Make your voice heard

To encourage specific research on the diet of white pelicans on the Upper Mississippi River. If results show significant consumption of game fish relative to population estimates for these species in the River, see the establishment of a maximum white pelican population number by pool on the Upper Mississippi River above which population controls would be implemented to prevent harmful over-predation of valuable game fish species.

How many pelicans are too many? At what point is the ecosystem out of balance?

It would be logical for the research required to establish these maximum numbers to be conducted first on Pool 13 since it harbors a large breeding population from Spring through Fall. While white pelican numbers are increasing across the entirety of the Upper Mississippi, Pool 13 is currently the only known breeding colony.

White pelicans are native to the Upper Mississippi River. However, their population plummeted during the mid-1900s due to harmful pesticides such as DDT that accumulated in the fish that the pelicans ate. 

The number of white pelicans on Pool 13 has increased dramatically over the last several decades and more and more are observed on other pools, as well. The most recent population estimate by U.S. Fish and Wildlife Service officials for Pool 13 during months when the birds are present is approximately 4,000 — ten times more than around the time the breeding colony was established.

White pelicans are primarily fish eaters. Research has shown that adult pelicans consume 2.5 to 4 pounds of fish per day (Hall 1925; Anderson 1987). White pelicans do not dive for fish, feeding only as deep as their necks can reach. Although they are often said to feed mainly on small schooling fish of little value to humans, such as gizzard shad and rough fish, they are non-selective and will eat fish that are available to them at any given time.

Because white pelicans are restricted to fishing in relatively shallow water and will eat all kinds of fish, the potential impact to game fish populations on the Upper Mississippi River is theoretically high. This is because fish such as largemouth bass, northern pike, crappies, bluegills, pumpkinseeds, and yellow perch spend much of their time in shallow backwater areas where white pelicans often forage. Additionally, white bass are known to spend time schooling high in the water column where they are vulnerable to pelicans.

With an estimated 4,000 white pelicans on Pool 13, fish consumption per day using the average cited above would be 10,000 to 16,000 pounds of fish per day. The annual total for the months that pelicans are present would be in the millions of pounds.

Although long-term resource monitoring has not shown any obvious coincidental patterns involving reductions in game fish populations and increases in white pelican abundance, many river users are increasingly concerned that an unchecked white pelican population could negatively impact fish populations. Many of the species of concern (centrarchid fish such as largemouth bass, bluegill, and crappie) are already facing survivability challenges from dwindling overwintering areas caused by continued sedimentation of backwaters. (Pitlo 1992; Raibley et al. 1997; Lubinski 1999)

Double-crested cormorants inhabit the same areas as white pelicans. The excrement of these fish eaters contains chemicals that alter soil chemistry and kills vegetation and trees growing in roosting areas. The resulting open areas attract white pelicans for breeding and loafing. High numbers of pelicans add to the soil damage and suppression of wood vegetation growth. Bare islands are more susceptible to erosion from strong currents during high water periods. This can ultimately lead to island loss. Destruction of trees and other vegetation also alters bird communities that formerly utilized the compromised islands.

Recreational fishing brings with it a large amount of economic benefit for communities along the river. Fishermen spend money on bait, tackle, fuel, food, drinks, and lodging among other things on their way to and from the river. Reductions in game fish populations would ultimately lead to a reduction in revenue related to fishing.

A 1995 study by the U.S. Army Corps of Engineers estimated that nearly 29% of all recreational activity on the Upper Mississippi River was related to fishing. When that percentage is applied to the U.S. Fish and Wildlife Service estimate of $4 billion in revenue generated by all recreational activities in the Upper Mississippi River corridor, the result is an estimated $1.16 billion in revenue from recreational fishing.