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• 1. [Article] The Aquarium Trade as an Invasion Pathway in the Pacific Northwest

  The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation ...

  Citation × Citation Citation Abstract Copy Title: The Aquarium Trade as an Invasion Pathway in the Pacific Northwest Author: Strecker, Angela L., Campbell, Philip M., Olden, Julian D. Year: 2011 The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation of the ornamental pet trade as an invasion pathway in the Pacific Northwest region of the United States, where a moderate climate and a large human population present ample opportunities for the introduction and establishment of aquarium trade species. Results from a regional survey of pet stores found that the number of fish (n=400) and plant (n=124) species currently in the aquarium trade is vast. Pet stores import thousands of fish every month, the majority of which (58%) are considered to pose an ecological threat to native ecosystems. Our propagule pressure model suggests that approximately 2,500 fish (maximum 21,000 individuals) are likely released annually to the Puget Sound region by aquarists, and that water temperatures in many parts of Washington are suitable for establishment of populations. In conclusion, the aquarium trade may be a significant source of past and future invasions in the Pacific Northwest, and we recommend enhanced public education programs, greater regulation of the aquarium industry, and improved legislation of nonnative species in the ornamental trade. Title: The Aquarium Trade as an Invasion Pathway in the Pacific Northwest Author: Strecker, Angela L., Campbell, Philip M., Olden, Julian D. Year: 2011 The aquarium trade moves thousands of species around the globe, and unwanted organisms may be released into freshwaters, with adverse ecological and economic effects. We report on the first investigation of the ornamental pet trade as an invasion pathway in the Pacific Northwest region of the United States, where a moderate climate and a large human population present ample opportunities for the introduction and establishment of aquarium trade species. Results from a regional survey of pet stores found that the number of fish (n=400) and plant (n=124) species currently in the aquarium trade is vast. Pet stores import thousands of fish every month, the majority of which (58%) are considered to pose an ecological threat to native ecosystems. Our propagule pressure model suggests that approximately 2,500 fish (maximum 21,000 individuals) are likely released annually to the Puget Sound region by aquarists, and that water temperatures in many parts of Washington are suitable for establishment of populations. In conclusion, the aquarium trade may be a significant source of past and future invasions in the Pacific Northwest, and we recommend enhanced public education programs, greater regulation of the aquarium industry, and improved legislation of nonnative species in the ornamental trade. Close

• 2. [Article] Invasive Predator, Bythotrephes, has Varied Effects on Ecosystem Function in Freshwater Lakes

  Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes ...

  Citation × Citation Citation Abstract Copy Title: Invasive Predator, Bythotrephes, has Varied Effects on Ecosystem Function in Freshwater Lakes Author: Strecker, Angela L., Arnott, Shelley E. Year: 2008 Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes on two measures of ecosystem function during a four month observational study of freshwater lakes on the boreal shield. Bythotrephes-invaded lakes had significantly lower epilimnetic zooplankton abundance and production compared to reference lakes. On average, Bythotrephes consumed 34% ofzooplankton production when it was present in lakes. There was some evidence of changes in the timing of zooplankton production, as well as shifts to cooler, less productive habitats, which may lessen the overall effect of the invader on the transfer of energy to higher trophic levels. We experimentally demonstrated a weak trophic cascade where invader predation reduced zooplankton biomass, and subsequently increased phytoplankton growth. However, the response was small in magnitude and not biologically relevant at the whole lake- scale. The most conspicuous effect of Bythotrephes that we measured was a diversion of energy away from native predators at higher trophic levels. Title: Invasive Predator, Bythotrephes, has Varied Effects on Ecosystem Function in Freshwater Lakes Author: Strecker, Angela L., Arnott, Shelley E. Year: 2008 Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes on two measures of ecosystem function during a four month observational study of freshwater lakes on the boreal shield. Bythotrephes-invaded lakes had significantly lower epilimnetic zooplankton abundance and production compared to reference lakes. On average, Bythotrephes consumed 34% ofzooplankton production when it was present in lakes. There was some evidence of changes in the timing of zooplankton production, as well as shifts to cooler, less productive habitats, which may lessen the overall effect of the invader on the transfer of energy to higher trophic levels. We experimentally demonstrated a weak trophic cascade where invader predation reduced zooplankton biomass, and subsequently increased phytoplankton growth. However, the response was small in magnitude and not biologically relevant at the whole lake- scale. The most conspicuous effect of Bythotrephes that we measured was a diversion of energy away from native predators at higher trophic levels. Close