The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Michelle A. Johnston - One of the best experts on this subject based on the ideXlab platform.
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Localized coral reef mortality event at East Flower Garden Bank, Gulf of Mexico
Bulletin of Marine Science, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, Michael T Lee, James Macmillan, John A. EmbesiAbstract:Flower Garden Banks National Marine Sanctuary contains the northernmost coral reef ecosystem in the Gulf of Mexico, with >50% living coral cover. Historically, this reef system has harbored a healthy coral community, relatively free of disease with limited mortality from bleaching or other factors. In July 2016 an unprecedented localized mortality event was documented at East Flower Garden Bank affecting an area of approximately 5.6 ha (2.6% of the coral reef). Within this area, up to 82% of the coral colonies succumbed to partial or total mortality, along with invertebrates spanning numerous taxa, including cnidarians, poriferans, echinoderms, crustaceans, and mollusks. Within the affected area, the impact was highly stratified, with many coral colonies exhibiting a clear line of delineation with polyps above appearing healthy, and those below exhibiting paling, bleaching, tissue sloughing, and/or mortality. The mortality of sessile invertebrates across multiple taxa was similar to observations from coral mortality events in other regions associated with low dissolved oxygen (DO) concentrations. While instrumentation for measuring DO was not in place on East Flower Garden Bank, DO sensors at similar depths located 50–70 km northwest of East Flower Garden Bank confirmed low DO levels (
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localized coral reef mortality event at east Flower Garden bank gulf of mexico
Bulletin of Marine Science, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, Michael T Lee, James Macmillan, John A. EmbesiAbstract:Flower Garden Banks National Marine Sanctuary contains the northernmost coral reef ecosystem in the Gulf of Mexico, with >50% living coral cover. Historically, this reef system has harbored a healthy coral community, relatively free of disease with limited mortality from bleaching or other factors. In July 2016 an unprecedented localized mortality event was documented at East Flower Garden Bank affecting an area of approximately 5.6 ha (2.6% of the coral reef). Within this area, up to 82% of the coral colonies succumbed to partial or total mortality, along with invertebrates spanning numerous taxa, including cnidarians, poriferans, echinoderms, crustaceans, and mollusks. Within the affected area, the impact was highly stratified, with many coral colonies exhibiting a clear line of delineation with polyps above appearing healthy, and those below exhibiting paling, bleaching, tissue sloughing, and/or mortality. The mortality of sessile invertebrates across multiple taxa was similar to observations from coral mortality events in other regions associated with low dissolved oxygen (DO) concentrations. While instrumentation for measuring DO was not in place on East Flower Garden Bank, DO sensors at similar depths located 50–70 km northwest of East Flower Garden Bank confirmed low DO levels (<3.5 mg L–1) at the time of the event. The mortality event likely resulted from a combination of stressors, but localized low DO is implicated as the primary contributing factor.
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Coral bleaching and recovery from 2016 to 2017 at East and West Flower Garden Banks, Gulf of Mexico
Coral Reefs, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, George P. SchmahlAbstract:East Flower Garden Bank (EFGB) and West Flower Garden Bank (WFGB), part of Flower Garden Banks National Marine Sanctuary (FGBNMS) in the northwestern Gulf of Mexico, support tropical coral reefs that exhibit over 50% living coral cover. These reefs have been monitored annually since 1989, and in 2016 were exposed to higher than normal seawater temperatures leading to a severe bleaching event. Corals at EFGB and WFGB showed no signs of bleaching until September 2016, occurring later in the year compared to other reefs in the Caribbean region. Coral bleaching and subsequent recovery at each bank were documented through a time series of repetitive photographs within previously established long-term monitoring stations. Preceding the event, mean live coral cover within monitoring stations was collectively 64 ± 2%. Prior to signs of bleaching from July to September 2016, seawater temperatures on the reef were above 30 °C for a total of 36 d at EFGB and 21 d at WFGB. By October 2016, 67 ± 5% of the coral cover within EFGB monitoring stations and 25 ± 3% within WFGB monitoring stations exhibited signs of bleaching or paling stress, with dissimilarities in the amount of bleaching most likely due to significant differences in thermal profiles between banks. Significantly increasing long-term trends for daily mean seawater temperature indicate that temperatures on the banks have become warmer over time, and calculated bleaching threshold curves suggest that more than 50 d above 29.5 °C would initiate a bleaching year at EFGB and WFGB. Even though recovery within monitoring stations at both banks was documented with no significant declines in mean coral cover from 2016 to 2017 (64% and 62%, respectively), it is likely FGBNMS will be subject to additional and more frequent bleaching events in the future as ocean temperatures continue to rise.
