United States

Department of

Agriculture

Forest Service

Southern 

Research Station

General Technical 

Report SRS–130

Past and Present Aquatic Habitats

and Fish Populations of the

Yazoo-Mississippi Delta

M.D. Bryant
November 2010 

Southern Research Station 

200 W.T. Weaver Blvd. 

Asheville, NC 28804

The Author: 

M.D. Bryant, Research Fishery Biologist, U.S. Department of Agriculture 

Forest Service, Southern Research Station, Center for Bottomland Hardwood 

Research, Stoneville, MS 38776.

Cover: Ten-mile Bayou, Delta National Forest, with large wood and riparian 

trees on bank and in the channel. 
Past and Present Aquatic Habitats

and Fish Populations of the

Yazoo-Mississippi Delta

M.D. Bryant

Abstract

The goal of this review and synthesis of the literature, published 

and unpublished, is to describe the major processes that shape and 

influence the aquatic habitats and fish communities in the YazooMississippi Delta (YMD) and to outline a program of research. The 

YMD is influenced by the large geographic and temporal scales of 

the Mississippi River watershed. It extends over 41 percent of the 

contiguous United States. The Mississippi River has existed in its 

current location for more than 1.2 million years, and ancient fish 

species are still present in the watershed. About 9,500 years BP, the 

Mississippi River formed into a predominantly meandering channel 

from which most of the aquatic habitats in the YMD developed. 

Oxbows formed in the meander belts shape the topography of the 

YMD and are a fundamental part of the development of the aquatic 

habitat of the YMD. Seasonal floods are keystone events in the YMD, 

but the process is altered substantially from its previous natural state. 

Levees, flood control structures, land use practices, and loss of large 

wood in river channels have modified natural processes throughout 

most of the YMD. However, most of the larger fish species present 

during aboriginal occupation of the YMD are still present. Given the 

large-scale loss of habitat throughout the YMD and the deterioration of 

water quality, the abundance and diversity of fish likely have declined. 

In the past few years, management of aquatic habitats in the YMD has 

centered on mitigating and preventing some of the adverse effects of 

anthropogenic disturbance. A program of “naturalization” to move 

aquatic ecosystem processes closer to natural conditions is possible 

within the context of socioeconomic constraints. The research approach 

proposed in this paper provides a model to develop an understanding 

of the fish and aquatic habitat that can contribute to a sustainable 

restoration program. 

Keywords: Aquatic habitat, bottomland hardwood forests, fish 

diversity, floodplain processes, floods, Mississippi River, YazooMississippi Alluvial Floodplain, Yazoo River.

Introduction

The Mississippi River watershed is large and diverse, 

draining more than 3 x 106 km2 (fig. 1). The Mississippi 

River and its tributaries, which include the Missouri and 

Ohio Rivers, constitute about 41 percent of the contiguous 

United States. It is the third largest river in the world 

(Baker and others 1991, Biedenharn and others 2000). The 

combined length of the Mississippi and Missouri Rivers is 

6,211 km. The Missouri River and its tributaries descend 

from 4,200 m above sea level in the Rocky Mountains to the 

west. The Ohio River watershed includes the industrial and 

agricultural lands to the east. The watershed encompasses 

nine physiographic provinces, which include the Great 

Plains, the Appalachian Mountains, and the Gulf Coastal 

Plain (Robison 1986). The Lower Mississippi Alluvial 

Valley (LMAV) is located in the latter province.

Discharge—more than 475 x 108 m3 of water per year—and 

sediment are dominant, naturally occurring geomorphic 

forces shaping habitats downstream. Human activity is the 

other major force and is directed at controlling the effects 

of discharge and sediment. The effects of these forces on 

downstream habitats are magnified by the large area of the 

watershed and by time scales that range from millennia to 

seasons. Seasonal floods shape habitats over the short term, 

but their cumulative effects are measured over centuries 

or more. The flood plain of the LMAV is the product of 

geologic evolution occurring over millennia.

The focus of this paper is the major processes that shape and 

influence the aquatic habitat and the fish communities in 

the Yazoo-Mississippi Delta (YMD). The four major goals 

of the paper are: (1) to provide a qualitative description of 

how major aquatic habitats and fish populations in the YMD 

evolved from geological and climatic conditions of the past; 

(2) to describe these processes before major anthropogenic 

alterations in the YMD; (3) to synthesize information on 

the hydrologic processes, existing landscape and aquatic 

habitats, and fish species communities in the YMD; and 4) 

Past and Present Aquatic Habitats and Fish Populations

of the Yazoo-Mississippi Delta 

M.D. Bryant

1

Welty, Eudora. The collected stories of Eudora Welty. 1980. Harcourt Brace Joanvich.

“The river had gone, three miles away, beyond 

sight and smell, beyond the dense trees. It came 

back only in flood, and boats ran over the houses.”

Eudora Welty: At the Landing1
to use this information to propose a template for research 

to provide a scientific baseline for the management and 

restoration of aquatic habitats in the YMD. Information 

from past and existing conditions is important to identify 

information needs that will contribute to the improvement of 

aquatic habitats and processes that support fish populations.

Description of the Area 

The YMD is a subregion of the LMAV. Saikku (2005) 

defines the YMD as the oval flood plain from the Mississippi 

River on the west with the eastern boundary on the bluffs 

from Memphis, TN, to Greenwood, MS, along the Yazoo 

River to Vicksburg, MS (fig. 2). The total area is 17,800 

km2. Major drainages within this area include the Yazoo 

River, fed by the Tallahatchie and Yalobusha Rivers on the 

eastern boundary (Fisk 1944). Between the Mississippi and 

Yazoo Rivers are the Big Sunflower River, Deer Creek, and 

Steele Bayou. The Coldwater, Little Tallahatchie, Yocona, 

and Yalobusha Rivers feed the YMD from the uplands to 

the east. The first three drain into the Tallahatchie River, 

which is part of the Yazoo River drainage. The confluence 

of the Tallahatchie and Yalobusha Rivers forms the Yazoo 

River. The upland rivers are controlled by dams that form 

Arkabutla, Sardis, Enid, and Grenada lakes, respectively, all 

located along the bluff line hills along the eastern border of 

the YMD. Before construction of the mainline levees along 

the Mississippi River, the YMD was part of that river’s flood 

plain and was historically prone to seasonal flooding (Fisk 

1944, Barry 1998). Although the YMD is the area of interest 

for this paper, the YMD is influenced by a much larger 

geographic and longer temporal scale. 

Figure 1—Mississippi River watershed and tributaries.

2
Figure 2—The Yazoo-Mississippi Delta flood plain and major drainages.

3
Geological History

The diverse ichthyofauna of the Mississippi River drainage 

is largely the result of the river’s geological evolution. The 

Mississippi River apparently originated 50 to 60 million 

years BP by the end of the Cretaceous period after the 

formation of the North American continent (Robison 1986, 

Baker and others 1991). Over this period, its course and 

size varied with the major geological events that shaped 

the North American continent. Throughout the Tertiary, 

continental shallow inland seas formed and receded. By 

the early Pleistocene, major mountain ranges formed. By 

the late Tertiary, four large drainage basins formed that 

contributed to the present-day Mississippi drainage (Robison 

1986). The upper and middle sections of the Missouri River 

flowed northward into the Hudson Bay drainage. The Great 

Plains drainage captured many of the rivers from the west, 

such as the Platte River and the Red River, and flowed 

southward into the Gulf of Mexico. The Laurentian System 

flowed through the Great Lakes and included rivers from 

the northeast, including the upper Ohio River. The TeaysMississippi drainage occupied a drainage that is roughly 

analogous to the present-day location of the middle and 

lower Mississippi River. The Teays River drained much of 

what is now the Ohio River drainage. It connected to the 

Mississippi River in Illinois. The preglacial Mississippi 

River flowed through central and southern Illinois. The two 

drainages were separate until Pleistocene glaciation, which, 

among other things, forced fish into southern drainages. The 

Teays basin provided a refuge and reservoir for dispersal of 

fish (Robison 1986).

The present size of the Mississippi River likely formed 

about 1.5 to 2.2 million years BP as a result of advancing 

Midwestern glaciers that forced continental waters 

southward on the approximate present course of the river 

(Robison 1986, Baker and others 1991). The channel 

morphology in the Mississippi River drainage alternated 

between braided and meandering channel forms as a result 

of increasing and decreasing sediment loads from glacial 

advances and retreats (Autin and others 1991). Changes in 

sediment regimes generated by glaciation created a pattern 

of channel braiding and meandering that alternated over 

thousands of years. This pattern, accompanied by rising 

sea level and increased deposition of sediment, formed the 

flood plain in the present LMAV. With decreasing meltwater 

and sediment load, the river evolved into a predominantly 

meandering channel between 8,000 and 12,000 years BP. 

During the present meandering phase, oxbows, cutoffs, 

sloughs, and side channels developed, filled in, or were 

overrun as the river moved across the extensive flood plain 

and formed the topography of the YMD.

Although the morphology of the Mississippi River basin 

has undergone extensive change throughout its geological 

history, fish species representing many of the families 

present more than 5 million years BP still reside in the basin 

(Baker and others 1991). Few known extinctions of other 

species have occurred (Briggs 1986, Smith 1981). During 

this period, new species radiated into the diverse habitats as 

the Mississippi watershed responded to glacial expansions 

and contractions and sea level fluctuations, some of which 

inundated large parts of the LMAV. These climatic pulses 

generally occurred over millennia, during which time 

species were able to respond to change.

Influence of Geological History on 

Ichthyofauna

The large and diverse fish community in the YMD may be 

attributed to two large-scale features of the Mississippi 

River basin. The lower Mississippi River basin has 

remained in its present location as a single large land mass 

for millions of years over several major geologic time 

periods and maintained north-south connectivity. Mayden 

(1988) argues that most species existed before Pleistocene 

glaciation. Reviewing the fossil records, Miller (1965) 

suggests that most of the freshwater fish fauna in North 

America originated shortly before and through the Cenozoic 

and Pliocene Eras. Sturgeons (Acipenser), bowfin (Amia), 

and paddlefish (Polydon) were in the drainage since at 

least the Eocene. Miller (1965) points out that most fossils 

recovered from the Pleistocene, post-Nebraska glaciation 

are “indistinguishable from living species.” Many of the 

species listed by Miller (1965) from Pliocene/Pleistocene 

beds well north of the YMD are common in the present 

day YMD. Among these are species of buffalo (Ictiobus), 

two bullheads (Ictalurus melas and I. nebulosus), and 

several sunfish (Lepomis spp.) and bass (Micropterus spp.). 

However, Cyprinidae do not appear until during or after the 

Miocene with many appearing in the Pleistocene (Miller 

1965). The north-south orientation of the Mississippi River 

basin provided both refugia and a center of dispersal for fish 

during the Pleistocene. 

With cooling and glacial advances, fish could move south. 

For example, species from the Great Lakes were found as 

far south as Kansas (Smith 1981). During the Wisconsin 

glaciation, the Mississippi River drainage basin served as a 

refugium for fishes of the Hudson Bay and central parts of 

present day Canada (Rempel and Smith 1997). At least 57 

species of the Hudson Bay drainage dispersed northward 

through Lake Agassiz and other glacial lakes eastward 

along the ice front that developed into the present day Great 

Lakes (Crossman and McAllister 1986). With rising sea 

4
levels that flooded the lower portions of the LMAV and most 

of the YMD, refuges were available throughout the upper 

tributaries to the lower Mississippi River (Cross and others 

1986).

Geological events and alternating channel morphologies 

can influence radiation of species within the watershed. 

The LMAV remained free of glaciers but was exposed to 

alternating geomorphic patterns and climatic fluctuations 

between wet and dry regimes (Saucier 1994). Large-scale 

changes in geomorphic regimes within the drainage as well 

as frequent re-colonization from refuges could provide 

sufficient isolation of species for a large-scale species 

radiation (Smith 1981). Pleistocene glacial advances and 

retreats alternately connected and isolated large areas. 

Watersheds were connected by changes in drainage patterns 

or the formation of large glacial lakes allowing species to 

disperse. As glaciers retreated and the climate dried, these 

areas became isolated and species could diverge from their 

original form. Expansions and contractions of species ranges 

accompanied these patterns. Mayden (1988) asserts that 

vicariance was a major process in speciation in the Central 

Highlands just above the LMAV and at the lead edge of the 

Pleistocene glaciers. Powers and Warren (2009) suggest a 

similar mechanism for the endemic Yazoo shiner (Notropis 

rafinesquei). 

Braided channels are inherently unstable and shift seasonally 

depending upon the flood cycle. Channel changes under a 

meander regime occur over longer time periods, and oxbow 

lakes and cut-offs that form as a result tend to persist for 

centuries (Hudson and Kesel 2000, Shankman 1991). For 

fish to survive in a braided channel regime, they must either 

locate to more stable environments for part of their life 

cycle or assume a life cycle with a rapid turnover that can 

accommodate the dynamics of the physical environment. 

A large number of species found in the YMD mature at 

< 120 mm in length and usually do not live longer than 2 or 

3 years (Ross 2001). These fish may have been widespread 

throughout the braided watershed. As the morphology 

shifted and habitats such as the Sunflower and Yazoo Rivers 

in the eastern floodplain of the Mississippi became isolated, 

previous ranges of fish would contract, resulting in localized 

populations, such as the endemic Yazoo shiner, a species 

now restricted to the upper Yazoo River basin (Ross 2001). 

Habitats formed by meanders in the YMD often are isolated 

and channels may only flow during high water or at 

barely measurable velocities between floods. Sloughs and 

bayous are often hypoxic or anoxic with dissolved oxygen 

concentrations < 3.0 mg/L, summer temperatures > 35 ̊ C, 

high turbidity, acidic conditions (pH < 5.0), and desiccation 

(Hoover and Killgore 1998). These conditions require life 

history strategies that either use habitats on a temporary 

basis or have physiological adaptations to withstand these 

conditions. Most species spawn in the YMD during the 

spring or early summer during high water (Ross 2001). 

The blackstripe topminnow (Fundulus notatus) uses the 

thin surface of oxygenated waters during periods of low 

oxygen and tolerates temperatures up to 42.6  ̊C (Ross 

2001). Several species including chubsuckers (Erimyzon 

spp.), bullheads (Ameriurus spp.), and grass pickerel (Esox 

americanus) may be able to switch to anaerobic metabolism, 

although this is not well documented (Hoover and Killgore 

1998). Gars and bowfin have vascularized swim bladders, 

and bowfin have modified gills to facilitate air breathing 

(Ross 2001). Other adaptations include tolerance to higher 

water temperatures, low pH, and turbid water (Hoover and 

Killgore 1998).

Smith (1981) asserts that we cannot assume “fishes have 

recently adapted to the environments and climates in 

which they presently live,” and that speciation is generally 

slower than changes in geography and climate. The fish 

communities in the LMAV and the YMD have persisted 

for a long time. The species that remain are those that have 

physiological adaptations and life cycles that allow them 

to successfully exploit the processes—hydrologic and 

geomorphic—and habitats created and maintained during 

the past several thousands of years. These advantages 

include tolerances for periods of low dissolved oxygen, high 

temperatures, and desiccation, as well as movement patterns 

timed with seasonal flooding. 

Phenotypic change occurs over much shorter periods. 

Thermal tolerance of organisms can change over relatively 

short (< 40 years) time periods (Skelly and others 2007). 

