Wisconsin officials cut diseased trees at state park

Wisconsin State officials are cutting down trees in Whitefish Dunes State Park in Door County that are infected with beech bark disease. The park has lots of beech trees and those that are infected pose a safety hazard, said Linda Williams, a Wisconsin Department of Natural Resources forest health specialist. Weakened limbs and trunks can snap off or fall over during strong winds. The idea is to remove dead trees before they harm visitors or staff. Infected trees that are within 75 feet of park trails are targeted, said Arnie Lindauer, a program analyst for the park.

Maps show spread of aquatic invasive species over time

The Nature Conservancy has animated how six invasive species have spread across the Great Lakes over time. The group has created six maps that show population increase and spread since the appearance of each species in the Great Lakes basin and beyond. Sea lamprey, the first of the six invasive species to appear in the area, initially showed up in Lake Erie in 1921. The map shows the population of the fish expanding into the rest of the Great Lakes up until present day. Also included in the maps are Asian carp, zebra and quagga mussels, round goby, Eurasian Ruffe and black carp.

Invasive Species: Asian Carp

By Evan KreagerGreat Lakes EchoAsian carp may be one of the better known of the many aquatic invasive species attempting to make their way into the Great Lakes basin. They are one of the five “usual suspects” recognized by The Nature Conservancy in a public awareness campaign. Big head and silver are the most common types of carp, having been spotted in 18 different states, according to The Nature Conservancy. Big head carp can grow up to 60 inches and weigh over 100 pounds. Silver carp are a bit smaller, with a length of about 40 inches and a weight of 60 pounds.

Invasive Species: Round Goby

By Evan KreagerGreat Lakes Echo

The Nature Conservancy has named the round goby one of the five “usual suspects” invading the Great Lakes basin. Round gobies are native to the Black and Caspian seas, but have found their way into the Mississippi River as well as Lake Michigan. These fish have a heightened ability to sense water movement, allowing them to feed in the dark. Round gobies feed on native fish and their eggs, and have a “blood vendetta” against zebra mussels, according The Nature Conservancy. These gobies can grow up to 10 inches in length and somewhat resemble an overgrown tadpole with black, gray or brown skin.

Invasive Species: Eurasian Ruffe

By Evan KreagerGreat Lakes Echo

The Nature Conservancy has named Eurasian Ruffe, a fish native to northern Europe and Asia, as one of the five “usual suspects” in the Great Lakes basin. This fish has invaded northern Lake Michigan and feeds on native fish eggs. It has sharp spines on its fins making it difficult for predators to catch and eat, giving it the nickname, “Dagger Fin.”

Eurasian Ruffe are generally just under a half a foot in length and have an olive or golden-brown color.

Invasive Species: Zebra Mussels

 

Zebra mussels are one of five aquatic invasive species that The Nature Conservancy has deemed “‘the usual suspects’ doing the most damage in the Great Lakes basin and beyond.”

Originally from Eastern Europe and western Russia, zebra mussels are the only freshwater mussels that can attach directly to other objects. They most likely have come over attached to the bottoms of ships. Once here, the mussels grow in population rapidly. Zebra mussels can produce 100,000 to 500,000 eggs per year, according to The Nature Conservancy. Nicknamed “the Silent Strangler,” these pests smother native freshwater mussels and kill plankton that some fish need to survive.