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Estuary restoration & Impacts of oil spills on marine and coastal ecosystems

Room: Carron B     2014-08-15; 17:30 - 19:30

NB: Unless specified otherwise, presentations are 15 minutes in length, and speed presentations are 5 mins in length.

Chair(s)/Moderator(s): Gedan, Keryn

C18.1  17:30  Biodiversity, Ecosystem Functioning and Value of Restored Saltmarshes in the Eden Estuary, Fife. Wade, K *, Sediment Ecology Research Group, Scottish Ocean Institute, School of Biology, University of St Andrews; Golléty, C Sediment Ecology Research Group, Scottish Ocean Institute, School of Biology, University of St Andrews; Hanley, N Department of Economics, University of Stirling; Paterson, DM Sediment Ecology Research Group, Scottish Ocean Institute, School of Biology, University of St Andrews;

Abstract: Saltmarshes are in decline worldwide due to human development and climate change. To restore and better manage these ecologically and economically important habitats requires an improved knowledge of their ecology and ecosystem functioning. In the Eden Estuary, Fife, the local marsh species Bolboschoenus maritimus has been successfully transplanted: sediment accumulation is comparable between restored and natural sites. So far, however, the effects of restoration on other measures of ecosystem functioning have not been assessed. Measurements of sediment stability, biofilm properties, infauna diversity, and macrophyte structure were taken between November 2011 and March 2013. A decade after transplantation, macrophyte height and density, relating to habitat provisioning and coastal protection, are now comparable to the original marsh. Other processes are developing along the same trajectory but at slower rates. This work improves our understanding of the time taken for ecosystem services to be restored. Combining this knowledge with economic valuation of ecosystem services enables policy makers to make more informed and cost-effective management decisions. Discrete choice analysis was used to place a monetary value on these saltmarshes as a form of coastal defence. Locals’ preferences for the type of the defences indicated a preference for combined, followed by soft and finally hard defences being used.

C18.2  17:45  Tracking estuary restoration in a tidal freshwater embayment, from nutrient loading reductions to bloom abatement to aquatic plant recovery. Jones, RC *, George Mason University;

Abstract: Plagued by large scale cyanobacterial blooms and loss of submersed aquatic plants, the tidal freshwater Potomac River was targeted for restoration as early as the mid-1960’s. Excess phosphorus (P) was identified as the major culprit and efforts were instituted to decrease loads. By 1980 P loads were greatly reduced, but blooms continued and aquatic plants were not recovering. An ecosystem monitoring program was initiated in 1983/84 in Gunston Cove, a substantial embayment of the river receiving treated wastewater with the goal of tracking the course of recovery in this area of the tidal Potomac. Variables measured by the study have included nutrient concentrations, chlorophyll a, and phytoplankton community structure. Results indicate partial recovery, but with substantial lags in ecosystem response. Nutrient loads were controlled up to 95% by 1980, but blooms continued through 1989, apparently due to internal loading of P from sediments. After cyanobacterial blooms abated, chlorophyll levels in summer still averaged near 100 ug/L through 2000, light transparency remained poor and aquatic plant growth was very limited. However, during the 2000’s chlorophyll steadily declined to summer averages of 30 ug/L and light transparency nearly doubled. Aquatic plants have restored themselves to nearly half of the embayment. Results indicate that estuary restoration processes may extend over several decades even after nutrient loading from the watershed has been greatly curtailed.

C18.4  18:00  Water quality effects of multiple foundation species on restored oyster reefs: models and empirical results. Gedan, KB *, University of Maryland, College Park; Kellogg, L Virginia Institute of Marine Science; Breitburg, DL Smithsonian Environmental Research Center;

Abstract: Many coastal habitat restoration projects are focused on restoring the population of a single foundation species to recover an ecological community. Estimates of ecosystem service provision are used to justify and evaluate such projects. These estimates can vastly underrepresent true provisioning when assumed to be provided by a single species where multiple foundation species are present, as we demonstrate with an example of oyster reefs, often restored to improve estuarine water quality. In the brackish Chesapeake Bay, the hooked mussel can have greater abundance and biomass than the focal restoration species, the eastern oyster. We measured temperature-dependent phytoplankton clearance rates of both bivalves and filtration efficiency on three sizes of phytoplankton to parameterize an annual model of oyster bed filtration. The inclusion of filtration by hooked mussels in the model increased the filtration capacity of the habitat >2-fold. Since hooked mussels were twice as effective as oysters at filtering picoplankton (1.5 to 3 μm), we conclude that they fill a distinct ecological niche. When mussel and oyster filtration are accounted for in this, albeit simplistic, model, restoration of oyster reefs at the tributary-scale is predicted to substantially control phytoplankton in summer months. As one such restoration is nearly complete within the Chesapeake Bay, we use recent data on water quality to validate the model.

C18.5  18:15  Year-round use of a coastal protected area network by Brown Pelicans in the Gulf of Mexico. Lamb, Juliet S. *, Clemson University School of Agricultural, Forest, and Environmental Sciences; Jodice, Patrick G.R. South Carolina Cooperative Fish and Wildlife Research Uit;

Abstract: Due to their sensitivity to anthropogenic stressors, particularly marine contaminants, Brown Pelicans represent one of several focal species for conservation and restoration efforts in the Gulf of Mexico. An extensive marine protected area network, encompassing over 280,800 square kilometers, was created in 2011 to address conservation needs of marine species in the region. However, since the establishment of the MPA network, no evaluation has been conducted of its use by target species. During summer 2013, we attached 60 GPS transmitters to Brown Pelicans nesting between the Florida Panhandle and Texas Coastal Bend, encompassing the majority of the species\' breeding habitat in the Gulf, and monitored individual movements for a full calendar year to assess habitat requirements and use of protected areas. Protected areas were disproportionately represented in Brown Pelican locations year-round, and GAP analysis indicates that the MPA network effectively represents significant breeding-season foraging and pre-migration staging habitat. During migration and wintering, however, tracked pelicans also used areas of Cuba, Mexico, Guatemala, and Belize with varying levels of protection. We suggest that an effort to coordinate the Gulf of Mexico MPA network on an international level would help to fill important habitat conservation gaps for both Brown Pelicans and nearshore marine species with comparable habitat requirements.

C18.6  18:30  Impact of hydrocarbon and dispersant exposure on the deep-water coral Leiopathes glaberrima . Ruiz-Ramos, DV. *, Pennsylvania State University; Baums, IB. Pennsylvania State University;

Abstract: Deep-water corals form vibrant communities in the deep Gulf of Mexico, and serves as habitat for many species in the region. These communities are very susceptible to anthropogenic impacts related to oil exploration, as demonstrated by the past DWH oil spill. Here, we aim to assess the mostly unknown impact of hydrocarbon and dispersant exposure on deep-water corals, focusing on the antipatharian Leiopathes glaberrima. To understand how crude oil and dispersant alter gene expression; we exposed the black corals to treatments of oil, dispersant, and oil and dispersant mixtures during 24 hours. RNA samples were barcoded by color (red and white) and treatment, and sequenced using Illumina RNAseq. Samples were processed and assembled using Trinity. Differentially expressed genes were discovered using Edge R and DESeq. Expressed genes differed between red and white corals. As in many non-model species, only half of the putative genes were annotated, still we found indicators of stress response to the different treatments. Understanding the physiological response of Cnidarians to hydrocarbon and dispersant stress would help design remediation strategies that are less damaging to corals.

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