scholarly journals Corals sustain growth but not skeletal density across the Florida Keys Reef Tract despite ongoing warming

2018 ◽  
Author(s):  
John Rippe ◽  
Justin H. Baumann ◽  
Daphne N. De Leener ◽  
Hannah E. Aichelman ◽  
Eric B. Friedlander ◽  
...  
Keyword(s):  
Extreme Temperature ◽  
Florida Keys ◽  
Past Century ◽  
Extension Rate ◽  
Subtropical Climate ◽  
Outer Reef ◽  
Skeletal Density ◽  
Continuous Growth ◽  
Reef Tract ◽  
Reef Zone

ABSTRACTThrough the continuous growth of their carbonate skeletons, corals record invaluable information about past environmental conditions and their effect on colony fitness. Here, we characterize century-scale growth records of inner and outer reef corals across ~200 km of the Florida Keys Reef Tract (FKRT) using skeletal cores extracted from two ubiquitous reef-building species, Siderastrea siderea and Pseudodiploria strigosa. We find that corals across the FKRT have sustained extension and calcification rates over the past century but have experienced a long-term reduction in skeletal density, regardless of reef zone. Notably, P. strigosa colonies exhibit temporary reef zone-dependent reductions in extension rate corresponding to two known extreme temperature events in 1969-70 and 1997-98. We propose that the subtropical climate of the FKRT may buffer corals from chronic growth declines associated with climate warming, though the significant reduction in skeletal density may indicate underlying vulnerability to present and future trends in ocean acidification.

scholarly journals Upwellings mitigated Plio-Pleistocene heat stress for reef corals on the Florida platform (USA)

2016 ◽  
Vol 13 (5) ◽  
pp. 1469-1489 ◽  
Author(s):  
Thomas C. Brachert ◽  
Markus Reuter ◽  
Stefan Krüger ◽  
Julia Kirkerowicz ◽  
James S. Klaus
Keyword(s):  
Surface Water ◽  
High Density ◽  
Early Pleistocene ◽  
Extension Rate ◽  
Skeletal Density ◽  
Florida Reef Tract ◽  
Reef Corals ◽  
Reef Tract ◽  
Annual Water ◽  
Middle Pliocene

Abstract. The fast growing calcareous skeletons of zooxanthellate reef corals (z corals) represent unique environmental proxy archives through their oxygen and carbon stable isotope composition (δ18O, δ13C). In addition, the accretion of the skeleton itself is ultimately linked to the environment and responds with variable growth rates (extension rate) and density to environmental changes. Here we present classical proxy data (δ18O, δ13C) in combination with calcification records from 15 massive z corals. The z corals were sampled from four interglacial units of the Florida carbonate platform (USA) dated approximately 3.2, 2.9, 1.8 and 1.2 Ma (middle Pliocene to early Pleistocene). The z corals (Solenastrea, Orbicella, Porites) derive from unlithified shallow marine carbonates and were carefully screened for primary preservation suited for proxy analysis. We show that skeletal accretion responded with decreasing overall calcification rates (decreasing extension rate but increasing density) to warmer water temperatures. Under high annual water temperatures, inferred from sub-annually resolved δ18O data, skeletal bulk density was high, but extension rates and overall calcification rates were at a minimum (endmember scenario 1). Maximum skeletal density was reached during the summer season giving rise to a growth band of high density within the annually banded skeletons (“high density band”, HDB). With low mean annual water temperatures (endmember scenario 2), bulk skeletal density was low but extension rates and calcification rates reached a maximum, and under these conditions the HDB formed during winter. Although surface water temperatures in the Western Atlantic warm pool during the interglacials of the late Neogene were  ∼  2 °C higher than they are in the present day, intermittent upwelling of cool, nutrient-rich water mitigated water temperatures off south-western Florida and created temporary refuges for z coral growth. Based on the sub-annually resolved δ18O and δ13C records, the duration of the upwelling episodes causing the endmember 2 conditions was variable and lasted from a few years to a number of decades. The episodes of upwelling were interrupted by phases without upwelling (endmember 1) which lasted for at least a few years and led to high surface water temperatures. This variable environment is likely one of the reasons why the coral fauna is dominated by the eurytopic genus Solenastrea, also a genus resistant to high turbidity. Over a period of  ∼  50 years, the oldest sub annually resolved proxy record available (3.2 Ma) documents a persistent occurrence of the HDB during winter. In contrast, the HDB forms in summer in modern z corals from the Florida reef tract. We suggest this difference should be tested as being the expression of a tendency towards decreasing interglacial upwelling since the middle Pliocene. The number of z coral sclerochronological records for the Plio-Pleistocene is still rather low, however, and requires more data and an improved resolution, through records from additional time slices. Nonetheless, our calcification data from the warm periods of past interglacials may contribute to predicting the effects of future ocean warming on z coral health along the Florida reef tract. The inconsistent timing of the HDB within single coral records or among specimens and time slices is unexpected and contrasts the common practice of establishing chronologies on the basis of the density banding.

