Bi-Annual Report 2010-2011: Shaping pulse flows to meet environmental and energy objectives

This report describes a bioenergetic model developed to allocate seasonal pulse flows to benefit salmon growth. The model links flow with floodplain inundation and production of invertebrate prey eaten by juvenile Chinook salmon. A unique quantile modeling approach is used to describe temporal variation among juvenile salmon spawned at different times. Preliminary model outputs are presented and future plans to optimize flows both to maximize salmon growth and hydropower production are outlined

Quantifying Temperature Effects on Fall Chinook Salmon

The motivation for this study was to recommend relationships for use in a model of San Joaquin fall Chinook salmon. This report reviews literature pertaining to relationships between water temperature and fall Chinook salmon. The report is organized into three sections that deal with temperature effects on development and timing of freshwater life stages, temperature effects on incubation survival for eggs and alevin, and temperature effects on juvenile survival. Recommendations are made for modeling temperature influences for all three life stages

Population viability analysis of the Endangered shortnose sturgeon

This study used population viability analysis (PVA) to partition the influences of potential threats to the endangered shortnose sturgeon (Acipenser brevirostrum). A workshop brought together experts to help identify potential threats including groundwater withdrawal, poor water quality, saltwater intrusion, mercury effects, harvest as by-catch, and sedimentation of spawning habitat. During the course of the project, we eliminated some threats and added new ones. Groundwater withdrawal was dismissed after a study failed to identify connection with groundwater and the majority of pumping is from a confined aquifer. We also eliminated activities on Fort Stewart as influences on spawning habitat because any successful spawning must occur upstream of Fort Stewart. We added climate change to the list of threats based on our assessment of temperature effects and expectations of sea-level rise. Our study highlighted the role of populations in nearby rivers in providing metapopulation support, raising the concern that the population in the Ogeechee River acts as a demographic sink. As part of this study, we carried out a field sampling study to analyze effects of training activities on headwater streams. We developed a new methodology for sampling design as part of this effort and used a mixed-modeling approach to identify relationships between land cover-land use, including those associated with military training activity and water quality. We found that tank training was associated with higher suspended sediment and equipment training was associated with higher organic carbon) and water quality. We detected effects of training on suspended sediment and organic carbon. We also carried out a field sampling effort in the Canoochee and Ogeechee Rivers. In the Ogeechee River, we found that dissolved oxygen in 40% of measurements during summer were below 4 mg L-1. To evaluate mercury as a potential threat, we developed a mercury uptake model and analyzed mercury levels in amphipod prey and sturgeon eggs. These did not exceed EPA guidelines. Finally, we developed a PVA model that including linkages between shortnose sturgeon growth, reproduction, and survival and each remaining threat; All three had significant influences. Preliminary simulations suggest that elevated temperatures under future climate will extirpate this population and add support to the hypothesis that this species requires access to spawning habitat far upstream to persist

Quantifying Temperature Effects on Fall Chinook Salmon

The motivation for this study was to recommend relationships for use in a model of San Joaquin fall Chinook salmon. This report reviews literature pertaining to relationships between water temperature and fall Chinook salmon. The report is organized into three sections that deal with temperature effects on development and timing of freshwater life stages, temperature effects on incubation survival for eggs and alevin, and temperature effects on juvenile survival. Recommendations are made for modeling temperature influences for all three life stages

Bi-Annual Report 2010-2011: Shaping pulse flows to meet environmental and energy objectives

This report describes a bioenergetic model developed to allocate seasonal pulse flows to benefit salmon growth. The model links flow with floodplain inundation and production of invertebrate prey eaten by juvenile Chinook salmon. A unique quantile modeling approach is used to describe temporal variation among juvenile salmon spawned at different times. Preliminary model outputs are presented and future plans to optimize flows both to maximize salmon growth and hydropower production are outlined

Population viability analysis of the Endangered shortnose sturgeon

This study used population viability analysis (PVA) to partition the influences of potential threats to the endangered shortnose sturgeon (Acipenser brevirostrum). A workshop brought together experts to help identify potential threats including groundwater withdrawal, poor water quality, saltwater intrusion, mercury effects, harvest as by-catch, and sedimentation of spawning habitat. During the course of the project, we eliminated some threats and added new ones. Groundwater withdrawal was dismissed after a study failed to identify connection with groundwater and the majority of pumping is from a confined aquifer. We also eliminated activities on Fort Stewart as influences on spawning habitat because any successful spawning must occur upstream of Fort Stewart. We added climate change to the list of threats based on our assessment of temperature effects and expectations of sea-level rise. Our study highlighted the role of populations in nearby rivers in providing metapopulation support, raising the concern that the population in the Ogeechee River acts as a demographic sink. As part of this study, we carried out a field sampling study to analyze effects of training activities on headwater streams. We developed a new methodology for sampling design as part of this effort and used a mixed-modeling approach to identify relationships between land cover-land use, including those associated with military training activity and water quality. We found that tank training was associated with higher suspended sediment and equipment training was associated with higher organic carbon) and water quality. We detected effects of training on suspended sediment and organic carbon. We also carried out a field sampling effort in the Canoochee and Ogeechee Rivers. In the Ogeechee River, we found that dissolved oxygen in 40% of measurements during summer were below 4 mg L-1. To evaluate mercury as a potential threat, we developed a mercury uptake model and analyzed mercury levels in amphipod prey and sturgeon eggs. These did not exceed EPA guidelines. Finally, we developed a PVA model that including linkages between shortnose sturgeon growth, reproduction, and survival and each remaining threat; All three had significant influences. Preliminary simulations suggest that elevated temperatures under future climate will extirpate this population and add support to the hypothesis that this species requires access to spawning habitat far upstream to persist