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Tracy Wiegner

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Unlocking Resilience Drivers to Inform Pacific Coral Reef Management
Coral reefs are threatened by climate change because warming ocean temperatures are causing corals to bleach (i.e. lose the algae that provides them with the majority of their energy) which can lead to coral starvation and death. Local environmental conditions can contribute to either the resilience or susceptibility of corals to the global stress of climate change. One such factor is the local nutrient input from terrestrial sources. Corals near remote islands with abundant seabird populations have been found to have increased growth rates and are more resilient to bleaching events than corals near islands without seabirds. Seabirds supply the reef with ample nutrients via their guano (seabird excreted waste) and...
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Coral Response to Land-to-Ocean Freshwater Flux: A Ridge-to-Reef Perspective
Assessments that incorporate areas from land-to-ocean, or “ridge-to-reef", are critical to examine how land-use practices are altering stream discharge and nearshore marine health and productivity. Stream systems in both Alaska and Hawaiʻi are expected to experience changes in water quality associated with changing environmental conditions and increased human-use. Watershed systems throughout the Hawaiian Islands are currently experiencing impacts from climate change that affect groundwater recharge and surface runoff, erosion, and total streamflow, and cause degradation of nearshore marine habitats. This study can provide useful insight for both Alaska and Hawaiʻi by providing resources on how patterns in stream...
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From Land to Sea: How Will Shifts in Stream Flow Influence Delivery of Nutrients, Organic Matter, and Organisms to Alaska and Hawai‘i Nearshore Marine Ecosystems?
Nearshore marine ecosystems in Alaska and Hawai‘i rely heavily on organic materials and nutrients delivered by rivers and streams. It is hypothesized that the magnitude and timing of stream flows influences this delivery of materials to coastal ecosystems. However, despite previous research on the topic, there is still considerable uncertainty about how stream flow may influence these land-to-water (“ridge-to-reef") linkages, and how climate change induced shifts in runoff may ripple across ecosystem boundaries to influence estuary and nearshore marine ecosystems and species of cultural and commercial importance (e.g., Pacific salmon, gobies, and coral reefs). This project is a collaborative study to examine...
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