Short-lived animals with rapid life cycles often are able to 

respond more rapidly to changing environmental conditions 

(Arendt and Wilson 1999). Genetic variation is also 

important. Small populations with low genetic variation 

are not likely to respond to rapid environmental changes. 

However, fishes often display a wide range of phenotypic 

response to environmental conditions. Pacific salmon 

(Oncorhynchus spp.) occupy a wide range of climatic 

conditions extending from Alaska to California and show 

phenotypic variation in response to regional climates 

(Halupka and others 2003, Hilborn and others 2003). 

Genetic variation both within and among stocks is a critical 

factor. Adaptations include return timing for spawning, 

incubation time, and juvenile residence in freshwater, among 

others. Phenotypic adaptations of fish in the YMD also are 

tuned to physical processes. Temperature and floods appear 

to be among the most influential forces; the former will 

influence physiological response, whereas, the latter shapes 

habitats and access to habitats (Finger and Stewart 1987, 

5
Gutreuter and others 1999). Spawning time may be related 

to floods. Of the 134 species associated with the LMAV, 88 

spawn in the spring and of these 27 have extended spawning 

periods that may continue into the summer or fall (table 1) 

(Ross 2001). In contrast to many northern species, none in 

the LMAV spawn in the fall.

Forests of the YMD

The forests of the YMD are the product of a complex 

geologic and climatic history and of human influences 

(Delcourt and others 1993). During the past 10,000 years, 

in response to glacial advances and retreats, pine (Picea 

spp.) forests declined, and oak (Quercus) and tupelo (Nyssa) 

forests expanded into the present bottomland hardwood 

forest ecosystem (Delcourt and Delcourt 1987, Delcourt 

and others 1993). Seasonal floods have shaped the past 

and present forest structure and connectivity between the 

forest and aquatic ecosystems. The chronicles of 16thcentury Spanish explorer Hernando DeSoto’s exploration 

include reports of extensive flooding in the YMD (Clayton 

and others 1993). Geomorphic processes occurring in 

the YMD created an uneven forest floor contoured with 

rounded ridges and valleys that vary in heights by 1 to 3 m 

(Autin and others 1991, Hodges 1994). The uneven forest 

floor accompanied by seasonal inundation creates a diverse 

forest structure (Conner and Sharitz 2005). Putnam and 

others (1960) classified southern hardwood forest into white 

oak-red oak-hickory associations and sweetgum-water oak 

associations that generally reflect tolerance to flooding, 

with the latter group being more tolerant to prolonged 

flooding. They also identified a third association, riverfront 

hardwoods, cottonwood (Populus sp.), and black willow 

(Salix nigra), that corresponds to riparian habitats. 

Riparian habitats are difficult to define in flooded forest 

environments such as those in the YMD (Howard and Allen 

1989). Often riparian forests include all of the bottomland 

forest (Brinson and others 1981). Howard and Allen (1989) 

use the term “streamside forest” to avoid the complexity 

of the definition of “riparian forest” and to provide a 

context for streamside management for timber harvest; 

however, distance from the active channel and elevation 

define the vegetation adjacent to streams and sloughs. 

The riparian cross section presented by Howard and Allen 

(1989) begins with baldcypress (Taxodium distichum) and 

tupelo in and along active channel margins followed by 

overcup oak (Quercus lyrata) and water hickory (Carya 

aquatica) in lower depressions in the flood plain. Sweet 

gum (Liquidambar styraciflua) and willow oak (Q. phellos) 

appear on lower natural levees, and swamp chestnut oak (Q. 

michauxii) and cherrybark oak (Q. falcata) are on higher 

levees. Extensive tracts of cypress were present throughout 

the sloughs and swamps of the YMD (Saikku 2005).

Canebrakes (giant cane, Arundinaria gigantea) were 

extensive along stream margins when DeSoto arrived in 

the YMD (Platt and Brantley 1997). The abundance of 

canebrakes was noted in several other early accounts of the 

YMD and surrounding area (see table 1 in Platt and Brantley 

1997). Canebrakes commonly appear on natural levees 

where they may be subject to floods but not long periods 

of submergence (Platt and Brantley 1997). Various sources 

suggest that canebrakes developed as a result of disturbance 

by aboriginal agriculture that removed large trees along 

some sections of streams (Platt and Brantley 1997). Even 

with aboriginal clearing of streamside forests, extensive 

tracts of large streamside trees likely remained along stream 

banks.

Trees in the riparian zone are the primary source of downed 

wood in the streams and sloughs. Large amounts of wood 

and downed trees in streams are alluded to in the chronicles 

of DeSoto’s journey as obstacles to navigation (Hudson 

1997). Historical accounts of wood in streams in other 

regions document large jams of wood debris throughout 

river and stream courses (Bryant and Sedell 1995). Intense 

logging of the stream banks removed most of the cypress 

from the stream margins before the late 1880s (Saikku 

2005). During this process, most of the large wood in 

streams was removed as trees were cut and floated to mills 

downstream. In addition, wood in streams was removed for 

navigation or in some cases salvaged for wood products 

(Kaeser and Litts 2008). Riparian trees disappeared as 

timber harvest expanded into the hardwoods and land was 

cleared for agriculture, reducing future recruitment of 

wood in streams. However, large wood jams such as those 

reported by Shields and others (2000) likely were common 

throughout the YMD before the 1800s. Killgore2

 reported a 

persistent log jam in the old channel of the Big Sunflower 

River near the Red Rock boat ramp. These sparse but large 

accumulations of large wood are evidence that wood in the 

streams and bayous of the YMD was extensive before largescale deforestation occurred. 

The extensive hardwood forests near the channels 

undoubtedly were the source of large amounts of wood in 

slough and stream channels. Wood enters the streams and 

bayous from various disturbance events that include wind, 

ice storms, and bank avulsion. In particular, hurricanes 

are relatively common events and can place large amounts 

of wood into the water (Stanturf and others 2007). Living 

2 Personal communication. 2008. K.J. Killgore, Research Fishery Biologist, U.S. 

Army Corps of Engineers, Waterways Experiment Station, 141 Cane Ridge Road, 

Vicksburg, MS 39180.

6
Table 1—Fish by family, genus, and species found in the lower Mississippi alluvial flood plain and its subregions

Family Genus Species Common Name MSa YMDb BLHc DNFd Steelee

Petromyzontidae Ichthyomyzon castaneus chestnut lamprey x x 

Petromyzontidae Ichthyomyzon gagei southern brook lamprey x 

Petromyzontidae Ichthyomyzon unicuspis silver lamprey x 

Petromyzontidae Ichthyomyzon aepyptera least brook lamprey x 

Acipenseridae Scaphirhynchus albus pallid sturgeon x x 

Acipenseridae Scaphirhynchus oxyrinchus Gulf sturgeon r x 

Acipenseridae Scaphirhynchus platorynchus shovelnose sturgeon x x 

Polyodontidae Polyodon spathula paddlefish x x x 

Lepisosteidae Atractosteus spatula alligator gar x x 

Lepisosteidae Lepisosteus oculatus spotted gar x x x x x 

Lepisosteidae Lepisosteus osseus longnose gar x x x x x 

Lepisosteidae Lepisosteus platostomus shortnose gar x x x x x 

Amiidae Amia calva bowfin x x x x 

Hiodontidae Hiodon alosoides goldeye x x 

Hiodontidae Hiodon tergius mooneye r 

Anguillidae Anguilla rostrata American eel x x x 

Clupeidae Alosa chrysochloris skipjack herring x x 

Clupeidae Dorosoma cepedianum gizzard shad x x x 

Clupeidae Dorosoma petenense threadfin shad x x x 

Cyprinidae Campostoma anomalum central stoneroller x 

Cyprinidae Carassius auratus Goldfish (non-native) x 

Cyprinidae Ctenopharyngodon idella grass carp (non-native) x x 

Cyprinidae Cyprinella camura bluntface shiner x x 

Cyprinidae Cyprinella lutrensis red shiner x x x 

Cyprinidae Cyprinella venusta blacktail shiner x x x x x 

Cyprinidae Cyprinella whipplei steelcolor shiner x 

Cyprinidae Cyprinus carpio common carp (non-native) x x x x 

Cyprinidae Hybognathus hayi cypress minnow x x 

Cyprinidae Hybognathus nuchalis Miss. silvery minnow x x 

Cyprinidae Notropis amnis pallid shiner x x 

Cyprinidae Hypopthalmichthys nobiliss bighead carp (non-native) x x 

Cyprinidae Luxilus chrysocephalus striped shiner x x 

Cyprinidae Lythrurus fumeus ribbon shiner x x 

Cyprinidae Lythrurus roseipinnis cherryfin shiner x 

Cyprinidae Lythrurus umbratilus redfin shiner x x 

Cyprinidae Macrhybopsis aestivalis speckled chub x x x 

Cyprinidae Macrhybopsis meeki sicklefin chub x 

Cyprinidae Macrhybopsis storeriana silver chub x x 

Cyprinidae Notemigonis crysoleucas golden shiner x x x x 

Cyprinidae Notropis atherinoides emerald shiner x x x 

Cyprinidae Notropis blennius river shiner x x 

Cyprinidae Notropis buchanani ghost shiner x x x 

Cyprinidae Notropis longirostris longnose shiner x 

Cyprinidae Notropis maculatus taillight shiner x x x x 

Cyprinidae Notropis sabinae sabine shiner x 

Cyprinidae Notropis shumardi silverband shiner x x 

Cyprinidae Notropis texanus weed shiner x x 

Cyprinidae Notropis volucellus mimic shiner x x 

Cyprinidae Notropis wickliffi channel shiner r x 

Cyprinidae Opsopoeodus emiliae pugnose minnow x x x 

Cyprinidae Phoxinus erythrogaster southern redbelly dace r 

Cyprinidae Pimephales notatus bluntnose minnow x x 

Cyprinidae Pimephales promelas fathead minnow x x x 

continued

7
Cyprinidae Pimephales vigilax bullhead minnow x x x 

Cyprinidae Platygobio gracilis flathead chub x x 

Cyprinidae Semotilus atromaculatus creek chub x x 

Catostomidae Carpiodes carpio river carpsucker x x 

Catostomidae Carpiodes cyprinus quillback carpsucker x x 

Catostomidae Carpiodes velifer highfin carpsucker x x 

Catostomidae Cycleptus elongatus blue sucker x x 

Catostomidae Erimyzon oblongus creek chubsucker x x 

Catostomidae Erimyzon sucetta lake chubsucker x x x 

Catostomidae Hypentelium nigricans northern hogsucker x x 

Catostomidae Ictiobus bubalus smallmouth buffalo x x x x x 

Catostomidae Ictiobus cyprinellus bigmouth buffalo x x x x 

Catostomidae Ictiobus niger black buffalo x x x x 

Catostomidae Minytrema melanops spotted sucker x 

Catostomidae Moxostoma erythrurum golden redhorse x 

Catostomidae Moxostoma poecilurum blacktail redhorse x 

Ictaluridae Ameriurus melas black bullhead x x x x x 

Ictaluridae Ameriurus natalis yellow bullhead x x x x x 

Ictaluridae Ameriurus nebulosus brown bullhead x x x 

Ictaluridae Ictalurus furcatus blue catfish x x 

Ictaluridae Ictalurus punctatus channel catfish x x x 

Ictaluridae Noturus flavus stonecat x x 

Ictaluridae Noturus gyrinus tadpole madtom x x x x 

Ictaluridae Noturus hildebrandi least madtom x 

Ictaluridae Noturus miurus brindled madtom x 

Ictaluridae Noturus nocturus freckled madtom x 

Ictaluridae Noturus phaeus brown madtom x 

Ictaluridae Noturus stigmosus northern madtom x 

Ictaluridae Pylodictis olivaris flathead catfish x x 

Esocidae Esox americanus grass pickerel x x x 

Esocidae Esox niger chain pickerel x x x 

Aphredoderidae Aphredoderus sayanus pirate perch x x x x x 

Fundulidae Fundulus chrysotus golden topminnow x x x x x 

Fundulidae Fundulus dispar northern starhead x x x 

Fundulidae Fundulus notatus blackstripe topminnow x x x 

Fundulidae Fundulus olivaceus blackspotted topminnow x x x x 

Poeciliidae Gambusia affinis western mosquitofish x x x x x 

Atherinidae Labidesthes sicculus brook silverside x x x x 

Atherinidae Menidia beryllina inland silverside x x x x 

Mugilidae Mugil cephalus striped mullet x x x 

Morinidae Morone chrysops white bass x x x x 

Morinidae Morone mississippiensis yellow bass x x 

Elassomatidae Elassoma zonatum banded pygmy sunfish x x x x 

Centrarchidae Centrarchus macropterus flier x x x x x 

Centrarchidae Lepomis cyanellus green sunfish x x x x 

Centrarchidae Lepomis gulosus warmouth x x x x x 

Centrarchidae Lepomis humlis orangespotted sunfish x x x x 

Centrarchidae Lepomis macrochirus bluegill x x x x 

Centrarchidae Lepomis marginatus dollar sunfish x x x x x 

Centrarchidae Lepomis megalotis longear sunfish x x x 

Centrarchidae Lepomis microlophus redear sunfish x x x 

Table 1—Fish by family, genus, and species found in the lower Mississippi alluvial flood plain and its subregions

Family Genus Species Common Name MSa YMDb BLHc DNFd Steelee

Petromyzontidae Ichthyomyzon castaneus chestnut lamprey x x

Petromyzontidae Ichthyomyzon gagei southern brook lamprey x

Petromyzontidae Ichthyomyzon unicuspis silver lamprey x

Petromyzontidae Ichthyomyzon aepyptera least brook lamprey x

Acipenseridae Scaphirhynchus albus pallid sturgeon x x

Acipenseridae Scaphirhynchus oxyrinchus Gulf sturgeon r x

Acipenseridae Scaphirhynchus platorynchus shovelnose sturgeon x x

Polyodontidae Polyodon spathula paddlefish x x x

Lepisosteidae Atractosteus spatula alligator gar x x

Lepisosteidae Lepisosteus oculatus spotted gar x x x x x

Lepisosteidae Lepisosteus osseus longnose gar x x x x x

Lepisosteidae Lepisosteus platostomus shortnose gar x x x x x

Amiidae Amia calva bowfin x x x x

Hiodontidae Hiodon alosoides goldeye x x

Hiodontidae Hiodon tergius mooneye r

Anguillidae Anguilla rostrata American eel x x x

Clupeidae Alosa chrysochloris skipjack herring x x

Clupeidae Dorosoma cepedianum gizzard shad x x x

Clupeidae Dorosoma petenense threadfin shad x x x

Cyprinidae Campostoma anomalum central stoneroller x

Cyprinidae Carassius auratus Goldfish (non-native) x

Cyprinidae Ctenopharyngodon idella grass carp (non-native) x x

Cyprinidae Cyprinella camura bluntface shiner x x

Cyprinidae Cyprinella lutrensis red shiner x x x

Cyprinidae Cyprinella venusta blacktail shiner x x x x x

Cyprinidae Cyprinella whipplei steelcolor shiner x

Cyprinidae Cyprinus carpio common carp (non-native) x x x x

Cyprinidae Hybognathus hayi cypress minnow x x

Cyprinidae Hybognathus nuchalis Miss. silvery minnow x x

Cyprinidae Notropis amnis pallid shiner x x

Cyprinidae Hypopthalmichthys nobiliss bighead carp (non-native) x x

Cyprinidae Luxilus chrysocephalus striped shiner x x

Cyprinidae Lythrurus fumeus ribbon shiner x x

Cyprinidae Lythrurus roseipinnis cherryfin shiner x

Cyprinidae Lythrurus umbratilus redfin shiner x x

Cyprinidae Macrhybopsis aestivalis speckled chub x x x

Cyprinidae Macrhybopsis meeki sicklefin chub x

Cyprinidae Macrhybopsis storeriana silver chub x x

Cyprinidae Notemigonis crysoleucas golden shiner x x x x

Cyprinidae Notropis atherinoides emerald shiner x x x

Cyprinidae Notropis blennius river shiner x x

Cyprinidae Notropis buchanani ghost shiner x x x

Cyprinidae Notropis longirostris longnose shiner x

Cyprinidae Notropis maculatus taillight shiner x x x x

Cyprinidae Notropis sabinae sabine shiner x

Cyprinidae Notropis shumardi silverband shiner x x

Cyprinidae Notropis texanus weed shiner x x

Cyprinidae Notropis volucellus mimic shiner x x

Cyprinidae Notropis wickliffi channel shiner r x

Cyprinidae Opsopoeodus emiliae pugnose minnow x x x

Cyprinidae Phoxinus erythrogaster southern redbelly dace r

Cyprinidae Pimephales notatus bluntnose minnow x x

Cyprinidae Pimephales promelas fathead minnow x x x

(continued)

continued

8
trees are an important source of wood in YMD aquatic 

ecosystems as well. Cypress are long lived and highly 

resistant to windthrow; however, they are an important 

element in the structure of aquatic habitat. Their ability 

to survive long periods with their roots submerged allows 

them to live in stream channel margins. Their complex root 

system and fluted buttresses are an important source of 

“living” large wood in streams. Wood from downed trees 

may be relatively short lived in YMD ecosystems, but living 

and downed cypress will remain in aquatic systems for 

centuries (Kaeser and Litts 2008).

