This paper provides a rigorous and directed research framework for fostering innovations in the design, implementation, and operation of barriers, traps, and fishways used to control the sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes. It was developed to support the Great Lakes Fishery Commission's milestone pledging to decrease reliance on chemical lampricides and achieve 50% of sea lamprey suppression through alternative control technologies, including barriers and traps. The paper first substantiates the need to develop a long-term research plan for barriers, traps, and fishways by summarizing (i) current management challenges, (ii) the barrier, trap, and fishway options being used to meet these challenges, and (iii) the key uncertainties in our knowledge regarding these options. The paper then proposes a long-term research strategy that envisions a transition from barriers designed to block the upstream spawning migrations of sea lamprey, to barrier and trap combinations that facilitate physical removal of sea lamprey and, in some cases, passage of non-target fishes, to barrier and trap designs that are specific to sea lamprey, transparent to non-target fishes, and safer for operators. Thirteen research needs are identified to support this strategy along with a general work plan on how they can be achieved. The research needs and work plan highlight the exceptional opportunity to develop the Great Lakes basin as a leading, international research center for fish migration and passage, and the development of environmentally friendly barriers.

This paper is one of a series supported by the Great Lakes Fishery Commission that describe research priorities related to each facet of the sea lamprey control program (assessment, pheromones, barriers and trapping, sterile males and lampricides). The specific focus of this paper is research needs related to the use of lampricides. To that end, we first provide a brief history of the lampricide control program and its processes and operations emphasizing the progress that has been made over the last 50 years. We then articulate research priorities for the continued improvement of lampricide use under four major categories; improving the effectiveness of lampricide treatments, improving the understanding of the effects of lampricides on non-target species, gaining a better understanding the mode(s) of toxic action of lampricides, and how they differ between lamprey and non-target species, and finally, initiatives designed to find new and more effective methods of applying existing lampricides and to develop new lampricides, based on new knowledge of chemical vulnerabilities unique to larval sea lamprey. Research priorities are summarized at the end of the paper and sources of additional information concerning lampricide research are provided.

Cost-effective integrated pest management of sea lampreys requires good assessment information. Assessment of sea lamprey populations is used to inform decisions about which control methods to use, as well as where and when to apply them. Additionally, assessment data are used to evaluate the performance of past management actions. This theme paper identifies key research questions that limit our understanding of sea lamprey population dynamics, as well as the quality of the assessment information currently used to inform management. The discussion is organized by dividing the sea lamprey life history into four stages—spawning, recruitment to age 1, larval, and parasitic—and examining the state of knowledge about population dynamics and assessment for each life stage. For spawning lamprey key research questions include migration timing, mating systems, and factors influencing spawning success. For recruitment to age 1, factors affecting recruitment variation and methods for age determination are critical needs. For larval lampreys, the primary target of control using lampricides, the key questions concern the accuracy of assessment methods used to guide lampricide treatment decisions and the effects of uncertainty on the utility of these methods. For parasitic lampreys, the main questions center on the nature of the host attack process and variation in survival during the parasitic phase. Finally, this review noted that the development of integrated models to evaluate control strategies remains a high priority for research. Because resources available for sea lamprey management are limited, high quality assessment information and good knowledge of sea lamprey population dynamics are key ingredients of a cost-effective control program.

Integrated pest management of sea lampreys in the Laurentian Great Lakes has recently been enhanced by addition of a sterile-male-release program, and future developments in genetic approaches may lead to additional methods for reducing sea lamprey reproduction. We review the development, implementation, and evaluation of the sterile-male-release technique (SMRT) as it is being applied against sea lampreys in the Great Lakes, review the current understanding of SMRT efficacy, and identify additional research areas and topics that would increase either the efficacy of the SMRT or expand its geographic potential for application. Key areas for additional research are in the sterilization process, effects of skewed sex ratios on mating behavior, enhancing attractiveness of sterilized males, techniques for genetic alteration of sea lampreys, and sources of animals to enhance or expand the use of sterile lampreys.

