Temperature, recreational fishing and diapause egg connections: dispersal of spiny water fleas (Bythotrephes longimanus)

Abstract

The spiny water flea (Bythotrephes longimanus) is spreading from Great Lakes coastal waters into northern inland lakes within a northern temperature-defined latitudinal band. Colonization of Great Lakes coastal embayments is assisted by winds and seiche surges, yet rapid inland expansion across the northern states comes through an overland process. The lack of invasions at Isle Royale National Park contrasts with rapid expansion on the nearby Keweenaw Peninsula. Both regions have comparable geology, lake density, and fauna, but differ in recreational fishing boat access, visitation, and containment measures. Tail spines protect Bythotrephes against young of the year, but not larger fish, yet the unusual thick-shelled diapausing eggs can pass through fish guts in viable condition. Sediment traps illustrate how fish spread diapausing eggs across lakes in fecal pellets. Trillions of diapausing eggs are produced per year in Lake Michigan and billions per year in Lake Michigamme, a large inland lake. Dispersal by recreational fishing is linked to use of baitfish, diapausing eggs defecated into live wells and bait buckets, and Bythothephes snagged on fishing line, anchor ropes, and minnow seines. Relatively simple measures, such as on-site rinsing of live wells, restricting transfer of certain baitfish species, or holding baitfish for 24 h (defecation period), should greatly reduce dispersal.

A plague of waterfleas (Bythotrephes): impacts on microcrustacean community structure, seasonal biomass, and secondary production in a large inland-lake complex

“…The spiny cladoceran (Bythotrephes longimanus) is an invasive, predaceous zooplankter that impacts Great Lakes assemblages and that is spreading out from coastal waters to colonize inland lakes across a temperature-related northern latitudinal band ( Fig. 1; Kerfoot et al 2011). The inland region stretches from Vermont, eastern Ontario, and New York, through Michigan, Wisconsin, Minnesota and Manitoba.…”

“…1; MacIsaac et al 2000MacIsaac et al , 2004Yan et al 2001;Branstrator et al 2006;Kerfoot et al 2011). Rapid inland expansion across the northern US states and Canadian provinces is linked to recreational fishing.…”

“…The unusual thick-shelled diapausing eggs can pass through fish guts in viable condition (Jarnagin et al 2000(Jarnagin et al , 2004. Inspection of fish guts (yellow perch, cisco, alewives) documented that large numbers of viable eggs end up in stomachs during summer and fall (Jarnagin et al 2004;Kerfoot et al 2011). Diapausing eggs that pass through fish guts may be defecated into live wells and bait buckets, or the eggladen fish transferred from one lake to another.…”

Dynamics of the invasive spiny water flea, Bythotrephes longimanus, in Lake Simcoe, Ontario, Canada

“…From 1999-2007, the mean annual epilimnetic temperature observed in Lake Simcoe from July through October varied from 18.7 to 21.6 °C (mean ±1 SE across all years was 19.8 ± 3.4 °C), which was higher than temperatures at which peak Bythotrephes population densities occurred in Lake Michigan (i.e., 14.6 ± 0.9 °C; Cavaletto et al 2010), but remained well within the range of Bythotrephes preferences and physiological tolerances (Garton et al 1990, Kim and Yan 2010, Kerfoot et al 2011). …”

Heterocope borealis in Norway - A copepod on the move, or on the edge of its natural distribution?

“…This could have taken place in many different ways. One possible mechanism is transfer with boats (Johnson et al 2001, Kerfoot et al 2011. During the last few decades it has become quite common for sport fishermen to have their boats on trailers and transport them between lakes.…”