This week my friend Dennie, who works for the Iowa DNR, came by with a large cooler full of native fish species for the kids to check out.
In the mainstream Mississippi River, numbers of shovelnose sturgeon have decreased sharply since 1900 (Becker 1983), although the species is still commonly taken by commercial fishermen. While shovelnose sturgeon roe is used as an acceptable caviar, over harvest has become a major detriment to the species. Alteration of large rivers and construction of locks and dams for navigation purposes has contributed significantly to the decline of shovelnose sturgeon by blocking access to ancestral spawning grounds.
of Iowa’s history. Searching for pearls imbedded
in mussels was a common hobby in the mid to
late 1800s. By 1899, 41 factories in Iowa alone
used freshwater mussel shells to make buttons,
but the introduction of plastic buttons brought
the pearl button industry to a halt in the 1940s.