Morphology of the YMD

The meander regime and the flood cycle are important 

processes that influence aquatic habitats in the YMD. They 

also operate on different time scales. The meander regime, 

the dominant force shaping flood plain morphology, operates 

on a scale of centuries and millennia (Fisk 1944, Saucier 

1994). Meanders occur as a river migrates across the flood 

plain creating new channels and abandoning old ones. The 

abandoned channels form cutoffs that evolve into oxbow 

lakes. Distributary channels may develop from abandoned 

channels. Floods, on the other hand, occur on a seasonal 

Centrarchidae Lepomis miniatus redspotted sunfish x x x 

Centrarchidae Lepomis symmetricus bantam sunfish x x x x x 

Centrarchidae Micropterus punctulatus spotted bass x x 

Centrarchidae Micropterus salmoides largemouth bass x x x x x 

Centrarchidae Pomoxis annularis white crappie x x x x 

Centrarchidae Pomoxis nigromaculatus black crappie x x x x x 

Percidae Ammocrypta beanii naked sand darter x 

Percidae Ammocrypta clara western sand darter x 

Percidae Ammocrypta vivax scaly sand darter x x 

Percidae Etheostoma asprigene mud darter x x 

Percidae Etheostoma caeruleum rainbow darter x 

Percidae Etheostoma chlorosoma bluntnose darter x x x 

Percidae Etheostoma fusiforme swamp darter x x x x 

Percidae Etheostoma gracile slough darter x x x x 

Percidae Etheostoma histrio harlequin darter x 

Percidae Etheostoma lynceum brighteye darter x 

Percidae Etheostoma nigrum johnny darter x x x 

Percidae Etheostoma parvipinne goldstripe darter x 

Percidae Etheostoma proeliare cypress darter x x x 

Percidae Etheostoma stigmaeum speckled darter x x 

Percidae Etheostoma swaini gulf darter x 

Percidae Etheostoma artesiae redfin darter x x 

Percidae Percina caprodes logperch x x 

Percidae Percina maculata blackside darter x 

Percidae Percina sciera dusky darter x 

Percidae Percina shumardi river darter x x 

Percidae Percina vigil saddleback darter x 

Percidae Stizostedion canadense sauger x x 

Percidae Stizostedion vitreum walleye x x 

Sciaeniidae Aplodinotus grunniens freshwater drum x x x x 

MS = State of Mississippi; YMD = Yazoo-Mississippi Delta; BLH = Bottomland Hardwood Forest Aquatic Habitats; DNF = Delta National Forest. 

a Ross (2001).

b Killgore and others (2008a).

c Hoover and Killgore (1998).

d Bryant unpublished data (footnote 4).

e Killgore and others (2008b).

Table 1—Fish by family, genus, and species found in the lower Mississippi alluvial flood plain and its subregions

Family Genus Species Common Name MSa YMDb BLHc DNFd Steelee

Petromyzontidae Ichthyomyzon castaneus chestnut lamprey x x

Petromyzontidae Ichthyomyzon gagei southern brook lamprey x

Petromyzontidae Ichthyomyzon unicuspis silver lamprey x

Petromyzontidae Ichthyomyzon aepyptera least brook lamprey x

Acipenseridae Scaphirhynchus albus pallid sturgeon x x

Acipenseridae Scaphirhynchus oxyrinchus Gulf sturgeon r x

Acipenseridae Scaphirhynchus platorynchus shovelnose sturgeon x x

Polyodontidae Polyodon spathula paddlefish x x x

Lepisosteidae Atractosteus spatula alligator gar x x

Lepisosteidae Lepisosteus oculatus spotted gar x x x x x

Lepisosteidae Lepisosteus osseus longnose gar x x x x x

Lepisosteidae Lepisosteus platostomus shortnose gar x x x x x

Amiidae Amia calva bowfin x x x x

Hiodontidae Hiodon alosoides goldeye x x

Hiodontidae Hiodon tergius mooneye r

Anguillidae Anguilla rostrata American eel x x x

Clupeidae Alosa chrysochloris skipjack herring x x

Clupeidae Dorosoma cepedianum gizzard shad x x x

Clupeidae Dorosoma petenense threadfin shad x x x

Cyprinidae Campostoma anomalum central stoneroller x

Cyprinidae Carassius auratus Goldfish (non-native) x

Cyprinidae Ctenopharyngodon idella grass carp (non-native) x x

Cyprinidae Cyprinella camura bluntface shiner x x

Cyprinidae Cyprinella lutrensis red shiner x x x

Cyprinidae Cyprinella venusta blacktail shiner x x x x x

Cyprinidae Cyprinella whipplei steelcolor shiner x

Cyprinidae Cyprinus carpio common carp (non-native) x x x x

Cyprinidae Hybognathus hayi cypress minnow x x

Cyprinidae Hybognathus nuchalis Miss. silvery minnow x x

Cyprinidae Notropis amnis pallid shiner x x

Cyprinidae Hypopthalmichthys nobiliss bighead carp (non-native) x x

Cyprinidae Luxilus chrysocephalus striped shiner x x

Cyprinidae Lythrurus fumeus ribbon shiner x x

Cyprinidae Lythrurus roseipinnis cherryfin shiner x

Cyprinidae Lythrurus umbratilus redfin shiner x x

Cyprinidae Macrhybopsis aestivalis speckled chub x x x

Cyprinidae Macrhybopsis meeki sicklefin chub x

Cyprinidae Macrhybopsis storeriana silver chub x x

Cyprinidae Notemigonis crysoleucas golden shiner x x x x

Cyprinidae Notropis atherinoides emerald shiner x x x

Cyprinidae Notropis blennius river shiner x x

Cyprinidae Notropis buchanani ghost shiner x x x

Cyprinidae Notropis longirostris longnose shiner x

Cyprinidae Notropis maculatus taillight shiner x x x x

Cyprinidae Notropis sabinae sabine shiner x

Cyprinidae Notropis shumardi silverband shiner x x

Cyprinidae Notropis texanus weed shiner x x

Cyprinidae Notropis volucellus mimic shiner x x

Cyprinidae Notropis wickliffi channel shiner r x

Cyprinidae Opsopoeodus emiliae pugnose minnow x x x

Cyprinidae Phoxinus erythrogaster southern redbelly dace r

Cyprinidae Pimephales notatus bluntnose minnow x x

Cyprinidae Pimephales promelas fathead minnow x x x

(continued)

9
cycle and vary in intensity from year to year. Flood effects 

extend over most of the YMD. 

Saucier (1994) identifies six meander LMAV belt stages 

beginning about 9,500 years BP that traverse the YMD. 

The chronosequence and locations of the various meander 

belts are not necessarily precise; however, the evidence is 

sufficient to show that the meander belts ranged over nearly 

all of the YMD alluvial flood plain. Over the course of more 

than 9,000 years, meander belts likely overlapped and older 

channels were obliterated as new ones were created. Fisk 

(1944) suggests that some of the earlier belts were derived 

from the Ohio River, but Saucier (1994) presents more 

recent evidence that the two rivers did not meander along 

parallel courses. The aquatic habitats found in the presentday YMD are derived from the meander regimes of the 

Mississippi River and the smaller rivers within the YMD, 

such as the Sunflower and Yazoo Rivers (Fisk 1944, Saucier 

1994). 

Oxbows formed in the meander belts shape the 

topography of the YMD and are a fundamental part of the 

development and succession of the aquatic habitat of the 

YMD (Shankman 1991). Meander scrolls formed by the 

succession of oxbows across the YMD are a series of curved 

channels and natural levees formed over thousands of years 

(Fisk 1944). The curvilinear ridges (meander scrolls) are 

natural levees of old river banks and are separated by broad 

depressions from the ancient abandoned river channels 

(Hupp and others 2005, Shankman 1991). Examples of 

large oxbow lakes formed by meanders in the Mississippi 

River are Lake Chicot near Lake Village, AR, and Lake 

Washington near Greenville, MS. Both lakes are close to 

the present river course. Smaller oxbow lakes are associated 

with the adjacent rivers, although many of the lakes have 

been obliterated by agriculture.

Hooke (2004) proposes five possible mechanisms driving 

the formation of oxbows. All are related to differential 

sedimentation and erosion of the river bank with deposition 

on one bank and erosion on the other, and range from a 

self-organizing system that has become chaotic to natural 

evolution of the system and exceptionally high flows that 

break through narrow points in the meander curves. The 

mechanisms described by Hooke (2004) do not incorporate 

the role of large wood in reshaping channels and redirecting 

river and stream courses (Maser and Sedell 1994). In the 

smaller rivers of the YMD and possibly in the Mississippi 

River, large wood accumulations such as those described by 

Shields and others (2000) would have played an important 

role in channel morphology of streams and rivers before the 

effects of intensive human disturbance.

The succession of oxbow lakes occurs over centuries and 

is not well documented for the YMD. Sedimentation and 

plant invasions are generally the primary mechanisms for 

succession. In the bottomland forests of the Southeastern 

United States, cypress is one of the first tree species to 

colonize abandoned channels and oxbow lakes. Harper 

(1912) suggested that cypress could be used to determine 

the age of succession of aquatic habitats that evolved from 

oxbow lakes. Shankman (1991) describes the vegetation 

succession in abandoned channels with cypress colonizing 

the margins along with willow (Salix). Cypress usually 

persists longer than shorter-lived willow. Seasonal floods 

will tend to suppress encroachment of vegetation and slow 

succession. As floods are attenuated, water levels will 

become lower, allowing greater encroachment of vegetation. 

Increased sedimentation will increase rates of succession 

(Richie and others 1983).

Extent and Duration of Historical Flooding

Before construction of the levees, all of the YMD was open 

to seasonal flooding. The area flooded was regulated by the 

height of the floodwaters and the topography of the land. 

The entire area quite likely was not flooded each year. In 

the unconstrained flood plain, floodwaters flowed laterally 

across the flood plain, following the contours of the land 

(Junk and others 1989). The same process would have 

occurred in the YMD as the Mississippi River, the Yazoo 

River, and the major distributary streams flooded. As the 

floodwaters flowed across the flood plain, isolated oxbows, 

sloughs, and swamps were connected.

Seasonal floods in the YMD are driven by hydrologic events, 

i.e., precipitation and snowmelt, in the upper watershed of 

the Mississippi River and by regional events. Annual cycles 

of precipitation and snowmelt are related to climatic patterns 

(Franklin and others 2003). The geographic separation also 

tends to extend the duration of the flood season, which 

can extend from January through May (fig. 3) (http://

countrystudies.us/united-states/weather. Date accessed: 

August 2008). Early in the season, high flows are from 

rainfall in the YMD and surrounding highlands (fig. 4). Later 

in the season, April through June, the flood pulse in the 

YMD is driven by precipitation, including spring snowmelt 

in the upper Mississippi River basin. The peak discharge in 

the Mississippi River increases through spring as snowmelt 

in the upper watershed of the Mississippi accompanies high 

precipitation in spring (fig. 3 and fig. 4).

Although events upstream affect hydrology downstream, 

interannual variation differed between the upper and lower 

Mississippi River (Franklin and others 2003). The within10
0

5000

10000

15000

20000

25000

30000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Discharge (m3/sec)

Month

Mississippi River

Mean Discharge (m3/sec) 

1932-1998

Figure 3—Mean monthly discharge for the Mississippi River over a period of 66 years.

Figure 4—Mean monthly rainfall for five locations throughout the YMD. http://countrystudies.us/united-states/weather. [Date accessed: 

August 2008].

0

2

4

6

8

10

12

14

16

18

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

cm

Month

Average Rainfall in YMD

Indianola

Greenville

Greenwood

Vicksburg

Clarksdale

11
year pattern of higher flows in the river is from February to 

June followed by six months of lower flows (Franklin and 

others 2003). This pattern is consistent between the upper 

and lower sections of the river. Levees, dams, and meander 

cutoff have substantially altered the natural pattern of 

flooding on the YMD. 

Effects of Seasonal Flooding on Habitats

The flood pulse connects the flood plain to the river (Barko 

and others 2006, Galat and others 1998, Goulding 1980, 

Junk and others 1989). Junk and others (1989) characterized 

the lateral movement of water across the flood plain as 

a moving littoral zone. As the flood pulse moved across 

the flood plain of the YMD, perennial aquatic habitats 

that include oxbows, swamps, bayous, and distributary 

channels (e.g., Deer Creek and the Sunflower River) were 

connected to the Mississippi River. Floodwaters flowed into 

ephemeral channels and depressions in bottomland forests 

and connected these to perennial habitats. The life cycle of 

many aquatic organisms is linked closely to the timing of the 

flood pulse.

