Gregor Hodgson - Academia.edu (original) (raw)

Papers by Gregor Hodgson

Science, Aug 15, 1997

Because a sentence added in a revised version of the letter from Thomas J. Goreau et al.(11 July,... more Because a sentence added in a revised version of the letter from Thomas J. Goreau et al.(11 July, p. 165) was not included in the printed letter, some readers may have formed the mistaken impression that the letter meant to criticize the purpose and value of the Reef ...

Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...

Marine Biology, Oct 1, 1990

Sediment deposition on coral reefs occurs naturally and is also caused by man-made disturbances s... more Sediment deposition on coral reefs occurs naturally and is also caused by man-made disturbances such as dredging; it can result in the death of scleractinian corals by an unknown mechanism. Sedimentation experiments with corals were carried out in E1 Nido, Northern Palawan, Philippines, in 1986, and in Honolulu, Oahu, Hawaii in 1988. Four species of Indo-Pacific reef corals (Oxypora glabra, Montipora verrucosa, Porites lobata, Pocillopora meandrina) were subjected to sedimentation tests with and without the antibiotic tetracycline to investigate the possible role of microorganisms in the process of sedimentation damage to corals. O. glabra, Porites lobata and Pocillopora meandrina were rapidly damaged and O. glabra was always killed by sedimentation. Montipora verrucosa was not injured and may be physiologically resistant to sedimentation damage. Tetracyclinetreated seawater reduced the rate of tissue necrosis and prevented colony mortality, suggesting that tetracycline-sensitive bacteria are involved in the process of tissue necrosis and may be partially responsible for coral mortality following sediment deposition.

Nature Communications, Mar 20, 2019

Thermal-stress events associated with climate change cause coral bleaching and mortality that thr... more Thermal-stress events associated with climate change cause coral bleaching and mortality that threatens coral reefs globally. Yet coral bleaching patterns vary spatially and temporally. Here we synthesize field observations of coral bleaching at 3351 sites in 81 countries from 1998 to 2017 and use a suite of environmental covariates and temperature metrics to analyze bleaching patterns. Coral bleaching was most common in localities experiencing high intensity and high frequency thermal-stress anomalies. However, coral bleaching was significantly less common in localities with a high variance in sea-surface temperature (SST) anomalies. Geographically, the highest probability of coral bleaching occurred at tropical midlatitude sites (15-20 degrees north and south of the Equator), despite similar thermal stress levels at equatorial sites. In the last decade, the onset of coral bleaching has occurred at significantly higher SSTs (∼0.5°C) than in the previous decade, suggesting that thermally susceptible genotypes may have declined and/or adapted such that the remaining coral populations now have a higher thermal threshold for bleaching.

Marine Ecology Progress Series, 1985

A plankton sampling program was designed for the capture of coral planulae. More than 250 surface... more A plankton sampling program was designed for the capture of coral planulae. More than 250 surface tows were made with a small, fine-mesh net along 5 transects established near the southeast fringing reef of Coconut Island, Oahu, Hawaii. Time between collection and sorting was minimized, and low temperature storage was employed in lieu of chemical fixation to prevent decomposition of the planulae prior to identification. More than 20,000 cnidarian larvae were collected and sorted, of which 90 % were scleractinian planulae. Twelve different types of cnidarian larvae were recognized. Six were identified as the planulae of the corals Pocillopora damicornis, Porites compressa, Montipora verrucosa, M. dilitata, Cyphastrea ocellina and Fungia scutaria. Two appear to be the zoanthina larvae of the zoanthids Palythoa vestitus and Zoanthus pacificus. Peak recovery of planulae generally occurred 3 to 7 d after onset of spawning or planulation. Limited data indicate that some coral planulae may undertake diurnal migration, residing near the surface at night and moving to several meters depth during the day. The potential for the export of large numbers of coral planulae from Kaneohe Bay is considered high, but whether this export is significant to recruitment on reefs outside the bay remains to be determined.