The Great Lakes Fishery Commission (GLFC) considers the application of sea lamprey pheromones a promising alternative-control method for its sea lamprey management program. Several components of two pheromones that regulate migration and reproduction, respectively, have been identified and synthesized. Potential utility of these pheromone compounds in lamprey management have been demonstrated in a series of field experiments. These discoveries have laid a solid foundation for development of pheromone-based management. In order to identify potential strategies that will be practical, effective, and economical, we propose a hypothesis driven approach that integrates concepts and experimental methods from several disciplines of biological science, such as neurobiology, biochemistry, and behavioral ecology to illustrate the exact function of identified compounds. In the interim, we identify the necessary steps, or issues critical to eventual implementation, to charter a pathway that leads from laboratory research to effective deployment of pheromones. Finally, we highlight a strategy that fosters collaboration among scientists across disciplines, as well as among research institutes and lamprey control agencies, to accomplish this research agenda.

The 1994 seepage piping failure of IVEX dam, resulting in catastrophic dewatering of the reservoir, was an analog for the one-step process commonly used for dam removals. This study evaluates the impact of the sediment release in the context of channel evolution models (CEMs), and compares short-term (2-month) versus long-term (12-year) released sediment volumes using a downstream reservoir that acted as a sediment trap. The CEM of Doyle et al. (2003) calls upon six stages (stage A-F) in the restoration of quasi-equilibrium conditions following a dam removal. This study confirmed the model's validity but proposes several significant changes: (1) a new stage A2 represents pre-dam failure sediment erosion including channeling and longitudinal scours in the reservoir sediments; (2) an extensively modified stage B represents development of an early-breach drainage network that cross-cut earlier features; and (3) an extensively modified stage E represents lateral channel migration and incision, resulting in channel backfilling (terraces and point bars). The 12-year study shows that respective stages lasted from minutes (stage B), to days (stage C), to 2–3 months (stages D and E), to 3–5 years (stage F). Failure of IVEX dam had significant impacts on the downstream reservoir. For the 2-month interval following failure, sedimentation rates increased about three orders of magnitude, and the volume of trapped sediment approximately doubled. However, over the subsequent decade this initial sediment flush was only about one-third of the decadal sediment loading, illustrating the importance of long-term downstream migration of the coarse-grained sediment fraction stored in the reservoir.

Because of its storied history, the Cuyahoga River in Ohio is often used as a measure of progress toward water resource integrity within the United States. The river has shown dramatic chemical/physical water quality improvements but is still not fully attaining water quality goals due to impacts to the river from non-regulated sources. A section of the Clean Water Act entitled Total Maximum Daily Load (TMDL) provides a process to address these impacts. A TMDL report for the Cuyahoga River near Kent, Ohio recommended modification or removal of two dams to restore habitat and meet water quality objectives in the river. In response to the TMDL, the historic Kent dam was modified in 2004 and the Munroe Falls dam located approximately 5 miles downstream from the Kent dam was removed in 2005. The Ohio Environmental Protection Agency sampled fish and macroinvertebrate communities, evaluated habitat, and monitored dissolved oxygen concentrations in the middle section of the Cuyahoga River near Kent. Data showing marked improvements of the fish community less than 1 year after dam modifications in Kent and improved dissolved oxygen concentrations after the Munroe Falls dam removal are presented. This paper will also discuss and contrast methods of interacting with the public and local governments and propose guidance for future projects.

