The Arrivals: Zebra Mussels In, Carp at the Gate

Aquatic invasives at DNR published strength — basin frame, township share stated honestly

Lead: Two arrivals frame this township's waters from opposite directions. The zebra mussel came down from the Great Lakes into Indiana's lakes and rivers and is established all around this ground. The invasive carps — bighead and silver, the fish long called Asian carp — have not arrived here at all: they are being held, by engineering, on the Illinois River side of a continental divide this township sits on the headwater edge of. Both halves are printed at the strength the record supports, and no stronger.

Zebra mussels (Dreissena polymorpha), European in origin and spread across North America in the 1990s, were in more than 75 Indiana waters in 43 counties by 2009 in DNR's account, and DNR's current “Indiana Zebra Mussel Waters” list (updated January 12, 2026) names Lake Michigan itself and a ring of northern Indiana waters around this township — Hudson Lake and Pine Lake in LaPorte County to the west, Simonton Lake and the St. Joseph River in Elkhart County to the east — a caution on names: the list's Allen County “St. Joseph River” entry is Fort Wayne's river, the Maumee tributary, not this county's Lake Michigan river, and the two must not be merged. Two negatives at published strength: the January 2026 DNR list reached for this row carries no entry for Spicer Lake, Lancaster Lake or the township's Kankakee headwater reach, and fishing and boating are prohibited at Spicer Lake by county parks rule — the preserve's kettle lakes are, on the record reached, unlisted and unboated, which is a status statement, not a guarantee.

Carp at the gate is a basin story, and this township's share of it is geographic, not zoological. The Kankakee River that rises at this county's divide flows west into Illinois, joins the Des Plaines to form the Illinois River, and so belongs to the Mississippi basin — the basin the invasive carps ascended after escaping into the Mississippi in the 1980s. The barrier question is therefore not on the Kankakee at all: it is at the basin's Great Lakes pinch points, principally the Brandon Road Lock and Dam near Joliet, Illinois, where the U.S. Army Corps of Engineers' Brandon Road Interbasin Project layers deterrents against upstream carp movement into the Great Lakes. The project's recent course is part of the published record — construction begun, a Corps stop-work order on July 24, 2026 lifted in early September 2026, and juvenile invasive carp found in August 2026 about 80 miles from Lake Michigan — and its stake for this ground is the reverse flow: a carp that entered Lake Michigan would stand at the mouth of this county's St. Joseph River, while a carp ascending the Illinois would still face the whole length of the Kankakee, most of it channelized ditch, before reaching this township's headwater edge. As of November 2026, no source reached reports an established bighead or silver carp population in St. Joseph County, the Kankakee in Indiana, or the St. Joseph River — the gate is holding, and the township's honest share of the carp story is that it has none, yet, by design and by distance.

Sources:

1. Indiana DNR, “Indiana Zebra Mussel Waters” (updated Jan. 12, 2026) — Lake Michigan; LaPorte County Hudson and Pine Lakes; Elkhart County Simonton Lake and St. Joseph River; Allen County St. Joseph River (Fort Wayne).
2. Indiana DNR (Aug. 27, 2009), “Zebra mussels mean trouble” — first Allen County river find; 75+ waters in 43 counties; European origin, 1990s spread.
3. U.S. Army Corps of Engineers, Brandon Road Interbasin Project — Joliet pinch point; purpose: prevent upstream invasive carp movement from the Illinois Waterway into the Great Lakes.
4. Alliance for the Great Lakes / Healthy Lakes (Aug. 26, 2026) and World Atlas carp-frontier account (Nov. 9, 2026) — July 24, 2026 stop-work order and September resumption; juvenile carp c. 80 miles from Lake Michigan, August 2026.
5. St. Joseph County Parks, Spicer Lake Nature Preserve — fishing and boating prohibited.