Ocean warming is increasing the incidence, scale, and severity of global-scale coral bleaching an... more Ocean warming is increasing the incidence, scale, and severity of global-scale coral bleaching and mortality, culminating in the third global coral bleaching event that occurred during record marine heatwaves of 2014-2017. While local effects of these events have been widely reported, the global implications remain unknown. Analysis of 15,066 reef surveys during 2014-2017 revealed that 80% of surveyed reefs experienced significant coral bleaching and 35% experienced significant coral mortality. The global extent of significant coral bleaching and mortality was assessed by extrapolating results from reef surveys using comprehensive remote-sensing data of regional heat stress. This model predicted that 51% of the world’s coral reefs suffered significant bleaching and 15% significant mortality, surpassing damage from any prior global bleaching event. These observations demonstrate that global warming’s widespread damage to coral reefs is accelerating and underscores the threat anthropo...

The huge earthquake and resulting tsunami which occurred on December 26, 2004 off the west coast ... more The huge earthquake and resulting tsunami which occurred on December 26, 2004 off the west coast of Sumatra resulted in regionally variable patterns of impact in and around the Indian Ocean basin. The coast of Sumatra was close to the earthquake epicenter and was the first to be struck, within one hour of the event. A collaborative expedition between the Khaled bin Sultan Living Oceans Foundation, Reef Check International and IUCN (World Conservation Union) to the northwest coast of Sumatra and Aceh Province, Indonesia, was conducted in October 2005. Reef surveys were conducted using two methods: Manta Tow and the Reef Check Plus protocol. A total of 9 sites (8 offshore island sites and 1 mainland Aceh site) were surveyed over a distance of 650 km. Typically tsunami damage was observed as overturned coral colonies and tree debris on the reef. Over half of the reefs surveyed indicated that there had been no tsunami damage and only 15 % of the sites surveyed indicated a high level of ...

Frontiers in Marine Science, 2019

Coral reefs are exceptionally biodiverse and human dependence on their ecosystem services is high... more Coral reefs are exceptionally biodiverse and human dependence on their ecosystem services is high. Reefs experience significant direct and indirect anthropogenic pressures, and provide a sensitive indicator of coastal ocean health, climate change, and ocean acidification, with associated implications for society. Monitoring coral reef status and trends is essential to better inform science, management and policy, but the projected collapse of reef systems within a few decades makes the provision of accurate and actionable monitoring data urgent. The Global Coral Reef Monitoring Network has been the foundation for global reporting on coral reefs for two decades, and is entering into a new phase with improved operational and data standards incorporating the Essential Ocean Variables (EOVs) (www.goosocean.org/eov) and Framework for Ocean Observing developed by the Global Ocean Observing System. Three EOVs provide a

Ecological and Socioeconomic Impacts of 1998 Coral Mortality in the Indian Ocean: An ENSO Impact ... more Ecological and Socioeconomic Impacts of 1998 Coral Mortality in the Indian Ocean: An ENSO Impact and a Warning of Future Change? ... Reefs in other parts of the IndianOcean, or in waters below 20 m, coral mortality was typically 50%. ...

La naturaleza y sus recursos, 1999

Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...

J MARINE ENVIR ENG, 1999

Disposal of dredged material at a specially-designated open water site in Mirs Bay, Hong Kong cea... more Disposal of dredged material at a specially-designated open water site in Mirs Bay, Hong Kong ceased in 1993. A sidescan sonar survey performed at the end of 1995 confirmed the presence of dredged material on the seafloor near the southwest corner of the Mirs Bay ...

Reef Check Foundation …, 2006

Global Change Biology, 2022

Marine heatwaves can cause coral bleaching and reduce coral cover on reefs, yet few studies have ... more Marine heatwaves can cause coral bleaching and reduce coral cover on reefs, yet few studies have identified "bright spots," where corals have recently shown a capacity to survive such pressures. We analyzed 7714 worldwide surveys from 1997 to 2018 along with 14 environmental and temperature metrics in a hierarchical Bayesian model to identify conditions that contribute to present-day coral cover. We also identified locations with significantly higher (i.e., "bright spots") and lower coral cover (i.e., "dark spots") than regionally expected. In addition, using 4-km downscaled data of Representative Concentration Pathways (RCPs) 4.5 and 8.5, we projected coral cover on reefs for the years 2050 and 2100. Coral cover on modern reefs was positively associated with historically high maximum sea-surface temperatures (SSTs), and negatively associated with high contemporary SSTs, tropical-cyclone frequencies, and human-population densities. By 2100, under RCP8.5, we projected relative decreases in coral cover of >40% on most reefs globally but projected less decline on reefs in Indonesia, Malaysia, the central Philippines, New Caledonia, Fiji, and French Polynesia, which should be focal localities for multinational networks of protected areas.

