The Experts below are selected from a list of 33 Experts worldwide ranked by ideXlab platform

Michael P Lesser - One of the best experts on this subject based on the ideXlab platform.

  • Photoacclimatization by the coral Montastraea cavernosa in the mesophotic zone: light, food, and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (

  • Photoacclimatization by the coral montastraea cavernosa in the mesophotic zone light food and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (<30 m) systems due to the technical limitations of conducting scientific diving deeper than 30 m. Compared to their shallow-water counterparts, these mesophotic coral reefs (30-150 m) are understudied, which has slowed our broader understanding of the biodiversity, ecology, and connectivity of shallow and deep coral reef communities. We know that the light environment is an important component of the productivity, physiology, and ecology of corals, and it restricts the distribution of most species of coral to depths of 60 m or less. In the Bahamas, the coral Montastraea cavernosa has a wide depth distribution, and it is one of the most numerous corals at mesophotic depths. Using a range of optical, physiological, and biochemical approaches, the relative dependence on autotrophy vs. heterotrophy was assessed for this coral from 3 to 91 m. These measurements show that the quantum yield of PSII fluorescence increases significantly with depth for M. cavernosa while gross primary productivity decreases with depth. Both morphological and physiological Photoacclimatization occurs to a depth of 91 m, and stable isotope data of the host tissues, symbionts, and skeleton reveal a marked decrease in productivity and a sharp transition to heterotrophy between 45 and 61 m. Below these depths, significant changes in the genetic composition of the zooxanthellae community, including genotypes not previously observed, occur and suggest that there is strong selection for zooxanthellae that are suited for survival in the light-limited environment where mesophotic M. cavernosa are occurring.

  • exposure to solar radiation increases damage to both host tissues and algal symbionts of corals during thermal stress
    Coral Reefs, 2004
    Co-Authors: Michael P Lesser, Julianne H Farrell
    Abstract:

    Elevated seawater temperatures have long been accepted as the principal stressor causing the loss of symbiotic algae in corals and other invertebrates with algal symbionts (i.e., “bleaching”). A secondary factor associated with coral bleaching is solar irradiance, both its visible (PAR: 400–700 nm) and ultraviolet (UVR: 290–400 nm) portions of the spectrum. Here we examined the synergistic role of solar radiation on thermally induced stress and subsequent bleaching in a common Caribbean coral, Montastraea faveolata. Active fluorescent measurements show that steady-state quantum yields of photosystem II (PSII) fluorescence in the zooxanthellae are markedly depressed when exposed to high solar radiation and elevated temperatures, and the concentration of D1 protein is significantly lower in high light when compared to low light treatments under the same thermal stress. Both photosynthetic pigments and mycosporine-like amino acids (MAAs) are also depressed after experimental exposure to high solar radiation and thermal stress. Host DNA damage is exacerbated under high light conditions and is correlated with the expression of the cell cycle gene p 53, a cellular gatekeeper that modulates the fate of damaged cells between DNA repair processes and apoptotic pathways. These markers of cellular stress in the host and zooxanthellae have in common their response to the enhanced production of reactive oxygen species during exposure to high irradiances of solar radiation and elevated temperatures. Taking these results and previously published data into consideration, we conclude that thermal stress during exposure to high irradiances of solar radiation, or irradiances higher than the current Photoacclimatization state, causes damage to both photochemistry and carbon fixation at the same time in zooxanthellae, while DNA damage, apoptosis, or necrosis are occurring in the host tissues of symbiotic cnidarians.

