Watershed managers in Hawaii have identified the need for data that can quickly lead to management actions/results "on the ground." One of the necessary pieces of information to aid coastal managers in key decision making are stressor thresholds, i.e. ambient concentrations of contaminant stressors above which deleterious impacts to coral reef species would be expected. Without this information, it is impossible to make effective management decisions based on sound scientific information.This project will use laboratory experiments to develop stressor threshold values for selected relevant contaminants using relevant Pacific coral reef species to also understand species sensitivities against the target pollutants. A Pacific coral (Pocillopora damicornis) that can be grown in the laboratory will be used, so that no sampling of live coral is necessary. In addition, other taxa will be tested to determine sensitivities of ecologically relevant trophic levels. These will include a Pacific amphipod and macroalgae (Ulva sp.) that serves as a food source in the reef food web as well as alsoconsumed as a traditional food source by humans. Fish embryos (non-native, due to availability of only local embryos) and sea urchin embryo developmental anomalies will be measured during exposure testing. Based on existing literature data, and published pesticide sales data for Hawaii, we have chosen to do exposure testing with a systemic pesticide, which are used in agriculture and for termite control that have the potential to cause multiple environmental issues. As time and resources permit testing of new-generation pyrethroids is also planned, specifically testing with bifenthrin and/or cis-/trans- permethrin. The second phase of the project (year two) will be assessing the ambient levels of these contaminants in priority watershed areas (e.g. West Maui and South Kohala) to determine if exceedances occur. This will involve water sampling at specific seasons and subsequent laboratory analysis.In the event that exceedances do occur, the final phase of the project (year 3) will evaluate possible management options (e.g. establishment of new best management practices for pesticide application).Project objectives 1. Conduct laboratory-based exposure-response experiments of a Pacific coral, Pocillopora damicornis, Hawaiian macroalgae and a Hawaiian amphipod to determine if a priority systemic pesticide and/or new generation pyrethroid displays adverse effects. 2. Conduct laboratory-based exposure-response testing of surrogate fish and sea urchin embryos to determine if a priority systemic pesticide and/or new generation pyrethroid displays adverse effects. 3. Develop a species sensitivity distribution and toxicity endpoint values for species-pesticide combination tested. 4. Conduct targeted sampling of ambient concentrations of priority pesticide, especially during rainy season in priority watersheds. 5. If exceedances of priority pesticides are observed, evaluate possible management options.
This project will result in multiple products: raw data, a technical memorandum and a peer review paper. Additionally, the larger goal is for this information to be used by coastal managers with the aim of ecosystem protection.
Jursdiction Priority Sites:
- Ka‘anapali-Kahekili (Maui)
- Pelekane Bay-Puako-Anaeho‘omalu Bay (Hawai‘i)
Land-based Sources of Pollution (LBSP)