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Correction to: Important juvenile manta ray habitat at Flower Garden Banks National Marine Sanctuary in the northwestern Gulf of Mexico
Marine Biology, 2018Co-Authors: Joshua D. Stewart, Emma L. Hickerson, Marissa F. Nuttall, Michelle A. JohnstonAbstract:In a recent paper (Stewart et al. 2018), we reported on the presence of juvenile manta rays in the Flower Garden Banks National Marine Sanctuary (FGBNMS) and suggested that the region serves as a nursery habitat for the species. Unfortunately we failed to consider the Masters thesis by Jeffrey N Childs (2001) entitled: ‘The occurrence, habitat use, and behavior of sharks and rays associating with topographic highs in the Northwestern Gulf of Mexico’. Childs (2001) was the first to document the presence of juvenile manta rays at the Flower Garden Banks and he suggested that the Flower Garden Banks serve as a nursery habitat for juvenile manta rays. We regret this oversight and apologize for failing to acknowledge and cite this relevant work.
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important juvenile manta ray habitat at Flower Garden banks national marine sanctuary in the northwestern gulf of mexico
Marine Biology, 2018Co-Authors: Joshua D. Stewart, Emma L. Hickerson, Marissa F. Nuttall, Michelle A. JohnstonAbstract:Oceanic manta rays (Mobula birostris) are large pelagic planktivores that are threatened globally by targeted fisheries and bycatch. While studies of oceanic mantas have increased substantially in the past decade, major knowledge gaps remain in their basic biology, ecology and life history. The juvenile stage in particular is virtually unstudied, as juvenile oceanic mantas are rarely observed in the wild and are known primarily from fisheries and captive individuals. Here, we present evidence suggesting that Flower Garden Banks National Marine Sanctuary (FGBNMS) is an important habitat for juvenile manta rays. Recent genetic evidence indicates that both oceanic mantas and a proposed third manta species (Mobula cf. birostris) are present at FGBNMS. Size estimates of mantas sighted at FGBNMS over 25 years of monitoring efforts indicate that 95% of individuals are smaller than the size at maturity for male M. birostris, and 80% are smaller than the size at maturity for M. alfredi. Photographic records of juvenile males with undeveloped claspers further corroborate these findings. Temporal patterns of use and the prevalence of juveniles suggest that this region may serve as nursery habitat for M. birostris and M. cf. birostris. Further research is necessary to determine the importance of the region to juveniles of each species, as well as long-term patterns of habitat use and residency.
Emma L. Hickerson - One of the best experts on this subject based on the ideXlab platform.
