scholarly journals The 4.2 ka event, ENSO, and coral reef development

2019 ◽  
Vol 15 (1) ◽  
pp. 105-119 ◽  
Author(s):  
Lauren T. Toth ◽  
Richard B. Aronson
Keyword(s):  
Coral Reef ◽  
Southern Oscillation ◽  
Global Scale ◽  
Tropical Eastern Pacific ◽  
Reef Accretion ◽  
Reef Development ◽  
Enso Variability ◽  
The Pacific ◽  
Ultimate Cause ◽  
Terrestrial Environments

Abstract. Variability of sea-surface temperature related to shifts in the mode of the El Niño–Southern Oscillation (ENSO) has been implicated as a possible forcing mechanism for the global-scale changes in tropical and subtropical precipitation known as the 4.2 ka event. We review records of coral reef development and paleoceanography from the tropical eastern Pacific (TEP) to evaluate the potential impact of the 4.2 ka event on coral reefs. Our goal is to identify the regional climatic and oceanographic drivers of a 2500-year shutdown of vertical reef accretion in the TEP after 4.2 ka. The 2500-year hiatus represents ∼40 % of the Holocene history of reefs in the TEP and appears to have been tied to increased variability of ENSO. When ENSO variability abated approximately 1.7–1.6 ka, coral populations recovered and vertical accretion of reef framework resumed apace. There is some evidence that the 4.2 ka event suppressed coral growth and reef accretion elsewhere in the Pacific Ocean as well. Although the ultimate causality behind the global 4.2 ka event remains elusive, correlations between shifts in ENSO variability and the impacts of the 4.2 ka event suggest that ENSO could have played a role in climatic changes at that time, at least in the tropical and subtropical Pacific. We outline a framework for testing hypotheses of where and under what conditions ENSO may be expected to have impacted coral reef environments around 4.2 ka. Although most studies of the 4.2 ka event have focused on terrestrial environments, we suggest that understanding the event in marine systems may prove to be the key to deciphering its ultimate cause.

scholarly journals The 4.2-ka event, ENSO, and coral-reef development

2018 ◽  
Author(s):  
Lauren T. Toth ◽  
Richard B. Aronson
Keyword(s):  
Coral Reef ◽  
Southern Oscillation ◽  
Global Scale ◽  
Tropical Eastern Pacific ◽  
Reef Accretion ◽  
Reef Development ◽  
Enso Variability ◽  
The Pacific ◽  
Ultimate Cause ◽  
Terrestrial Environments

Abstract. Variability of sea-surface temperature related to shifts in the mode of the El Niño–Southern Oscillation (ENSO) has been implicated as a possible forcing mechanism for the changes in global-scale, tropical and subtropical precipitation known as the 4.2-ka event. We explore records of coral-reef development and paleoceanography from the tropical eastern Pacific (TEP) to evaluate the potential impact of the 4.2-ka event on coral reefs. Our goal is to identify the regional climatic and oceanographic drivers of a 2500-year shutdown of vertical reef accretion in the TEP beginning 4.2 ka. The 2500-year hiatus represents ~ 40 % of the Holocene history of reefs in the TEP and was tied to increased variability of ENSO. When ENSO variability abated approximately 1.7–1.6 ka, coral populations recovered and vertical accretion of reef framework resumed apace. The 4.2-ka event appears to have suppressed coral populations and reef accretion elsewhere in the Pacific Ocean as well. Although the ultimate causality behind the global 4.2-ka event remains elusive, correlations between shifts in ENSO variability and the impacts of the 4.2-ka event suggest that ENSO played a role in climatic changes at that time, at least in the tropical and subtropical Pacific. We outline a framework for testing hypotheses of where and under what conditions ENSO may be expected to have impacted coral-reef environments around 4.2 ka. Although most studies of the 4.2-ka event have focused on terrestrial environments, we suggest that understanding the event in marine systems may prove to be the key to deciphering its ultimate cause.

