ◽  
Physical Fields ◽  
The North Atlantic

Predicting the ambient environmental conditions in the coming several years to one decade is of key relevance for elucidating how deep-sea habitats, like for example sponge habitats, in the North Atlantic will evolve under near-future climate change. However, it is still not well known to what extent the deep-sea environmental properties can be predicted in advance. A regional downscaling prediction system is developed to assess the potential predictability of the North Atlantic deep-sea environmental factors. The large-scale climate variability predicted with the coupled Max Planck Institute Earth System Model with low-resolution configuration (MPI-ESM-LR) is dynamically downscaled to the North Atlantic by providing surface and lateral boundary conditions to the regional coupled physical-ecosystem model HYCOM-ECOSMO. Model results of two physical fields (temperature and salinity) and two biogeochemical fields (concentrations of silicate and oxygen) over 21 sponge habitats are taken as an example to assess the ability of the downscaling system to predict the interannual to decadal variations of the environmental properties based on ensembles of retrospective predictions over the period from 1985 to 2014. The ensemble simulations reveal skillful predictions of the environmental conditions several years in advance with distinct regional differences. In areas closely tied to large-scale climate variability and ice dynamics, both the physical and biogeochemical fields can be skillfully predicted more than 4 years ahead, while in areas under strong influence of upper oceans or open boundaries, the predictive skill for both fields is limited to a maximum of 2 years. The simulations suggest higher predictability for the biogeochemical fields than for the physical fields, which can be partly attributed to the longer persistence of the former fields. Predictability is improved by initialization in areas away from the influence of Mediterranean outflow and areas with weak coupling between the upper and deep oceans. Our study highlights the ability of the downscaling regional system to predict the environmental variations at deep-sea benthic habitats on time scales of management relevance. The downscaling system therefore will be an important part of an integrated approach towards the preservation and sustainable exploitation of the North Atlantic benthic habitats.

The Growth of Shipping Services, 1902-1909

2012 ◽  
pp. 107-142
Author(s):  
Gordon Boyce
Keyword(s):  
South America ◽  
North Atlantic ◽  
Environmental Conditions ◽  
Persian Gulf ◽  
Freight Rates ◽  
Atlantic Trade ◽  
The North ◽  
The Poor ◽  
The North Atlantic ◽  
The Persian Gulf

This chapter charts the expansion of the Furness Group from 1902 to 1909 as they responded to the growth of American liner competition and shifting environmental conditions by engaging in other trades and amassing other resources. It analyses trends in trade, freight rates, tonnage, profit; the Furness Group’s profitability between 1900 and 1909; changes in patterns of growth; the North Atlantic trade stalemate between 1902 and 1909; the poor financial performance of Manchester-based liners; the Furness Group’s attempt to develop new liner trades beyond the North Atlantic into the Persian Gulf, South America and Australia; developments in tramp and contract trades; fleet expansion and consolidation; and insurance, salvage, repair, and provisioning interests. It concludes that by changing the composition of the Furness Group’s interests between 1902 and 1909 the company developed new and productive trade interests beyond the North Atlantic and escaped the trade deadlock. They would adjust the direction of services and expansion again in 1910, once the demand for shipping services resurfaced.

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