Science, Aug 15, 1997

Because a sentence added in a revised version of the letter from Thomas J. Goreau et al.(11 July,... more Because a sentence added in a revised version of the letter from Thomas J. Goreau et al.(11 July, p. 165) was not included in the printed letter, some readers may have formed the mistaken impression that the letter meant to criticize the purpose and value of the Reef ...

Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...

Marine Biology, Oct 1, 1990

Sediment deposition on coral reefs occurs naturally and is also caused by man-made disturbances s... more Sediment deposition on coral reefs occurs naturally and is also caused by man-made disturbances such as dredging; it can result in the death of scleractinian corals by an unknown mechanism. Sedimentation experiments with corals were carried out in E1 Nido, Northern Palawan, Philippines, in 1986, and in Honolulu, Oahu, Hawaii in 1988. Four species of Indo-Pacific reef corals (Oxypora glabra, Montipora verrucosa, Porites lobata, Pocillopora meandrina) were subjected to sedimentation tests with and without the antibiotic tetracycline to investigate the possible role of microorganisms in the process of sedimentation damage to corals. O. glabra, Porites lobata and Pocillopora meandrina were rapidly damaged and O. glabra was always killed by sedimentation. Montipora verrucosa was not injured and may be physiologically resistant to sedimentation damage. Tetracyclinetreated seawater reduced the rate of tissue necrosis and prevented colony mortality, suggesting that tetracycline-sensitive bacteria are involved in the process of tissue necrosis and may be partially responsible for coral mortality following sediment deposition.

Nature Communications, Mar 20, 2019

Thermal-stress events associated with climate change cause coral bleaching and mortality that thr... more Thermal-stress events associated with climate change cause coral bleaching and mortality that threatens coral reefs globally. Yet coral bleaching patterns vary spatially and temporally. Here we synthesize field observations of coral bleaching at 3351 sites in 81 countries from 1998 to 2017 and use a suite of environmental covariates and temperature metrics to analyze bleaching patterns. Coral bleaching was most common in localities experiencing high intensity and high frequency thermal-stress anomalies. However, coral bleaching was significantly less common in localities with a high variance in sea-surface temperature (SST) anomalies. Geographically, the highest probability of coral bleaching occurred at tropical midlatitude sites (15-20 degrees north and south of the Equator), despite similar thermal stress levels at equatorial sites. In the last decade, the onset of coral bleaching has occurred at significantly higher SSTs (∼0.5°C) than in the previous decade, suggesting that thermally susceptible genotypes may have declined and/or adapted such that the remaining coral populations now have a higher thermal threshold for bleaching.

Marine Ecology Progress Series, 1985

A plankton sampling program was designed for the capture of coral planulae. More than 250 surface... more A plankton sampling program was designed for the capture of coral planulae. More than 250 surface tows were made with a small, fine-mesh net along 5 transects established near the southeast fringing reef of Coconut Island, Oahu, Hawaii. Time between collection and sorting was minimized, and low temperature storage was employed in lieu of chemical fixation to prevent decomposition of the planulae prior to identification. More than 20,000 cnidarian larvae were collected and sorted, of which 90 % were scleractinian planulae. Twelve different types of cnidarian larvae were recognized. Six were identified as the planulae of the corals Pocillopora damicornis, Porites compressa, Montipora verrucosa, M. dilitata, Cyphastrea ocellina and Fungia scutaria. Two appear to be the zoanthina larvae of the zoanthids Palythoa vestitus and Zoanthus pacificus. Peak recovery of planulae generally occurred 3 to 7 d after onset of spawning or planulation. Limited data indicate that some coral planulae may undertake diurnal migration, residing near the surface at night and moving to several meters depth during the day. The potential for the export of large numbers of coral planulae from Kaneohe Bay is considered high, but whether this export is significant to recruitment on reefs outside the bay remains to be determined.

Ocean warming is increasing the incidence, scale, and severity of global-scale coral bleaching an... more Ocean warming is increasing the incidence, scale, and severity of global-scale coral bleaching and mortality, culminating in the third global coral bleaching event that occurred during record marine heatwaves of 2014-2017. While local effects of these events have been widely reported, the global implications remain unknown. Analysis of 15,066 reef surveys during 2014-2017 revealed that 80% of surveyed reefs experienced significant coral bleaching and 35% experienced significant coral mortality. The global extent of significant coral bleaching and mortality was assessed by extrapolating results from reef surveys using comprehensive remote-sensing data of regional heat stress. This model predicted that 51% of the world’s coral reefs suffered significant bleaching and 15% significant mortality, surpassing damage from any prior global bleaching event. These observations demonstrate that global warming’s widespread damage to coral reefs is accelerating and underscores the threat anthropo...