ENSO Drove 2500-Year Collapse of Eastern Pacific Coral Reefs

Science ◽  
2012 ◽  
Vol 337 (6090) ◽  
pp. 81-84 ◽  
Author(s):  
Lauren T. Toth ◽  
Richard B. Aronson ◽  
Steven V. Vollmer ◽  
Jennifer W. Hobbs ◽  
Dunia H. Urrego ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Global Climate Change ◽  
Southern Oscillation ◽  
Global Climate ◽  
Intertropical Convergence Zone ◽  
Eastern Pacific ◽  
Convergence Zone ◽  
Reef Growth ◽  
Tropical Eastern Pacific

Cores of coral reef frameworks along an upwelling gradient in Panamá show that reef ecosystems in the tropical eastern Pacific collapsed for 2500 years, representing as much as 40% of their history, beginning about 4000 years ago. The principal cause of this millennial-scale hiatus in reef growth was increased variability of the El Niño–Southern Oscillation (ENSO) and its coupling with the Intertropical Convergence Zone. The hiatus was a Pacific-wide phenomenon with an underlying climatology similar to probable scenarios for the next century. Global climate change is probably driving eastern Pacific reefs toward another regional collapse.

scholarly journals RELACIONES FILOGEOGRÁFICAS DE ALGUNAS COLONIAS DE ALIMENTACIÓN Y ANIDACIÓN DE LA TORTUGA CAREY (ERETMOCHELYS IMBRICATA) EN EL PACÍFICO Y CARIBE COLOMBIANOS

2016 ◽  
Vol 43 (1) ◽  
Author(s):  
Natalia Trujillo Arias ◽  
Diego F Amorocho ◽  
Diana López Álvarez ◽  
Luz M Mejía Ladino
Keyword(s):  
Isolation By Distance ◽  
Divergence Time ◽  
Sea Turtle ◽  
Global Scale ◽  
Eastern Pacific ◽  
Tropical Eastern Pacific ◽  
Eretmochelys Imbricata ◽  
Distance Analysis ◽  
The Pacific ◽  
High Diversity

The sea turtle Eretmochelys imbricata inhabits tropical waters of all oceans. IUCN considers this species to be critically endangered and its populations are affected by illegal international shell traffic. We present a pioneer research for Colombia and the Tropical Eastern Pacific, since populations located in 1) Parque Nacional Natural Gorgona, 2) Corales del Rosario y San Bernardo, and 3) Cabo de la Vela (Guajira) were genetically characterized using mtDNA control region sequences. Two new haplotypes for the Eastern Pacific were found, although with low diversity indexes (h: 0.2857 ± 0.1964; π: 0.0009 ± 0.0008). Five haplotypes were found for Corales del Rosario and San Bernardo’s populations, with high diversity indexes (h: 0.9333 ± 0.1217; π: 0.0089 ± 0.0056). Finally, Cabo de la Vela population presented relatively high diversity indexes (h: 0.6429 ± 0.0539; π: 0.0076 ± 0.0041). The genetic distance analysis revealed no significant differentiation between the Colombian Caribbean rookeries (Φst = 0.002, p > 0.05; Fst = 0.083, p > 0.05). However, significant differences were found between Cabo de la Vela nesting rookery and eight nesting rookeries along the Caribbean Sea, which is a genetic pattern characteristic of sea turtles on a global scale. Our phylogeographic analysis revealed a deep split between the Atlantic and the Pacific-Indian Ocean. For Atlantic phylogroup no clear clustering between haplotypes was perceived, while in the Pacific-Indian phylogroup a possible distribution of isolation by distance was observed. The divergence time reported in this study between the Atlantic and Pacific-Indian lineages suggests a separation that may have occurred between the Pliocene and Pleistocene (7 Ma), possibly influenced by the rise of the Panama Isthmus.

scholarly journals Eigendecomposition filtering and reconstruction of the climatic indexes for the Brazilian Northeast

2018 ◽  
Vol 40 ◽  
pp. 51
Author(s):  
Cleber Souza Corrêa ◽  
Roberto Lage Guedes ◽  
Karlmer Abel Bueno Corrêa
Keyword(s):  
Time Series ◽  
Southern Oscillation Index ◽  
Decadal Variability ◽  
Southern Oscillation ◽  
Global Scale ◽  
Northeastern Brazil ◽  
Time Period ◽  
The Pacific ◽  
Behavior Characteristics ◽  
Brazilian Northeast

This work seeks through the intermediary of the eigendecomposition filtering and reconstructing technique the signal of the time series of Southern Oscillation Index (SOI), and analyze possible cycles that can be observed in this SOI time series. The technique of decomposition was very consistent and can show possible trends in cycles in time series of SOI. The final result is featuring a composition of components operating in the formation of the SOI variability signal, the first component is featuring approximately 1.33, 2.66, 3.58, 4.83 years and decadal time period, larger scales and periods, matching a variance approximately of 70% of the signal of the SOI time series. In addition to the influence of cycles of solar activity, associated with its number of sunspots, the variability observed from 20 to 27 years may be related to the interaction between Pacific Decadal Oscillation (PDO) and Southern Oscillation Index (SOI). The understanding the dynamics that control the decadal variability in the Pacific Ocean and its interactions with climate change on a global scale. These results can be correlated to behavior characteristics of the atmospheric dynamics and predominance in northeastern Brazil, has importance and affecting activities in Rocket Launch Centre in Alcântara (CLA).