The flood pulse functions both as a transport mechanism and 

a transport corridor. As floodwater moves across the flood 

plain, it alters the water chemistry of previously isolated 

aquatic habitats, carries inorganic and organic material 

across the flood plain, and replenishes water in pools 

and isolated sloughs (Amoros and Bornette 2002, Ewing 

1991, Junk and others 1989, Schramm and Eggleton 2006, 

Tockner and others 1999). In the Atchafalaya River basin 

in southeastern Louisiana, water temperatures decreased 

and dissolved oxygen increased, as did organic carbon, 

with a resulting increase in the abundance of planktonic 

rotifers as floodwaters covered the flood plain (Holland and 

others 1983). They concluded that the flushing of backwater 

habitats by the flood pulse was an important factor in 

maintaining planktonic diversity. Larval fish may be subject 

to passive movement during flooding; however, larger 

mobile species may use the flood pulse as a transportation 

corridor (Killgore and Baker 1996, Sheaffer and Nickum 

1986, Turner and others 1994). Ross and Baker (1983) 

identified the group of species that moved into the flood 

plain for feeding or spawning as “flood exploitive.” In the 

Atchafalaya River in Louisiana, spotted gar (Lepisosteus 

oculatus) migrated into flood plain habitats with the spring 

floods to spawn (Snedden and others 1999). More than 62 

species were captured in natural (i.e., unleveed) flood plain 

habitats associated with the Mississippi River near Louisiana 

(Guillory 1979). Before the levees along the Mississippi 

River, the flood pulse provided a corridor from the main 

channel to the aquatic habitats in the flood plain of the YMD 

(Puth and Wilson 2001).

During dry periods, the flood plain and the main channel 

existed as separate entities within the watershed. Increased 

connectivity also may increase similarity among habitats 

(Thomaz and others 2007). Thomaz and others (2007) 

suggested that the variation in many physical/chemical 

measures decreased with increasing connectivity during 

floods. Similarity among fish communities would increase 

with greater access as well. Differences among habitats 

increase with time as flood frequency and intensity decrease 

and habitats remain isolated for longer periods of time. 

If habitats are isolated for longer periods of time—many 

years versus annual—differences in physical attributes and 

biological communities would increase. Temperatures will 

increase and dissolved oxygen concentrations will decrease 

as habitats are isolated for longer periods of time. Both of 

these trends tend to be detrimental to most fishes, as well as 

many amphibians and other aquatic organisms (Matthews 

1987, Smale and Rabeni 1995). Deterioration of water 

quality and loss of connectivity will decrease biological 

diversity in isolated habitats (Capone and Kushlan 1991, 

Rutherford and others 2001). 

Seasonal floods redistribute fishes throughout flooded 

habitats. Even under present conditions, oxbow lakes that 

are connected to the Mississippi River support a different 

species assemblage than those that are isolated (Miranda 

2005). Before the levees, unconstrained flooding linked 

habitats throughout the YMD to the Mississippi River. The 

winter and spring floods provided pathways for fish dispersal 

throughout the YMD. In a recent flood event in the upper 

Mississippi River, Barko and others (2006) observed 42 

species of fishes that dispersed into a flood plain. As habitats 

become connected, diversity among habitats decreased, but 

biodiversity throughout the flood plain may become greater 

than habitats that are not flooded periodically (Thomaz and 

others 2007). 

Distribution of Fish in the YMD 

Before the Levees

No records exist of the fish communities in the YMD before 

the levees existed. However, observations based on the 

archaeological record show that fish were an important part 

of the diet of aboriginal people. This record also shows 

that certain species were widespread over the YMD. The 

fish most likely were collected as food and represent larger 

taxa. As a result, the list is far from a random sample of the 

species assemblage. The archeological record is also biased 

12
by collection methods, sampling intensity, and identification 

procedures. Furthermore, fish were captured by a range 

of methods by aboriginal people (Scott 1995). The best 

record is from the Rock Levee Site approximately 400 to 

900 C.E. (current era) located along the Mississippi River 

near Clarksdale, MS (Scott 1995). The site was sampled 

intensively, and among more than 39,000 bone fragments, 

25,502 were from 31 fish taxa. Most were identified to 

species; the rest were identified to genera (table 2). Of 

these, catfishes (Ictaluridae) and suckers (Catostomidae) 

comprised 28 percent and 21 percent, respectively. They 

were followed by sunfish (Lepomis spp.), bowfin, and gars 

at 18 percent, 15 percent, and 10 percent, respectively 

(Scott 1995). Bowfin and gars were present at the other sites 

where fish samples were identified; catfishes were present 

at two other sites, one of which was located near the Yazoo 

River. Gars, bowfin, basses (Centrarchids), and sunfishes 

(Centrarchids) were present at the Palusha Creek site near 

Greenwood, MS, along the Yazoo River. 

The species assemblages from these sites often represent 

samples from time spans that extend over hundreds of years 

from a single site. During this time, surrounding habitats 

may have changed. For example, a bayou or river cutoff 

may have evolved into an oxbow lake or a slough from one 

sample strata to the next. Present analysis of the samples 

has not proceeded to a point where a time sequence can be 

reliably identified.3

With few exceptions, fish found at the various archeological 

sites throughout the YMD are still present, and most are, 

or appear to be, reasonably abundant. Sauger (Stizostedion 

canadense) and possibly walleye (Stizostedion spp.) 

(table 2) are either absent or extremely rare in the YMD, 

although they are reported in the lower Mississippi River 

drainage (Ross 2001). Their presence in archeological 

remains suggests that they were more common during 

aboriginal times (about 500 C.E.). One explanation for 

their decline may be that the climate was cooler during 

this period; however, water quality and habitat conditions 

were undoubtedly more conducive to these species as well. 

Spotted bullhead (Ameriurus serracanthis) was reported 

from one site in Leflore County, Mississippi. It is not listed 

in Ross (2001) but does occur in southeastern Alabama 

(Boschung and Mayden 2004).

The archeological record provides sufficient evidence that 

fishes were an important part of the diet of aboriginal people 

in the YMD. For that to be the case, fishes had to have been 

abundant. Given the massive loss of aquatic habitats from 

anthropogenic activity in the past 300 years, it can be easily 

concluded that the number of fish was substantially greater 

than the number at present. Further, aquatic habitats were 

qualitatively different than present, which would affect 

fish communities. Channels with well-developed riparian 

forests, including hardwoods along the bank and cypress in 

and along the stream margin, would lead to highly complex 

habitats with abundant large wood. With the absence of large 

tracts of industrial agricultural lands, sediment recruitment 

into bayous and stream was lower and, without flood control 

dams, was flushed out more readily. The ubiquity of gars 

and bowfin in the archeological remains suggests that low 

dissolved oxygen and high temperatures were present in at 

least some habitats. Greater connectivity between the flood 

plain and the rivers would improve water quality and provide 

access to the flood plain for spawning and rearing. This, in 

turn, would contribute to greater numbers of species.

Post-European Habitats of the YMD

The landscape of the YMD has a long history of 

anthropogenic disturbance. Humans were present in the 

YMD perhaps as early as 14,000 to 10,000 years ago and 

developed agriculture in the flood plain about 2,000 years 

ago (Delcourt 1987, Saikku 2005). For the most part, forest 

clearing for agriculture was concentrated along river and 

slough corridors in the flood plains and adjacent terraces 

(Delcourt 1987, Delcourt and others 1993), but it probably 

had only localized influence on the flood plain dynamics 

and did little to disrupt the natural rhythms of seasonal flood 

pulses of the river. However, Peacock and others (2004) 

suggest that sediment from aboriginal agriculture may 

have been responsible for a decline in freshwater mussel 

populations. With the collapse of aboriginal populations 

in the 1500s, aboriginal clearings were recolonized by 

hardwood forests (Hamel and Buckner 1998). The onset of 

European settlement brought large-scale land clearing and 

intensive agricultural development during the 1800s. By 

the 1840s, intensive timber harvest was underway (Saikku 

2005). High-value baldcypress along waterways such as 

Steele Bayou and the bayous between Deer Creek and 

the Sunflower River were harvested first (Saikku 2005). 

Conversion of forest land to agriculture was a major part of 

deforestation of the YMD as well. Currently, bottomland 

hardwood forests comprise < 17 percent of the remaining 

land in the YMD.

Three interrelated primary anthropogenic forces that altered 

the landscape and aquatic habitats in the YMD—flood 

3 Personal communication. 2007. E. Jackson, Professor, Dept of Anthropology and 

Sociology, University of Southern Mississippi, 118 College Drive, Hattiesburg, MS 

39406.

13
Table 2—Species recovered in archaeological sites in the Yazoo Mississippi Delta (YMD) 

Taxa Common name

Site

RL WC MC FR PC LW

Amia calva Bowfin x x x x x x

Lepisosteus sp. Gar x x x x x x

L. osseus Longnose gar x x

Atractosteus spatula Alligator gar x x

Clupeidae Shad/herring x x

Alosa sp. Shad/herring x

Dorosoma cepedianum Gizzard shad x

Esox sp. Pickerel x x

Cyprinidae Minnow x x x

Catostomidae Sucker x x x x

Moxostoma sp. Redhorse x

Ictiobus bubalus Smallmouth buffalo x

I. cyprinellus Bigmouth buffalo x x

Minytrema melanops Spotted sucker x

Ictalurus spp. Catfish x x x x

Ictalurus punctatus Channel catfish x x x x

I. furcatus Blue catfish x

I. melas Black bullhead x

I. natalis Yellow bullhead x

Ameriurus spp. Bullheads x x

Ameriurus nebulosus Brown bullhead x x

A. natalis Yellow bullhead x

A. serracanthis Spotted bullhead x

Pylodictis olivaris Flathead catfish x x

Perciformes Perch x

Probably Morone x

Morone sp. White/Yellow bass x

Morone chrysops x

Centrarchidae Sunfish x x x

Micropterus sp. Bass x x

Micropterus salmoides Largemouth bass x x

M. punctulatus Spotted bass x

Lepomis sp. Sunfish x x x

Lepomis microlophus Redear sunfish x

L. macrochirus Bluegill x x x

L. gulosus Warmouth x

Pomoxis sp. Crappie x x

Stizostedion Sauger/walleye x

Stizostedion canadense Sauger x

Aplodinotus sp. Freshwater drum x x x x X

Chaenobryttus spp. = 

Lepomis gulosus

Warmouth x

RL = Rock levee site (400-1400 C.E.) (Scott 1995); WC = Welcome Center (1-1500 C.E.) (Mooney and others 2003); 

MC = Mcknight (900-1200 C.E.) (Breitburg 1998); FR = French site (100-1200 C.E.) (Wilson 1987; PC = Palusha Creek 

(500-900 C.E.) (Brown and others 1994); LW = Law site (1100-1500 C.E.) (Coxe 1999). 

14
control levees, deforestation, and large-scale agriculture—

occurred during the past 150 years. The levees isolated 

the larger rivers from their flood plains and effectively 

stopped the creation of new oxbow lakes. Deforestation 

removed riparian trees as well as trees in the water such as 

cypress. Recent large-scale industrial agriculture changed 

landscape topography from small ridges and valleys formed 

by meander scrolls to large areas of level fields. Bayous, 

streams, and tributaries were dredged and straightened to 

remove water from the land. Small oxbows and sloughs 

were filled or isolated. Over a period of < 150 years, the 

flood plain was effectively decoupled from the Mississippi 

and Yazoo Rivers.

Hydrology

The hydrology of the YMD has changed substantially from 

pre-European conditions. Massive flood control projects, in 

conjunction with engineering projects to ensure navigation 

routes, have included dredging in the main channel, wood 

removal (snagging), removal of channel meanders, bank 

stabilization, and construction of a massive levee system 

that extends along most of the Mississippi and Yazoo 

Rivers (Brown and others 2005, Jackson and Ye 2000). 

Water control structures have been installed throughout the 

streams and bayous of the YMD as flood control and water 

management efforts, further isolating habitats. In addition, 

large-scale pump projects move water from rivers such 

as the Little Sunflower River onto wetlands to coincide 

with waterfowl use. Diversion channels have been built 

throughout the YMD to carry excess water during floods 

and often carry water throughout the year. These measures 

are effective for flood control (Kemper 1928) but have 

decoupled the flood pulse from the flood plain.

Levees, dams, and meander cutoffs along and in the 

Mississippi and Yazoo Rivers have altered the timing and 

intensity of hydrological processes of the YMD (Brown and 

others 2005). The purpose of the structures is to keep water 

off developed lands in the flood plain (agricultural, urban, 

and suburban areas). The levees along the Mississippi River 

have effectively stopped lateral movement of the flood pulse 

across the historic flood plain. In all recent flood events since 

1927, the lateral movement of the Mississippi River has been 

restricted to the area between the river bank and the levees, 

also known as “batture land.” By concentrating floodwaters 

in a smaller area, water rises faster and velocities are higher 

on the land between the river and the levees. Lateral flooding 

of the flood plain is restricted primarily to the sections of 

distributary channels without levees (e.g., Sunflower River, 

Steele Bayou). Dams on the major tributaries of the Yazoo 

River attenuate spring flows across the YMD. The example 

from the Sardis lake dam shows the higher flows in the Little 

Tallahatchie River above the dam from December through 

April and decreasing into the summer; below the dam, low 

flows occur in April and increase through the summer (fig. 

5). Cutoffs and reservoirs reduce the intensity and change 

the duration of winter and spring floods. In the Mississippi 

River, meander cutoffs increase channel incision and reduce 

peak flows (Biedenharn and others 2000). Natural bayous 

and tributaries have been modified to remove water from 

agricultural land as rapidly as possible, usually by changing 

them from meanders to linear drainage ditches. Diversion 

and storage of water extend the amount of time water 

remains on flooded areas. Smaller areas are flooded for 

longer periods of time.

As a result, a large part of the historical flood plain is no 

longer exposed to the flood pulse of the Mississippi. The 

result is that the rise and fall of floodwaters on the flood 

plain are disconnected from the rise and fall of floodwaters 

in the river. Franklin and others (2003) concluded that intraannual periodicity of flooding in the Mississippi River was 

not altered by flood control alterations, but high and low 

flow events tended to be less variable and were lower and 

higher, respectively, than events before 1929 that were used 

as the before control period. The timing and duration of the 

flood pulse may approximate historical conditions, but the 

effect across the flood plain is greatly different. Many areas 

receive less flooding for shorter periods, whereas other areas 

may receive more for longer periods. 

Aquatic Habitats of the YMD

Virtually all aquatic habitats in the YMD have been 

subjected to intensive anthropogenic modification, either 

physical or hydrologic, and usually both. More than 80 

percent of the land in the YMD is used for large-scale 

agriculture (Killgore and others 2008b). Most of the 

remaining land is urban or suburban and is protected from 

large-scale floods. An undocumented number of sloughs, 

swamps, and small natural ponds have been obliterated. 

Larger oxbow lakes remain but are subjected to high rates of 

sedimentation from surrounding agricultural land. Streams 

and sloughs that flow through agricultural land have been 

altered and now have either no riparian trees or only a small 

band of 10 m or less. As a result, few areas in the YMD 

provide habitat conditions that are similar to those present 

before European settlement. 

The largest contiguous tract of bottomland hardwood 

forest (24,700 ha) in the YMD is in the Delta National 

15
Forest (DNF). Patches of forests also occur in the 40,400 

ha in the Theodore Roosevelt National Wildlife Refuge 

Complex, which comprises seven units and includes 

active and abandoned agricultural land. Patches of forest 

also exist on private lands; however, these are usually 

intensively managed for timber production and often 

are reclaimed agricultural land. The result is a highly 

fragmented mosaic of forest land in the YMD. For fish, the 

primary corridors are the rivers and bayous that eventually 

flow into the Mississippi River. Large tracts of privately 

owned timberland are present in the batture land between 

the Mississippi River and the levees, and these areas are 

regularly exposed to seasonal flooding. 