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Localized coral reef mortality event at East Flower Garden Bank, Gulf of Mexico
Bulletin of Marine Science, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, Michael T Lee, James Macmillan, John A. EmbesiAbstract:Flower Garden Banks National Marine Sanctuary contains the northernmost coral reef ecosystem in the Gulf of Mexico, with >50% living coral cover. Historically, this reef system has harbored a healthy coral community, relatively free of disease with limited mortality from bleaching or other factors. In July 2016 an unprecedented localized mortality event was documented at East Flower Garden Bank affecting an area of approximately 5.6 ha (2.6% of the coral reef). Within this area, up to 82% of the coral colonies succumbed to partial or total mortality, along with invertebrates spanning numerous taxa, including cnidarians, poriferans, echinoderms, crustaceans, and mollusks. Within the affected area, the impact was highly stratified, with many coral colonies exhibiting a clear line of delineation with polyps above appearing healthy, and those below exhibiting paling, bleaching, tissue sloughing, and/or mortality. The mortality of sessile invertebrates across multiple taxa was similar to observations from coral mortality events in other regions associated with low dissolved oxygen (DO) concentrations. While instrumentation for measuring DO was not in place on East Flower Garden Bank, DO sensors at similar depths located 50–70 km northwest of East Flower Garden Bank confirmed low DO levels (
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localized coral reef mortality event at east Flower Garden bank gulf of mexico
Bulletin of Marine Science, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, Michael T Lee, James Macmillan, John A. EmbesiAbstract:Flower Garden Banks National Marine Sanctuary contains the northernmost coral reef ecosystem in the Gulf of Mexico, with >50% living coral cover. Historically, this reef system has harbored a healthy coral community, relatively free of disease with limited mortality from bleaching or other factors. In July 2016 an unprecedented localized mortality event was documented at East Flower Garden Bank affecting an area of approximately 5.6 ha (2.6% of the coral reef). Within this area, up to 82% of the coral colonies succumbed to partial or total mortality, along with invertebrates spanning numerous taxa, including cnidarians, poriferans, echinoderms, crustaceans, and mollusks. Within the affected area, the impact was highly stratified, with many coral colonies exhibiting a clear line of delineation with polyps above appearing healthy, and those below exhibiting paling, bleaching, tissue sloughing, and/or mortality. The mortality of sessile invertebrates across multiple taxa was similar to observations from coral mortality events in other regions associated with low dissolved oxygen (DO) concentrations. While instrumentation for measuring DO was not in place on East Flower Garden Bank, DO sensors at similar depths located 50–70 km northwest of East Flower Garden Bank confirmed low DO levels (<3.5 mg L–1) at the time of the event. The mortality event likely resulted from a combination of stressors, but localized low DO is implicated as the primary contributing factor.
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Coral bleaching and recovery from 2016 to 2017 at East and West Flower Garden Banks, Gulf of Mexico
Coral Reefs, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, George P. SchmahlAbstract:East Flower Garden Bank (EFGB) and West Flower Garden Bank (WFGB), part of Flower Garden Banks National Marine Sanctuary (FGBNMS) in the northwestern Gulf of Mexico, support tropical coral reefs that exhibit over 50% living coral cover. These reefs have been monitored annually since 1989, and in 2016 were exposed to higher than normal seawater temperatures leading to a severe bleaching event. Corals at EFGB and WFGB showed no signs of bleaching until September 2016, occurring later in the year compared to other reefs in the Caribbean region. Coral bleaching and subsequent recovery at each bank were documented through a time series of repetitive photographs within previously established long-term monitoring stations. Preceding the event, mean live coral cover within monitoring stations was collectively 64 ± 2%. Prior to signs of bleaching from July to September 2016, seawater temperatures on the reef were above 30 °C for a total of 36 d at EFGB and 21 d at WFGB. By October 2016, 67 ± 5% of the coral cover within EFGB monitoring stations and 25 ± 3% within WFGB monitoring stations exhibited signs of bleaching or paling stress, with dissimilarities in the amount of bleaching most likely due to significant differences in thermal profiles between banks. Significantly increasing long-term trends for daily mean seawater temperature indicate that temperatures on the banks have become warmer over time, and calculated bleaching threshold curves suggest that more than 50 d above 29.5 °C would initiate a bleaching year at EFGB and WFGB. Even though recovery within monitoring stations at both banks was documented with no significant declines in mean coral cover from 2016 to 2017 (64% and 62%, respectively), it is likely FGBNMS will be subject to additional and more frequent bleaching events in the future as ocean temperatures continue to rise.
