Knowledge of habitats used by fish throughout their life history is important for management and conservation of riverine fish populations and habitats. Naturally occurring chemical markers in otoliths have recently been used to determine natal origins and environmental history of fishes in a variety of marine and freshwater environments.However, to our knowledge no studies have examined the applicability of this technique in large floodplain rivers in the U.S.A. We evaluated otolith microchemistry and stable The ability to reconstruct environmental history of individual fish using naturally occurring isotopic markers in otoliths may also facilitate efforts to quantify nutrient and energy subsidies to the Illinois River provided by fishes that emigrate from floodplain lakes or tributaries.3

Naturally occurring stable isotope and trace elemental markers in otoliths have emerged as powerful tools for determining natal origins and environmental history of fishes in a variety of marine and freshwater environments. However, few studies have examined the applicability of this technique in large river-floodplain ecosystems. This study evaluated otolith microchemistry and stable isotopic composition as tools for determining environmental history of fishes in the Middle Mississippi River, its tributaries, and 3

The Provincelands Hook, an area of marshes and dunes, was built out from the northern end of the glacial deposits of Outer Cape Cod. The hook, a wedge 60 m at its thickest, of marine, beach, and dune material, rests in part on Tertiary Coastal Plain sediments that are probably only an isolated patch on the crystalline basement. About 18,000 years ago, when late Tazewell ice melted away from the region of present day Cape Cod, the Gulf of Maine was filled with ice, and Georges Bank was above sea level. Between 18,000 and 6,000 years ago, sand that eroded from the coast was moved along the east side of Cape Cod from north to south, where it accumulated as a part of the sand wave complex southeast of the cape. Waves from the east and southeast that would have tended to move sand northward along the Capo were blocked by Georges Shoals and Nantucket Shoals. By 6,000 years ago, sea level had so risen that deeper water over Georges Bank permitted more waves to reach Cape Cod from the east and southeast. The dominant direction of littoral drift which had been to the south, then received a strong north component and material moved northward, accumulating to form the Provincelands Hook. Based on 14C dates and other evidence, the hook formed between 6,000 years ago and the present and is still growing. Shoreline reconstructions are guided by 14C dates, well information, regional topography, and known behavior of hooks. It is noted that hooks are characteristic features of Cape Cod spits and tend to trap lakes behind them. The depressions containing lakes in the modern Provincelands are interpreted as low areas trapped behind hooks. A change in the growth habits of spits is thought to have taken place about 2,000 years ago, coinciding with the abrupt decrease in the rate of rise of sea level.

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Ten nest colonies of black crappie Pomoxis nigromaculatus were visually located and verified by angling in Campus Lake, a small urban impoundment in southern Illinois. Habitat characteristics were measured at these nest sites and compared to habitat measurements obtained from 45 unused sites. Seven habitat characteristics (substrate firmness, temperature, dissolved oxygen, distance to deep water [3.8‐m depth contour], substrate type, vegetation height, and vegetation density) were significantly different between nest sites and unused sites. Although temperature and dissolved oxygen were significantly different between nest sites and unused sites, all values were within the suitable range for black crappie spawning to occur. Black crappies selected nest sites close to deep water with firm substrates and low vegetation height and density. Our results present insight on habitat characteristics of black crappie spawning locations in a small urban impoundment. Interestingly, we located several black crappie nesting colonies with more than 10 individual nests in close proximity to one another; colonial nesting by black crappies has not previously been reported in the literature. Furthermore, we suggest that degree of shoreline modification and other anthropogenic influences in and adjacent to Campus Lake did not affect black crappie nest site selection. Black crappie nest sites in Campus Lake were always located near deep water (3.8 m), in low‐density, short vegetation, and on firm clay or sand substrate; because nest site selection can influence earlylife survival and recruitment of black crappie, the availability of these habitat characteristics may regulate black crappie population demographics in Campus Lake. Efforts to limit sediment inputs will be important for maintaining suitable black crappie spawning habitat in Campus Lake and other small impoundments.

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