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
Analysis of Legacy Phosphorous in Agricultural Drainage Ditches of the Lake Erie WatershedOHSU-TD-1515 ABSTRACT:
Agricultural best management practices have reduced the total phosphorous (P) being delivered to Lake Erie for almost 40 years, yet the proportion of bioavailable P (soluble reactive phosphorous, SRP) has steadily increased, contributing to harmful algal blooms. A possible continuous source of P to Lake Erie is sediment in agricultural drainage ditches, which contains SRP in pore waters, as well as sorbed P that can be released due to changes in redox conditions. Physical sediment properties and P content were analyzed in ten cores collected during the spring of 2018 from two agricultural drainage ditches in the Lake Erie watershed. These spring cores were compared to summer cores that were collected at the end of the previous growing season from the same locations. A two-step extraction process designed to measure loosely sorbed P and P sorbed to redox-sensitive iron and manganese oxides was utilized to determine concentrations of P. On average, the concentration of P sorbed to redox-sensitive metal oxides was an order of magnitude greater than loosely sorbed P, demonstrating the potential importance of metal oxidation state in the mobility of P. Overall P content was greater in summer cores. Seasonal changes could be due to agricultural practices such as fertilizer application or more natural changes in aquatic plant growth and flow within ditches. Stagnant summertime flow and an abundance of organic matter could drive anoxic conditions in pore water and mobilize P associated with redox-sensitive metal oxides. One site consistently had greater P concentrations across both seasons, but P concentration also varied strongly within sites. Cores with more organic matter tended to have greater P content. Overall, these results suggest that variations in hydrology and sediment composition could influence hot spots of P retention and release throughout the watershed.
LENGTH: 23 pages
|Thesis / Dissertation|
DURATION: ~ 1 hr, 44 mins
|Broadcast, Podcast, Webinar|
Early onset of a microcystin-producing cyanobacterial bloom in an agriculturally-infl uenced Great Lakes tributaryOHSU-RS-1585 ABSTRACT:
In late May 2016, a cyanobacterial harmful algal bloom (cHAB) was detected in the Maumee River, the largest tributary to Lake Erie, the southernmost lake of the Laurentian Great Lakes system. Testing on 31 May identified Planktothrix agardhii as the dominant cyanobacterium with cell abundance exceeding 1.7×109 cells/L and total microcystins (MC) reaching 19 μg/L MC-LR equivalents, a level over 10-fold higher than the 2015 revised U.S. Environmental Protection Agency (EPA) national health advisory levels for drinking water exposure to adults. Low river discharge coincident with negligible precipitation through the latter half of May coincided with an 80% decline in river turbidity that likely favored bloom formation by a low-light adapted P. agardhii population. Also contributing to the cHAB were high initial nutrient loads and an increase of the river temperature from 13°C to 26°C over this same period. The bloom persisted through 5 June with microcystins exceeding 22 μg/L MC-LR equivalents at the bloom peak. By 6 June, the river had returned to its muddy character following a rain event and sampling on 7 June detected only low levels of toxin (<0.6 μg/L) at public water systems located near the bloom origin. The elevated toxin production associated with this early onset bloom was without precedent for the Maumee River and an unique attribute of the cHAB was the high proportion of potentially-toxic genotypes. Whereas Planktothrix spp. is common in lotic environments, and has been previously detected in the Maumee, blooms are not commonly reported. This early onset, microcystin-producing cHAB provided a rare opportunity to glean insights into environmental factors that promote bloom development and dominance by Planktothrix in lotic environments.
DOI: https://doi.org/10.1007/s00343-018-7164-z VOLUME: 36 ISSUE: 4 LENGTH: 13 pages
Mixed Bacillus Species Enhance the Innate Immune Response and Stress Tolerance in Yellow Perch Subjected to Hypoxia and Air-Exposure StressOHSU-B-1554 ABSTRACT:
Stress enhances the disease susceptibility in fish by altering the innate immune responses, which are essential defense mechanisms. The use of probiotics is increasingly popular in the aquaculture industry. Yellow perch is a promising candidate for aquaculture. We investigated the efficiency of a mixed Bacillus species in minimizing the potential problems resulting from husbandry practices such as hypoxia and exposure to air in yellow perch. We showed that hypoxia and air exposure conditions induced a significant reduction in the early innate immune response (lysozyme activity, interferon-induced-GTP-binding protein-Mx1 [mx], interleukin-1β [il1β], serum amyloid-A [saa]), and a substantial increase in cortisol, heat shock protein (Hsp70), glutathione peroxidase (Gpx), superoxide dismutase (Sod1) that associated with a decline in insulin-like growth factor-1 (Igf1). Mixed Bacillus species administration improved the early innate responses, reduced cortisol, Hsp70, Gpx and Sod1, and elevated Igf1 levels. Bacillus species treated group showed faster recovery to reach the baseline levels during 24 h compared to untreated group. Therefore, mixed Bacillus species may enhance yellow perch welfare by improving the stress tolerance and early innate immune response to counterbalance the various husbandry stressors. Further studies are warranted to investigate the correlations between the aquaculture practices and disease resistance in yellow perch.
DOI: https://doi.org/10.1038/s41598-018-25269-z LENGTH: 9 pages
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
Compiled PDF of all lessons from Ohio Sea Grant’s Solar Technology Curricula. Components include an introduction, four complete lessons on solar technology, and a reference sheet of vocabulary and how to use a multimeter.
