New databases reveal 200 years of change on the Mississippi River system
[No abstract available]
Eos, Transactions, American Geophysical Union↗
Geology topics
B. Ickes
Publications and source records attributed to B. Ickes.
Challenges in merging fisheries research and management: The Upper Mississippi River experience
The Upper Mississippi River System (UMRS) is a geographically diverse basin extending 10?? north temperate latitude that has produced fishes for humans for millennia. During European colonization through the present, the UMRS has been modified to meet multiple demands such as navigation and flood control. Invasive species, notably the common carp, have dominated fisheries in both positive and negative ways. Through time, environmental decline plus reduced economic incentives have degraded opportunities for fishery production. A renewed focus on fisheries in the UMRS may be dawning. Commercial harvest and corresponding economic value of native and non-native species along the river corridor fluctuates but appears to be increasing. Recreational use will depend on access and societal perceptions of the river. Interactions (e. g., disease and invasive species transmission) among fish assemblages within the UMRS, the Great Lakes, and other lakes and rivers are rising. Data collection for fisheries has varied in intensity and contiguousness through time, although resources for research and management may be growing. As fisheries production likely relies on the interconnectivity of fish populations and associated ecosystem processes among river reaches (e. g., between the pooled and unpooled UMRS), species-level processes such as genetics, life-history interactions, and migratory behavior need to be placed in the context of broad ecosystem- and landscape-scale restoration. Formal communication among a diverse group of researchers, managers, and public stakeholders crossing geographic and disciplinary boundaries is necessary through peer-reviewed publications, moderated interactions, and the embrace of emerging information technologies. ?? Springer Science+Business Media B.V. 2010.
Hydrobiologia↗
Assessing habitat use by breeding Great Blue Herons (Ardea herodias) on the Upper Mississippi River, USA
Approximately 7,610 to 3,175 pairs of Great Blue Herons ( Ardea herodias ) nested along 420 river km of the Upper Mississippi River (UMR) from 1993 to 2003. Numbers declined precipitously in the mid-1990s stabilizing somewhat in the early 2000s. The average number of nests in colonies was 349 (SD = 283). Annual colony turn over rate for the eleven year period was 0.15 and ranged from 0.06 to 0.29 each year. The number of years that a colony was active was positively correlated with the average number of nests present while the colony was active. Of the eight colonies active in 1993 that averaged more than 349 nests, four were abandoned by 2003. Only one colony grew to greater than 349 nests during the study period. Custer et al. (2004) suggested that herons on the UMR may be limited by forage resources or foraging habitat and social factors, as evidenced by the even spacing of colonies that reflects the maximum feeding range of herons on the river. To rule out nesting and foraging habitat limitation, landscape habitat features of terrestrial and aquatic areas were examined for colony areas and areas without colonies. Available fish monitoring data were used to examine potential interactions between herons and forage resources. Colony areas did not differ from areas without colonies in any habitat feature. Indices of potential heron forage fish increased from 1993 to 2002, although low indices of fish abundance in 1993 were likely influenced by flood conditions that year. Although fish availability to herons is related to flows and water levels, available data suggested that herons did not negatively impact their potential forage base. Numbers of herons were not correlated with indices of fish abundance from the preceding year on a pool-wide scale. Indices of fish abundance were higher within 5 km of colonies than farther than 5 km from colonies, and indices of fish abundance increased from June through August both near and far from colonies. Numbers of herons and locations and sizes of colonies varied annually, whereas landscape features typically vary little if at all from year to year. Indices of fish abundance also varied greatly by sample location and year. Disturbance, particularly by humans in this highly used river, should be examined in relation to limiting foraging opportunities and influencing behavior (colony and individual) and productivity in colonies.
Illinois, Iowa, Minnesota, Missouri, Wisconsin↗