scholarly journals Corals sustain growth but not skeletal density across the Florida Keys Reef Tract despite ongoing warming

2018 ◽  
Vol 24 (11) ◽  
pp. 5205-5217 ◽  
Author(s):  
John P. Rippe ◽  
Justin H. Baumann ◽  
Daphne N. De Leener ◽  
Hannah E. Aichelman ◽  
Eric B. Friedlander ◽  
...  
Keyword(s):  
Florida Keys ◽  
Skeletal Density ◽  
Reef Tract

scholarly journals Upwellings mitigated Plio–Pleistocene heat stress for reef corals on the Florida platform (USA)

2015 ◽  
Vol 12 (19) ◽  
pp. 16553-16602 ◽  
Author(s):  
T. C. Brachert ◽  
M. Reuter ◽  
S. Krüger ◽  
J. Kirkerowicz ◽  
J. S. Klaus
Keyword(s):  
Surface Water ◽  
Warm Pool ◽  
High Density ◽  
Extension Rate ◽  
Skeletal Density ◽  
Reef Corals ◽  
Atlantic Warm Pool ◽  
Reef Tract ◽  
Annual Water ◽  
Middle Pliocene

Abstract. The fast growing calcareous skeletons of zooxanthellate reef corals (z-corals) represent unique environmental proxy archives through their oxygen and carbon stable isotope composition (δ18O, δ13C). In addition, the accretion of the skeleton itself is ultimately linked to the environment and responds with variable growth rates (extension rate) and density to environmental changes. Here we present classical proxy data (δ18O, δ13C) in combination with calcification records from 15 massive z-corals. The z-corals were sampled from four interglacial units of the Florida carbonate platform (USA) dated approximately 3.2, 2.9, 1.8 and 1.2 Ma (middle Pliocene to early Pleistocene). The z-corals (Solenastrea, Orbicella, Porites) derive from unlithified shallow marine carbonates and were carefully screened for primary preservation suited for proxy analysis. We show that skeletal accretion was non-linear and responded with decreasing overall calcification rates (decreasing extension rate but increasing density) to warmer water temperatures. Under high annual water temperatures, inferred from subannually resolved δ18O data, skeletal bulk density was high, but extension rates and overall calcification rates were at a minimum (endmember scenario 1). Maximum skeletal density was reached during the summer season giving rise to a growth band of high density within the annually banded skeletons ("high density band", HDB). With low mean annual water temperatures (endmember scenario 2), bulk skeletal density was low but extension rates and calcification rates reached a maximum, and under these conditions the HDB formed during winter. Although surface water temperatures in the Western Atlantic warm pool during the interglacials of the late Neogene where ∼ 2 °C higher than they are in the present-day, intermittent upwelling of cool, nutrient rich water mitigated water temperatures off southwestern Florida in the middle of the Atlantic warm pool and created temporary refuges for z-coral growth. Based on the subannually resolved δ18O and δ13C records, the duration of the upwelling episodes causing the endmember 2 conditions was variable and lasted from a few years to a number of decades. The episodes of upwelling were interrupted by phases without upwelling (endmember 1) which lasted for at least a few years and led to high surface water temperatures. This variable environment is likely one of the reasons why the coral fauna is dominated by the eurytopic genus Solenastrea, also a species resistant to high turbidity. Over a period of ∼ 50 years, the oldest subannually resolved proxy record available (3.2 Ma) documents a persistent occurrence of the HDB during winter. In contrast, the HDB forms in summer in modern z-corals from the Florida reef tract. We suggest this difference to be the expression of a tendency towards decreasing upwelling since the middle Pliocene. The number of z-coral sclerochronological records for this time period is still, however, rather low and requires an improved resolution through data from additional time-slices. These data can contribute to predicting the effects of future ocean warming on z-coral health along the Florida reef tract.

