Grantee Research Project Results

2007 Progress Report: Nonlinear Response of Pacific Northwest Estuaries to Changing Hydroclimatic Conditions: Flood Frequency, Recovery Time and Resilience

EPA Grant Number: R833015
Title: Nonlinear Response of Pacific Northwest Estuaries to Changing Hydroclimatic Conditions: Flood Frequency, Recovery Time and Resilience
Investigators: D'Andrea, Anthony F. , Wheatcroft, Robert A.
Current Investigators: Wheatcroft, Robert A. , D'Andrea, Anthony F.
Institution: Oregon State University
EPA Project Officer: Packard, Benjamin H
Project Period: July 1, 2006 through June 30, 2010
Project Period Covered by this Report: July 1, 2006 through June 30,2007
Project Amount: $620,182
RFA: Nonlinear Responses to Global Change in Linked Aquatic and Terrestrial Ecosystems and Effects of Multiple Factors on Terrestrial Ecosystems: A Joint Research Solicitation- EPA, DOE (2005) RFA Text | Recipients Lists
Research Category: Aquatic Ecosystems , Climate Change

Objective:

Rainfall intensity is on the rise and the sediment yield from Pacific Northwest (PNW) basins has increased. Consequently, sediment input to estuaries has increased in magnitude and intensity, with important, but unknown ramifications for the health of, and ecosystem services provided by, PNW estuaries. However, it is difficult to evaluate the risk to estuarine ecosystems because the studies to date have tracked only a handful of species and rarely track recovery from the flood sedimentation events. Without a community‐level understanding of the changes in biodiversity and functional redundancy in the intertidal benthic ecosystem, it is difficult to assess the risk of flood sedimentation to Pacific estuaries. The questions that motivate the research are (1) What is the impact of flood events on the mortality, functional group composition, and resilience of the intertidal macrobenthic invertebrate community? (2) How does the within‐year frequency of flood events affect the recovery of the benthic community? and (3) Do flood sedimentation events increase the susceptibility of the benthic community to colonization by non‐indigenous species (NIS)? Hypotheses based on these research questions are being tested using a manipulative field study in Netarts Bay, Oregon.

There are four major research objectives for the project:

(1) Design and implement a manipulative field study which simulates different frequencies of flood sedimentation events (no, one or two events in a single rain season) to determine the ecological effects of flood sedimentation on intertidal benthic macroinvertebrate communities

(2) Use a combination of high resolution benthic sampling and multivariate analyses of benthic community metrics to track the initial mortality, recovery, and resilience of the benthic community.

(3) Collect and analyze sediment samples parallel to the benthic community samples to track changes in important sediment properties that have direct or indirect effects on survival or habitat suitability of sediments to the benthic invertebrate community.

(4) Synthesize the data sets from this study to develop an empirical and theoretical framework for predicting the effects of flood sedimentation events on tideflat macrobenthic communities in PNW estuaries and how these changes impact ecologically and economically important biotic resources and ecosystem services.

Progress Summary:

This grant award was made on July 30, 2007. The project period predated the award and was July 1, 2006 - June 30, 2010. This progress summary for the project period before the award date was made by EPA based on the preaward justification statements made by the PI. Pre-award costs were incurred in response to spring 2007 flood events along the Oregon coast to track the deposition of a real flood sedimentation event and subsequent fate of that material. These data will be used to further develop the methods that will be used in the field work starting this summer, particularly the depth and composition of sediment deposits in real flood events, to ensure the flood events in our field experiments simulate natural events that occur in Pacific estuaries.

Future Activities:

This study will develop an empirical and theoretical framework for predicting the effects of flood sedimentation events on sand flat macrobenthic communities in PNW estuaries and how these changes impact ecologically and economically important biotic resources and ecosystem services. This study will be used to quantify the resilience of intertidal benthic communities and identify important structural changes that may indicate a threshold or catastrophic shift in the benthic ecosystem in response to increasingly frequent sedimentation events. Because neither sufficient data nor models currently exist to conduct risk analyses, these data sets will significantly improve our ability to perform ecorisk assessments in PNW estuaries. In addition, the information obtained in this study can be used by watershed and coastal resource managers to make better informed decisions regarding actions (e.g., restoration) to minimize or eliminate the risks to these systems.

Journal Articles:

No journal articles submitted with this report: View all 4 publications for this project

Supplemental Keywords:

Coastal ecosystem, biodiversity, ecosystem assessment, environmental measurement, meteorology, global change, anthropogenic, greenhouse gases, climate models, UV radiation, environmental stress, water quality, ecological models, flood trends, atmospheric chemistry, climate variability, global climate change, land use, regional anthropogenic stresses, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Air, Ecological Risk Assessment, Atmosphere, Regional/Scaling, Monitoring/Modeling, Air Pollution Effects, Hydrology, climate change, Environmental Monitoring, water quality, biodiversity, Global Climate Change, ecosystem assessment, climate model, coastal ecosystem, global change, atmospheric chemistry, ecological models, coastal ecosystems, climate models, environmental measurement, climate variability, environmental stress, UV radiation, flood trends, anthropogenic, meteorology, land use, regional anthropogenic stresses, greenhouse gases

Progress and Final Reports:

Original Abstract

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.