Dams have been built on waterways for centuries, acting as barriers to fish migration and possible impediments to gene flow. We tested whether the Munroe Falls low-head dam, constructed in 1817 on the middle Cuyahoga River in the northeast Ohio portion of the Lake Erie watershed, formed a barrier for fish migration. Subsequent to our sampling, the dam was removed in fall 2005. The present study characterized the population genetic composition of two species of darters (Family Percidae), Etheostoma blennioides (greenside darter) and Percina caprodes (logperch darter), upstream and downstream from the dam in comparison with an outlying population from the Grand River, Ohio using mitochondrial DNA control region and cytochrome b gene sequences. Results found a single genotype in the greenside darter samples that was shared upstream and downstream from the dam, and thus no evidence for effect of the dam could be discerned. In contrast, samples of logperch darter differed in genotypic frequencies above and below the dam, with unique alleles occurring below the dam. It thus is possible that the Munroe Falls low-head dam acted as a one-way barrier to gene flow for logperch. Further genetic studies should test for possible after-effects of the dam removal on these darter populations, and relate these data to variation along and among river systems, including other potential barriers to gene flow.

Dams decrease stream gradient and flow velocity, and often trap a stream's sediment load. For 188 years, sedimentation in the Munroe Falls dam pool on the Cuyahoga River, Ohio created a sediment record of both natural and anthropogenic variability. A wooden dam, first constructed in 1817, was replaced with a 3.66-m-high stone dam in 1902 to better serve local industrial needs. Before this dam was removed in 2005, a coring and transect profiling study was undertaken to characterize the dam pool sediments. To a distance of 600 m upstream of the Munroe Falls Dam, only ~30 cm of sediment overlaid the bedrock in the thalweg, indicating that the deep-water channel was an area of sediment transport. However, in the low-velocity shallow-water margins of the dam pool, up to 3 m of organic-rich, clayey silt had accumulated above pre-dam floodplain deposits. Past flooding events are recorded in these dam pool sediment deposits by an increase in woody debris and sand. A distinctive lithology having an oily sheen, abundant woody debris, and elevated trace metal concentrations occurs at depth throughout the deposits in the shallow-water margins of the dam pool. ²¹⁰Pb dating places the top of this layer at approximately 1918. The 1913 flood in northeast Ohio probably deposited this contaminated layer from washed-out upstream sources. A direct relationship between sediment trace metal (Pb, Zn) and magnetic mineral concentrations demonstrates that magnetic parameters can provide rapid pollution assessment of dam pool sediments.

The removal of the 3.66-m-high Munroe Falls Dam from the Cuyahoga River in Summit County, Ohio, between August and October 2005, follows an accelerating trend to remove dams for the purpose of river restoration. The response of the middle reach of the Cuyahoga River to this dam removal resulted in sedimentologic, morphologic and hydrologic changes. These changes were monitored by measuring transects, discharge and velocity, and collecting bed sediment both pre-removal and post-removal. The overall change to the mean grain size of the channel-floor deposits was characterized by coarsening upstream, and fining downstream of the former dam. The greatest degree of coarsening occurred within 1,000 m upstream of the former dam site. Following dam removal, changes in channel morphology were characterized by approximately 1 m of bed aggradation downstream of the dam site. Upstream, the channel quickly incised to the pre-1817 (pre-dam) substrate within a month of dam removal. Once the pre-1817 substrate was reached, downcutting stopped, and channel-widening became the dominant morphologic response. Prior to dam removal, flow velocity within the impoundment limited sediment transport to suspended load in all but the largest flows of the year. Following removal, reduced cross-sectional area and greater slope, increased flow velocity by 4 to 15 times. Now the river erodes and transports sand-sized sediment as bedload even during the low-flow periods. Bedload discharge measurements indicate the largest sediment source is the former impoundment sediment.

