title: Effects of cypermethrin on marine plankton communities: a simulated field study using mesocosms.
abstract: In earlier single-species toxicity tests we showed the negative effects on the calanoid copepod Acartia tonsa upon exposure to cypermethrin, a pesticide used in treatment for sea lice in salmon farming. In the present study we assessed effects at a higher level of biological organization and under a more realistic exposure scenario using mesocosms. The results showed that simulated field studies (SFSs) could be conducted with the mesocosms designed here. When cypermethrin was applied inside these mesocosms, its concentration decreased exponentially following a first-order kinetics model. The pesticide immediately reduced zooplankton density and biodiversity not only directly, by killing copepods, but also indirectly, by increasing the numbers of rotifers. Zooplankton density recovered after treatment, but zooplankton biodiversity remained altered. In an open environment, however, the rapid dissipation of the pesticide, coupled with population processes of compensation, migration, and immigration, may lead to recovery of the affected zooplankton communities.
authors.affiliation: Environment Group, Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, UK. mmedina@bio.puc.cl
authors.forename: Matías
authors.initials: M
authors.lastname: Medina
authors.forename: Carlos
authors.initials: C
authors.lastname: Barata
authors.forename: Trevor
authors.initials: T
authors.lastname: Telfer
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Baird
mesh_terms: D000818:Animals; D044822:Biodiversity; D033342:Copepoda / Q000187:drug effects; D004463:Ecology / Q000295:instrumentation / Q000379:methods*; D007306:Insecticides / Q000633:toxicity*; D010839:Phytoplankton / Q000187:drug effects* / Q000502:physiology; D011156:Population Density; D011722:Pyrethrins / Q000032:analysis / Q000633:toxicity*; D018570:Risk Assessment; D012403:Rotifera / Q000187:drug effects; D012623:Seawater; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D015048:Zooplankton / Q000187:drug effects* / Q000502:physiology
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C017160:cypermethrin