Protecting Fish from Agricultural Impacts as Climate Changes: How Much Conservation Is Enough?

The most commonly cited ecosystem stressors from agricultural lands are altered hydrology, temperature, nutrients, and sediments.  Future climate change will directly interact with these stressors to further impact ecosystems.  Despite a solid understanding of the linkages between agricultural activities and these stressors, there still exists insufficient information on the relative benefits of various conservation practices to desired ecological conditions.  As a result, conservation practitioners struggle with river restoration projects in the agricultural Midwest because there is a lack of empirical information to determine how much conservation is necessary to achieve success.  For successful long-term conservation outcomes, we need to also consider whether additional conservation will be needed in the future due to climate change.  We utilized the Soil and Water Assessment Tool (SWAT) to evaluate improvements in hydrologic, nutrient and sediment regimes under three different conservation practice scenarios (existing, 25%, & 50% of watershed) and four different climate scenarios (existing and three scenarios of increased temperature and precipitation) for select high priority watersheds in the Saginaw Bay region.  These were evaluated for improvements toward key biological endpoints—identified using relationships between stressors and fish community metrics in a previous phase of the project.