Skiing, wake boarding and now surfing are popular sports on the area lakes. Specialty boats, to create the wakes for wake boarding and surfing, have now been added to the numerous sports boats, cruisers and pontoons used on the lakes. These boats can create wakes up to 4 feet for wake boarders and surfers to enjoy.
But there is a rising concern about where these boats are used on lakes. Many have seen skiers, wakeboarders, surfers coming close to the buoy lines, which has an average water depth of 5 feet, stirring up the lake bottom.
It’s nothing new, just more noticeable with the newer boats.
“In addition to stirring up the sediments and releasing phosphorus, boating in shallow areas also disturbs aquatic plants. This can be harmful in a couple of ways,” stated Lyn Crighton, Tippecanoe Watershed Foundation. Crighton explained boat props can cut the invasive aquatic plans into small pieces, which can grow new plants from the smaller pieces. “So chopping them up actually helps them spread even more.” She also explained native aquatic plants can also be damaged, the reason why some lakes have worked with the Indiana Department of Natural Resources to create ecozones, protecting plant communities by restricting boats from the shallow areas.
Diana Castell, Wawasee Area Conservancy Foundation Education Committee, explained “phosphorus promotes plant growth. When applied to lawns or agriculture fields excess phosphorous washes into streams, rivers and lakes. Phosphorous becomes part of the aquatic plants, which dies and releases phosphorus into the water. Phosphorous will bind to soil and rocks or sediment. When the sediment is disturbed it is released to be picked up by more plants.” She added “the problem then becomes boats that stir up the bottom of our lakes. Wawasee is overall a shallow lake so when we have large boats, or any boat that stirs the bottom, phosphorous is released to be picked up by plants.” Algae blooms are often a cause of this release of phosphorous.
Dr. Nate Bosch, assistant professor at Grace College in Environmental Science, noted Lake Tippecanoe was once 46 feet deeper than its current 123 feet. Sediment, the result of excessive amounts of soils along with dead plant material, is found in local water resources, and is problematic rather than beneficial. “One of the problems with sediments is they accumulate on the bottom … this accumulation reduces the ability of fish to reproduce, decreases the amount of oxygen in the water and makes the lakes shallower. … Another problem with sediments is they often carry with them nutrients, which cause algae and aquatic weeds to grow in abundance. … Sediments can remain suspended in the water for several days before settling to the bottom, which reduces the clarity of the water and makes it look dirty. … We can keep sediment from getting stirred up in our lakes by using natural vegetation along shorelines or glacial stone, which dissipate wave energy and by confining high-speed boating to deeper areas of our lakes.”
Numerous studies have been conducted on physical impacts of boating on lakes. Bosch noted there has been discussion about doing a research study on what depth of water is needed to avoid re-suspending sediment “to know what we can recommend.”
“It’s creating a huge disturbance,” said Dan Berkey, WACF board member. “Boats are angling deeper than ever. When the ballast system is filled with water, the bow goes higher, stern lower and goes even deeper and closer to the bottom. It creates a wash 2-foot to 3-foot scouring the bottom and leaves a mud trail.” Berkey, as the studies indicate, noted these boats need to be kept in deep water. “So many who own these boats don’t know the average depth is 15 feet. It’s a shallow lake.”
Education to keep these type of boats to the middle of the lake is key Berkey feels, not along the buoy line.