scholarly journals Genetic structure and diversity of the mustard hill coral Porites astreoides along the Florida Keys reef tract

2021 ◽  
Vol 51 (4) ◽  
Author(s):  
Dominique N. Gallery ◽  
Michelle L. Green ◽  
Ilsa B. Kuffner ◽  
Elizabeth A. Lenz ◽  
Lauren T. Toth
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Relatedness ◽  
Florida Keys ◽  
Genetic Population ◽  
High Genetic Diversity ◽  
Western Atlantic ◽  
Porites Astreoides ◽  
Single Well ◽  
Reef Tract

AbstractIncreases in local and global stressors have led to major declines in coral populations throughout the western Atlantic. While abundances of other species have declined, however, the relative abundance of the mustard hill coral, Porites astreoides, has increased. Porites astreoides is relatively resilient to some stressors, and because of its mixed reproductive strategies, its populations often recover quickly following disturbances. The ability for P. astreoides to continue as a potential “winner” in western Atlantic reefs relies on maintaining sufficient genetic variation within populations to support acclimatization and adaptation to current and future environmental change. Without high genetic diversity and gene flow within the population, it would have limited capacity for adaptation and the species’ competitive advantages could be short-lived. In this study, we determined the genetic relatedness of 37 P. astreoides colonies at four shallow reefs along the offshore Florida Keys Reef Tract (FKRT), a region particularly hard-hit by recent disturbances. Using previously designed microsatellite markers, we determined the genetic diversity and connectivity of individuals among and between sites. Our results suggest that the FKRT likely contains a single, well-mixed genetic population of P. astreoides, with high levels of gene flow and evidence for larval migration throughout the region. This suggests that regional populations of P. astreoides likely have a higher chance of maintaining resilience than many other western Atlantic species as they face current and future disturbances.

scholarly journals Regional Temperature-Sensitive Diseases and Attributable Fractions in China

2019 ◽  
Vol 17 (1) ◽  
pp. 184
Author(s):  
Xuemei Su ◽  
Yibin Cheng ◽  
Yu Wang ◽  
Yue Liu ◽  
Na Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Extreme Temperature ◽  
Attributable Fraction ◽  
Mortality Data ◽  
Temperature Sensitive ◽  
Subtropical Climate ◽  
Climate Zones ◽  
Attributable Fractions ◽  
Regional Temperature ◽  
Study Sites

Few studies have been carried out to systematically screen regional temperature-sensitive diseases. This study was aimed at systematically and comprehensively screening both high- and low-temperature-sensitive diseases by using mortality data from 17 study sites in China located in temperate and subtropical climate zones. The distributed lag nonlinear model (DLNM) was applied to quantify the association between extreme temperature and mortality to screen temperature-sensitive diseases from 18 kinds of diseases of eight disease systems. The attributable fractions (AFs) of sensitive diseases were calculated to assess the mortality burden attributable to high and low temperatures. A total of 1,380,713 records of all-cause deaths were involved. The results indicate that injuries, nervous, circulatory and respiratory diseases are sensitive to heat, with the attributable fraction accounting for 6.5%, 4.2%, 3.9% and 1.85%, respectively. Respiratory and circulatory diseases are sensitive to cold temperature, with the attributable fraction accounting for 13.3% and 11.8%, respectively. Most of the high- and low-temperature-sensitive diseases seem to have higher relative risk in study sites located in subtropical zones than in temperate zones. However, the attributable fractions for mortality of heat-related injuries were higher in temperate zones. The results of this research provide epidemiological evidence of the relative burden of mortality across two climate zones in China.

