Science meets policy: A framework for determining impairment designation criteria for large waterbodies affected by cyanobacterial harmful algal bloomsOHSU-RS-1581 ABSTRACT:
Toxic cyanobacterial harmful algal blooms (cyanoHABs) are one of the most significant threats to the security of Earth’s surface freshwaters. In the United States, the Federal Water Pollution Control Act of 1972 (i.e., the Clean Water Act) requires that states report any waterbody that fails to meet applicable water quality standards. The problem is that for fresh waters impacted by cyanoHABs, no scientifically-based framework exists for making this designation. This study describes the development of a data-based framework using the Ohio waters of western Lake Erie as an exemplar for large lakes impacted by cyanoHABs. To address this designation for Ohio’s open waters, the Ohio Environmental Protection Agency (EPA) assembled a group of academic, state and federal scientists to develop a framework that would determine the criteria for Ohio EPA to consider in deciding on a recreation use impairment designation due to cyanoHAB presence. Typically, the metrics are derived from on-lake monitoring programs, but for large, dynamic lakes such as Lake Erie, using criteria based on discrete samples is problematic. However, significant advances in remote sensing allows for the estimation of cyanoHAB biomass of an entire lake. Through multiple years of validation, we developed a framework to determine lake-specific criteria for designating a waterbody as impaired by cyanoHABs on an annual basis. While the criteria reported in this manuscript are specific to Ohio’s open waters, the framework used to determine them can be applied to any large lake where long-term monitoring data and satellite imagery are available.
DOI: https://doi.org/10.1016/j.hal.2018.11.016 VOLUME: 81 LENGTH: 5 pages
DURATION: ~ 1 hr, 44 mins
|Broadcast, Podcast, Webinar|
Plastics make our life easier through convenience, but that convenience comes at a cost to our environment. In the spring 2018 issue of Conservation watch, Jill Bartolotta explains the dangers plastics pose to our planet and some ways people can help.
LENGTH: 3 pages
River sediment nitrogen removal and recycling within an agricultural Midwestern USA watershedEXT-1550 ABSTRACT:
The Lower Great Miami River (LGMR) lies within the Mississippi River watershed and contributes to nutrient loads that promote seasonal hypoxia in the northern Gulf of Mexico. Moreover, the LGMR has recently experienced algal blooms caused by excess N and P. To investigate N cycling in the LGMR, we incubated intact sediment cores with stable 15N isotope additions in a continuous-flow system. We measured sediment nutrient fluxes, N sinks and sources (denitrification/anammox and N fixation, respectively), and potential dissimilatory NO3 2 reduction to NH4 1 (DNRA) in spring and summer at 6 locations along a river reach (~50 km) influenced by urban and agricultural nutrient loads. LGMR sediments were a source of bioavailable NH4 and orthophosphate to river water. However, high denitrification rates resulted in LGMR sediments being a net sink for N in the river reach. NO3 2 amendments did not consistently stimulate denitrification, a result suggesting that denitrifiers were functioning at or near maximum rates. Anammox and DNRA were not consistently observed, and N fixation occurring simultaneously with denitrification was not observed. We estimate that denitrification in LGMR sediments removed 8 to 33% of external N loads to the river from the watershed, with the remainder exported downstream. This result indicates that denitrification can be an important N sink in the LGMR, but further decrease of external N inputs will be required to minimize eutrophication in the LGMR and N export to downstream systems.
VOLUME: 37 LENGTH: 11 pages
|External Partner Publication|
Needs Assessment Report: Barriers and Benefits to Desired Behaviors for Single-Use Plastic Items in Northeast Ohio’s Lake Erie BasinOHSU-TS-1522 This report summarizes the a marine debris analysis conducted by the Ohio Sea Grant College Program in the fall of 2016.
LENGTH: 24 pages
The Cuyahoga River isn’t at risk of catching fire anymore, but that doesn’t mean it’s in great shape either. The Cuyahoga River is a designated Area of Concern. This fact sheet explains what that means, and what’s being done to fix it.
LENGTH: 1 page