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Correction to: Important juvenile manta ray habitat at Flower Garden Banks National Marine Sanctuary in the northwestern Gulf of Mexico
Marine Biology, 2018Co-Authors: Joshua D. Stewart, Emma L. Hickerson, Marissa F. Nuttall, Michelle A. JohnstonAbstract:In a recent paper (Stewart et al. 2018), we reported on the presence of juvenile manta rays in the Flower Garden Banks National Marine Sanctuary (FGBNMS) and suggested that the region serves as a nursery habitat for the species. Unfortunately we failed to consider the Masters thesis by Jeffrey N Childs (2001) entitled: ‘The occurrence, habitat use, and behavior of sharks and rays associating with topographic highs in the Northwestern Gulf of Mexico’. Childs (2001) was the first to document the presence of juvenile manta rays at the Flower Garden Banks and he suggested that the Flower Garden Banks serve as a nursery habitat for juvenile manta rays. We regret this oversight and apologize for failing to acknowledge and cite this relevant work.
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important juvenile manta ray habitat at Flower Garden banks national marine sanctuary in the northwestern gulf of mexico
Marine Biology, 2018Co-Authors: Joshua D. Stewart, Emma L. Hickerson, Marissa F. Nuttall, Michelle A. JohnstonAbstract:Oceanic manta rays (Mobula birostris) are large pelagic planktivores that are threatened globally by targeted fisheries and bycatch. While studies of oceanic mantas have increased substantially in the past decade, major knowledge gaps remain in their basic biology, ecology and life history. The juvenile stage in particular is virtually unstudied, as juvenile oceanic mantas are rarely observed in the wild and are known primarily from fisheries and captive individuals. Here, we present evidence suggesting that Flower Garden Banks National Marine Sanctuary (FGBNMS) is an important habitat for juvenile manta rays. Recent genetic evidence indicates that both oceanic mantas and a proposed third manta species (Mobula cf. birostris) are present at FGBNMS. Size estimates of mantas sighted at FGBNMS over 25 years of monitoring efforts indicate that 95% of individuals are smaller than the size at maturity for male M. birostris, and 80% are smaller than the size at maturity for M. alfredi. Photographic records of juvenile males with undeveloped claspers further corroborate these findings. Temporal patterns of use and the prevalence of juveniles suggest that this region may serve as nursery habitat for M. birostris and M. cf. birostris. Further research is necessary to determine the importance of the region to juveniles of each species, as well as long-term patterns of habitat use and residency.
Marissa F. Nuttall - One of the best experts on this subject based on the ideXlab platform.
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Localized coral reef mortality event at East Flower Garden Bank, Gulf of Mexico
Bulletin of Marine Science, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, Michael T Lee, James Macmillan, John A. EmbesiAbstract:Flower Garden Banks National Marine Sanctuary contains the northernmost coral reef ecosystem in the Gulf of Mexico, with >50% living coral cover. Historically, this reef system has harbored a healthy coral community, relatively free of disease with limited mortality from bleaching or other factors. In July 2016 an unprecedented localized mortality event was documented at East Flower Garden Bank affecting an area of approximately 5.6 ha (2.6% of the coral reef). Within this area, up to 82% of the coral colonies succumbed to partial or total mortality, along with invertebrates spanning numerous taxa, including cnidarians, poriferans, echinoderms, crustaceans, and mollusks. Within the affected area, the impact was highly stratified, with many coral colonies exhibiting a clear line of delineation with polyps above appearing healthy, and those below exhibiting paling, bleaching, tissue sloughing, and/or mortality. The mortality of sessile invertebrates across multiple taxa was similar to observations from coral mortality events in other regions associated with low dissolved oxygen (DO) concentrations. While instrumentation for measuring DO was not in place on East Flower Garden Bank, DO sensors at similar depths located 50–70 km northwest of East Flower Garden Bank confirmed low DO levels (
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localized coral reef mortality event at east Flower Garden bank gulf of mexico
Bulletin of Marine Science, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, Michael T Lee, James Macmillan, John A. EmbesiAbstract:Flower Garden Banks National Marine Sanctuary contains the northernmost coral reef ecosystem in the Gulf of Mexico, with >50% living coral cover. Historically, this reef system has harbored a healthy coral community, relatively free of disease with limited mortality from bleaching or other factors. In July 2016 an unprecedented localized mortality event was documented at East Flower Garden Bank affecting an area of approximately 5.6 ha (2.6% of the coral reef). Within this area, up to 82% of the coral colonies succumbed to partial or total mortality, along with invertebrates spanning numerous taxa, including cnidarians, poriferans, echinoderms, crustaceans, and mollusks. Within the affected area, the impact was highly stratified, with many coral colonies exhibiting a clear line of delineation with polyps above appearing healthy, and those below exhibiting paling, bleaching, tissue sloughing, and/or mortality. The mortality of sessile invertebrates across multiple taxa was similar to observations from coral mortality events in other regions associated with low dissolved oxygen (DO) concentrations. While instrumentation for measuring DO was not in place on East Flower Garden Bank, DO sensors at similar depths located 50–70 km northwest of East Flower Garden Bank confirmed low DO levels (<3.5 mg L–1) at the time of the event. The mortality event likely resulted from a combination of stressors, but localized low DO is implicated as the primary contributing factor.
