CHAPTER IV: WILDLIFE HABITATS FOR MISSISSIPPI’S SGCN,
THREATS AND CONSSERVATION ACTIONS^215CONDITION AND CONSERVATION STATUS
Streams in the Mississippi alluvial plain have been extensively modified for flood control and
agricultural development. Many streams have been converted to straight canals to improve drainage.
Weirs and lowhead dams block many streams. Diversion canals have been constructed to divert water
from streams during high flow. Overall water quality is lower in this area than anywhere else in the
state, with a region-wide advisory regarding fish consumption and numerous consumption bans in some
waters of the alluvial plain because of high pesticide levels. Dewatering of the alluvial plain has
resulted in extremely low flows in some streams. For example, the Sunflower River flow rate often
drops below the 7Q10 flow rate established by the U.S. Geological Survey.
The Mississippi alluvial plain is considered critically imperiled because of its high conservation
priority rank and the widespread degradation of stream habitats in this region.
12.8.a. Small streams. (similar to 12.2a definition, but low gradient and fine substrate).
12.8.b. Medium streams. (similar to 12.2b definition, but low gradient and fine substrate).
12.8.c. Large streams. (similar to 12.3c definition, but low gradient and fine substrate).SPECIES OF GREATEST CONSERVATION NEED ASSOCIATED WITH
MISSISSIPPI ALLUVIAL PLAN (MAP)
GROUP SCIENTIFIC NAME COMMON NAME TIER
Fish Fundulus dispar Northern Starhead Topminnow 2
Atractosteus spatula Alligator Gar 3
Polyodon spathula Paddlefish 3
Ictiobus niger Black Buffalo 3
Mussels Actinonaias ligamentina Mucket 1
Elliptio dilatata Spike 1
Lampsilis hydiana Louisiana Fatmucket 1
Ligumia recta Black Sandshell 1
Plethobasus cyphyus Sheepnose 1
Pleurobema rubrum Pyramid Pigtoe 1
Potamilus capax Fat Pocketbook 1
Quadrula cylindrica cylindrica Rabbitsfoot 1
Anodontoides radiatus Rayed Creekshell 2
Arcidens confragosus Rock Pocketbook 2
Ellipsaria lineolata Butterfly 2
Lampsilis cardium Plain Pocketbook 2
Quadrula nodulata Wartyback 2
Strophitus undulatus Squawfoot 2
Uniomerus caroliniana Florida Pondhorn 2
Uniomerus declivis Tapered Pondhorn 2