  • depth dependent Photoacclimatization to solar ultraviolet radiation in the caribbean coral montastraea faveolata
    Marine Ecology Progress Series, 2000
    Co-Authors: Michael P Lesser
    Abstract:

    The importance of solar ultraviolet radiation (UVR, 290 to 400 nm), and UVB (290 to 320 nm) in particular, as an environmental factor affecting the biology and ecology of coral reefs has taken on renewed interest since the demonstration of global stratospheric ozone loss through human activities. The hermatypic coral Montastraea faveolata occurs over a wide bathymetric range in the Florida Keys reef tract. The bathymetric range of M. faveolata and its role in reef community structure make it an important species for which to assess the effects of present day UVR irradiances. Both UVR irradiances and UVR-absorbing mycosporine-like amino acids (MAAs) decreased significantly with increasing depth in M. faveolata. UVB irradiances were measured to a depth of 30 m during this study and maximum rates of productivity in M. faveolata were significantly affected by the presence of UVR. Action spectra (= biological weighting function) for the photoinhibition of photosynthesis by UVR were measured for samples of M. faveolata at 3, 10, 18, 23, and 30 m. Using these action spectra, radiation amplification factors (RAFs) were calculated for corals at the same depths. RAFs for M. faveolata suggest that corals at depths greater than 3 m will be more sensitive to increases in UVB irradiance, such as might be caused by ozone depletion, than their shallow-water counterparts. Despite this increase in sensitivity to UVB, calculations incorporating continued ozone depletion suggest that at the present rate of stratospheric ozone depletion corals deeper than 5 m in the Florida Keys will be affected very little, if at all, by increases in UVR. These results, however, do not incorporate the interacting and synergistic effects of UVR with other physical parameters (e.g. temperature) that will be essential to understanding and predicting the fate of coral reefs under conditions of global change.

Andrea G Grottoli - One of the best experts on this subject based on the ideXlab platform.

  • Photoacclimatization by the coral montastraea cavernosa in the mesophotic zone light food and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (<30 m) systems due to the technical limitations of conducting scientific diving deeper than 30 m. Compared to their shallow-water counterparts, these mesophotic coral reefs (30-150 m) are understudied, which has slowed our broader understanding of the biodiversity, ecology, and connectivity of shallow and deep coral reef communities. We know that the light environment is an important component of the productivity, physiology, and ecology of corals, and it restricts the distribution of most species of coral to depths of 60 m or less. In the Bahamas, the coral Montastraea cavernosa has a wide depth distribution, and it is one of the most numerous corals at mesophotic depths. Using a range of optical, physiological, and biochemical approaches, the relative dependence on autotrophy vs. heterotrophy was assessed for this coral from 3 to 91 m. These measurements show that the quantum yield of PSII fluorescence increases significantly with depth for M. cavernosa while gross primary productivity decreases with depth. Both morphological and physiological Photoacclimatization occurs to a depth of 91 m, and stable isotope data of the host tissues, symbionts, and skeleton reveal a marked decrease in productivity and a sharp transition to heterotrophy between 45 and 61 m. Below these depths, significant changes in the genetic composition of the zooxanthellae community, including genotypes not previously observed, occur and suggest that there is strong selection for zooxanthellae that are suited for survival in the light-limited environment where mesophotic M. cavernosa are occurring.

  • Photoacclimatization by the coral Montastraea cavernosa in the mesophotic zone: light, food, and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (

Marc Slattery - One of the best experts on this subject based on the ideXlab platform.

  • Photoacclimatization by the coral montastraea cavernosa in the mesophotic zone light food and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (<30 m) systems due to the technical limitations of conducting scientific diving deeper than 30 m. Compared to their shallow-water counterparts, these mesophotic coral reefs (30-150 m) are understudied, which has slowed our broader understanding of the biodiversity, ecology, and connectivity of shallow and deep coral reef communities. We know that the light environment is an important component of the productivity, physiology, and ecology of corals, and it restricts the distribution of most species of coral to depths of 60 m or less. In the Bahamas, the coral Montastraea cavernosa has a wide depth distribution, and it is one of the most numerous corals at mesophotic depths. Using a range of optical, physiological, and biochemical approaches, the relative dependence on autotrophy vs. heterotrophy was assessed for this coral from 3 to 91 m. These measurements show that the quantum yield of PSII fluorescence increases significantly with depth for M. cavernosa while gross primary productivity decreases with depth. Both morphological and physiological Photoacclimatization occurs to a depth of 91 m, and stable isotope data of the host tissues, symbionts, and skeleton reveal a marked decrease in productivity and a sharp transition to heterotrophy between 45 and 61 m. Below these depths, significant changes in the genetic composition of the zooxanthellae community, including genotypes not previously observed, occur and suggest that there is strong selection for zooxanthellae that are suited for survival in the light-limited environment where mesophotic M. cavernosa are occurring.

