Search

Search Results

• 1. [Article] Bridging the Marine–Terrestrial Disconnect to Improve Marine Coastal Zone Science and Management

  Coastal zone ecosystems sit between larger terrestrial and marine environments and, therefore, are strongly affected by processes occurring in both systems. Marine coastal zone systems provide a range ...

  Citation × Citation Citation Abstract Copy Title: Bridging the Marine–Terrestrial Disconnect to Improve Marine Coastal Zone Science and Management Author: Ruttenberg, Benjamin I., Granek, Elise F. Year: 2011 Coastal zone ecosystems sit between larger terrestrial and marine environments and, therefore, are strongly affected by processes occurring in both systems. Marine coastal zone systems provide a range of benefits to humans, and yet many have been significantly degraded as a result of direct and indirect human impacts. Management efforts have been hampered by disconnects both between management and scientific research and across linked marine–terrestrial systems. Management jurisdictions often start or end at the shoreline, and multiple agencies at different levels of government often have overlapping or conflicting management goals or priorities, or suffer from a lack of knowledge or interest. Scientists also often fail to consider connections among linked marine–terrestrial systems, and communication among agencies, among scientists in different disciplines, and between scientists and managers is often inadequate. However, despite the institutional and scientific challenges inherent in improving coastal zone management, there are examples of increased coordination and cooperation among different organizations. We discuss a number of examples— including where the marine–terrestrial and science–management disconnects persist and where better integration has led to successes in coastal zone management—and provide recommendations to scientists and managers on how to better link their efforts in science and management across marine and terrestrial systems. Title: Bridging the Marine–Terrestrial Disconnect to Improve Marine Coastal Zone Science and Management Author: Ruttenberg, Benjamin I., Granek, Elise F. Year: 2011 Coastal zone ecosystems sit between larger terrestrial and marine environments and, therefore, are strongly affected by processes occurring in both systems. Marine coastal zone systems provide a range of benefits to humans, and yet many have been significantly degraded as a result of direct and indirect human impacts. Management efforts have been hampered by disconnects both between management and scientific research and across linked marine–terrestrial systems. Management jurisdictions often start or end at the shoreline, and multiple agencies at different levels of government often have overlapping or conflicting management goals or priorities, or suffer from a lack of knowledge or interest. Scientists also often fail to consider connections among linked marine–terrestrial systems, and communication among agencies, among scientists in different disciplines, and between scientists and managers is often inadequate. However, despite the institutional and scientific challenges inherent in improving coastal zone management, there are examples of increased coordination and cooperation among different organizations. We discuss a number of examples— including where the marine–terrestrial and science–management disconnects persist and where better integration has led to successes in coastal zone management—and provide recommendations to scientists and managers on how to better link their efforts in science and management across marine and terrestrial systems. Close

• 2. [Article] The release of total and dissolved organic carbon from macroalgae and phytoplankton

  Many phytoplankton and macroalgae release dissolved organic carbon (DOC). Many macroalgae also produce and store secondary metabolites which in some case have been shown to deter their grazers. The metabolites ...

  Citation × Citation Citation Abstract Copy Title: The release of total and dissolved organic carbon from macroalgae and phytoplankton Author: Kawasaki, Nobuyuki Many phytoplankton and macroalgae release dissolved organic carbon (DOC). Many macroalgae also produce and store secondary metabolites which in some case have been shown to deter their grazers. The metabolites may be released into the surrounding seawater and could inhibit primary production. On the other hand, some phytoplankton can use DOC as a supplemental nutrient. In the first part of my experimental work, I tested the toxic or stimulatory effect of released materials from macroalgae on phytoplankton growth. Two out of six macroalgal culture media showed a weak inhibitory effect on phytoplankton growth, but the effect was far less than expected. Data from these experiments provided preliminary estimates of DOC release rates of both macroalgae and phytoplankton. The release rates of phytoplankton were nearly a hundred times higher than those of macroalgae. The DOC release seemed to be positively correlated with the surface area to volume (SA:V) ratio. This result implies that the release of DOC may be dominated by a passive diffusion. In the second part of my experimental work, I tested whether the DOC release rates differed with growth conditions. In the macroalgal experiment, the release rates were not different between batch and continuous cultures. Extremely high DOC release in the continuous culture reported by Sieburth (1969) seemed to be a result of adverse experimental conditions. In the phytoplankton experiment, the release rates seemed to be positively correlated with growth rate. The highest release rate was observed during the exponential growth phase. This result and reports in the literature suggest that both quantitative and qualitative differences in phytoplankton DOC release are a function of growth phase. For example, phytoplankton may produce and release more nitrogen-rich low-molecular-weight organic carbon during the exponential growth phase and more carbon-rich high-molecular-weight organic carbon during the stationary growth phase. DOC is a main food source for heterotrophic microbes. Both quantitative and qualitative variations in phytoplankton DOC release are likely to have a large influence on the microbial loop. More detailed information on the composition of the released materials and mechanism involved in the release is needed to understand these processes and the role they play in the carbon cycle in coastal ecosystems. Title: The release of total and dissolved organic carbon from macroalgae and phytoplankton Author: Kawasaki, Nobuyuki Many phytoplankton and macroalgae release dissolved organic carbon (DOC). Many macroalgae also produce and store secondary metabolites which in some case have been shown to deter their grazers. The metabolites may be released into the surrounding seawater and could inhibit primary production. On the other hand, some phytoplankton can use DOC as a supplemental nutrient. In the first part of my experimental work, I tested the toxic or stimulatory effect of released materials from macroalgae on phytoplankton growth. Two out of six macroalgal culture media showed a weak inhibitory effect on phytoplankton growth, but the effect was far less than expected. Data from these experiments provided preliminary estimates of DOC release rates of both macroalgae and phytoplankton. The release rates of phytoplankton were nearly a hundred times higher than those of macroalgae. The DOC release seemed to be positively correlated with the surface area to volume (SA:V) ratio. This result implies that the release of DOC may be dominated by a passive diffusion. In the second part of my experimental work, I tested whether the DOC release rates differed with growth conditions. In the macroalgal experiment, the release rates were not different between batch and continuous cultures. Extremely high DOC release in the continuous culture reported by Sieburth (1969) seemed to be a result of adverse experimental conditions. In the phytoplankton experiment, the release rates seemed to be positively correlated with growth rate. The highest release rate was observed during the exponential growth phase. This result and reports in the literature suggest that both quantitative and qualitative differences in phytoplankton DOC release are a function of growth phase. For example, phytoplankton may produce and release more nitrogen-rich low-molecular-weight organic carbon during the exponential growth phase and more carbon-rich high-molecular-weight organic carbon during the stationary growth phase. DOC is a main food source for heterotrophic microbes. Both quantitative and qualitative variations in phytoplankton DOC release are likely to have a large influence on the microbial loop. More detailed information on the composition of the released materials and mechanism involved in the release is needed to understand these processes and the role they play in the carbon cycle in coastal ecosystems. Close