ENSO teleconnection over the Euro-Mediterranean sector: the role of extratropical Pacific modulation

2020 ◽  
Author(s):  
Marianna Benassi ◽  
Giovanni Conti ◽  
Silvio Gualdi ◽  
Paolo Ruggeri ◽  
Javier Garcia–Serrano ◽  
...  
Keyword(s):  
Climate Variability ◽  
Southern Oscillation ◽  
Low Frequency ◽  
Global Scale ◽  
Large Variability ◽  
Tropical Forcing ◽  
The North ◽  
The Pacific ◽  
Sst Forcing

<p>El Nino Southern Oscillation (ENSO) represents the major driver of interannual climate variability at the global scale. Observational and model-based studies have fostered a long-standing debate on the shape and the intensity of ENSO influence over the Euro-Mediterranean sector. Indeed, the detection of this signal is strongly affected by the large variability which characterizes the atmospheric circulation in the North Atlantic and European sector.</p><p>Different mechanisms have been proposed as involved in the propagation of ENSO signal from low to mid latitude, and we want to investigate if and how the low frequency variability of North Pacific sea-surface temperature (SST) may affect their efficacy. In this work, we study how the different phases of the extratropical SST pattern linked to the Pacific Decadal Oscillation (PDO) modulates the ENSO fingerprint over the Euro-Mediterranean region.</p><p>A set of idealized sensitivity experiments designed in the framework of the MEDSCOPE project has permitted to identify the ENSO teleconnection over the Euro-Mediterranean domain and to reveal the potential modulating role of the different phases of the extratropical PDO SST forcing.</p><p>In order to place this process in a dynamical framework, a tropospheric pathway has been proposed. The propagation of planetary waves from low to mid latitude has been investigated, by looking at the sensitivity of this mechanism to different underlying mean state.</p><p>These results allow to gain a deeper understanding of the links between mid-latitude climate variability and tropical forcing and of the processes ruling the low-mid latitude teleconnection in the Northern Hemisphere. Moreover, a clearer insight of these processes may lead to a new comprehension of possible sources of predictability for the Euro-Mediterranean domain over different time scales.</p><p> </p>

Imprint of Regional Oceanography on Foraminifera of Eastern Pacific Coral Reefs

2020 ◽  
Vol 50 (3) ◽  
pp. 279-290
Author(s):  
M. Angelica Zamora-Duran ◽  
Richard B. Aronson ◽  
James J. Leichter ◽  
Jennifer A. Flannery ◽  
Julie N. Richey ◽  
...  
Keyword(s):  
Coral Reef ◽  
Environmental Variability ◽  
Southern Oscillation ◽  
Climatic Variability ◽  
Mean Annual Temperature ◽  
The Pacific ◽  
Coral Reef Ecosystems ◽  
Magnesium Calcite ◽  
High Magnesium Calcite ◽  
Natural Laboratory

ABSTRACT The marginal marine environments of the eastern tropical Pacific (ETP) serve as an ideal natural laboratory to study how oceanographic and climatic variability influence coral-reef ecosystems. Reefs along the Pacific coast of Panamá span a natural gradient of nutrients, pH, and temperature as a result of stronger seasonal upwelling in the Gulf of Panamá relative to the Gulf of Chiriquí. The ecosystems are not only influenced by spatial and seasonal variations in oceanography but are affected by the climatic variability of the El Niño-Southern Oscillation (ENSO). Foraminifera can be robust indicators of ecosystem condition because the composition of their assemblages and the geochemistry of their tests can change rapidly in response to environmental variability. We studied benthic foraminifera in sediment samples collected from 3 m below mean sea level in the Gulf of Panamá and the Gulf of Chiriquí. Temperature loggers deployed from 2016 to 2019 showed that average temperatures were lower and more variable in the Gulf of Panamá due to seasonal upwelling. All sites in both gulfs were dominated by heterotrophic foraminifera, which was likely the result of nutrient enrichment due to upwelling, combined with ENSO effects. However, the Gulf of Chiriquí was characterized by higher abundances of symbiont-bearing foraminifera than the Gulf of Panamá. The orders Miliolida and Rotaliida dominated the foraminiferal assemblages in both gulfs, with Quinqueloculina and Rosalina being the most abundant genera in the two orders, respectively. Miliolids were less abundant in the Gulf of Panamá than in the Gulf of Chiriquí, whereas rotaliid densities were not significantly different between the two gulfs. Lower pH in the Gulf of Panamá as a result of upwelling may have contributed to the lower abundance of miliolids, which secrete tests of high-magnesium calcite. Geochemical analysis of tests of the symbiont-bearing miliolid Sorites marginalis revealed that foraminiferal Mg/Ca ratios were lower in the Gulf of Panamá than in the Gulf of Chiriquí. The offset in foraminiferal Mg/Ca is consistent with the lower mean annual temperature observed in the Gulf of Panamá due to stronger seasonal upwelling. Because the geochemistry and assemblages of foraminifera reflect differences in environmental conditions, they could potentially be used in tandem with coral proxies to reconstruct past environmental change and project the future of coral-reef systems within the ETP.