With the widespread construction of levees, a new 

ecosystem was created in the land between the river and 

the levees (Stanturf and Schoenholtz 1998). The aquatic 

landscape of the YMD may be separated into the batture 

lands and the historic flood plain outside the levees. Both 

are distinct with respect to their exposure to flooding. 

Oxbow lakes are the dominant natural aquatic habitat 

in the batture lands (Miranda 2005). Most other aquatic 

habitats such as ponds formed from borrow pits are the 

result of anthropogenic activities generally associated 

with the construction and maintenance of the levees or 

with river control measures such as dredging or wingdike construction. Some of these listed by Baker and 

others (1991) are flood plain ponds that may be perennial 

or ephemeral, seasonally flooded tributaries, and borrow 

pits. Borrow pits and side channels may retain water after 

floodwaters recede and can provide refuge habitat for fish 

(Hoover and Killgore 2002).

The aquatic habitats in the flood plain are either rivers that 

developed during deglaciation of the upper watershed or 

habitats that were derived from the meander belt of the river 

(Autin and others 1991). Lotic habitats are separated into 

three groups: rivers, bayous, and tributaries. Lentic habitat 

types include oxbow lakes, ponds, sloughs, and swamps. 

In the YMD, most of the lentic habitats were derived from 

meanders. Oxbow lakes form when a meander cutoff, the 

meander bend, is blocked at the upstream end of the cutoff. 

Over time the oxbow lake is isolated from the river channel 

and fills with sediment, and ultimately vegetation encroaches 

across the lake as it fills with sediment. In a forest setting, 

succession in oxbow lakes occurs over thousands of years. 

With disturbance events that increase sediment rates, the 

process proceeds more rapidly (Richie and others 1983). 

This has important consequences for habitats located in the 

flood plain isolated by levees (Miranda and Lucas 2004). 

Levees effectively halt the meander process in the flood 

plain that they isolate and prevent future development of 

oxbow lakes.

0

0.5

1

1.5

2

2.5

3

3.5

4

1 2 3 4 5 6 7 8 9 10 11 12

Stage (m)

Month

Above and Below Sardis Dam

Below

Above

Figure 5—Mean monthly stages for 2008 above and below the Sardis Dam from the Batesville (below) and Etta (above) gages.

16
No definitive system of habitat classification for the YMD 

or alluvial flood plain habitats appears to exist. Names and 

criteria for classification often differ among studies; six are 

listed by Baker and others (1991). Baker and others (1991) 

define sloughs as remnants of abandoned river channels 

that have water in them throughout the year. They may 

either be connected or disconnected from the river and are 

differentiated from oxbow lakes primarily on the basis of 

size. Hodges (1994) defined sloughs as shallow depressions 

that collect water but eventually dry out. They are 

characterized by baldcypress and swamp tupelo. Turner and 

others (1994) separated habitats into “low-no flow” (bayous 

and sloughs) and “main river,” e.g., the Mississippi River. 

Habitats listed in table 3 are adapted from distinctions by 

Baker and others (1991) that separate naturally occurring 

habitats into flowing (lotic) and pond (lentic) habitats that 

have perennial water (Baker and others 1991, Killgore and 

Hoover 1992). Lotic habitats, such as the Sunflower River 

and the Steele, Howell, and Black bayous, drain the YMD 

and flow into the Yazoo or Mississippi Rivers. Although 

rivers and bayous have been altered by various land use 

practices, their distribution is relatively unaffected by land 

use. Oxbow lakes are the dominant lentic habitat in the 

YMD. Their distribution is dictated by distance from the 

Mississippi River; however, oxbows are also formed by 

interior rivers such as the Sunflower and Yazoo Rivers. 

Their numbers decrease with distance from the river, as does 

their connectivity with the river (Miranda 2005). Smaller 

habitats such as sloughs, pools, and swamps are uncommon 

on developed land, but are common throughout forested 

land found on public lands such as the DNF and the various 

national wildlife refuges in the YMD. 

Land use patterns affect habitat quality as well as 

distribution of aquatic habitat. Sediment and chemicals 

associated with agriculture are among the most significant 

stressors in aquatic habitats in the YMD. These two 

stressors have resulted in lower species diversity in lotic 

habitats of the YMD (Killgore and others 2008b). Higher 

sediment deposition also occurs in oxbow lakes surrounded 

by agricultural land (Richie and others 1983). Increased 

nutrient loading from agricultural runoff contributes to 

eutrophication of aquatic habitats resulting in anoxic 

conditions. Algal blooms driven by the input of nutrients 

from agricultural activity produce huge variation in 

dissolved oxygen concentrations, with conditions capable 

of ranging from supersaturation during the day to anoxic 

conditions at night (Shields and others, no date).

Riparian corridors through developed land are commonly 

devoid of trees in the YMD. Associated with the absence of 

streamside trees is the paucity of instream large wood, an 

important element in the biotic community of streams in the 

Southern United States (Benke and others 1985, Wallace 

and Benke 1984, Warren and others 2002). In contrast, 

bayous flowing through forested lands appear to have 

greater amounts of instream large wood from standing live 

Table 3—Perennial aquatic habitats of the YMD 

Name Type Description Source

Slough Lentic/Lotic Narrow, shallow < 3 m; may be 

connected to main channel 

(contiguous); mud substrate

Baker and others 1991

Oxbow lake Lentic Large (200 to > 3500 ha) up to 1 m 

wide and 25 km long; may stratify 

during the summer

Baker and others 1991

Flood plain 

pond/swamp

Lentic May be low points in intermittent 

tributaries (< 500 m2); mud 

substrate with abundant organic 

debris

Baker and others 1991

Tributary Lotic Small (< 6 m wide approximate); 

flow into larger streams (e.g., 

Sunflower, Deer Creek) within the 

YMD; may drain forested wetlands 

or modified into agricultural 

drainage ditches

Distributary 

channel/river

Lotic Larger channels (> 6 m wide) 

within the boundaries of the YMD 

that drain the flood plain

Main channel rivers Lotic Mississippi River; Yazoo River

17
baldcypress and downed streamside trees (fig. 6). Riparian 

shading tends to suppress aquatic macrophyte growth. Small 

tributaries and ponds, as well as swamps, are distributed 

throughout forested habitats that have not been previously 

exposed to agriculture. These areas tend to be inundated 

during spring floods and may be important seasonal 

spawning and nursery areas for flood-dependent species 

(Killgore and Baker 1996, Sheaffer and Nickum 1986).

Fish Populations in the YMD

The LMAV supports a highly diverse fish community within 

the highly diverse fish community of the Southeastern 

United States (Warren and others 2000). Ross (2001) lists 

134 species for the LMAV within the State of Mississippi. 

Of these, 102 are reported for the YMD (table 1). The list for 

the YMD includes paddlefish and sturgeons that are found 

primarily in the Sunflower, Yazoo, and Mississippi Rivers. 

Hoover and Killgore (1998) list 40 species associated with 

bottomland hardwood forests, but the list is derived from 

relatively few studies, most of which are outside the YMD. 

More than 70 species were reported for the bottomland 

hardwood forests near the Cache River, Arkansas (Killgore 

and Hoover 1992). This is one of the few remaining large 

tracts of bottomland hardwood forest in the LMAV. In 

a recent survey of habitats in the DNF, 37 species were 

captured with seines and backpack electrofishing equipment.4

The wide range of life history characteristics is manifested 

in the species diversity found in the LMAV and the 

YMD. Ross (2001) provides a synopsis of the life history 

characteristics of all fish known from the State of 

Mississippi based on a wide range of literature. However, 

few studies are from the YMD. Some useful characteristics 

for various assessment projects are habitat use, trophic guild, 

and reproductive strategy. Habitat was used by Ross and 

Baker (1983), who separate species into “flood exploitive” 

Figure 6—Ten-mile Bayou, Delta National Forest, with large wood and riparian trees on bank and in the channel. 

4

Bryant, M.D.; Warren, M.L. 2008. Floods, forests, and fishes in the Delta National 

Forest, Mississippi: a study of fish assemblages in the Delta National Forest and 

nearby aquatic habitats. 25 p. Unpublished manuscript. On file with: Center for 

Bottomland research, P.O. Box 227, Stoneville, MS 38776.

18
and “flood quiescent” on the basis of the movement 

of species in response to flooding, a classification that 

Kwak (1988) uses to identify fish that moved into flood 

plain habitats during high water. Many of these fish were 

juveniles. Other studies in bottomland hardwood forests 

near the YMD show that the flooded forest habitats are 

used for spawning and rearing during the first year of life 

for a range of species (Killgore and Baker 1996). Killgore 

and Hoover (1992) identify four reproductive strategies 

(pelagic, benthic, vegetation, and crevice spawning) and 

three habitat types (oxbow lakes, flood plain ponds, and 

flowing water) to develop a matrix that describes fish species 

assemblages. Hoover and Killgore (1998) review a range 

of studies on fish of forested wetlands, identifying life 

history characteristics that include morphology, physiology, 

reproduction, and predation. Of these studies, only two were 

located in Mississippi and one in the most northern part of 

the YMD. Studies of sport fish in larger oxbow lakes are 

more numerous. 

Oxbow lakes are important to recreational fishing in the 

YMD (Miranda 2005, Miranda and Lucas 2004). Miranda 

and Lucas (2004) identified 61 species (> 70 mm) in 29 

lakes in the LMAV. Sunfish and bluegills (L. macrochirus) in 

particular dominated the catch (> 50 percent). Largemouth 

bass (Micropterus salmoides) (9 percent) and black 

(Pomoxis nigromaculatus) and white crappie (Pomoxis 

annularis) (7 percent) were also important species. All 

are considered sport fish. Fish communities appear to be 

influenced by turbidity and lake morphology. Temperate 

bass (Morone spp.), black crappie, redear sunfish (Lepomis 

microlophus), warmouth (L. gulosus), and gar (Lepisosteus 

spp.) tended to be associated with less turbid waters 

(Miranda and Lucas 2004).

In a similar study, Miranda (2005) observed a relationship 

between connectivity to the Mississippi River and fish 

communities. Fish often associated with flowing water 

were more common in lakes with greater connectivity. 

These included skipjack herring (Alosa chrysochloris), river 

carpsucker (Carpoides carpio), and white bass (Morone 

chrysops). During this study, all species captured in lakes 

outside the levees also were captured in lakes within the 

levees (Miranda 2005). Seven species were captured only 

in lakes between the levees and the river: skipjack herring, 

river carpsucker, highfin carpsucker (Carpoides velifer), 

spotted sucker (Minytrema melonops), striped bass (Morone 

saxatilis), flier (Centrarchus macropterus), and grass carp 

(Ctenopharyngodon idella). Of these, only the flier was 

captured in the survey of the DNF. Smaller fish (< 70 mm) 

with shorter life cycles were not sampled in the studies of 

oxbow lakes. Oxbow lakes within the batture lands support 

different fish communities than those in the flood plain 

(Stanturf and Schoenholtz 1998). This appears to be related 

to turbidity, but frequent connection to the river would also 

influence the fish community.

Fish in the YMD are a significant part of the cultural 

heritage of the region. Fish are caught in artesian fisheries 

(small-scale commercial fisheries) and recreational fisheries 

(Jackson 2004). Artesian fisheries tend to be low-profit 

enterprises but are an important part of the lifestyle of 

residents of the region. They target larger individuals of the 

three buffalo species (Ictiobius spp.) and three species of 

catfish: blue catfish (Ictalurus furcatus), channel catfish (I. 

punctatus) and flathead catfish (Pylodictus olivaris). The 

legal limits reported by Jackson (2004) are 410 mm and 

305 mm for buffalos and catfish, respectively. Gar, bowfin, 

several centrarchids, and catfish are part of the recreational 

fishery (Jackson 2005). Within the centrarchid group are a 

variety of sunfish (Lepomis spp.), black basses (Micropterus 

spp.), and both species of crappies (Pomoxis spp.). Although 

most are caught with hook and line, larger catfish are caught 

by hand grappling, a technique unique to the Southeastern 

United States (Jackson and others 1997). As a group, these 

fisheries represent an important part of the social and 

economic life of the region.

The landscape of the YMD is modified extensively by 

human activity and, as a result, diversity is likely to be lower 

in the YMD than in many forested habitats elsewhere in 

the LMAV. Few published studies exist for fish or aquatic 

habitat in the YMD. In a recent evaluation of a restoration 

project on Steele Bayou, north of Vicksburg, MS, Killgore 

and others (2008b) reported an increase in the number of 

fish species captured from 20 to 30 species following the 

removal of soft substrate, sediment abatement, and bank 

stabilization (Killgore and others 2008b). Notably, the 

number of species intolerant of poor water quality increased 

after the project. Overlap occurred between the fish 

communities at Steele Bayou and the DNF, with 25 species 

in common (table 1). Of the 34 species captured in the DNF, 

only 4 are classified as intolerant of low water quality, but 

26 are classified as moderately tolerant or tolerant of lower 

water quality.

Management of Aquatic Habitat in the YMD

Until recently, little attention was given to management of 

habitats for aquatic resources in the YMD. Protection of 

riparian areas and aquatic habitats is relatively piecemeal 

and is often directed at creating wildlife or waterfowl 

19
habitat. Creation of buffer strips or management zones 

along streams and sloughs flowing through private lands 

is voluntary. Conservation reserve and wetland reserve 

programs (CRP, WRP) are based on economic incentives, 

whereby the landowner is paid for lost revenue from land 

that is set aside from agriculture to create a buffer area. 

Smaller tracts of public lands represented by National 

Forests (U.S. Department of Agriculture Forest Service), 

Wildlife Management Areas (U.S. Department of the 

Interior, Fish and Wildlife Service), and State parks 

exist as patches throughout the YMD. These occupy 

a relatively small part of the land base (< 3.7 percent) 

and have varying management objectives. Most riparian 

areas and aquatic habitats are exposed to a wide range of 

effects that accompany extensive and intensive agricultural 

development.

Given the present condition of aquatic habitat in the YMD, 

restoration is a high management priority. Killgore and 

others (2008b) identified three stressors that arise from 

agricultural practices in the YMD: deforestation, increased 

sediment, and reduced stream flow. In Steele Bayou, 

Killgore and others (2008b) proposed restoration procedures 

to increase summer water storage, to remove soft substrate, 

and to create riparian buffers that address three principal 

stressors operating: water level management, soft substrate, 

and lack of suitable riparian habitat. Steele Bayou is 

representative of many bayous and streams in the YMD, and 

these measures have utility for restoring habitats elsewhere. 

Broader issues remain with respect to improving aquatic 

conditions throughout the YMD. 

Agriculture and flood control impose multiple stressors 

on the aquatic habitat of the YMD. The National Research 

Council (NRC 1992) identified a set of stressors for lakes 

and flowing waters that incorporates those of Killgore and 

others (2008b) and includes hydrologic and morphological 

modifications, erosion and siltation, water quality, and 

introduction of exotic species. Flow mistiming is a 

hydrological stressor that affects connectivity between 

mainstream rivers and flood plain habitats and retention 

of water on the flood plain. Morphological modifications 

include loss of riparian vegetation and trees, dredging, and 

channelization. Excessive erosion and sedimentation affect 

substrate quality and are related to agricultural erosion 

and bank destabilization. Deterioration of water quality 

arises from increased nutrient levels and toxic compounds 

that are incorporated into the biota. A suite of additional 

symptoms of deteriorating water quality includes decreased 

concentrations of dissolved oxygen, low pH, and increased 

water temperatures. Exotic species often have an adverse 

effect on native species and frequently are better adapted 

to deteriorating habitat and water quality (Jackson and 

Mandrak 2002, Meador and others 2005, Schade and Bonar 

2005).