The huge earthquake and resulting tsunami which occurred on December 26, 2004 off the west coast ... more The huge earthquake and resulting tsunami which occurred on December 26, 2004 off the west coast of Sumatra resulted in regionally variable patterns of impact in and around the Indian Ocean basin. The coast of Sumatra was close to the earthquake epicenter and was the first to be struck, within one hour of the event. A collaborative expedition between the Khaled bin Sultan Living Oceans Foundation, Reef Check International and IUCN (World Conservation Union) to the northwest coast of Sumatra and Aceh Province, Indonesia, was conducted in October 2005. Reef surveys were conducted using two methods: Manta Tow and the Reef Check Plus protocol. A total of 9 sites (8 offshore island sites and 1 mainland Aceh site) were surveyed over a distance of 650 km. Typically tsunami damage was observed as overturned coral colonies and tree debris on the reef. Over half of the reefs surveyed indicated that there had been no tsunami damage and only 15 % of the sites surveyed indicated a high level of ...

Frontiers in Marine Science, 2019

Coral reefs are exceptionally biodiverse and human dependence on their ecosystem services is high... more Coral reefs are exceptionally biodiverse and human dependence on their ecosystem services is high. Reefs experience significant direct and indirect anthropogenic pressures, and provide a sensitive indicator of coastal ocean health, climate change, and ocean acidification, with associated implications for society. Monitoring coral reef status and trends is essential to better inform science, management and policy, but the projected collapse of reef systems within a few decades makes the provision of accurate and actionable monitoring data urgent. The Global Coral Reef Monitoring Network has been the foundation for global reporting on coral reefs for two decades, and is entering into a new phase with improved operational and data standards incorporating the Essential Ocean Variables (EOVs) (www.goosocean.org/eov) and Framework for Ocean Observing developed by the Global Ocean Observing System. Three EOVs provide a

Ecological and Socioeconomic Impacts of 1998 Coral Mortality in the Indian Ocean: An ENSO Impact ... more Ecological and Socioeconomic Impacts of 1998 Coral Mortality in the Indian Ocean: An ENSO Impact and a Warning of Future Change? ... Reefs in other parts of the IndianOcean, or in waters below 20 m, coral mortality was typically 50%. ...

La naturaleza y sus recursos, 1999

Biblioteca de la Universidad Complutense de Madrid, Base de datos de artículos de revistas, ...

J MARINE ENVIR ENG, 1999

Disposal of dredged material at a specially-designated open water site in Mirs Bay, Hong Kong cea... more Disposal of dredged material at a specially-designated open water site in Mirs Bay, Hong Kong ceased in 1993. A sidescan sonar survey performed at the end of 1995 confirmed the presence of dredged material on the seafloor near the southwest corner of the Mirs Bay ...

Reef Check Foundation …, 2006

Global Change Biology, 2022

Marine heatwaves can cause coral bleaching and reduce coral cover on reefs, yet few studies have ... more Marine heatwaves can cause coral bleaching and reduce coral cover on reefs, yet few studies have identified "bright spots," where corals have recently shown a capacity to survive such pressures. We analyzed 7714 worldwide surveys from 1997 to 2018 along with 14 environmental and temperature metrics in a hierarchical Bayesian model to identify conditions that contribute to present-day coral cover. We also identified locations with significantly higher (i.e., "bright spots") and lower coral cover (i.e., "dark spots") than regionally expected. In addition, using 4-km downscaled data of Representative Concentration Pathways (RCPs) 4.5 and 8.5, we projected coral cover on reefs for the years 2050 and 2100. Coral cover on modern reefs was positively associated with historically high maximum sea-surface temperatures (SSTs), and negatively associated with high contemporary SSTs, tropical-cyclone frequencies, and human-population densities. By 2100, under RCP8.5, we projected relative decreases in coral cover of >40% on most reefs globally but projected less decline on reefs in Indonesia, Malaysia, the central Philippines, New Caledonia, Fiji, and French Polynesia, which should be focal localities for multinational networks of protected areas.