Prominence of environmental and anthropogenic agents on the occurrence of coral reef bleaching syndrome and coral diseases

2024 ◽  
Vol 74 (10) ◽  
pp. 6139-2024
Author(s):  
MICHAŁ SCHULZ ◽  
ALEKSANDRA ŁOŚ ◽  
PATRYCJA SKOWRONEK ◽  
ANETA STRACHECKA
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Oil Spills ◽  
Global Scale ◽  
Ecological Processes ◽  
Coral Diseases ◽  
Rapid Changes ◽  
Anthropogenic Threats ◽  
Negative Factors ◽  
Main Relationship

Coral reefs are the most productive ecosystems on Earth. They ensure the conservation of biodiversity and are a live habitat for 25% of all marine organisms. The main relationship on the coral reef is the symbiosis between corals and algae from the genus Symbiodinium (commonly called zooxanthellae). The authors of this publication have characterized and described the factors limiting the occurrence of coral reefs, including: water temperature, salinity, access to sunlight, contamination, physicochemical and hydromechanical parameters of water. Moreover anthropogenic threats to coral reefs have been specified, including diving tourism, ecological disasters (e.g. oil spills) and the development of marine aquaristics. Rapid changes in the basic living conditions are dangerous for corals and their symbionts and may cause the unsuitability of the new environment resulting in diseases such as coral bleaching. Corals bleaching is a disease associated with the break of the coral and algae relationship which results in a coral reef death on a global scale. Awareness of these negative factors, often related to human activity, may allow us to better understand the ecological processes that are the basis of reef functioning and might enable us to prevent and oppose to the changes and ecological recessions of coral reefs.

A Fuzzy Logic Model to Predict Coral Reef Development under Nutrient and Sediment Stress

1998 ◽  
Vol 12 (5) ◽  
pp. 957-965 ◽  
Author(s):  
Erik H. Meesters ◽  
Rolf P. M. Bak ◽  
Susie Westmacott ◽  
Mark Ridgley ◽  
Steve Dollar
Keyword(s):  
Fuzzy Logic ◽  
Coral Reef ◽  
Logic Model ◽  
Reef Development ◽  
Fuzzy Logic Model

scholarly journals The evolving response of mesopelagic fishes to declining midwater oxygen concentrations in the southern and central California Current

2018 ◽  
Vol 76 (3) ◽  
pp. 626-638 ◽  
Author(s):  
J Anthony Koslow ◽  
Pete Davison ◽  
Erica Ferrer ◽  
S Patricia A Jiménez Rosenberg ◽  
Gerardo Aceves-Medina ◽  
...  
Keyword(s):  
Baja California ◽  
Southern Oscillation ◽  
Global Climate ◽  
California Current ◽  
Deep Ocean ◽  
Near Surface ◽  
Oxygen Minimum Zones ◽  
The North ◽  
The Pacific ◽  
Oxygen Concentrations

Abstract Declining oxygen concentrations in the deep ocean, particularly in areas with pronounced oxygen minimum zones (OMZs), are a growing global concern related to global climate change. Its potential impacts on marine life remain poorly understood. A previous study suggested that the abundance of a diverse suite of mesopelagic fishes off southern California was closely linked to trends in midwater oxygen concentration. This study expands the spatial and temporal scale of that analysis to examine how mesopelagic fishes are responding to declining oxygen levels in the California Current (CC) off central, southern, and Baja California. Several warm-water mesopelagic species, apparently adapted to the shallower, more intense OMZ off Baja California, are shown to be increasing despite declining midwater oxygen concentrations and becoming increasingly dominant, initially off Baja California and subsequently in the CC region to the north. Their increased abundance is associated with warming near-surface ocean temperature, the warm phase of the Pacific Decadal oscillation and Multivariate El Niño-Southern Oscillation Index, and the increased flux of Pacific Equatorial Water into the southern CC.

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