These stressors are interrelated, and some can be addressed 

by managing land use practices. Modification of land 

management practices is an important prerequisite to 

restoration of natural processes to aquatic habitats in the 

YMD. The NRC (1992) provides a generalized approach 

to restoration and specific examples. A key element in their 

approach is to conduct a triage to identify priorities. They 

also give a detailed list of requisites for project design 

and implementation, including identification of goals and 

objectives, an economic evaluation, collection of baseline 

information, a monitoring plan, and selection of criteria 

to measure performance. They also offer a feedback 

mechanism for use during project implementation that 

facilitates ongoing evaluation and modifications where 

needed. The post-project evaluation is designed to determine 

how well objectives were achieved, what was learned 

from the project, and how the design could be improved or 

modified for future projects. The realities of the landscape 

and socioeconomics of the YMD are such that little 

probability exists of restoring large areas of the YMD to preEuropean conditions.

The definition of restoration by the NRC is to transform 

an ecosystem to close to its state before anthropogenic 

modification, a difficult if not impossible task for the aquatic 

ecosystems of the YMD (National Research Council 1992). 

Sparks and others (1998) applied the term naturalization 

to their approach to improve conditions in the upper 

Mississippi River. The goal was to move aquatic ecosystem 

processes closer to natural conditions within the context of 

socioeconomic constraints. They used manipulation of flows 

in their example. Reestablishing riparian vegetation and 

trees along streams and bayous in the YMD is an example of 

a “naturalization” project that could be applied in the YMD. 

Riparian trees can recreate natural processes of shading, 

large wood recruitment, and instream structure to bayous 

and sloughs with degraded channels. Some naturalization 

projects and their outcomes appear to be intuitive and 

relatively straightforward to implement. However, in the 

case of sediment reduction, evaluation and measurement 

are more complex, and results may not be straightforward 

(Shields 2008). As defined, “naturalization” is a more 

realistic approach than “restoration” to improving aquatic 

habitats in the YMD, but a systematic approach similar to 

that outlined by the NRC will greatly improve probabilities 

of success.

20
Natural processes that depend on the flood cycle and the 

forest in flood plain habitats have not existed in the YMD 

for decades and are not well documented in the YMD. In 

addition, communities of fish species that were present 

before major disruption of these processes are not known. 

Studies from other locations and an understanding of life 

history patterns of species in the YMD provide a starting 

point to reconstruct these relationships. A quantitative 

assessment of existing conditions and fish communities in 

the YMD also is important. As the assessment proceeds, the 

results can lead to the development of studies to provide 

a better understanding of the relationships of individual 

species and fish communities to the physical habitat and 

to geomorphic and hydrologic processes. With increased 

knowledge of the aquatic habitat and the processes that 

influence its biological community, a framework to design 

and implement naturalization programs that target specific 

habitats and fish communities can be developed.

Research in the YMD

The YMD is a unique region. It has been intensively 

affected by human activities, but processes that affect fish 

communities and their habitat in the YMD have been poorly 

investigated. The focus of the few surveys and studies has 

been on sport fishes (Lucas 1985), large species in oxbow 

lakes (Miranda and Lucas 2004), assessments of habitat 

improvement projects (Killgore and others 2008b), or 

syntheses of museum records of fishes collected over the 

years in the region (Ross 2001). Two important assessments 

have been completed for the YMD. The first assessment, 

by the Yazoo River Basin Team, addresses water quality 

and land use (YRBT 2000). The second assessment, 

which includes two reports, describes the development 

of two indices of biological integrity (IBI) for fish in 

habitats in the Yazoo River Delta and the oxbow lakes in 

the YMD (Killgore and others 2008a, Miranda and others 

2007). These reports provided a description of the water 

quality, fish communities in the YMD and, in the case of 

the development of the IBIs, a preliminary analysis of 

the effects of physical and chemical factors on fish. Both 

assessments address two pressing issues facing fish in the 

YMD—sediment and water quality—and provide a plan 

of action to address them. A better understanding of the 

interactions of fish with their habitat and the processes in 

the YMD that influence fish distribution and abundance 

is needed to address the larger tasks of recreating natural 

processes and habitat restoration. 

Some of the major processes and habitats that influence fish 

distribution in the YMD were discussed in earlier sections of 

this paper. The few studies that describe the response of fish 

to natural processes have been conducted outside the YMD. 

These studies can provide a template for naturalization/

rehabilitation projects for the YMD. However, systematic 

and quantitative studies within the YMD are essential 

to effective and efficient development, implementation, 

and evaluation of such projects. Three major unanswered 

questions concerning the fish communities in the YMD are 

proposed.

1. What are the limiting factors that affect fish abundance 

and diversity?

2. How do ecological processes and disturbances structure 

aquatic habitats and fish communities?

3. What are the relationships between fish communities and 

habitat structure?

No priority is assigned to the three categories. Studies within 

one category may have application to other questions in 

other categories. The purpose at this point is to identify an 

approach and to provide some examples of studies that can 

begin to address these large and complex questions. The 

results of these studies can contribute to the development, 

evaluation, and implementation of projects designed to 

reestablish natural function of aquatic habitats. 

What Are the Limiting Factors That Affect Fish 

Abundance and Diversity?

One prerequisite to an effective program to improve 

conditions for fish is to identify characteristics of their 

habitat that limit their abundance and diversity. These 

conditions may be physical features of the habitat, such 

as space and cover, water quality, or the biological 

characteristics of the desired species. The index of biotic 

integrity developed by Killgore and others (2008a) for the 

YMD provides a starting point to identify several variables 

that may limit populations. Access to critical habitats is 

linked to isolation of the flood plain by levees or dams 

and is one example of a limiting factor of fish abundance 

and diversity. The diversity of species and the range of 

anthropogenic disturbance in the YMD create a complex 

environment for limiting factors analysis.

Fish communities respond to water and habitat quality. 

Killgore and others (2008b) separated species into those 

tolerant and intolerant of low water quality, and certain 

species—gars and bowfins—are adapted to survive low 

dissolved oxygen conditions. Other species require higher 

concentrations of dissolved oxygen. Establishment of 

21
measurable criteria to identify “tolerant” and “intolerant” 

species along a gradient would provide a useful tool to 

examine water quality as a limiting factor.

Increased knowledge of life histories of individual species 

can contribute to understanding the response to effects such 

as limited access to spawning habitats, seasonal changes 

in dissolved oxygen, or cumulative effects of sediment 

accumulation. Often water quality is cited as a limiting 

factor for fish; however, connectivity among habitats can 

be important if access to critical habitats is blocked. Three 

questions within this category provide a starting point for the 

analysis.

1. Can measures of water quality and habitat quality be 

used to determine the relative tolerance of species to 

environmental conditions? 

2. What is the effect of seasonal fluxes in dissolved oxygen 

on fish communities in perennial habitats in the YMD? 

3. Does connectivity between riverine and flood plain 

habitats limit fish species diversity in the YMD?

Studies addressing these questions can form the basis for 

a limiting factors analysis that systematically evaluates 

physical and biological conditions that may increase 

diversity and abundance of target species. Results also 

may be used to establish regulatory standards such as for 

total maximum daily loads (TMDL) for potential stressors 

such as dissolved oxygen. One desirable outcome of the 

investigation of limiting factors is the development of a 

model that can be used to prioritize and evaluate potential 

outcomes of habitat improvement projects. 

How Do Ecological Processes and Disturbances 

Structure Aquatic Habitats and Fish Communities?

Seasonal floods are keystone events in the YMD, but the 

process is substantially altered from the natural state. 

Although fish movement onto the flood plain during high 

water is reasonably well documented, the effect of timing 

and duration of flooding on the species of the YMD is not 

well known. Some fish communities may be dependent on 

seasonal flooding to complete their life histories (obligate); 

others may be opportunistic users of the flood plain 

(facultative). The ability to exploit the flood plain can affect 

fish communities in adjacent habitats. Spawning of many 

species in the YMD occurs during periods of high water 

in the late winter and spring. Timing, duration, and water 

quality may affect spawning success of some species. 

Afforestation, the term used to describe planting agricultural 

land with trees, is used to reestablish commercial forests 

in the YMD. This practice also offers an opportunity to 

“naturalize” aquatic habitats located within the newly 

created forests. A quantitative evaluation of the fish 

communities and aquatic habitats in agricultural lands, 

forested lands, and afforested lands would provide a starting 

point for a systematic approach to a naturalization program 

for the YMD.

A few questions that address these issues are:

1. Which species are obligate users of the flood pulse and 

which are facultative users of the flood pulse?

2. How do timing and duration of floods affect water quality 

and the fish communities on the flood plain? 

3. How does the flood pulse affect fish communities on 

batture land? 

4. How do fish communities respond to seasonal floods in 

forested habitats and habitats in afforested lands?

Water and habitat quality also are linked to connectivity 

between the flood plain and the river. Water quality variables 

are likely to respond differently to seasonal floods and 

influence fish populations. Understanding how fish respond 

to seasonal floods can contribute to the development of 

techniques to control water levels in habitats isolated by 

levees and other flood control structures.

What Are the Relationships between Fish 

Communities and Habitat Structure?

The development of a method to classify habitats based on 

measurable geomorphic and hydrological features that can 

be related to fish/aquatic organisms is an important starting 

point in the analysis of relationships between fish and 

habitats. Such a methodology can be used to stratify habitats 

to determine relationships. It would also provide a useful 

tool for inventory and assessment of habitat that could be 

applied during planning of restoration projects. 

Complexity within habitats appears to be greatly reduced 

throughout the YMD. The removal of large riparian trees 

throughout the YMD and large-scale removal of large wood 

from nearly all flowing waters have substantially altered 

the physical habitat in most rivers, streams, and bayous. 

Furthermore, removal of instream wood has shaped the 

human perception of habitat complexity. In many areas of 

the Southeastern United States, large wood has not received 

22
the same emphasis as an integral part of fish habitat as it has 

elsewhere (Bisson and others 1987, Bryant and Sedell 1995). 

Benke and others (1985) recognized the importance of large 

wood to aquatic production, and Warren and others (2002) 

observed correlations between fish abundance and large 

wood in the loessial region of north central Mississippi. The 

effects of large wood accumulations on channel morphology 

and fish in the YMD were recognized by Shields and others 

(2000). However, the response of fish communities and 

abundance has not been explored for the YMD.

Some of the questions that begin to address these issues are:

1. How do fish communities differ among major habitat 

classifications in the YMD? 

2. What is the distribution of large wood in the YMD and its 

effect on species diversity and abundance?

3. How does habitat structure created by large wood and 

artificial structures such as large rock rip-rap affect fish 

communities?

4. Do riparian buffer strips increase habitat complexity, and 

what is their effect on the fish community?

The habitats in the YMD are diverse and range from large 

rivers to small sloughs and ephemeral ponds. Within each of 

these habitats, the complexity and structure also vary with 

corresponding effects on fish communities. Large wood may 

be a common feature that defines habitat structure in most 

of them. The preceding questions offer one approach to 

investigate how habitat structure influences fish communities 

in the YMD.

The three categories are relatively broad in scope, but 

provide a means of organizing an approach to understanding 

processes in aquatic ecosystems of the YMD that affect fish. 

The questions are examples that address gaps in information 

needed for projects to improve aquatic habitat quality in 

the YMD. They also provide a starting point for a larger 

discussion among agencies and stakeholders to develop 

a comprehensive research program for the YMD. This 

program can form a foundation for management of fish and 

aquatic resources.

Collaboration among government agencies, landowners, 

and nongovernmental organizations is an essential element 

in the successful implementation of a research program 

in the YMD. Collaboration needs to begin with planning 

and prioritizing a comprehensive long-term program. This 

process can identify the most critical information needs for 

ongoing and future restoration and management programs 

for the YMD. As studies are developed, coordination of 

effort among groups will contribute to efficient allocation 

of resources. Cooperative research has the advantage of 

forming a critical mass to undertake large-scale and longterm studies, whereas independent studies can focus on 

smaller short-term projects.

The Yazoo River Basin Team organization provides a 

template to develop a comprehensive and collaborative 

research agenda for the YMD (YRBT 2000). The team is 

broad based with representatives from Federal, State, and 

local government agencies, from stakeholder organizations 

representing landowners, and from nongovernment 

organizations such as The Nature Conservancy. The team 

has developed and implemented a long-range plan for 

management and restoration of aquatic habitats for the 

YMD. It provides a forum to coordinate existing projects, 

to apply new ideas, to propose and discuss new projects, 

and to generate and maintain public awareness of fish and 

aquatic resource management. All of these elements are 

essential for a successful, collaborative research effort that 

would complement a successful regional restoration and 

management program. 

Summary

The Mississippi River and the LMAV are products of 

geological processes that have continued since the early 

Eocene > 50 million years BP. The river has maintained its 

north-south location on the North American continent for 

the past 1.2 million years. During this time, the watershed 

has been exposed to extensive shifts in climate, sea level, 

and sediment regimes. The presence of ancient fish species, 

such as gar and bowfin, and the persistence of the large 

species assemblage in the Mississippi River valley may be 

attributed to the river’s long geological history and northsouth orientation. The present diverse fish community 

of the LMAV developed as a result of its geological and 

geomorphic history.

The Mississippi River alternated between a braided system 

and a meandering system through its geological history. Its 

present meandering phase formed about 9,000 years BP 

and shaped the present morphology of the YMD. Nearly 

all aquatic habitats in the YMD were formed as a result 

of channel meanders across the flood plain. Distributary 

channels, oxbow lakes, sloughs, bayous, and swamps were 

formed through the succession of meander bends and cutoffs 

from abandoned channels. Levees, flood control structures, 

23
land use practices, and loss of large wood in stream and 

river channels have modified and curtailed these processes 

throughout most of the YMD. 

Virtually all of the landscape in the YMD has been modified 

by human activity. Logging and land clearing for large-scale 

agriculture have removed nearly all of the hardwood forests 

in the YMD. Only patches remain, and these are regrowth 

from previous land clearing. Agriculture has removed most 

of the natural contours formed by meander scrolls and 

abandoned stream channels. Streams and bayous have been 

channelized (straightened) and ditched to facilitate drainage. 

Loss of riparian trees, in combination with snagging and 

channel clearing, has removed most large wood from rivers, 

streams, and bayous throughout the YMD. Levees and 

flood control structures, including bypass channels, have 

isolated most of the historic flood plain and have greatly 

attenuated the formation of new aquatic habitats in the flood 

plain of the YMD. However, the levees have created a new 

landscape, the batture land between the levees and the river 

where new aquatic habitats were created. Large areas of 

bottomland forest exist in batture land, but few examples of 

aquatic habitats exist that resemble those found in the YMD 

before European development either in the batture land or in 

the YMD flood plain.

