Invasion biology and ecological impacts of brown trout Salmo trutta in New Zealand

Brown trout Salmo trutta were introduced to New Zealand in 1867. Successful establishment was broadly predictable in terms both of the characteristics of brown trout and of the receiving community. There is evidence of impacts of brown trout on the abundance of some native fish and invertebrates, and brown trout have been responsible for the local extinction and fragmentation of certain species. An intensive study of the Taieri River has revealed that several native galaxiid fishes are now restricted to headwaters above large waterfalls that prevent the upstream migration of brown trout. Brown trout may profoundly affect the functioning of stream communities, reducing the abundance of grazing invertebrates and altering their grazing behaviour so that algal biomass increases. A trophic cascade was predictable on the basis of the attributes of the invader and of the stream community. Brown trout seem to have been responsible for the evolution among invertebrates of novel anti-predator behaviours with far-reaching community consequences. The ecological and evolutionary consequences of the introduction of brown trout to New Zealand are probably reversible.

[1]  C. Townsend,et al.  Assessment of the Environmental Risk Posed by an Exotic Fish: The Proposed Introduction of Channel Catfish (Ictalurus punctatus) to New Zealand , 1992 .

[2]  C. Townsend,et al.  Competition for space between introduced brown trout (Salmo trutta L.) and a native galaxiid (Galaxias vulgaris Stokell) in a New Zealand stream , 1992 .

[3]  Harold A. Mooney,et al.  Ecology of Biological Invasions of North America and Hawaii , 1986, Ecological Studies.

[4]  S. L. Lima,et al.  Behavioral decisions made under the risk of predation: a review and prospectus , 1990 .

[5]  C. Townsend,et al.  Fragmented population structure in a native New Zealand fish: an effect of introduced brown trout? , 1991 .

[6]  C. Townsend,et al.  Predation and the prey community of a headwater stream , 1988 .

[7]  M. Crawley.  The population biology of invaders , 1986 .

[8]  G. Eldon.  Habitat and interspecific relationships of the Canterbury mudfish, Neochanna burrowsius (Salmoniformes: Galaxiidae) , 1979 .

[9]  J. Lawton,et al.  The Population and Community Ecology of Invading Insects [and Discussion] , 1986 .

[10]  F. Kruger,et al.  Invasive alien organisms in the Namib Desert, Upper Karoo and the arid and semi-arid savannas of western southern Africa. , 1986 .

[11]  C. L. Hopkins.  Production of fish in two small streams in the north island of New Zealand , 1971 .

[12]  R. McDowall,et al.  New Zealand Freshwater Fishes , 1978 .

[13]  M. Crawley.  Chance and timing in biological invasions , 1989 .

[14]  M. Power,et al.  Effects of Fish in River Food Webs , 1990, Science.

[15]  P. Ramakrishnan.  Ecology of biological invasion in the tropics , 1991 .

[16]  R. McDowall.  Interactions of the Native and Alien Faunas of New Zealand and the Problem of Fish Introductions , 1968 .

[17]  Mark Williamson,et al.  The characters of successful invaders , 1996 .

[18]  Mark A. McPeek,et al.  Predation, Competition, and Prey Communities: A Review of Field Experiments , 1985 .

[19]  Charles C. Elton,et al.  The Ecology of Invasions by Animals and Plants. , 1959 .

[20]  Donald R. Strong,et al.  ARE TROPHIC CASCADES ALL WET? DIFFERENTIATION AND DONOR-CONTROL IN SPECIOSE ECOSYSTEMS' , 1992 .

[21]  J. M. Elliott.  Quantitative ecology and the brown trout , 1995 .

[22]  B. Harvey.  Benthic assemblages in Utah headwater streams with and without trout , 1993 .

[23]  K. Crowell.  Experimental Zoogeography: Introductions of Mice to Small Islands , 1973, The American Naturalist.

[24]  D. Lodge,et al.  Biological invasions: Lessons for ecology. , 1993, Trends in ecology & evolution.

