Thalassia testudinum response to the interactive stressors hypersalinity, sulfide and hypoxia

Koch, Marguerite S.; Schopmeyer, Stephanie; Holmer, Marianne; Madden, C.J.; Kyhn-Hansen, C.

doi:10.1016/j.aquabot.2007.03.004

Cited by 68 publications

(30 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Elemental sulfur [S 0 ; assessed after methanol extraction by RP-HPLC after Zopfi et al (2001)] is one reoxidation product of sulfide, which has been found accumulating in seagrass tissues (Holmer et al, 2005bFrederiksen et al, , 2007Koch et al, 2007;Hasler-Sheetal, 2014). High S 0 concentrations were found in Z. marina and Thalassia testudinum (up to 46% of TS), when plants were exposed to high sulfide concentrations in laboratory experiments (Holmer et al, 2005b;Koch et al, 2007;Mascaro et al, 2009;Hasler-Sheetal, 2014), but also field plants show accumulation of S 0 and it is possibly a wide-spread mechanism for detoxification of sulfide in seagrasses (Holmer et al, 2005aHaslerSheetal, 2014). In field plants S 0 primarily accumulates in the roots, and the highest tissue contents found are in Z. marina with about 0.5%DW, corresponding to 5-10% of TS content of the plants.…”

Section: Fate Of Sulfide Inside Seagrassesmentioning

confidence: 99%

“…Similarly, direct exposure of T. testudinum to high pore water concentrations of sulfide (6 mM) and hypersalinity (65) resulted in declining δ 34 S in the plants and was followed by decreased plant performance (Koch et al, 2007). Combinations of increasing temperature and increasing biomass of the drifting algae Gracilaria comosa increased the sulfide intrusion in H. ovalis, and had detrimental impact on this small seagrass through interactive effects of shading, anoxia, and pore water sulfide (Holmer et al, 2011;Höffle et al, 2012).…”

Section: Relationships Between Environmental and Biological Stressorsmentioning

confidence: 99%

See 1 more Smart Citation

Sulfide intrusion in seagrasses assessed by stable sulfur isotopesâ€”a synthesis of current results

Holmer

Hasler-Sheetal

2014

Front. Mar. Sci.

Self Cite

View full text Add to dashboard Cite

Sulfide intrusion in seagrasses, as assessed by stable sulfur isotope signals, is widespread in all climate zones, where seagrasses are growing. Seagrasses can incorporate substantial amounts of 34 S-depleted sulfide into their tissues with up to 87% of the total sulfur in leaves derived from sedimentary sulfide. Correlations between 34 δ S in leaves, rhizomes, and roots show that sedimentary sulfide is entering through the roots, either in the form of sulfide or sulfate, and translocated to the rhizomes and the leaves. The total sulfur content of the seagrasses increases as the proportion of sedimentary sulfide in the plant increases, and accumulation of elemental sulfur (S 0 ) inside the plant with 34 δ S values similar to the sedimentary sulfide suggests that S 0 is an important reoxidation product of the sedimentary sulfide. The accumulation of S 0 can, however, not account for the increase in sulfur in the tissue, and other sulfur containing compounds such as thiols, organic sulfur, and sulfate contribute to the accumulated sulfur pool. Experimental studies with seagrasses exposed to environmental and biological stressors show decreasing 34 δ S in the tissues along with reduction in growth parameters, suggesting that sulfide intrusion can affect seagrass performance.

show abstract

Section: Fate Of Sulfide Inside Seagrassesmentioning

confidence: 99%

Section: Relationships Between Environmental and Biological Stressorsmentioning

confidence: 99%

Sulfide intrusion in seagrasses assessed by stable sulfur isotopesâ€”a synthesis of current results

Holmer

Hasler-Sheetal

2014

Front. Mar. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In subtropical and tropical estuaries and coastal lagoons, large contiguous seagrass meadows support a range of ecosystem services including nutrient cycling, nursery grounds for many fish and crustacean species, food for endangered large grazers, such as dugong and turtles, and coastal protection by sediment accretion and stabilization [1][2][3]. Seagrasses are productive carbon fixers [4,5], which places their economic value among the highest of the world's ecosystems [6].…”

