Species spotlight: Lake sturgeon

March 18th, 2015 by
Where we take a moment to explore some of the unique and impressive species that call the Great Lakes home.
Skin like a shark, feeding habits akin to those of a whale, and a lifespan comparable to our own—the lake sturgeon is a peculiar species indeed. Found in large lakes and rivers, this toothless, whiskered bottom feeder is the largest, longest living, and one of the most ancient species in the Great Lakes. With an average length of 3-5 feet and a weight of 10-80 pounds, some lake sturgeon have grown to be 8 feet long and 300 pounds. Males typically live around 50 years while females’ lifespans range anywhere between 80-150. And with origins during the late cretaceous period, this species has remained relatively unchanged since the time of the triceratops and the tyrannosaurus rex.
The lake sturgeon’s skeleton is partly cartilaginous. Its body has no scales and is lined with five rows of bony plates called skutes—one on top and two rows along each side. Two pairs of fleshy sensory organs called barbels hang from its shovel-like snout like whiskers to help the lake sturgeon find prey. Its diet consists primarily of benthic organisms—small bottom-dwelling creatures like mussels, snails, crustaceans, aquatic insects—but they have been known to eat small fish. With no teeth, the lake sturgeon uses its snout to dig up whatever prey it finds and then sucks it up through its protractile mouth, filtering out sediment through its gills while digesting the organic material.
As hardy as the lake sturgeon may seem, its population suffered almost incalculable losses in the late 19th century. Initially thought of as a nuisance fish that damaged fishing equipment, lake sturgeon were slaughtered en masse. They’d be buried on shore or lined up to dry in the sun like stacks of timber and later used as fuel for steam ships due to the high oil content of their meat. Over time, lake sturgeon meat and eggs became prized commodities, leading to overfishing and an eventual collapse in population. 
Recovery has historically been a challenge due to the lake sturgeon’s naturally slow reproductive cycle, with males only reaching maturity around 15 years of age and females at closer to 20. This in combination with lake and river pollution, habitat loss, and dam activity blocking access to spawning grounds has lead to a long decline of lake sturgeon populations across the U.S. and Canada. As a result, lake sturgeon are listed as an endangered, threatened, or species of special concern by 19 of the 20 states where they are found. 
But in recent years, some populations have started to rebound. State and Canadian governments now enforce strict policies that limit the number of sturgeon caught each year. Spawning habitats have been constructed, watersheds have been stocked, and eggs have been raised in artificial cultures. People are also encouraged to report any sightings of lake sturgeon to help get a better idea of their numbers. 
***Photo by Great Lakes Aquarium 

Wisconsin students learn about Great Lakes cleanup

December 10th, 2012 by
Illinois-Indiana Sea Grant’s environmental social scientist Caitie McCoy informs and engages communities about important Great Lakes cleanup and restoration projects that affect them, and works with students to teach them more about Great Lakes ecology. One of her most recent opportunities to work with students was in Sheboygan, Wisconsin, where she provided information and lessons about a project close to home.

Caitie writes, “I visited Sheboygan, Wisconsin last Tuesday and spoke to high school biology students, answering questions about the
Great Lakes Legacy Act dredging project happening just two miles from their school. This was my final school to visit in Sheboygan as part of a 12-school, countywide tour, which began this past October and reached about 600 high school science students. Now the students know the purpose of a cleanup happening right in their downtown, and they understand the science behind it.
IISG is a collaborating member of Sheboygan’s ‘Testing the Waters’ program, through which students visit some of the Sheboygan River cleanup and habitat projects and learn techniques for testing water quality. My classroom visits helped set the stage for this program, and IISG also provided water sampling instruments for their use.
Some of the specific topics that we discussed with students included the chemical qualities of the pollution, the effects that pollution has on the food web, and the cleanup process under the Great Lakes Legacy Act. I also spoke with them about habitat restoration projects, which are removing invasive species, creating natural, softened shorelines, and improving filtration of runoff.

This project is part of a larger effort to provide students with stewardship opportunities and supplemental hands-on education about remediation and restoration efforts throughout the Great Lakes. It has been great to work with students in Sheboygan and
Northwest Indiana, and I look forward to bringing this program to more Great Lakes students soon.”
For more information about Great Lakes educational programs and opportunities, visit our education page and follow our posts here on the blog.
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