Recent changes in stream channel and pattern morphology, hydrology, and channel and floodplain stratigraphy of nine streams in west-central Ohio are evaluated as part of a data-gathering phase of a stream resource protection plan. The study reaches represent the variation in external and internal drainage basin variables that likely control differences in channel hydrology in the county, including watershed area, underlying geology, and land use. A longitudinal profile and 6–8 cross sections were surveyed for each reach; particle sizes were measured and bank stra tigraphy was described at each cross section. Former channel positions were delineated from georeferenced aerial photographs from the period 1938 to 2002. Currently most streams are moderately to slightly entrenched into their basal channel gravels and the underlying till, outwash, or bedrock. Entrenchment is likely the result of channel straightening, mostly after 1938, but may also be due to reduced sediment yield resulting from improved soil conservation practices or urbanization. The physiographic floodplain is no longer accessible by more frequent flood events (RI < 5 yr), but active point bars and unit bars confined within the entrenched channels are redefining bankfull conditions and incipient meander migration is developing a new floodplain. Changes in sinuosity, radius of curvature, and meander wavelength between 1938 and 2002 along less-actively managed streams indicate the reaches are moving toward equilibrium relationships between bankfull channel and meander properties. A first approximation of the space in which the equilibrium pattern will develop is provided by the equilibrium relation between bankfull channel width and channel belt width.

The Sandusky River basin, located in northwest Ohio, has been influenced by agriculture since the late-1800s. In 2003, the Ohio Environmental Protection Agency identified various tributaries of the Sandusky River as failing to meet biological water quality standards mainly due to siltation. To assess the effectiveness of best management practices (BMPs), a cutoff channel of the Sandusky River in Crawford County, Ohio was used as a unique archive of channel bed material that existed in the previous channel. Historical aerial photographs and USGS peak discharge data suggest the channel was likely abandoned between 1957 and 1964. Twelve sediment cores between 2 and 3 meters in depth were collected with a vibracore, and grain-size analyses of the cutoff channel substrate were compared to similar data collected from the modern channel. Results showed an historical fining-upward trend in the mean grain size of the coarse fraction, from gravel in the cutoff channel to sand in the modern channel, but no change in the mean grain size of the fine fraction. A series of alternative explanations were examined to elucidate this fining, including sediment storage, trends in population and crop cultivation, existence of BMPs, and sediment transport during floods. Evidence from this study strongly suggests that a shift from the cultivation of low-cover crops (hay and oats) to high-cover crops (corn and soybeans) has changed the proportion of coarse-grained to fine-grained sediment loading in this section of the Sandusky River. The results have implications both for the effectiveness of BMPs in Crawford County and possibly for Lake Erie sediment budgets.

The Ballville Dam (Sandusky River) is one of the major structures in the Lake Erie watershed, impounding 1.7 million m³ of water and sediment. Removal of the dam would open > 40 km of suitable upstream habitat for aquatic species, but there are concerns about contaminated sediment in the reservoir. In cooperation with the Ohio EPA, sediment cores were evaluated for 18 metals and 138 organic contaminants. Geochronology was provided by ¹³⁷Cs and ²¹⁰Pb, recognition of historical flood horizons, and stratigraphic correlation to 14 previously dated cores. Seven metals (Al, As, Cr, Fe, Ni, Pb, Zn) exceeded Threshold Effect Levels (TEL) and four others (Cd, Cu, Hg, Mn) were close. Only Fe exceeded the Probable Effect Levels (PEL) although Al, As and Ni were close. Most metal concentrations were uniform throughout the cores (when normalized for Al content), with the exception of upward increases in Cr and Se, and downward increases in Mn. DDT residues (DDD and DDE) exceeded PEL values between 50–125 cm in the cores (corresponding to mid-1940s to late-1970s). Total petroleum hydrocarbons (C₁₅ to C₂₄) showed moderate levels (1-9 mg/kg) of petroleum pollution. Finally, PAH concentrations reach TEL values only below the redox zone (pre-1950) in the sediments. Possibly this is an historical archive of a 757,000-liter toluene spill reported in 1988 on the Sandusky River upstream of the reservoir. Removal of the dam would require dredging or release downstream of 0.35 million m³ of sediment to re-establish the channel of the Sandusky River. Sediment contamination in the Ballville reservoir involves concentrations less than or equal to those in existing Lake Erie sediment, and the effects would be diluted by mixing with downstream or nearshore Lake Erie sediments.