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Coral bleaching and recovery from 2016 to 2017 at East and West Flower Garden Banks, Gulf of Mexico
Coral Reefs, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, George P. SchmahlAbstract:East Flower Garden Bank (EFGB) and West Flower Garden Bank (WFGB), part of Flower Garden Banks National Marine Sanctuary (FGBNMS) in the northwestern Gulf of Mexico, support tropical coral reefs that exhibit over 50% living coral cover. These reefs have been monitored annually since 1989, and in 2016 were exposed to higher than normal seawater temperatures leading to a severe bleaching event. Corals at EFGB and WFGB showed no signs of bleaching until September 2016, occurring later in the year compared to other reefs in the Caribbean region. Coral bleaching and subsequent recovery at each bank were documented through a time series of repetitive photographs within previously established long-term monitoring stations. Preceding the event, mean live coral cover within monitoring stations was collectively 64 ± 2%. Prior to signs of bleaching from July to September 2016, seawater temperatures on the reef were above 30 °C for a total of 36 d at EFGB and 21 d at WFGB. By October 2016, 67 ± 5% of the coral cover within EFGB monitoring stations and 25 ± 3% within WFGB monitoring stations exhibited signs of bleaching or paling stress, with dissimilarities in the amount of bleaching most likely due to significant differences in thermal profiles between banks. Significantly increasing long-term trends for daily mean seawater temperature indicate that temperatures on the banks have become warmer over time, and calculated bleaching threshold curves suggest that more than 50 d above 29.5 °C would initiate a bleaching year at EFGB and WFGB. Even though recovery within monitoring stations at both banks was documented with no significant declines in mean coral cover from 2016 to 2017 (64% and 62%, respectively), it is likely FGBNMS will be subject to additional and more frequent bleaching events in the future as ocean temperatures continue to rise.
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Correction to: Important juvenile manta ray habitat at Flower Garden Banks National Marine Sanctuary in the northwestern Gulf of Mexico
Marine Biology, 2018Co-Authors: Joshua D. Stewart, Emma L. Hickerson, Marissa F. Nuttall, Michelle A. JohnstonAbstract:In a recent paper (Stewart et al. 2018), we reported on the presence of juvenile manta rays in the Flower Garden Banks National Marine Sanctuary (FGBNMS) and suggested that the region serves as a nursery habitat for the species. Unfortunately we failed to consider the Masters thesis by Jeffrey N Childs (2001) entitled: ‘The occurrence, habitat use, and behavior of sharks and rays associating with topographic highs in the Northwestern Gulf of Mexico’. Childs (2001) was the first to document the presence of juvenile manta rays at the Flower Garden Banks and he suggested that the Flower Garden Banks serve as a nursery habitat for juvenile manta rays. We regret this oversight and apologize for failing to acknowledge and cite this relevant work.
