Skunk River Navy (SRN)


The Skunk River Navy

Student volunteers guide canoes during the Skunk River Navy

About the Skunk River Navy

The Skunk River Navy (SRN) was started in the fall of 1998 by professor Jim Colbert as a service-learning activity for the Biology Education Success Teams (B.E.S.T.) Learning Community.  This all-day event provides students with the opportunity to learn more about the biodiversity of Iowa's rivers, meet new people and make friends, and make a positive contribution to their local community through service.  Activities include monitoring the diversity of benthic macro-invertebrates and reporting findings to the IOWATER database, and improving the aesthetic quality of the Skunk River and its tributaries by removing trash.  

The first piece of "trophy trash" removed during the first SRN was a claw-foot cast-iron bathtub: 

The first piece of "trophy trash" removed by the 1998 SRN

Since the first SRN in 1998, approximately 2,100 volunteers have removed over 72 tons of trash from the Skunk River and its tributaries, and over 30 sets of benthic macro-invertebrate data have been collected.

Benthic macro-invertebrate collection

About the Skunk River

The Skunk River is a tributary of the Mississippi River with two forks: the North Skunk River and the South Skunk River.  The Skunk River Navy operates on the South Skunk River, which runs through Story County and the city of Ames.  Approximately 92% of land in Story County is either cropland or urban, with much of the rest being pasture land; the river corridor of the South Skunk River represents one of the very few and relatively undisturbed natural areas remaining in the county.  Some portions of the river corridor, called the Skunk River Greenbelt, are publicly owned.

Numerous species of animals and plants make their home in and along the Skunk River.  White-tailed deer (Odocoileus virginianus), raccoons (Proycon lotor), oposums (Didelphis virginiana), mink (Mustela vison), and beaver (Caster canadensis) are common mammalian visitors.  Otters (Lutra canadensis) have been reintroduced into the Skunk River as well.  Common bird species include the great blue heron (Ardea herodias), belted kingfisher (Megaceryle alcyon), great horned owl (Bubo virginianus), turkey vultures (Cathartes aura), and wood ducks (Aix sponsa).  Insect species that frequent the river include the six-spotted tiger beetle (Cicindela sexguttata), black-winged damselfly (Calopteryx maculata), water strider (Gerridae family), and tiger swallowtail butterfly (Papilio glaucus).  Snapping turtles (Chelydra serpentina), leopard frogs (Lithobates spp.), and the occasional garter snake (Thamnophis sirtalis) or fox snake (Pantherophis vulpinus) can be found in the river corridor.  

A snapping turtle caught by the SRN admiral, Jim Colbert

Aquatic invertebrates include crawfish, freshwater sponges, bryozoans, flatworms, and several species of freshwater mussels including plain pocketbooks (Lampsilis cardium).  Fish species include the native creek chubs (semotilus atromaculatus), channel catfish (Ictalurus punctatus), green sunfish (Lepomis cyanellus), smallmouth bass (Micropterus dolomieu), various minnow species, and several introduced species.  

The riparian forests that border the Skunk River are dominated by silver maple (Acer saccharinium), elm (Ulmus spp.), and boxelder (Acer negundo), with plenty of woodland stinging nettle (Urtica dioica) in the herbaceous layer.  Rare plant species found in the river corridor include dwarf bulrush (Hemicarpha micranthea), cardinal flower (Lobelia cardinalis), buttonbush (Cephalanthus spp.), and obedient plant (Physostegia virginiana).  

Issues Facing the Skunk River

Like most rivers in Iowa, the South Skunk River has been significantly affected by various human activities.  

Soil Erosion and Sedimentation.  Large quantities of soil are being transported to streams.  This causes increased turbidity and siltation, which degrades both aquatic habitat and the anesthetic quality of streams.  Increased siltation is due to overland erosion and bank collapse.

An example of soil erosion along the Skunk River

Excessive bank collapse is a result of tiling, wetland draining, and impervious surfaces that can rapidly convey large quantities of water from rain and melting snow into streams.  In essence, human activities over the past 150 years have converted north-central Iowa from a "sponge" into a "storm sewer."  

Human activities transforming our streams into storm sewers

Toxic Contamination.  Migration of pesticides and other chemicals, from surface and ground water, may endanger public water supplies and can have impacts on biological organisms in rivers.

Eutrophication.  Agricultural runoff from fertilizers and industrial/municipal sewage effluent increases production of algae in streams and reservoirs.  As this excessive growth of algae die off, the decay of the algae by bacteria lowers the oxygen concentration in the stream.  This alters species composition in our streams and reduces biodiversity, as some species cannot survive in oxygen concentrations below a certain level.

Non-native and Invasive Species.  Introduction of non-native species is usually facilitated by humans.  Novel species introductions can alter biological communities and ecosystems.  In the case of aggressive or invasive non-native species, these effects can be dramatic.  Examples of troublesome non-native species humans have introduced include the common carp (Cyprinus carpio) and Japanese hops (Humulus japonicus).  

Aesthetics.  The South Skunk River is used extensively for recreation, and large quantities of trash deposited in the river corridor diminish this experience.  

Trash collected by the Skunk River Navy

Student Comments about the Skunk River Navy

“I learned just how much people litter and disrespect our rivers, but I also learned that there is still hope if we can get 120 people to come out, at 9 AM, on a Saturday, and walk through a freezing river for a few miles pushing heavy canoes and picking up trash. I respect every person who came out yesterday (or any SRN day) to lend a little helping hand to our river.”

"It was great fun to strengthen friendships by picking up trash with fellow students. Additionally, seeing and interacting with my professors during SRN gave me a better idea of what kind of people they are outside the context of a conventional classroom. Looking back on the experience, I can hardly wait until SRN takes to the river again."

"I envisioned that there would be a lot of garbage, but I never imagined that people could treat the Earth with such disrespect... The Skunk River Navy was an educational as well as character building experience for all of us."

"This episode made me realize all of the camaraderie involved with SRN. If someone needed help pushing their canoe through shallow water, or just a hand getting a piece of trash out of the mud, someone else was there to help them, all in the name of a cleaner river."