- Taxon: Freshwater fish
- Range: Upper Barren River system, north-central Tennessee and south-central Kentucky
- Status: Not listed
Appearance and life history
A small fish averaging about five and a half inches in length, the blackfin sucker has a body patterned with two dark, brownish-black horizontal lines below the lateral line (a faint line of sense organs extending from the gill cover to the tail) and six or seven additional lines in the back and the side of the body, with intervening olive-gold stripes. The lower body surface to the lowest lateral stripe and the belly are white. The top of the blackfin’s body, the single belly fin near the tail, and pelvic, paired belly fins near the head fins are white; the back fin has a conspicuous black blotch on the distal half of the front five or six rays. The paired side fins near the head are pinkish olive. Blackfins reach sexual maturity by three years old with some males maturing by age two. The fish has a maximum lifespan of five years. Female blackfins spawn in March and April.
Blackfin suckers are found in clear headwater streams near bedrock ledges, slabrock boulders, root wads, and undercut banks in pools and slow runs. U.S. Fish and Wildlife Service biologists observed that adult suckers were attracted to bedrock ledges, crevices, large rock slabs, and boulders. Adult blackfin suckers also are found in deeper water than sites where the species was not found. Schools of juvenile suckers are found in pools with moderate current and shallower water than the pools occupied by adults. Reproductive males occupy swift riffles, in areas under or behind large rocks several weeks before the females are ready to spawn. During spawning, the females occupy pools and are occasionally found under flat rocks at the edges of riffles.
The blackfin’s primary food item is larval midges. Other items include crustaceans, larval black flies, larval fishflies and hellgrammites, and larval caddisflies.
According to pre-2007 data, the blackfin sucker was historically found in 23 streams in the Upper Barren River Basin.
Blackfin sucker status in all streams of historical or recent occurrence in the Upper Barren River Basin
|Sub-Basin||Stream||Drainage Area||Status||County of Last Observation|
|Boyds Creek||Boyds Creek||14.5||extant||Barren, KY|
|Skaggs Creek||Skaggs Creek||147.0||extant||Monroe, KY|
|Falling Timber||59.7||extant||Metcalfe, KY|
|Glover Creek||22.7||unknown||Barren, KY|
|Nobob Creek||17.4||extant||Barren, KY|
|Peter Creek||Peter Creek||69.0||extant||Barren, KY|
|Caney Fork||11.7||extant||Barren, KY|
|East Fork Barren River||Indian Creek||33.9||extant||Monroe, KY|
|East Fork Barren River||335.4||extant||Monroe, KY|
|Mill Creek||32.9||extant||Monroe, KY|
|Gully Creek||5.2||extant||Monroe, KY|
|Cable Branch||3.4||likely extant||Monroe, KY|
|Trace Creek||18.3||extant||Clay, TN|
|Line Creek||68.9||extant||Clay, TN|
|Wilson Branch||1.8||likely extant||Clay, TN|
|Hurricane Creek||7.8||likely extant||Clay, TN|
|Salt Lick Creek||52.8||extant||Macon, TN|
|Little Salt Lick Creek||8.4||extant||Macon, TN|
|Long Hungry Creek||14.0||extant||Macon, TN|
|Long Fork||33.0||extant||Macon, TN|
|White Oak Creek||118.5||extant||Macon, TN|
|Puncheon Creek||Puncheon Creek||26.8||extant||Allen, KY|
|Pinchgut Creek||Pinchgut Creek||7.1||extant||Allen, KY|
|Long Hungry Creek||Long Hungry Creek||6.7||unknown||Allen, KY|
|Long Creek||Long Creek||69.5||extant||Macon, TN|
|West Fork Long Creek||11.3||extant||Macon, TN|
|Hanging Rock Branch||3.5||extant||Macon, TN|
|Rhoden Creek||Rhoden Creek||5.0||extant||Allen, KY|
|Walnut Creek||Walnut Creek||4.2||extant||Allen, KY|
According to historical and present survey data, the blackfin sucker is extant in 24 streams, likely extant in three streams, and of unknown status in two streams within the Upper Barren River Basin.