Section: Introductionmentioning

confidence: 99%

“…The Florida Bay ecosystem has experienced large changes in water quality concurrent with massive die-offs of seagrasses [32]. In 1987 approximately 40 km 2 of Thalassia testudinum meadows experienced a major "die-off" in Florida Bay, and that die-off has been followed by smaller (<1 km 2 ) patchy episodes of mortality on an annual basis [1]. Despite tremendous losses suffered in the past 30 years, South Florida still supports roughly 55%-65% of Florida's seagrass resources and the greatest population densities on the state's coastline [33].…”

Section: Introductionmentioning

confidence: 99%

Supervised Classification of Benthic Reflectance in Shallow Subtropical Waters Using a Generalized Pixel-Based Classifier across a Time Series

2015

View full text Add to dashboard Cite

Abstract:We tested a supervised classification approach with Landsat 5 Thematic Mapper (TM) data for time-series mapping of seagrass in a subtropical lagoon. Seagrass meadows are an integral link between marine and inland ecosystems and are at risk from upstream processes such as runoff and erosion. Despite the prevalence of image-specific approaches, the classification accuracies we achieved show that pixel-based spectral classes may be generalized and applied to a time series of images that were not included in the classifier training. We employed in-situ data on seagrass abundance from 2007 to 2011 to train and validate a classification model. We created depth-invariant bands from TM bands 1, 2, and 3 to correct for variations in water column depth prior to building the classification model. In-situ data showed mean total seagrass cover remained relatively stable over the study area and period, with seagrass cover generally denser in the west than the east. Our approach achieved mapping accuracies (67% and 76% for two validation years) comparable with those attained using spectral libraries, but was simpler to implement. We produced a series of annual maps illustrating inter-annual variability in seagrass occurrence. Accuracies may be improved in future work by better addressing the spatial mismatch between pixel size of remotely sensed data and footprint of field data and by employing atmospheric correction techniques that normalize reflectances across images. OPEN ACCESSRemote Sens. 2015, 7 5099

show abstract

“…Recent modelling efforts have projected that seagrass species distribution throughout Florida Bay would change with increasing freshwater flow associated with restoration of upstream wetlands (Herbert et al 2011). Similarly, hypersalinity has been hypothesised as a contributor to seagrass die-off in Florida Bay, when combined with sulfide intrusion and hypoxia (Koch et al 2007), and restructuring of seagrass communities (Herbert et al 2011).…”

Section: Seagrassesmentioning

confidence: 99%

Science behind management of Shark Bay and Florida Bay, two P-limited subtropical systems with different climatology and human pressures

Kendrick

Fourqurean

Fraser

et al. 2012

Mar. Freshwater Res.

View full text Add to dashboard Cite

Abstract. This special issue on 'Science for the management of subtropical embayments: examples from Shark Bay and Florida Bay' is a valuable compilation of individual research outcomes from Florida Bay and Shark Bay from the past decade and addresses gaps in our scientific knowledge base in Shark Bay especially. Yet the compilation also demonstrates excellent research that is poorly integrated, and driven by interests and issues that do not necessarily lead to a more integrated stewardship of the marine natural values of either Shark Bay or Florida Bay. Here we describe the status of our current knowledge, introduce the valuable extension of the current knowledge through the papers in this issue and then suggest some future directions. For management, there is a need for a multidisciplinary international science program that focusses research on the ecological resilience of Shark Bay and Florida Bay, the effect of interactions between physical environmental drivers and biological control through behavioural and trophic interactions, and all under increased anthropogenic stressors. Shark Bay offers a 'pristine template' for this scale of study.

show abstract

Thalassia testudinum response to the interactive stressors hypersalinity, sulfide and hypoxia

Cited by 68 publications

References 30 publications

Sulfide intrusion in seagrasses assessed by stable sulfur isotopesâ€”a synthesis of current results

Sulfide intrusion in seagrasses assessed by stable sulfur isotopesâ€”a synthesis of current results

Supervised Classification of Benthic Reflectance in Shallow Subtropical Waters Using a Generalized Pixel-Based Classifier across a Time Series

Science behind management of Shark Bay and Florida Bay, two P-limited subtropical systems with different climatology and human pressures

Contact Info

Product

Resources

About