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important juvenile manta ray habitat at Flower Garden banks national marine sanctuary in the northwestern gulf of mexico
Marine Biology, 2018Co-Authors: Joshua D. Stewart, Emma L. Hickerson, Marissa F. Nuttall, Michelle A. JohnstonAbstract:Oceanic manta rays (Mobula birostris) are large pelagic planktivores that are threatened globally by targeted fisheries and bycatch. While studies of oceanic mantas have increased substantially in the past decade, major knowledge gaps remain in their basic biology, ecology and life history. The juvenile stage in particular is virtually unstudied, as juvenile oceanic mantas are rarely observed in the wild and are known primarily from fisheries and captive individuals. Here, we present evidence suggesting that Flower Garden Banks National Marine Sanctuary (FGBNMS) is an important habitat for juvenile manta rays. Recent genetic evidence indicates that both oceanic mantas and a proposed third manta species (Mobula cf. birostris) are present at FGBNMS. Size estimates of mantas sighted at FGBNMS over 25 years of monitoring efforts indicate that 95% of individuals are smaller than the size at maturity for male M. birostris, and 80% are smaller than the size at maturity for M. alfredi. Photographic records of juvenile males with undeveloped claspers further corroborate these findings. Temporal patterns of use and the prevalence of juveniles suggest that this region may serve as nursery habitat for M. birostris and M. cf. birostris. Further research is necessary to determine the importance of the region to juveniles of each species, as well as long-term patterns of habitat use and residency.
George P. Schmahl - One of the best experts on this subject based on the ideXlab platform.
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Localized coral reef mortality event at East Flower Garden Bank, Gulf of Mexico
Bulletin of Marine Science, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, Michael T Lee, James Macmillan, John A. EmbesiAbstract:Flower Garden Banks National Marine Sanctuary contains the northernmost coral reef ecosystem in the Gulf of Mexico, with >50% living coral cover. Historically, this reef system has harbored a healthy coral community, relatively free of disease with limited mortality from bleaching or other factors. In July 2016 an unprecedented localized mortality event was documented at East Flower Garden Bank affecting an area of approximately 5.6 ha (2.6% of the coral reef). Within this area, up to 82% of the coral colonies succumbed to partial or total mortality, along with invertebrates spanning numerous taxa, including cnidarians, poriferans, echinoderms, crustaceans, and mollusks. Within the affected area, the impact was highly stratified, with many coral colonies exhibiting a clear line of delineation with polyps above appearing healthy, and those below exhibiting paling, bleaching, tissue sloughing, and/or mortality. The mortality of sessile invertebrates across multiple taxa was similar to observations from coral mortality events in other regions associated with low dissolved oxygen (DO) concentrations. While instrumentation for measuring DO was not in place on East Flower Garden Bank, DO sensors at similar depths located 50–70 km northwest of East Flower Garden Bank confirmed low DO levels (
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localized coral reef mortality event at east Flower Garden bank gulf of mexico
Bulletin of Marine Science, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, Michael T Lee, James Macmillan, John A. EmbesiAbstract:Flower Garden Banks National Marine Sanctuary contains the northernmost coral reef ecosystem in the Gulf of Mexico, with >50% living coral cover. Historically, this reef system has harbored a healthy coral community, relatively free of disease with limited mortality from bleaching or other factors. In July 2016 an unprecedented localized mortality event was documented at East Flower Garden Bank affecting an area of approximately 5.6 ha (2.6% of the coral reef). Within this area, up to 82% of the coral colonies succumbed to partial or total mortality, along with invertebrates spanning numerous taxa, including cnidarians, poriferans, echinoderms, crustaceans, and mollusks. Within the affected area, the impact was highly stratified, with many coral colonies exhibiting a clear line of delineation with polyps above appearing healthy, and those below exhibiting paling, bleaching, tissue sloughing, and/or mortality. The mortality of sessile invertebrates across multiple taxa was similar to observations from coral mortality events in other regions associated with low dissolved oxygen (DO) concentrations. While instrumentation for measuring DO was not in place on East Flower Garden Bank, DO sensors at similar depths located 50–70 km northwest of East Flower Garden Bank confirmed low DO levels (<3.5 mg L–1) at the time of the event. The mortality event likely resulted from a combination of stressors, but localized low DO is implicated as the primary contributing factor.
