Chapter 5: Biology and Natural History of Bighead Carp
In their native range, bighead carp are primarily creatures of large rivers and associated floodplain lakes (Yi et al. 1988). They have been introduced widely to ponds, lakes, reservoirs, and large canals where they exist and grow well, although reproduction and recruitment is probably rare without access to an appropriate riverine environment for spawning. Successful spawning of bighead carp in the Kara Kum Canal, Turkmenistan (Aliyev 1976), and possibly in a reservoir in Taiwan (Tang 1960), however, indicate that spawning in additional habitat types is possible. Nikolsky (1963) and Chang (1966) reported that adult bighead carp generally remained in river channels, reservoirs, or lakes, except during spawning periods when they moved to areas of rapids. Little information is available concerning the ecology and habitat of wild juvenile bighead carp past the larval stage. Young of year and juvenile bighead carp in the Yangtze (Changjiang) River are thought to migrate to floodplain lakes (Yi et al. 1988). Abdusamadov (1987) reported that, in the Terek Region of Russia, bighead carp fingerlings migrated into the coastal areas of the Caspian Sea.
In a telemetry study on the Illinois River (May through July of 2003 and 2004), movement rates of bighead carp were found to be highly variable. Although mean movement per day over the study was 1.7 km/d, in some cases fish moved long distances in a short period of time, up to 14 km/d (Peters et al. 2006). Longer movements may have been associated with spawning events. In another telemetry study (2002–2004) on the Missouri River, Chapman (unpublished data) found that adult bighead carp primarily used low velocity habitats behind wing dikes (rock structures extending from shore into the navigation channel; Figure 5.1) and also extensively used tributaries of the Missouri River, particularly the sections of the tributaries that cross the Missouri River floodplain. These segments are often deep and generally have low velocity except during periods of local rainfall (Figure 5.2). Bighead carp often moved between the Missouri River and a tributary multiple times. The water depth at 90% of adult bighead carp locations was 3 m or more. Adult bighead carp strongly preferred spur dikes (dikes at right angles to the flow) over L-head dikes (dikes shaped like an “L” with one arm extending from the bank at right angle to the flow and the other arm extending downstream; Figure 5.1). L-head dikes create an environment more protected from the fast-moving portion of the river, but the pools behind L-head dikes are often shallower than those behind spur dikes. Tagged adult bighead carp did not use sandbar areas without associated wing dikes.