As with its landscape, the hydrology of the YMD has been 

substantially modified from its natural cycle. It is still driven 

by seasonal climatic events and upstream conditions of 

rainfall and snowmelt; however, the duration and intensity 

of the upstream discharge cycle have been altered by 

upstream human activity. Within the YMD, the flood pulse 

has been changed both qualitatively and quantitatively. The 

Mississippi River no longer floods laterally across the flood 

plain. Connectivity is maintained as floodwaters back up 

the tributaries that flow across parts of the flood plain not 

isolated by levees. Drainage is accelerated on agricultural 

land and prolonged elsewhere by dams. All of these factors 

removed the natural dynamic flow and ebb of the flood 

pulse across the flood plain. Although little remains of the 

natural hydrology of the YMD, fish move in and out of the 

remaining flood plain on the altered flood pulse. 

Most of the larger fish species present during aboriginal 

occupation of the YMD are still present. Few archeological 

remains exist for smaller species, such as many of the 

Cyprinidae and smaller Percidae (darters); therefore, their 

diversity before development in the YMD is not known. 

These two families are a diverse group within the YMD, and 

within these families few species are listed as “species of 

concern” (Ross 2001). Given the large-scale loss of habitat 

throughout the YMD and the deterioration of water quality 

in much of the remaining habitat, the abundance of most 

species likely has declined. Fish communities may have 

changed, but this is difficult to assess based on the historical 

record. Although the general habitat requirements of most 

species are known (Ross 2001), the relationships of the fish 

to specific habitat features and their response to disturbance 

are not well defined for most species. Furthermore, 

responses of fish communities to the large-scale alterations 

of aquatic processes in the YMD are not clear. 

In the past few years, management of aquatic habitats 

in the YMD has centered on mitigating and preventing 

some of the adverse effects of anthropogenic disturbance, 

primarily intensive agriculture. Effort has been made to 

reduce sediment and chemical input to water bodies and to 

address other easily observable effects, including control of 

aquatic vegetation. These projects provide obvious benefits; 

however, a broader approach that restores natural aquatic 

processes can lead to more permanent and cost-effective 

measures. The research approach proposed in this paper is 

a starting point to develop an understanding of the response 

of fish communities to important processes in the aquatic 

ecosystem of the YMD. Understanding these relationships 

can contribute to a sustainable rehabilitation program within 

the socioeconomic context of the YMD. 

Acknowledgments

The technical reviews by Jack Killgore, Ph.D., Doug 

Shields, Ph.D., and Paul Hamel, Ph.D. were extremely 

helpful. I thank them for sharing their insights on the Delta 

from their years of experience working in the region. The 

discussions with Paul Hamel, Emile Gardiner, and others 

at the Center for Bottomland Hardwood Research provided 

invaluable insights and were enjoyable. I learned a great 

deal from them. I was fortunate to meet Ed Jackson, Ph.D. 

of the University of Southern Mississippi at his research 

site in Winterville, MS. He not only shared his knowledge 

of the early aboriginal cultures and their use of fish but 

also provided data on the fish remains that he and his team 

discovered. Don Jackson, Ph.D. shared his perspectives and 

papers on the importance of fish to the people in the area. I 

appreciate the support and positive environment created by 

Ted Leininger, Ph.D. and Mel Warren, Ph.D. 

24
Literature Cited

Amoros, C.; Bornette, G. 2002. Connectivity and biocomplexity in 

waterbodies of riverine floodplains. Freshwater Biology. 47: 761–776.

Arendt, J.D.; Wilson, D.S. 1999. Countergradient selection for rapid growth 

in pumpkinseed sunfish: disentangling ecological and evolutionary effects. 

Ecology. 80(8): 2793–2798.

Autin W.J.; Burns, S.F.; Miller, B.J. [and others]. 1991. Quaternary geology of 

the lower Mississippi Valley. In: Morrison, R.B., ed. Quaternary nonglacial 

geology: conterminous U.S. Boulder, CO: The Geological Society of 

America: 547–582.

Baker, J.A.; Killgore, K.J.; Kasul, R.L. 1991. Aquatic habitats and fish 

communities in the lower Mississippi River. Reviews in Aquatic Sciences. 

3(4): 313–356.

Barko, V.A.; Herzog, D.P.; O’Connell, M.T. 2006. Response of fishes to 

floodplain connectivity during and following a 500-year flood event in the 

unimpounded upper Mississippi River. Wetlands. 26(1): 244–257.

Barry, J.M. 1998. Rising tide. New York: Simon & Schuster. 524 p.

Benke, A.C.; Henry, R.L.; Gillespie, D.M.; Hunter, D.M. 1985. Importance 

of snag habitat for animal production in southeastern streams. Fisheries. 

10(5): 8–13.

Biedenharn, D.S.; Thorne, C.R.; Watson, C.C. 2000. Recent morphological 

evolution of the Lower Mississippi River. Geomorphology. 34(3-4): 227–249.

Bisson, P.A.; Bilby, R.E.; Bryant, M.D. [and others]. 1987. Large woody 

debris in forested streams in the Pacific Northwest: past, present, and future. 

In: Salo, E.O.; Cundy, T.W., eds. Streamside management: forestry and 

fishery interactions: Proceedings of a conference. Seattle: University of 

Washington, Seattle. College of Forest Resources: 143–190.

Boschung, H.T.; Mayden, R.L. 2004. Fishes of Alabama. Washington, DC: 

Smithsonian Books. 726 p.

Breitburg, E. 1998. Faunal remains. In: Chapman, S.; Walling, R., eds. 

Archaeological data recovery at the McNight site (22CO560), Coahoma 

County, Mississippi. Report prepared for the Mississippi Department 

of Transportation by Pan-American Consultants, Inc. Memphis TN: 

209–216. On file at: Southern Hardwoods Laboratory, 432 Stoneville Road, 

Stoneville, MS 38776.

Briggs, J.C. 1986. Introduction to the zoogeography of North American fishes. 

In: Hocutt, C.H.; Wiley, E.O., eds. The zoogeography of North American 

fishes. New York: John Wiley: 1–16.

Brinson, M.M.; Swift, B.L.; Plantico, R.C.; Barclay, J.S. 1981. Riparian 

ecosystems: their ecology and status. Biological Services Publication FWS/

OBS 81/17. Kearneysville, WV: Department of the Interior, U.S. Fish & 

Wildlife Service. 154 p.

Brown, A.V.; Brown, K.B.; Jackson, D.C.; Pierson, W.K. 2005. Lower 

Mississippi River and its tributaries. In: Benke, A.C.; Cushing, C.E., eds. 

Rivers of North America. New York: Elsevier Press: 231–281.

Brown, C.; Fenn, T.; Hinks, S. [and others]. 1994. A cultural resource 

assessment of the Palusha Creek 2 site, 22LF649, Leflore County, 

Mississippi. Report prepared for the U.S. Army Corps of Engineers by 

Christopher Goodwin and Associates, Inc. (New Orleans, LA). New 

Orleans: [Not paged]. On file at: Southern Hardwoods Laboratory, 432 

Stoneville Road, Stoneville, MS 38776. 

Bryant, M.D.; Sedell, J.R. 1995. Riparian forests, wood in the water, and 

fish habitat complexity. In: Armantrout, N.B., ed. Condition of the world’s 

aquatic habitats: Proceedings of the World Fisheries Congress. Athens, 

Greece: Oxford & IBH Publishing Co.: 202–224.

Capone, T.A.; Kushlan, J.A. 1991. Fish community structure in dry-season 

stream pools. Ecology. 72(3): 983–992.

Clayton, A.; Knight V.J., Jr.; Moore, E.C., eds. 1993. The DeSoto Chronicles: 

the expedition of Hernando de Soto to North America in 1539–1543, 

Volume 1. Tuscaloosa, AL: The University of Alabama Press. 569 p.

Conner, W.H.; Sharitz, R.R. 2005. Forest communities of bottomlands. 

In: Fredrickson, L.H., King, S.L.; Kaminski, R.M., eds. Ecology 

and management of bottomland hardwood systems: the state of our 

understanding. Special Publication No. 10. Puxico, MO: University of 

Missouri-Columbia. Gaylord Memorial Laboratory: 93–120.

Coxe, C.L. 1999. Vertebrate faunal analysis. In: Perrault, S.L.; Davoli, E.L.; 

Coxe, C.L.; Cash, W., eds. Cultural resources inventory, Upper Steele Bayou 

project, Swan Lake mitigation area, Washington County, Mississippi. Report 

prepared for the U.S. Army Corps of Engineers by Coastal Environments, 

Inc. (Baton Rouge, LA). Vicksburg, MS: 225–232. On file at: Southern 

Hardwoods Laboratory, 432 Stoneville Road, Stoneville, MS 38776.

Cross, F.B.; Mayden, R.L.; Stewart, J.D. 1986. Fishes in the western 

Mississippi basin (Missouri, Arkansas and Red Rivers). In: Hocutt, C.H.; 

Wiley, E.O., eds. The zoogeography of North American freshwater fishes. 

New York: John Wiley: 363–412.

Crossman, E.J.; McAllister, D.E. 1986. Zoogeography of freshwater fishes of 

the Hudson Bay drainage, Ugava Bay and Arctic Archipelago. In: Hocutt, 

C.H.; Wiley, E.O., eds. The zoogeography of North American freshwater 

fishes. New York: John Wiley: 53–104.

Delcourt, H. 1987. The impact of prehistoric agriculture and land occupation 

on natural vegetation. Trends in Ecology & Evolution. 2(2): 39–44.

Delcourt, P.A.; Delcourt, H.R. 1987. Long-term forest dynamics of the 

temperate zone: a case study of late-quaternary forests in eastern North 

America. New York: Springer-Verlag. 439 p.

Delcourt, P.A.; Delcourt, H.R.; Morse, D.F.; Morse, P.A. 1993. History, 

evolution, and organization of vegetation and human culture. In: 

Martin, W.H.; Boyce, S.G.; Echternacht, A.C., eds. Biodiversity of the 

Southeastern United States: lowland terrestrial communities. New York: 

John Wiley: 47–49.

Ewing, M.S. 1991. Turbidity control and fisheries enhancement in a 

bottomland hardwood backwater system in Louisiana (U.S.A.). Regulated 

Rivers: Research & Management 6(2): 87–99.

Finger, T.R.; Stewart, E.M. 1987. Response of fishes to flooding regime 

in lowland hardwood wetlands. In: Matthews, W.J.; Heins, D.C., eds. 

Community and evolutionary ecology of North American stream fishes. 

Norman, OK: University of Oklahoma Press: 86–92.

Fisk, H.N. 1944. Geological investigation of the alluvial valley of the lower 

Mississippi valley. Vicksburg, MS: U.S. Army Corps of Engineers, 

Mississippi River Commission. 78 p.

Franklin, S.B.; Wasklewicz, T.; Grubaugh, J.W.; Greulich, S. 2003. 

Hydrologic stage periodicity of the Mississippi River before and after 

systematic channel modifications. Journal of the American Water Resources 

Association. 39(3): 637–648.

25
Galat, D.L.; Fredrickson, L.H.; Humburg, D.D. [and others]. 1998. Flooding

 to restore connectivity of regulated, large-river wetlands. BioScience. 

48: 721–733.

Goulding, M. 1980. The fishes and the forest: explorations in Amazonian 

natural history. Berkeley, CA: University of California Press. 280 p.

Guillory, V. 1979. Utilization of an inundated floodplain by Mississippi River 

fishes. Florida Scientist. 42(4): 222–228.

Gutreuter, S.; Bartels, A.D.; Irons, K.; Sandheinrich, M.B. 1999. Evaluation 

of the flood-pulse concept based on statistical models of growth of selected 

fishes of the Upper Mississippi River system. Canadian Journal of Fisheries 

and Aquatic Sciences. 56(12): 2282.

Halupka, K.C.; Willson, M.F.; Bryant, M.D. [and others]. 2003. Conservation 

of population diversity of Pacific salmon in southeast Alaska. North 

American Journal of Fisheries Management. 23(4): 1057–1086.

Hamel, P.; Buckner, E.R. 1998. How far could a squirrel travel in the treetops? 

a prehistory of the southern forest. In: Transactions of the 63rd North 

American Wildlife and Natural Resources Conference. Washington, DC: 

Wildlife Management Institute: 309–315.

Harper, R.M. 1912. Botanical evidence of the age of certain ox-bow lakes. 

Science. 36(935): 760–761.

Hilborn, R.; Quinn, T.P.; Schindler, D.E.; Rogers, D.E. 2003. Biocomplexity 

and fisheries sustainability. Proceedings of the National Academy of 

Sciences. Washington, DC: National Academy of Sciences. 100(11): 

6564–6568.

Hodges, J.D. 1994. The southern bottomland hardwood region and brown 

loam bluffs subregion. In: Barret, J.W., ed. Regional Silviculture of the 

United States. New York: John Wiley: 227–269.

Holland, L.E.; Bryan, C.F.; Newman, J.P. 1983. Water quality and the rotifer 

population in the Atchafalaya River basin, Louisiana. Hydrobiologia.

98(1): 55–69.

Hooke, J.M. 2004. Cutoffs galore! occurrence and causes of multiple cutoffs 

on a meandering river. Geomorphology. 61(3–4): 225–228.

Hoover J.J.; Killgore, K.J. 1998. Fish communities. In: Messina, M.G.; 

Conner, W.H., eds. Southern forested wetlands: ecology and management. 

Boca Raton, LA: Lewis Publishers: 237–260.

Hoover, J.J.; Killgore, K.J. 2002. Small floodplain pools as habitat for fishes and 

amphibians: methods for evaluation. ERDC TN EMRRP EM 03. Vicksburg, 

MS: U.S. Army Engineer Research and Development Center. 13 p.

Howard, R.J.; Allen, J.A. 1989. Streamside habitats in southern forested 

wetlands: their role and implications for management. In: Hook, D.D.; 

Lea, R., eds. Proceedings of the symposium: The forested wetlands of 

the Southern United States. Gen. Tech. Rep. SE–50. Asheville, NC: U.S. 

Department of Agriculture Forest Service, Southeastern Forest Experiment 

Station: 97–106.

Hudson, C. 1997. Knights of Spain, warriors of the sun: Hernando de Soto 

and the South’s ancient chiefdoms. Athens, GA: University of Georgia 

Press. 561 p.

Hudson, P.F.; Kesel, R.H. 2000. Channel migration and meander-bend 

curvature in the lower Mississippi River prior to major human modification. 

Geology. 28(6): 531–534.

Hupp, C.R.; Walbridge, M.R.; Lockaby, B.G. 2005. Fluvial geomorphic 

processes and landforms, water quality, and nutrients in bottomland 

hardwood forests of southeastern USA. In: Fredrickson, L.H.; King, S.L.; 

Kaminski, R.M., eds. Ecology and management of bottomland hardwood 

systems: the state of our understanding. Special Publication No. 10. 

Puxico, MO: University of Missouri-Columbia. Gaylord Memorial 

Laboratory: 37–55.

Jackson, D.A.; Mandrak, N.E. 2002. Changing fish biodiversity: predicting 

the loss of cyprinid biodiversity due to global climate change. In: McGinn, 

N.A., ed. Fisheries in a changing climate. American Fisheries Society 

Symposium 32, Bethesda, MD: American Fisheries Society: 89–98.

Jackson, D.C. 2004. Fisheries dynamics in the Yazoo River Basin. In: 

Welcomme, R.L.; Petr, T., eds. Proceedings of the second international 

symposium on the management of large rivers for fisheries: volume 2. 

RAP Publication 2004/17. Bangkok: FAO Regional Office for Asia and the 

Pacific: 103–115.

Jackson, D.C. 2005. Fisheries dynamics in temperate floodplain rivers. 

