Little Things, Big Problems: Spiny water flea

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Last year, the Great Lakes Restoration Initiative began producing a series of educational videos about invasive species in the Great Lakes for the National Park Service. New videos are being uploaded this spring, and you can watch the entire “Little Things, Big Problems” series here on Echo.

This video discusses the impact spiny water fleas have on the Great Lakes food web.

6 thoughts on “Little Things, Big Problems: Spiny water flea

  1. Zooplankton drops are directly related to quagga mussels, which are found at depths far greater than any perch will roam. Perch in Green Bay might be eating fleas at times, but they’re nowhere near their preferred diet and the flea outbreak on the bay out of Menominee was outrageous this summer, hard to even reel in lines. We have a lot of perch on Green Bay. Tom, you are at least consistent with your anti-alewife, anti-salmon message. But guess what’s selling licenses and packing the rivers now? Hint: even though the perch bite is good to excellent, there are far more anglers fishing for salmon.

  2. Thanks Kevin, We have all these invasives a band or layer if you will that feed on the lower levels of the food chain, keeping the energy from going up the ladder. I’m not against native cisco or herring, but given we have way to many planktivores at this time, Alewives, gobies etc… soon asian carp, stocking predators would be more prudent, stocking more planktivores should wait. Perch would move the food up the ladder now trapped by invasives, because they are natural prey for larger predators. I’m told the Crustacean zooplankton densities down yonder down 90% from pre carp levels. The experts have said asian carp can feed on zooplankton down to micron levels making the ecosystem a mono fish system. The zooplankton we have is already controlled by invasives, more predators would be the more prudent action.

  3. Well I think you touched on a good point that there is some locality to consumption; the yellow perch in Green Bay as you mentioned. But Bythotrephes appears to show up in numerous areas and diets, native and non-native. It would be nice to use one set fish community as an apt controller, but it might not be that easy.

    And do not discount the impact of how consumption, regardless of fish species, can change/limit production on the invasive Bythotrephes (Pothoven et al. 2007). After all, controlling Bythotrephes, doesn’t need to mean they constitute >50% of a fish diet.

    And you are correct, the given energetic value of Bythotrephes is much less than that of other native zooplankton. So growth would likely be much greater with other zooplankton prey items.

  4. Well, Kevin, Perch in Green bay were found packed with spiny fleas, even grew faster they said. Inland lakes are seeing the blooms after spinys show up. Plus alewives eat more zooplankton than spiny pleas, they’re bigger, 4 pounds of zooplankton per alewife to hit .1 pounds, I don’t think a spiny can do that. However increasing the alewives increases the negative impacts of spiny fleas and thier other invasive friends from out of town. Increasing predators decreases planktivores, of which we have too many.

  5. In general drops in zooplankton “directly” from the spiny water flea have come in the form of Daphnia and cyclopoid species, not overall zooplankton biomass levels.

    Fish do have the ability to control the invasive. However some of the fish that can control the species are themselves non-natives species (alewife).

    The good news is that native species such as cisco/lake herring do consume a lot of Bythotrephes in Lake Superior and are a possible candidate for reintroduction measures in the lower Great Lakes.

  6. Whare the zooplankton levels pre spiny fleas, and now? How much have they dropped. Experts say spiny fleas can be controlled with predators “Wouldn’t be a problem” why are we not pursuing this course of action? Wouldn’t be a problem sounds good to me.

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