Summary of recent Blackfin sucker surveys (2007-2016). Streams are organized by stream and sub-basin (in bold).
|Stream||Location River km (mi)||Watershed size (km2(mi2))||Collection Date||# observed|
|Boyds Creek||7.6 (4.7)||19.9 (7.7)||20091||10|
|Skaggs Creek||13.0 (8.1)||122.2 (47.2)||20091||6|
|Falling Timber Creek||10.9 (6.8)||58.5 (22.6)||20091||1|
|Falling Timber Creek||18.0 (11.2)||17.6 (6.8)||20163||3|
|Nobob Creek||1.3 (0.8)||45.6 (17.6)||20112||1|
|Peter Creek||20.9 (13.0)||128.2 (49.5)||20091||2|
|Caney Fork||1.3 (0.8)||29.3 (11.3)||20112||18|
|East Fork Barren River||14.0 (8.7)||91.9 (35.5)||20091||2|
|18.2 (11.3)||65.3 (25.2)||20163||5|
|7.9 (4.9)||113.7 (43.9)||20112||2|
|Indian Creek||1.1 (0.7)||80.0 (30.9)||20112||1|
|Indian Creek||8.2 (5.1)||51.0 (19.7)||20112||16|
|Mill Creek||4.7 (2.9)||54.4 (21.0)||20091||6|
|Gully Creek||0.5 (0.3)||13.2 (5.1)||20094||P5|
|Line Creek||21.1 (13.1)||54.1 (20.9)||20112||10|
|Trace Creek||6.0 (3.7)||29.8 (11.5)||20112||27|
|Salt Lick Creek||1.4 (0.9)||305.6 (118)||20091||1|
|Salt Lick Creek||5.0 (3.1)||135.5 (52.3)||20091||5|
|Salt Lick Creek||16.8 (10.3)||107.2 (41.4)||20112||16|
|Salt Lick Creek||24.0 (14.9)||38.8 (15.0)||20156||8|
|Little Salt Lick Creek||1.9 (1.2)||16.8 (6.5)||20112||36|
|Little Salt Lick Creek||3.9 (2.4)||14.5 (5.6)||20112||14|
|Little Hungry Creek||1.3 (0.8)||33.7 (13.0)||20112||7|
|Long Fork||8.2 (5.1)||76.7 (29.6)||20112||2|
|Long Fork||19.6 (12.2)||26.9 (10.4)||20112||3|
|White Oak Creek||10.1 (6.3)||51.0 (19.7)||20112||24|
|White Oak Creek||13.8 (8.6)||34.7 (13.4)||20107||6|
|White Oak Creek||19.2 (11.9)||12.2 (4.7)||20112||25|
|Puncheon Creek||3.5 (2.2)||64.0 (24.7)||20091||1|
|Puncheon Creek||6.1 (3.8)||49.2 (19.0)||20112||3|
|Puncheon Creek||7.6 (4.7)||33.4 (12.9)||20112||1|
|Puncheon Creek||8.7 (5.4)||29.3 (11.3)||20126||P5|
|Puncheon Creek||11.3 (7.0)||23.6 (9.1)||20126||P5|
|Pinchgut Creek||9.8 (6.1)||5.7 (2.2)||20112||10|
|Long Creek||17.9 (11.1)||141.2 (54.5)||20112||1|
|Long Creek||19.6 (12.2)||130.3 (50.3)||20084||P5|
|Hanging Rock Branch||0.6 (0.4)||8.5 (3.3)||20088||1|
|West Fork||3.7 (2.3)||20.7 (8.0)||20112||24|
|Rhoden Creek||4.7 (2.9)||11.7 (4.5)||20112||9|
|Walnut Creek||5.8 (3.6)||8.5 (3.3)||20112||3|
The blackfin sucker is only found in habitat with rock ledges, crevices, and boulder slabs, and these features are susceptible to sedimentation (built-up material that sinks to the bottom of the water). Excess sediment can bury blackfin habitat, damage fish gills and eggs, and kill or affect the blackfin sucker’s prey.
Degradation, caused primarily by agricultural uses in the Upper Barren River Basin, is the primary threat to blackfin sucker habitat. Stream channelization, along with loss of waterside habitat, bank erosion, sedimentation, and fertilizer and pesticide runoff, can result from agricultural use.
The effects of climate change also may impact blackfin populations. An increase in mean temperature and average annual rainfall within the species’ range, combined with increases in the frequency, duration, and intensity of droughts, could be detrimental.
Reasons for “Not Warranted For Listing” finding
The blackfin sucker was one of 404 aquatic, riparian, and wetland species, petitioned to be listed under Endangered Species Act by the Center for Biological Diversity and others on April 20, 2010.
