Background and Rationale
Between the 18th and early 20th centuries, the quality of many North American watersheds decreased greatly, in large part due to an increase in industrial production and extraction of the raw materials needed to supply new industry. Furthermore, there was no legislation that placed restrictions on how a business was allowed to operate with regards to the environment. Without any incentive to do otherwise, many industrial centers pumped wastewater directly into streams, causing myriads of environmental and human health issues. One consequence of increased water pollution was the decline of many populations of fish, particularly those that are sensitive to water quality. Many species exhibited decreases in population density, contracted ranges, extirpation, and even extinction.
In 1948, the Federal Water Pollution Control Act was passed. This was the first widely governing piece of legislation to address water pollution and marked the beginning of a long and ongoing recovery for polluted US waterways. This law was rewritten and expanded in 1977 and is now referred to as the Clean Water Act. These developments, along with others, such as the establishment of the Ohio Environmental Protection Agency and broader public awareness of environmental issues, have led to improvements in water quality across Ohio watersheds.
With an improvement in water quality comes an opportunity for the recovery of fish populations that were negatively impacted by pollution. Many species have shown evidence of natural recovery, with populations increasing and ranges expanding to match or even exceed their historic range. However, some populations are limited in their ability to reach historic localities by large geographic distances and physical barriers such as dams. One conservation strategy used to overcome these obstacles is translocation. This strategy entails taking a subset of one or more existing population/s of a species and moving them to a different location. This reintroduction method can have advantages over captive propagation in terms of cost-effectiveness and increased genetic diversity of founding populations.
Since 2000, the Bluebreast Darter (Etheostoma camurum) has shown impressive range expansion in Ohio waterways including; the upper Ohio River and its tributaries, most of the Muskingum Basin, and the Scioto River and its tributaries from Columbus southward. However, historic records show the fish’s presence at three separate localities that cannot be reached without human intervention. These include the Mahoning River in Youngstown (Baird 1853), the Stillwater River near Dayton (Osburn 1899), and North Fork Licking River in Newark (Osburn 1899). In particular, Dillon Reservoir, an impoundment on the Licking River, prevents already expanding populations in the Muskingum River from recolonizing this system. This barrier, combined with the Bluebreast Darter’s recent state delisting in 2012 made this species an ideal candidate for our first translocation project.
Translocation of Bluebreast Darters began in the summer of 2016. Fish were captured from robust populations in the Muskingum River and its tributaries using a backpack electrofishing unit and a seine net. These fish were then released in one of six sites in the Licking River system. In between capture and transport, the fish were tagged with Visible Implant Elastomer (VIE). Different color tags and positions gives us important information during follow up surveys at the release sites. We can tell what year fish were released and if they were released at that site or have moved from another site. 971 Bluebreast Darters were tagged and released in 2016 followed by another 942 in 2017. Follow up surveys have shown promising results, particularly in South Fork Licking River where the fish have shown persistence in high numbers. In addition, we have seen evidence of movement between riffles as well as multiple years of reproduction, showing the potential of the released population to expand and recolonize more of the Licking River system. Surveys to monitor the success of the Bluebreast Darter at the release site will continue in 2019.
Darters were tagged and released in 2016 followed by another 942 in 2017. Follow up surveys have shown promising results, particularly in South Fork Licking River where the fish have shown persistence in high numbers. In addition, we have seen evidence of movement between riffles as well as multiple years of reproduction, showing the potential of the released population to expand and recolonize more of the Licking River system. Surveys to monitor the success of the Bluebreast Darter at the release site will continue in 2019.
Tippecanoe Darter and Longhead Darter
In 2018, we began a second translocation project with two new species: the Tippecanoe Darter (Etheostoma tippecannoe) and the Longhead Darter (Percina macrocephala). Both species have historic records in the upper Muskingum watershed, specifically the Walhonding River. However, no recent records exist and both species were presumed to be extirpated from then upper reaches of the system. Furthermore, the ability of either species to recolonize the system is stifled by the large number of dams on the Muskingum River and its tributaries. The Tippecanoe Darter and Longhead Darter are of particular importance for conservation efforts because of their state-listed status as threatened and extirpated, respectively.
Tippecanoe Darters were collected in the summer of 2018 from the Scioto River and its tributaries and released in the upper Muskingum River system. Although a population of Tippecanoe Darters persists in a reach of the Muskingum River near its confluence with the Ohio River, the Scioto River was chosen as a source population because of the species’ relatively large distribution and high abundance in the system. 1259 individuals were captured and again tagged with VIE. These fish were then released at six localities on four rivers including the Kokosing, Walhonding, and Tuscarawas Rivers, as well as the main stem of the Muskingum River itself. Although it’s too early to draw any conclusions about the long term success of the released fish, sampling in the fall of 2018 yielded juvenile Tippecanoe Darters at one of the sites on the Kokosing River, indicating that the fish had successfully spawned shortly after release.
The translocation of Longhead Darters occurred in the fall of 2018. Capturing these darters presented several unique challenges compared to the two previous species. Firstly, because the Longhead Darter was extirpated from Ohio, collection of a source population would have to occur out of state. Secondly, unlike the Tippecanoe and Bluebreast Darters that inhabit shallow, fast moving riffles, the Longhead Darter prefers deeper, slower moving water near vegetation and structure. This meant that seine nets and backpack electrofishing units were not effective methods of capturing them and more involved techniques including boat electrofishing and benthic trawling needed to be used. However, with the cooperation of Doug Fischer of the Pennsylvania Fish & Boat Commission, we were successful in capturing 702 individuals from the Allegheny River near Franklin, PA. These fish were tagged and released at three of the six release sites in the Kokosing, Tuscarawas, and Walhonding rivers. The release of these fish marked the first time since 1939 that these fish have been seen in Ohio Waters.
Further release events and follow up surveys are planned for 2019 in order to bolster the chance of the released fish establishing healthy populations in the upper Muskingum River system.
Honick, A. S., Zimmerman, B. J., Stauffer, Jr., J. R., Argent, D. G., & Porter, B. A. (2017). Expanded Distributions of Three Etheostoma Darters (Subgenus Nothonotus) within the Upper Ohio River Watershed. Northeastern Naturalist, 24(2), 209-234. https://doi.org/10.1656/045.024.0214