In: Fredrickson, L.H.; King, S.L.; Kaminski, R.M., eds. Ecology 

and management of bottomland hardwood systems: the state of our 

understanding. Special Publication No. 10. Puxico, MO: University of 

Missouri-Columbia, Gaylord Memorial Laboratory: 201–212.

Jackson, D.C.; Francis, J.M.; Ye, Q. 1997. Hand grappling blue catfish in the 

main channel of a Mississippi river. North American Journal of Fisheries 

Management. 17: 1019–1024.

Jackson, D.C.; Ye, Q. 2000. Riverine fish stock and regional agronomic 

responses to hydrological and climatic regimes in the upper Yazoo River 

basin. Cowx, I.G., ed. Management and ecology of river fisheries. Oxford, 

UK: Fishing News Books: 242–257.

Junk, W.G.; Bayley, P.B.; Sparks, R.E. 1989. The flood pulse concept in riverfloodplain systems. Canadian Special Publications of Fisheries and Aquatic 

Sciences. 106: 110–127.

Kaeser, A.J.; Litts, T.L. 2008. An assessment of deadhead logs and large 

woody debris using side scan sonar and field surveys in streams of 

southwest Georgia. Fisheries. 33(12): 589–597.

Kemper, J.P. 1928. Floods in the valley of the Mississippi. New Orleans: 

National Flood Commission. 255 p.

Killgore, K.J.; Baker, J.A. 1996. Patterns of larval fish abundance in a 

bottomland hardwood wetland. Wetlands. 16: 288–295.

Killgore, K.J.; Hoover, J.J. 1992. A guild for monitoring and evaluating fish 

communities in bottomland hardwood wetlands. WRP Technical Note FWEV-2.2. Vicksburg, MS: U.S. Army Engineer Research and Development 

Center. 7 p.

Killgore, K.J.; Hoover, J.; Murphy, C.; George, S. 2008a. Index of biological 

integrity for fishes of the Yazoo River Delta, Mississippi (draft). Vicksburg, 

MS: U.S. Army Corps of Engineers, Engineer Research and Development 

Center. 34 p.

Killgore, K.J.; Hoover, J.J.; Murphy, C.E. [and others]. 2008b. Restoration 

of delta streams: a case history and conceptual model. EMRRP Technical 

Notes Collection. ERDC TN-EMRRP-ER-08. Vicksburg, MS: U.S. Army 

Engineer Research and Development Center. 19 p.

Kwak, T.J. 1988. Lateral movement and use of floodplain habitat by fishes of 

the Kankakee River, Illinois. American Midland Naturalist. 120(2): 241-249.

26
Lucas, G.M. 1985. Survey of the fisheries of the Mississippi Delta. 

Mississippi Project F-68. Oxford, MS: Mississippi Department of Wildlife 

Conservation. 51 p.

Maser, C.; Sedell, J.R. 1994. From the forest to the sea: the ecology of wood 

in streams, rivers, estuaries, and oceans. Delray Beach, FL: St. Lucie 

Press. 200 p.

Matthews, W.J. 1987. Physicochemical tolerance and selectivity of stream 

fishes as related to their geographic ranges and local distributions. In: 

Matthews, W.J.; Heins, D.C., eds. Community and evolutionary ecology 

of North American stream fishes. Norman, OK: University of Oklahoma 

Press: 111–120.

Mayden, R.L. 1988. Vicariance biogeography, parsimony, and evolution in 

North American freshwater fishes. Systematic Zoology. 37(4): 329–355.

Meador, M.R.; Coles, J.F.; Zappia, H. 2005. Fish assemblage responses to 

urban intensity gradients in contrasting metropolitan areas: Birmingham, 

Alabama and Boston, Massachusetts. American Fisheries Society 

Symposium. 47: 409–423.

Miller, R.R. 1965. Quaternary freshwater fishes of North America. In: Wright, 

H.E., Jr.; Frey, D.G., eds. The quaternary of the United States. Princeton, 

NJ: Princeton University Press: 569–581.

Miranda, L.E. 2005. Fish assemblages in oxbow lakes relative to connectivity 

with the Mississippi River. Transactions of the American Fisheries Society. 

134: 1480–1489.

Miranda, L.E.; Aycock, J.N.; Miyazono, S.; Steffen, C.J. 2007. Biotic integrity 

of alluvial lakes in the Yazoo River Basin. Progress Report to U.S. Army 

Corps of Engineer, Engineer Research and Development Center, Waterways 

Experiment Station. Starkville, MS: USGS Mississippi Cooperative Fish 

and Wildlife Unit and Department of Wildlife and Fisheries, Mississippi 

State University. 47 p.

Miranda, L.E.; Lucas, G.M. 2004. Determinism in fish assemblages of 

floodplain lakes of the vastly disturbed Mississippi Alluvial Valley. 

Transactions of the American Fisheries Society. 133: 358–370.

Mooney, J.P.; Wilkerson, S.; Mead, T.; Wilson, J.P. 2003. Cultural resource 

phase III mitigation of sites 22CO573/773and 22CO788 for the construction 

of the Coahoma welcome center at the interchange of U.S. Highway 49 

and 61. Report prepared for the Mississippi Department of Transportation 

by Michael Baker, Inc. White Hall, AR. [Not paged]. On file at: Southern 

Hardwoods Laboratory, 432 Stoneville Road, Stoneville, MS 38776. 

National Research Council. 1992. Restoration of aquatic ecosystems. 

Washington, DC: National Academy Press. 552 p.

Peacock, E.; Haag, W.R.; Warren, M.L. 2004. Prehistoric decline in freshwater 

mussels coincident with the advent of maize agriculture. Conservation 

Biology. 19(2): 547–551.

Platt, S.G.; Brantley, C.G. 1997. Canebrakes: an ecological and historical 

perspective. Castanea. 62(1): 8–21.

Powers, S.L.; Warren, M.L., Jr. 2009. Phylogeography of three snubnose 

darters (Percidae: subgenus Ulocentra) endemic to the Southeastern U.S. 

coastal plain. Copeia. 3: 526–531.

Puth, L.M.; Wilson, K.A. 2001. Boundaries and corridors as a continuum 

of ecological flow control: lessons from rivers and streams. Conservation 

Biology. 15(1): 21–30.

Putnam, J.A.; Furnival, G.M.; McKnight, J.S. 1960. Management and 

inventory of southern hardwoods. Agric. Handb. 181. Washington, DC: U.S. 

Department of Agriculture. 102 p.

Rempel, L.L.; Smith, D.G. 1997. Postglacial fish dispersal from the 

Mississippi refuge to the Mackenzie basin. Canadian Journal of Fisheries 

and Aquatic Sciences. 55: 893–899.

Richie, J.C.; Cooper, C.M.; McHenry, J.R.; Schiebe, F.R. 1983. Sediment 

accumulation in Lake Chicot, Arkansas. Environmental Geology. 5(2): 

79–82.

Robison, H.W. 1986. Zoogeographic implications of the Mississippi River 

basin. In: Hocutt, C.H.; Wiley, E.O., eds. The zoogeography of North 

American freshwater fishes. New York: John Wiley: 267–286.

Ross, S.T. 2001. Inland fishes of Mississippi. Jackson, MS: University Press of 

Mississippi. 624 p.

Ross, S.T.; Baker, J.A. 1983. The response of fishes to periodic spring floods 

in a southeastern stream. American Midland Naturalist. 109: 1–14.

Rutherford, D.A.; Gelwicks, K.R.; Kelso, W.E. 2001. Physiochemical effects 

of the flood pulse in the Atchafalaya River Basin, Louisiana. Transactions of 

the American Fisheries Society. 130: 276–288.

Saikku, M. 2005. This delta, this land: an environmental history of the YazooMississippi floodplain. Athens, GA: The University of Georgia Press. 373 p.

Saucier, R.T. 1994. Geomorphology and quaternary geologic history of the 

lower Mississippi valley. Vicksburg, MS: U.S. Army Engineer Waterways 

Experiment Station, Mississippi River Commission. 364 p.

Schramm, H.L., Jr.; Eggleton, M.A. 2006. Applicability of the flood-pulse 

concept in a temperate floodplain river ecosystem: thermal and temporal 

components. River Research and Applications. 22(5): 543–553.

Schade, C.B.; Bonar, S.A. 2005. Distribution and abundance of nonnative 

fishes in streams of the western United States. North American Journal of 

Fisheries Management. 25: 1386–1394.

Scott S.L. 1995. Vertebrate faunal remains. In: Weinstein, R.A.; Fuller, S.; 

Scott, S.L. [and others]. The rock levee site: late Marksville through late 

Mississippi period settlement, Boliver County, Mississippi. Report prepared 

for the U.S. Army Corps of Engineers by Coastal Environments, Inc. (Baton 

Rouge, LA). Vicksburg, MS: 243–262. On file at: Southern Hardwoods 

Laboratory, 432 Stoneville Road, Stoneville, MS 38776.

Shankman, D. 1991. Forest regeneration on abandoned meanders of a coastal 

plain river in western Tennessee. Castanea. 3(56): 157–167.

Sheaffer, W.A.; Nickum, J.G. 1986. Backwater areas as nursery habitats 

for fishes in pool 13 of the Upper Mississippi River. Hydrobiologia. 136: 

131–139.

Shields, F.D., Jr. 2008. Effects of a regional channel stabilization project on 

suspended sediment yield. Journal of Soil and Water Conservation. 63(2): 

59–69.

Shields, F.D.; Knight, S.S.; Cooper, C.M. 2000. Cyclic perturbation of lowland 

river channels and ecological response. Regulated Rivers: Research & 

Management. 16(4): 307–325.

Shields, F.D.; Knight, S.S; Lizotte, R.E. [N.d.]. General design criteria for river 

backwater restoration. Oxford, MS: U.S. Department of Agriculture, ARS 

National Sedimentation Laboratory, Water Quality & Ecology Unit. 25 p.

27
Skelly, D.; Joseph, L.N.; Possingham, H.P. [and others]. 2007. Evolutionary 

responses to climate change. Conservation Biology. 21(5): 1353–1355.

Smale, M.A.; Rabeni, C.F. 1995. Hypoxia and hyperthermia tolerances of 

headwater stream fishes. Transactions of the American Fisheries Society. 

124: 698–710.

Smith, G.R. 1981. Late Cenozoic freshwater fishes of North America. Annual 

Review of Ecology and Systematics. 12: 163–193.

Snedden, G.A.; Kelso, W.E.; Rutherford, D.A. 1999. Diel and seasonal 

patterns of spotted gar movement and habitat use in the Lower Atchafalaya 

River basin, Louisiana. Transactions of the American Fisheries Society. 

128: 144–154.

Sparks, R.E.; Nelson, J.C.; Yin, Y. 1998. Naturalization of the flood regime in 

regulated rivers. BioScience. 48(9): 706–720.

Stanturf, J.A.; Goodrick, S.L.; Outcalt, K.W. 2007. Disturbance and coastal 

forests: a strategic approach to forest management in hurricane impact 

zones. Forest Ecology and Management. 250: 119–135.

Stanturf, J.A.; Schoenholtz, S.H. 1998. Soils and landforms. In: Messina, 

M.G.; Conner, W.H., eds. Southern forested wetlands: ecology and 

management. Boca Raton, LA: Lewis Publishers: 123–147.

Thomaz, S.M.; Bini, L.M.; Bozelli, R.L. 2007. Floods increase similarity 

among aquatic habitats in river-floodplain systems. Hydrobiologia.

 579(1): 1–13.

Tockner, K.; Pennetzdorfer, D.; Reiner, F.; Ward, J. V. 1999. Hydrological 

connectivity, and the exchange of organic matter and nutrients in a dynamic 

river-floodplain system (Danube, Austria). Freshwater Biology. 41(3): 

521–535.

Turner, T.F.; Trexler, J.C.; Miller, G.L.; Toyer, K.E. 1994. Temporal and spatial 

dynamics of larval and juvenile fish abundance in a temperate floodplain 

river. Copeia. 1: 174–183.

Wallace, J.B.; Benke, A.C. 1984. Quantification of wood habitat in subtropical 

coastal plain streams. Canadian Journal of Fisheries and Aquatic Sciences. 

41(11): 1643–1652.

Warren, M.L.; Burr, B.M.; Walsh, S.J. [and others]. 2000. Diversity, 

distribution, and conservation status of the freshwater fishes of the Southern 

United States. Fisheries. 25(10): 7–29.

Warren, M.L.; Haag, W.R.; Wendell, R.; Adams, S.B. 2002. Forest linkages to 

diversity and abundance in lowland stream fish communities. In: Holland, 

M.M.; Warren, M.L.; Stanturf, J.A., eds. Proceedings of a conference on 

sustainability of wetlands and water resources. Gen. Tech. Rep. SRS–50. 

Asheville, NC: U.S. Department of Agriculture Forest Service, Southern 

Research Station: 168–182.

Wilson R.C. 1987. Analysis of the faunal remains from the French Site 

22Ho565/19 p10, Holmes County, Mississippi. In: Marshall, R. A. 

ed. Archaeological data recovery at the French Site. Cobb Institute of 

Archaeology, Mississippi State University, Starkville: 1-10.

Yazoo River Basin Team (YRBT). 2000. Yazoo River Basin Status Report 

2000. Jackson, MS: Mississippi Department of Environmental Quality. 29 p. 

http://www.deq.state.ms.us. [Date accessed: March 2009].

28


Bryant, M.D. 2010. Past and present aquatic habitats and fish populations of the Yazoo-Mississippi 

Delta. Gen. Tech. Rep. SRS–130. Asheville, NC: U.S. Department of Agriculture Forest Service, 

Southern Research Station. 28 p.

The goal of this review and synthesis of the literature, published and unpublished, is to describe the 

major processes that shape and influence the aquatic habitats and fish communities in the YazooMississippi Delta (YMD) and to outline a program of research. The YMD is influenced by the large 

geographic and temporal scales of the Mississippi River watershed. It extends over 41 percent of 

the contiguous United States. The Mississippi River has existed in its current location for more than 

1.2 million years, and ancient fish species are still present in the watershed. About 9,500 years BP, 

the Mississippi River formed into a predominantly meandering channel from which most of the 

aquatic habitats in the YMD developed. Oxbows formed in the meander belts shape the topography 

of the YMD and are a fundamental part of the development of the aquatic habitat of the YMD. 

Seasonal floods are keystone events in the YMD, but the process is altered substantially from its 

previous natural state. Levees, flood control structures, land use practices, and loss of large wood 

in river channels have modified natural processes throughout most of the YMD. However, most of 

the larger fish species present during aboriginal occupation of the YMD are still present. Given the 

large-scale loss of habitat throughout the YMD and the deterioration of water quality, the abundance 

and diversity of fish likely have declined. In the past few years, management of aquatic habitats in 

the YMD has centered on mitigating and preventing some of the adverse effects of anthropogenic 

disturbance. A program of “naturalization” to move aquatic ecosystem processes closer to natural 

conditions is possible within the context of socioeconomic constraints. The research approach 

proposed in this paper provides a model to develop an understanding of the fish and aquatic habitat 

that can contribute to a sustainable restoration program. 

Keywords: Aquatic habitat, bottomland hardwood forests, fish diversity, floodplain processes, 

floods, Mississippi River, Yazoo-Mississippi Alluvial Floodplain, Yazoo River.
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