  • Photoacclimatization by the coral Montastraea cavernosa in the mesophotic zone: light, food, and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (

Michael Stat - One of the best experts on this subject based on the ideXlab platform.

  • Photoacclimatization by the coral montastraea cavernosa in the mesophotic zone light food and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (<30 m) systems due to the technical limitations of conducting scientific diving deeper than 30 m. Compared to their shallow-water counterparts, these mesophotic coral reefs (30-150 m) are understudied, which has slowed our broader understanding of the biodiversity, ecology, and connectivity of shallow and deep coral reef communities. We know that the light environment is an important component of the productivity, physiology, and ecology of corals, and it restricts the distribution of most species of coral to depths of 60 m or less. In the Bahamas, the coral Montastraea cavernosa has a wide depth distribution, and it is one of the most numerous corals at mesophotic depths. Using a range of optical, physiological, and biochemical approaches, the relative dependence on autotrophy vs. heterotrophy was assessed for this coral from 3 to 91 m. These measurements show that the quantum yield of PSII fluorescence increases significantly with depth for M. cavernosa while gross primary productivity decreases with depth. Both morphological and physiological Photoacclimatization occurs to a depth of 91 m, and stable isotope data of the host tissues, symbionts, and skeleton reveal a marked decrease in productivity and a sharp transition to heterotrophy between 45 and 61 m. Below these depths, significant changes in the genetic composition of the zooxanthellae community, including genotypes not previously observed, occur and suggest that there is strong selection for zooxanthellae that are suited for survival in the light-limited environment where mesophotic M. cavernosa are occurring.

  • Photoacclimatization by the coral Montastraea cavernosa in the mesophotic zone: light, food, and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (

Michiko Ojimi - One of the best experts on this subject based on the ideXlab platform.

  • Photoacclimatization by the coral montastraea cavernosa in the mesophotic zone light food and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (<30 m) systems due to the technical limitations of conducting scientific diving deeper than 30 m. Compared to their shallow-water counterparts, these mesophotic coral reefs (30-150 m) are understudied, which has slowed our broader understanding of the biodiversity, ecology, and connectivity of shallow and deep coral reef communities. We know that the light environment is an important component of the productivity, physiology, and ecology of corals, and it restricts the distribution of most species of coral to depths of 60 m or less. In the Bahamas, the coral Montastraea cavernosa has a wide depth distribution, and it is one of the most numerous corals at mesophotic depths. Using a range of optical, physiological, and biochemical approaches, the relative dependence on autotrophy vs. heterotrophy was assessed for this coral from 3 to 91 m. These measurements show that the quantum yield of PSII fluorescence increases significantly with depth for M. cavernosa while gross primary productivity decreases with depth. Both morphological and physiological Photoacclimatization occurs to a depth of 91 m, and stable isotope data of the host tissues, symbionts, and skeleton reveal a marked decrease in productivity and a sharp transition to heterotrophy between 45 and 61 m. Below these depths, significant changes in the genetic composition of the zooxanthellae community, including genotypes not previously observed, occur and suggest that there is strong selection for zooxanthellae that are suited for survival in the light-limited environment where mesophotic M. cavernosa are occurring.

  • Photoacclimatization by the coral Montastraea cavernosa in the mesophotic zone: light, food, and genetics
    Ecology, 2010
    Co-Authors: Michael P Lesser, Marc Slattery, Michael Stat, Michiko Ojimi, Ruth D Gates, Andrea G Grottoli
    Abstract:

    Most studies on coral reefs have focused on shallow reef (