Distribution of early life history stages of fishes in selected pools of the Upper Mississippi River

Abstract

Effective management of the fishery resources of the Upper Mississippi River and successful mitigation of the loss of critical habitat depend in part on an understanding of the reproductive and early life history requirements of the affected fishes. However, little is known about the use of nursery areas by fishes in the river. Of the nearly 130 species identified in the adult ichthyofauna, only a few are represented proportionally in the available data on early life stages because study designs have not included consideration of the early stages, collection gears have not adequately sampled the young, and eggs and larvae of some species are difficult to sample by conventional approaches. For the species collected, information is available on seasonal variations in total densities, composition, and catch among different habitat types. However, the data are most accurate for species with buoyant early life stages, such as freshwater drum (Aplodinotus grunniens) and gizzard shad (Dorosoma cepedianum). Eggs and larvae of freshwater drum dominate collections made in the main channel, whereas other larval fishes are usually most abundant in backwater habitats. The species found there usually deposit eggs on the substrate or on vegetation. Habitat preferences (as indicated by relative abundance) often shift as development proceeds and physical and behavioral changes occur in the larvae. Only limited information is available on the distribution of larvae within habitats, but it is clear that variations within habitats are significant.

Laboratory Experiments on the Effects of Blade Strike from Hydrokinetic Energy Technologies on Larval and Juvenile Freshwater Fishes

“…In large rivers the highest concentrations of fish early life stages are most often found in backwater habitats (Holland 1986). Backwater habitats are generally characterized by their water velocities (a low kinetic energy environment).…”

“…Backwater habitats are generally characterized by their water velocities (a low kinetic energy environment). The faster currents of main channel waters in large rivers facilitate downstream dispersal for fish larvae from pelagic broadcast spawners such as freshwater drum or white bass (Holland 1986, Sheaffer and Nickum 1986, Scheidegger and Bain 1995. Because early life stages of fish are delicate and easily damaged, physical contact with solid objects present a potential hazard to the survival of these organisms.…”

Fish larvae assemblages in two floodplain lakes with different degrees of connection to the Paraná River, Brazil

“…The species captured most often were sedentary and characteristic of lentic environments (e.g., Plagioscion squamosissimus, Hypophthalmus edentatus and Catathyridium jenynsii). The prevalence of these species may be related to the nature of their initial development, which favors dispersal to surface waters (Holland, 1986) because of the presence of oil droplets in the eggs (Plagioscion squamosissimus and Catathyridium jenynsii), which increases their buoyancy (Bialetzki et al, 2005).…”

Otolith trace element and stable isotopic compositions differentiate fishes from the Middle Mississippi River, its tributaries, and floodplain lakes

“…Tributary streams may also contribute to fish assemblages in large rivers, at least near their confluences (Brown & Coon, 1994;Robinson et al, 1998;Kiffney et al, 2006). Larval fishes are sometimes abundant in the main channel of large rivers, suggesting that main channels may be more hospitable as larval nursery areas than previously thought; species composition of larval fishes in the main channel is often distinct from that of off-channel habitats (Holland, 1986;Dettmers et al, 2001). Nearshore, slack-water habitats may provide the primary nursery area for rheophilic fishes in some rivers (i.e., the "inshore retention concept", Scheimer et al, 2001;Keckeis & Scheimer, 2002).…”