Final Rule to List the Pearl darter as ThreatenedSeptember 19, 2017
What action is the U.S. Fish and Wildlife Service (Service) taking?
The Service is protecting the Pearl darter under the Endangered Species Act (ESA) as a threatened species. Threatened status means this fish may become endangered throughout a significant part of its range in the foreseeable future if steps are not taken to conserve it and its habitat.
What is the Pearl darter?
The Pearl darter is a freshwater fish measuring about two and a half inches in length. It has a blunt snout, a horizontal mouth, and large eyes situated high on its head.
How did the Service determine that the Pearl darter is threatened?
The Pearl darter has been a candidate for federal listing since 1999. A multi-district litigation settlement agreement included a commitment to address the status of the Pearl darter. After assessing the best science available and commercial data regarding the Pearl darter’s status, and considering the present and future threats, the Service found that it meets the definition of a threatened species.
Why is the Pearl darter’s status threatened instead of endangered?
A: Though its overall range has been reduced substantially, there are indications that the Pearl darter is maintaining reproducing populations in portions of several river drainages. In addition, the threats affecting this fish’s habitat are having more of a localized impact. For example, water quality degradation is not as pervasive within areas where best management practices for timber management are being successfully implemented. As a result of work like that, the Pearl darter’s status fits the threatened definition referenced above.
How does the final listing rule differ from the proposed listing rule?
The final rule incorporates minor changes to the proposed rule based on comments we received and newly available survey information. This new data allowed the Service to refine information on the distribution of the darter. Thus, the final, total, current range is now 415 river miles as opposed to 279 river miles in the proposed rule.
What are the threats to the Pearl darter?
The primary threat to the Pearl darter is water quality degradation caused by pollution in association with land-surface, storm water, and effluent runoff from urban and municipal areas. In addition, the Pearl darter’s localized distribution, apparent low population numbers, and indications of the species’ low genetic diversity all make it more vulnerable to catastrophic events such as oil or chemical spills.
What are the Pearl darter’s habitat requirements?
Pearl darters occur in slow flowing, coastal plain rivers and creeks. There have been no comprehensive microhabitat studies on the Pearl darter; however, based on field observations, microhabitat features consist of a bottom substrate mixture of sand, silt, loose clay, gravel, organic material and snags. The species has been collected from the steep ends of sandbars and inside river bends where material is deposited.
What are the Pearl darter’s current and historical ranges?
Currently, the Pearl darter is only known to occur in seven drainages within the Pascagoula River basin in south Mississippi. It has been found in scattered locations within the Pascagoula, Leaf, Chickasawhay, Chunky, and Bouie rivers; and the Black and Okatoma creeks. Historically, the Pearl darter also was known from the Pearl River system of Louisiana and Mississippi, however, for the last 40-plus years, it has not been collected there and is considered extirpated from that drainage.
How many Pearl darters are left?
Current population estimates are not available for the Pearl darter. Reproducing populations have been documented in recent years in the Leaf and Chickasawhay rivers and populations in the Pascagoula River appear stable. However, collection efforts indicate low numbers within Bouie and Chunky rivers and the Black and Okatoma creeks.
What kinds of activities could help conserve the Pearl darter?
A number of actions can help conserve the Pearl darter including:
- Don’t dump chemicals into streams and rivers.
- Do report spills to state environmental protection agencies.
- During timber harvest, construction or other projects, implement certified best management practices for sediment and erosion control.
- Start a watershed group or assist in stream and water quality monitoring efforts.
- Plant trees and other native woody vegetation along stream banks to help restore and preserve water quality.
- Replace or remove culverts and low-water bridge crossings that are barriers to passage for this species and other fishes and aquatic organisms.
Who should you contact for more information?
For more information regarding the listing of the Pearl darter, please contact Daniel Drennen at email@example.com, (601) 321-1127, or Connie Dickard at firstname.lastname@example.org, (601) 321-1121, both at the same address: U.S. Fish and Wildlife Service, Mississippi Field Office, 6578 Dogwood View Parkway, Suite A, Jackson, Mississippi 39213. Also please visit the Mississippi Ecological Services Field Office webpage.