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Coral bleaching and recovery from 2016 to 2017 at East and West Flower Garden Banks, Gulf of Mexico
Coral Reefs, 2019Co-Authors: Michelle A. Johnston, Emma L. Hickerson, Marissa F. Nuttall, Ryan J. Eckert, Raven D. Blakeway, Travis K. Sterne, George P. SchmahlAbstract:East Flower Garden Bank (EFGB) and West Flower Garden Bank (WFGB), part of Flower Garden Banks National Marine Sanctuary (FGBNMS) in the northwestern Gulf of Mexico, support tropical coral reefs that exhibit over 50% living coral cover. These reefs have been monitored annually since 1989, and in 2016 were exposed to higher than normal seawater temperatures leading to a severe bleaching event. Corals at EFGB and WFGB showed no signs of bleaching until September 2016, occurring later in the year compared to other reefs in the Caribbean region. Coral bleaching and subsequent recovery at each bank were documented through a time series of repetitive photographs within previously established long-term monitoring stations. Preceding the event, mean live coral cover within monitoring stations was collectively 64 ± 2%. Prior to signs of bleaching from July to September 2016, seawater temperatures on the reef were above 30 °C for a total of 36 d at EFGB and 21 d at WFGB. By October 2016, 67 ± 5% of the coral cover within EFGB monitoring stations and 25 ± 3% within WFGB monitoring stations exhibited signs of bleaching or paling stress, with dissimilarities in the amount of bleaching most likely due to significant differences in thermal profiles between banks. Significantly increasing long-term trends for daily mean seawater temperature indicate that temperatures on the banks have become warmer over time, and calculated bleaching threshold curves suggest that more than 50 d above 29.5 °C would initiate a bleaching year at EFGB and WFGB. Even though recovery within monitoring stations at both banks was documented with no significant declines in mean coral cover from 2016 to 2017 (64% and 62%, respectively), it is likely FGBNMS will be subject to additional and more frequent bleaching events in the future as ocean temperatures continue to rise.
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Persistence of coral assemblages at East and West Flower Garden Banks, Gulf of Mexico
Coral Reefs, 2016Co-Authors: Michelle A. Johnston, Emma L. Hickerson, Marissa F. Nuttall, Ryan J. Eckert, John A. Embesi, George P. SchmahlAbstract:Since 1989 a federally supported long-term coral reef monitoring program has focused on two study sites atop East and West Flower Garden Banks in the northwestern Gulf of Mexico. We examined 25 yr of benthic cover data to provide a multi-decadal baseline and trend analysis of the community structure for this coral reef system. Despite global coral reef decline in recent decades, mean coral cover at East and West Flower Garden Banks was above 50% for the combined 25 yr of continuous monitoring, and represented a stable coral community. However, mean macroalgal cover increased significantly between 1998 and 1999, rising from approximately 3 to 20%, and reaching a maximum above 30% in 2012. In contrast to many other shallow water reefs in the Caribbean region, increases in mean macroalgal cover have not been concomitant with coral cover decline at the Flower Garden Banks.
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Back to the future: The history of acroporid corals at the Flower Garden Banks, Gulf of Mexico, USA
Marine Geology, 2014Co-Authors: William F. Precht, Emma L. Hickerson, George P. Schmahl, Marissa F. Nuttall, Kenneth J.p. Deslarzes, Richard B. AronsonAbstract:Fossil elkhorn corals, Acropora palmata, were discovered at the Flower Garden Banks (FGB) on the shelf-margin off the Texas coast in 2006. Radiocarbon dating revealed an A. palmata-dominated community aged 10,157–6838 cal BP. The Acropora reefs correspond in time to an interval of warmer-than-present sea-surface temperatures (SSTs) during the Holocene thermal maximum (HTM). The subsequent demise of A. palmata in the middle Holocene was a consequence of the inability of the shallowest reef facies to keep pace with rising sea level following complete submergence of the banks, possibly coupled with decreasing SSTs following the HTM. In 2007, the first fossil staghorn corals, Acropora cervicornis, were discovered at the FGB. Based on radiocar bon dating of these corals to 1027–211 cal BP, it appears that populations of A. cervicornis flourished in deeper waters (~25–32 m depth) on the edges of the banks until the peak of the Little Ice Age (LIA) when they died, pre sumably from cold-water exposure. The recent return of A. palmata to reefs of the FGB associated with increasing sea temperatures appears to be both an echo of the past and a harbinger of the future. © 2013 Published by Elsevier B.V.