scholarly journals PRACTICAL GUIDELINES FOR ASSESSING CORAL CALCIFICATION VIA COMPUTED TOMOGRAPHY

2018 ◽  
Vol 43 (2) ◽  
pp. 95-99
Author(s):  
Intan Suci Nurhati
Keyword(s):  
Computed Tomography ◽  
Ocean Acidification ◽  
Environmental Changes ◽  
Interdisciplinary Approach ◽  
Standard Operating Procedure ◽  
Ecological Impacts ◽  
Extension Rate ◽  
Skeletal Density ◽  
Coral Calcification ◽  
Practical Guidelines

Coral calcification as the product of extension rate and skeletal density, is projected to change under marine environmental changes of local (e.g., sedimentation, eutrophication) and global (e.g., warming, ocean acidification) scales. For the regional effort to monitor the ecological impacts of ocean acidification on coral reef ecosystems, the Intergovernmental Oceanographic Commission Sub-Commission for the Western Pacific (IOC-WESTPAC) has incorporated an interdisciplinary approach that includes monitoring of seawater carbonate parameters, coral calcification, net calcification minus bioerosion, and reef community structure. Currently, there is a need to formulate a standard operating procedure (SOP) for assessing coral calcification over the recent years via coral cores. The SOP needs to yield accurate data in a cost-effective way that can be applied by researchers in the region. High variation of coral calcification parameters between coral colonies warrants a sufficiently large number of samples thus a rapid method for analyzing coral extension rate, skeletal density, and calcification. This paper outlines practical guidelines for assessing coral calcification from the field to laboratory using the three-dimensional computed tomography (CT) method.

scholarly journals Physiological Differences in Bleaching Response of the Coral Porites astreoides Along the Florida Keys Reef Tract During High-Temperature Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Elizabeth Ann Lenz ◽  
Lucy A. Bartlett ◽  
Anastasios Stathakopoulos ◽  
Ilsa B. Kuffner
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Florida Keys ◽  
High Temperature Stress ◽  
Geologic History ◽  
Reef Management ◽  
Porites Astreoides ◽  
Dry Tortugas ◽  
Bleaching Response ◽  
Reef Tract

The Florida Keys reef tract (FKRT) has a unique geological history wherein Holocene sea-level rise and bathymetry interacted, resulting in a reef-building system with notable spatial differences in reef development. Overprinted on this geologic history, recent global and local stressors have led to degraded reefs dominated by fleshy algae, soft corals, and sponges. Here, we assessed how coral physiology (calcification rate, tissue thickness, reproduction, symbiosis, and bleaching) varies seasonally (winter vs. summer) and geographically using 40 colonies of the mustard hill coral Porites astreoides from four sites across 350 km along the FKRT from 2015 to 2017. The study coincided with a high-temperature event in late summer 2015 that caused heterogeneous levels of coral bleaching across sites. Bleaching severity differed by site, with bleaching response more aligned with heat stress retroactively calculated from local degree heating weeks than those predicted by satellites. Despite differences in temperature profiles and bleaching severity, all colonies hosted Symbiodiniaceae of the same genus (formerly Clade A and subtypes). Overall, P. astreoides at Dry Tortugas National Park, the consistently coolest site, had the highest calcification rates, symbiont cell densities, and reproductive potential (all colonies were reproductive, with most planula larvae per polyp). Corals at Dry Tortugas and Fowey Rocks Light demonstrated strong seasonality in net calcification (higher in summer) and did not express visual or partial-mortality responses from the bleaching event; in contrast, colonies in the middle and southern part of the upper keys, Sombrero Key and Crocker Reef, demonstrated similar reduced fitness from bleaching, but differential recovery trajectories following the heat stress. Identifying reefs, such as Dry Tortugas and possibly Fowey Rocks Light that may serve as heat-stress refugia, is important in selecting candidate sites for adaptive reef-management strategies, such as selective propagation and assisted gene flow, to increase coral-species adaptation to ocean warming.