Existing state laws in Kentucky and Tennessee offer some protection
Under the Tennessee Nongame and Endangered or Threatened Wildlife Species Conservation Act of 1974 (Tennessee Code Annotated §§ 70-8-101-112): “[I]t is unlawful for any person to take, attempt to take, possess, transport, export, process, sell or offer for sale or ship nongame wildlife, or for any common or contract carrier knowingly to transport or receive for shipment nongame wildlife.” Further, regulations included in the Tennessee Wildlife Resources Commission Proclamation 00-14 (Wildlife in Need of Management) (1) prohibits the knowing destruction of habitat of designated species without authorization and (2) provides circumstances for which permits can be given to take, possess, transport, export, ship, remove, capture, or destroy a designated species.
The blackfin sucker and its habitat also get some protection through the following laws: Federal Water Pollution Control Act of 1977, commonly referred to as the Clean Water Act (33 U.S.C. 1251 et seq.); Kentucky’s Forest Conservation Act of 1998 (KRS §§149.330–355); Kentucky’s Agriculture Water Quality Act of 1994 (KRS §§ 224.71–140), additional Kentucky statutes and regulations regarding natural resources and environmental protection (KRS §§ 146.200–360; KRS § 224; 401 KAR §§ 5:026, 5:031), and Tennessee’s Water Quality Control Act of 1977 (T.C.A. 69–3–101).
Threats experienced by the blackfin sucker are not expected to change significantly in the future
Agriculture has been the dominant land use in the Upper Barrens River Basin for more than 150 years, and populations of the blackfin sucker have not declined. Despite the creation of Barren River Lake by a dam in 1964, risks to the blackfin’s genetic diversity are expected to remain the same. However, the effects of the resulting genetic isolation may become more pronounced over time, especially in the smaller populations.
Some of the blackfin sucker’s native predators in the Upper Barren River system include fish such as smallmouth bass, spotted bass, rock bass, and wading birds such as the great blue heron. Predation might increase with the introduction of new predator species. The Kentucky Department of Fish and Wildlife Resources has historically stocked non-native rainbow trout in Peter Creek from Barren River Lake upstream to near Dry Fork. While introduced trout may prey on blackfin suckers, they would only be present during the colder months and would not persist in this region without additional stocking. Kentucky Department of Fish and Wildlife Resources is not currently stocking rainbow trout within the Upper Barren River Basin. Because the blackfin is adapted to living with native predators and the influence of introduced predators is minimal, predation does not likely have a significant effect on blackfin sucker populations.
Climate change, such as an increase in annual temperatures and rainfall, intensified flooding, and increased droughts, is expected to negatively affect the blackfin sucker. However, there is currently no data available to analyze when or if those climatic changes will result in a change in the blackfin sucker’s viability.
The blackfin sucker’s resiliency and ability to survive catastrophic events are estimated as moderate to high
There is a relatively high abundance of blackfin suckers observed in multiple streams during recent (2007-2016) surveys (observations ranging from one to 36, with a median of eight). The blackfin’s resiliency was further demonstrated by the presence of multiple age classes (evidence of recruitment) at many collection sites. All of these observations suggest that there are multiple, self-sustaining, moderately large populations across the species range. The Service’s moderate to high estimate of redundancy is based on the blackfin’s relatively high number of 27 occupied streams that are distributed across nine separate sub-basins in the Upper Barren River watershed. These streams provide a margin of safety for the species to reduce the risk of extirpation from a single catastrophic event. Representation can be measured through genetic diversity within and among populations and the ecological diversity of populations across the blackfin’s range.
The blackfin sucker is extant or likely extant in 27 of 29 streams with previous collection records. It also is extant in nine of the 10 sub-basins with historical records. The blackfin’s status is unknown in the remaining two streams and one sub-basin. The Fish and Wildlife Service cannot conclude that the blackfin sucker is currently extirpated from any portion of its historical range.
Federal Register notices
The following Federal Register documents were automatically gathered by searching the Federal Register Official API with this species’ scientific name ordered by relevance. You can conduct your own search on the Federal Register website.
- Stillings and Harrel (2010). Date of record is listed as 2009; actual date may be 2009 or 2010. [return]
- Stringfield (2013). Date of record is listed as 2011; actual date may be 2011 or 2012. [return]
- USFWS (2016). [return]
- KDFWR (2016). [return]
- P = Indicates record of presence with no recorded number of individuals. [return]
- TWRA (2016). [return]
- Johansen (2010). [return]
- TDEC (2017). [return]
- We're sorry but an error occurred. Visit the Federal Register to conduct your own search.