James Sinclair - One of the best experts on this subject based on the ideXlab platform.
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Genetic Connectivity in Scleractinian Corals across the Northern Gulf of Mexico: Oil/Gas Platforms, and Relationship to the Flower Garden Banks
PloS one, 2012Co-Authors: Paul W. Sammarco, Daniel A. Brazeau, James SinclairAbstract:The 3,000 oil/gas structures currently deployed in the northern Gulf of Mexico (GOM) provide hard substratum for marine organisms in a region where such has been rare since the Holocene. The major exception to this are the Flower Garden Banks (FGB). Corals are known to have colonized oil/gas platforms around the FGB, facilitating biogeographic expansion. We ask the question, what are the patterns of genetic affinity in these coral populations. We sampled coral tissue from populations of two species occurring on oil and gas platforms: Madracis decactis (hermatype) and Tubastraea coccinea (invasive ahermatype). We sampled 28 platforms along four transects from 20 km offshore to the continental shelf edge off 1) Matagorda Island, TX; 2) Lake Sabine, TX; 3) Terrebonne Bay, LA; and 4) Mobile, AL. The entire population of M. decactis was sampled between depths of 5 m and 37 m. T. coccinea populations were sub-sampled. Genetic variation was assessed using the PCR-based Amplified Fragment Length Polymorphisms (AFLPs). Data were analyzed via AFLPOP and STRUCTURE. Genetic connectivity among M. decactis platform populations was highest near the FGB and decreased to the east. Connectivity increased again in the eastern sector, indicating isolation between the populations from different sides of the Mississippi River (Transects 3 and 4). A point-drop in genetic affinity (relatedness) at the shelf edge south of Terrebonne Bay, LA indicated a population differing from all others in the northern GOM. Genetic affinities among T. coccinea were highest in the west and decreased to the east. Very low genetic affinities off Mobile, AL indicated a dramatic difference between those populations and those west of the Mississippi River, apparently a formidable barrier to larval dispersal.
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genetic connectivity in scleractinian corals across the northern gulf of mexico oil gas platforms and relationship to the Flower Garden banks
PLOS ONE, 2012Co-Authors: Paul W. Sammarco, Daniel A. Brazeau, James SinclairAbstract:The 3,000 oil/gas structures currently deployed in the northern Gulf of Mexico (GOM) provide hard substratum for marine organisms in a region where such has been rare since the Holocene. The major exception to this are the Flower Garden Banks (FGB). Corals are known to have colonized oil/gas platforms around the FGB, facilitating biogeographic expansion. We ask the question, what are the patterns of genetic affinity in these coral populations. We sampled coral tissue from populations of two species occurring on oil and gas platforms: Madracis decactis (hermatype) and Tubastraea coccinea (invasive ahermatype). We sampled 28 platforms along four transects from 20 km offshore to the continental shelf edge off 1) Matagorda Island, TX; 2) Lake Sabine, TX; 3) Terrebonne Bay, LA; and 4) Mobile, AL. The entire population of M. decactis was sampled between depths of 5 m and 37 m. T. coccinea populations were sub-sampled. Genetic variation was assessed using the PCR-based Amplified Fragment Length Polymorphisms (AFLPs). Data were analyzed via AFLPOP and STRUCTURE. Genetic connectivity among M. decactis platform populations was highest near the FGB and decreased to the east. Connectivity increased again in the eastern sector, indicating isolation between the populations from different sides of the Mississippi River (Transects 3 and 4). A point-drop in genetic affinity (relatedness) at the shelf edge south of Terrebonne Bay, LA indicated a population differing from all others in the northern GOM. Genetic affinities among T. coccinea were highest in the west and decreased to the east. Very low genetic affinities off Mobile, AL indicated a dramatic difference between those populations and those west of the Mississippi River, apparently a formidable barrier to larval dispersal.