scholarly journals Composition of Microbial Communities in Waters Around the Florida Reef Tract and Their Potential Significance for Stony Coral Tissue Loss Disease

2021 ◽  
Author(s):  
Peeter Laas ◽  
Kelly Ugarelli ◽  
Breege Boyer ◽  
Michael J. Absten ◽  
Henry O. Briceño ◽  
...  
Keyword(s):  
Community Structure ◽  
Abiotic Factors ◽  
Florida Keys ◽  
Fish Parasites ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Shellfish Poisoning ◽  
Florida Reef Tract ◽  
Stony Coral ◽  
Reef Tract

The Florida Keys, a delicate archipelago of sub-tropical islands extending from the south-eastern tip of Florida, host the vast majority of the only coral barrier reef in the continental United States. Stony Coral Tissue Loss Disease (SCTLD), which was first detected near Virginia Key in 2014, has spread throughout the Florida Reef Tract and to reefs throughout the Caribbean, af-fecting nearly all reef-building corals. Molecular studies of SCTLD have identified opportunistic pathogens associated with the disease, but so far no single pathogen can be clearly pinpointed as its cause. One focus of recent research has been the surrounding environment of the corals, coined the 'coral ecosphere'. Abiotic and microbial components of the coral ecosphere are pivot-al for understanding the health of a reef, and could play an important role in SCTLD in Florida. In this study, we analyzed microbial community structure and abiotic factors that can impact coral (and human) health. Both, bacterial and eukaryotic community structure were significantly linked with variations in temperature, dissolved oxygen and total organic carbon values. High abundances of copiotrophic bacteria as well as several potentially harmful microbes, including coral pathogens, fish parasites, and taxa that have been previously associated with Red Tide and shellfish poisoning, were present in our datasets and can have a pivotal impact on coral health in this ecosystem.

scholarly journals Calcification and growth rate recovery of the reef-buildingPocilloporaspecies in the northeast tropical Pacific following an ENSO disturbance

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3191 ◽  
Author(s):  
Jose de Jesús A. Tortolero-Langarica ◽  
Alma P. Rodríguez-Troncoso ◽  
Amílcar L. Cupul-Magaña ◽  
Juan P. Carricart-Ganivet
Keyword(s):  
Growth Rates ◽  
Linear Extension ◽  
Growth Parameters ◽  
Southern Oscillation ◽  
Enso Event ◽  
Tropical Pacific ◽  
Extension Rate ◽  
Skeletal Density ◽  
Thermal Anomalies ◽  
Strong Enso

Pocilloporids are one of the major reef-building corals in the eastern tropical Pacific (ETP) and also the most affected by thermal stress events, mainly those associated with El Niño/Southern Oscillation (ENSO) periods. To date, coral growth parameters have been poorly reported inPocilloporaspecies in the northeastern region of the tropical Pacific. Monthly and annual growth rates of the three most abundant morphospecies (P. cf. verrucosa,P. cf. capitata, andP. cf. damicornis) were evaluated during two annual periods at a site on the Pacific coast of Mexico. The first annual period, 2010–2011 was considered a strong ENSO/La Niña period with cool sea surface temperatures, then followed by a non-ENSO period in 2012–2013. The linear extension rate, skeletal density, and calcification rate averaged (±SD) were 2.31 ± 0.11 cm yr−1, 1.65 ± 0.18 g cm−3, 5.03 ± 0.84 g cm−2yr-1respectively, during the strong ENSO event. In contrast, the respective non-ENSO values were 3.50 ± 0.64 cm yr−1, 1.70 ± 0.18 g cm−3, and 6.02 ± 1.36 g cm−2yr−1. This corresponds to 52% and 20% faster linear extension and calcification rates, respectively, during non-ENSO period. The evidence suggests thatPocilloporabranching species responded positively with faster growth rates following thermal anomalies, which allow them to maintain coral communities in the region.

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