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https://hdl.handle.net/11681/4031
Title: | Restoration of delta streams : a case history and conceptual model |
Authors: | Killgore, K. Jack Hoover, Jan Jeffrey, 1954- Murphy, Catherine E. Parrish, Kent D. Johnson, David R. Myers, Karen F. |
Keywords: | Wetland restoration Floodplain ecology Fishes--Habitat |
Publisher: | Engineer Research and Development Center (U.S.) |
Series/Report no.: | Technical Note (Ecosystem Management and Restoration Research Program (U.S.)) ; no. ERDC TN-EMRRP-ER-08 |
Abstract: | Delta streams, forming in the floodplains of large river systems, are widespread throughout the United States. Delta streams are most prevalent in the Mississippi Embayment, also referred to as the lower Mississippi River Basin. The alluvial flood-plain deposits are typically rich in organic material. Consequently, most delta streams have been altered through intense agricultural activities and flood control measures. Low water, excessive sedimentation in smaller delta streams, and the accumulation of pesticides such as DDT are the consequences of these anthropogenic disturbances resulting in dominance of tolerant fish species. Characteristics of tolerant fish assemblages include adaptations to low dissolved oxygen and high pulses of suspended solids, no direct requirements for clean, firm substrates for spawning, and ability to live in shallow, slackwater pools for extended periods. Although degraded delta streams are prevalent in the United States, attempts have been made to restore habitat conditions as part of ecosystem restoration or mitigation of flood control projects. One such project occurred in the Upper Steele Bayou System (USBS) in west central Mississippi. The USBS encompasses 282 square miles in the Yazoo Delta of the lower Mississippi River basin. All of the streams in the USBS lie within a predominately agricultural landscape and were highly degraded from low water and sedimentation. Fishes were sampled in 1990, and again in 1994, to establish baseline conditions and evaluate potential impacts and mitigation requirements of a pro-posed flood control project (Killgore and Hoover 1991). However, restoration measures were also incorporated into the plan. Between 1995 and 2001, seven weirs were constructed; 66 drop pipes were placed in surrounding agricultural lands next to the streambank to reduce erosion; and approximately 63 miles of channel enlargement, cleanout, and selective snagging were completed that removed soft, unconsolidated substrates and improved flow conveyance (Figure 1). These were recognized as watershed-level benefits to aquatic communities. Consequently, habitat and fishes of the USBS were re-sampled repeatedly from 2000 to 2005 to document the current status of the fish assemblage and compare these data to collections made in the early 1990s. |
Description: | Technical Note |
Gov't Doc #: | ERDC TN-EMRRP-ER-08 |
Rights: | Approved for public release; distribution is unlimited |
URI: | http://hdl.handle.net/11681/4031 |
Size: | 19 pages/1.41 MBs |
Types of Materials: | PDF/A |
Appears in Collections: | Technical Note |
Files in This Item:
File | Description | Size | Format | |
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ERDC-TN-EMRRP-ER-08.pdf | 1.45 MB | Adobe PDF | ![]() View/Open |