LENGTH: 60 pages
|Education / Curriculum Publication|
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
Efficacy of formalin, iodine and sodium chloride in improvement of egg hatching rate and fry survival prior to the onset of exogenous feeding in yellow perchOHSU-RS-1508 ABSTRACT:
Egg disinfection is considered the most important routine work in hatcheries to avoid fungal and/or bacterial infection of fish eggs. The aim of this study was to determine the effectiveness of three disinfectants: formalin, iodine and sodium chloride on the hatching success of yellow perch eggs. The disinfectants were tested in triplicate at different concentrations for 15 and 30 min bath treatments. Two experiments were conducted; formalin at five concentrations (25, 50, 100, 150 and 200 mg L⁻¹) and 25 mg L⁻¹ iodine were tested in the first experiment. The second experiment involved formalin at three concentrations (250, 500 and 1000 mg L⁻¹), iodine at three concentrations (50, 100 and 250 mg L⁻¹) and sodium chloride at three concentrations (500, 1000 and 3000 mg L⁻¹) were used. Iodine and sodium chloride‐treated eggs hatched earlier than formalin‐treated eggs. The highest mean percentage of eyed stage, hatching rate and survival to first feeding fry was observed at 200 mg L⁻¹ formalin for 30 min, 50 mg L⁻¹ iodine for 15 min and 500 mg L⁻¹ sodium chloride for 30 min. High concentrations of formalin (1000 mg L⁻¹), iodine (250 mg L⁻¹) and sodium chloride (1000 and 3000 mg L⁻¹) showed toxicity to yellow perch eggs, resulting in low hatching rate and survival to first feeding fry. We recommended formalin at a concentration of 150–200 mg L⁻¹ for 30 min as an effective, easily available and low‐cost disinfectant for routine use to improve yellow perch hatchability.
DOI: 10.1111/are.12694 VOLUME: 47 ISSUE: 8 LENGTH: 8 pages
A Comprehensive Approach to Evaluating Watershed Models for Predicting River Flow Regimes Critical to Downstream Ecosystem ServicesOHSU-RS-1516 ABSTRACT:
Selection of strategies that help reduce riverine inputs requires numerical models that accurately quantify hydrologic processes. While numerous models exist, information on how to evaluate and select the most robust models is limited. Toward this end, we developed a comprehensive approach that helps evaluate watershed models in their ability to simulate flow regimes critical to downstream ecosystem services. We demonstrated the method using the Soil and Water Assessment Tool (SWAT), the Hydrological Simulation Program–FORTRAN (HSPF) model, and Distributed Large Basin Runoff Model (DLBRM) applied to the Maumee River Basin (USA). The approach helped in identifying that each model simulated flows within acceptable ranges. However, each was limited in its ability to simulate flows triggered by extreme weather events, owing to algorithms not being optimized for such events and mismatched physiographic watershed conditions. Ultimately, we found HSPF to best predict river flow, whereas SWAT offered the most flexibility for evaluating agricultural management practices.
DOI: 10.1016/j.envsoft.2014.07.004 VOLUME: 61
Diet Shift Response in Round Goby, Neogobius melanostomus, Based on Size, Sex, Depth and Habitat in the Western Basin of Lake ErieOHSU-RS-514 ABSTRACT:
This study examines the diet of the round goby (Neogobius melanostomus) in the western basin of Lake Erie. As an invasive benthic feeder, the round goby has the potential to affect smallmouth bass and other native species. Round goby (n = 100) were collected during summer 2011 and stomach contents were examined to determine diet patterns and possible ontogenetic diet shifts. Individual round goby were grouped by sex, size (small < 65 mm, large ≥ 65 mm), depth of habitat (shallow < 2 m, deep > 5 m), and habitat type (natural shallows, anthropogenically modified shallows, and deep waters). Gut fullness ranged from 10 to 100% with 23 stomachs presenting 100% fullness. Round goby consumed 27 different food items including abiotic (sand grains, gravel), floral (algae, fine leaved vascular plants), and fauna items. The Index of Relative Importance (IRI) and comparative z‐tests were used to assess correlations and differences. Two‐way z‐tests revealed a significant difference in mouth gape related to size (z = −5.56377, P = 2.64e‐08), and habitat depth (z = 3.34262, P = 0.00083). A significant linear correlation was also found between mouth gape standardized by head length (HL) for both males (P = 2.63e‐9) and females (P = 1.3e‐4). Two‐way z‐tests also revealed a significant difference in gonadosomatic index (GSI) related to sex (z = 6.07727, P = 6.11248e‐10), but not size. A significant difference in gut fullness was also found related to sex (z = −3.34743, P = 0.00082), habitat depth (z = 3.16336, P = 0.00156), and habitat type (z = −2.7398, P = 0.00615). IRI values demonstrated a diet selective of veliger mussels (IRI = 2462.01), juvenile mussels (IRI = 1073.03), cladocerans (IRI = 4804.31), and chironomids (IRI = 1012.12). While previous studies have focused on round goby diet shifts from macroinvertebrates to bivalves, most studies did not evaluate changes in diet among multiple categories. Furthering knowledge of multiple aspects of goby diet may aid in developing management techniques to deter future round goby invasion.
DOI: https://doi.org/10.1111/jai.12441 VOLUME: 30 ISSUE: 5 LENGTH: 7 pages