[25]  M. Holdgate.  Summary and conclusions: characteristics and consequences of biological invasions , 1986 .

[26]  F. Kruger,et al.  The ecology and management of biological invasions in southern Africa. , 1986 .

[27]  B. Coblentz,et al.  Exotic Organisms: A Dilemma for Conservation Biology , 1990 .

[28]  H. Maccrimmon,et al.  World Distribution of Brown Trout, Salmo trutta , 1968 .

[29]  C. Townsend,et al.  Community‐Wide Consequences of Trout Introduction in New Zealand Streams , 1994 .

[30]  C. Townsend.  EXOTIC SPECIES MANAGEMENT AND THE NEED FOR A THEORY OF INVASION ECOLOGY , 1991 .

[31]  Robert K. Colwell,et al.  The Planned Introduction of Genetically Engineered Organisms: Ecological Considerations and Recommendations , 1989 .

[32]  C. Townsend,et al.  Size‐related impacts of introduced brown trout on the distribution of native common river galaxias , 1994 .

[33]  C. Townsend,et al.  Interpopulation variation in mayfly antipredator tactics: differential effects of contrasting predatory fish , 1994 .

[34]  E. Best.  Fishing Methods and Devices of the Maori , 1925 .

[35]  T. Ebenhard.  Bank Vole [Clethrionomys glareolus (Schreber, 1780)] Propagules of Different Sizes and Island Colonization , 1989 .

[36]  J. R. Stauffer,et al.  Distribution, biology, and management of exotic fishes , 1984 .

[37]  C. Townsend,et al.  Isozyme analysis of Galaxias species (Teleostei: Galaxiidae) from the Taieri River, South Island, New Zealand: a species complex revealed , 1996 .

[38]  K. Collier.  Review of the status, distribution, and conservation of freshwater invertebrates in New Zealand , 1993 .

[39]  D. Chapman.  Food and Space as Regulators of Salmonid Populations in Streams , 1966, The American Naturalist.

[40]  S. Pimm.  The Balance of Nature?: Ecological Issues in the Conservation of Species and Communities , 1992 .

[41]  J. Thorp.  Two distinct roles for predators in freshwater assemblages , 1986 .

[42]  S. Strauss,et al.  Indirect effects in community ecology: Their definition, study and importance. , 1991, Trends in ecology & evolution.

[43]  C. Townsend,et al.  ANTI-PREDATOR BEHAVIOURS OF A FRESHWATER CRAYFISH (PARANEPHROPS ZEALANDICUS )T O AN ATIVE AND AN INTRODUCED PREDATOR , 1994 .

[44]  N. C. Boustead.  Fish diseases recorded in New Zealand, with a discussion on potential sources and certification procedures , 1982 .

[45]  R. McDowall.  When galaxiid and salmonid fishes meet–a family reunion in New Zealand , 1990 .

[46]  B. Peckarsky,et al.  Diel Feeding and Positioning Periodicity of a Grazing Mayfly in a Trout Stream and a Fishless Stream , 1994 .

[47]  M. Power,et al.  TOP-DOWN AND BOTTOM-UP FORCES IN FOOD WEBS: DO PLANTS HAVE PRIMACY? , 1992 .

[48]  S. Pimm,et al.  Species Introductions to Hawaii , 1986 .

[49]  Michael J. Crawley,et al.  Colonization, Succession, and Stability , 1988 .

[50]  A. Dobson.  Restoring island ecosystems the potential of parasites to control introduced mammals , 1988 .

[51]  Andrew Sih,et al.  Predation: direct and indirect impacts on aquatic communities , 1988 .

[52]  J. Roughgarden,et al.  Effects of reduced perch-height separation on competition between two Anolis lizards , 1985 .

[53]  D. Simberloff.  COMMUNITY EFFECTS OF INTRODUCED SPECIES , 1981 .

[54]  M. H. Nitecki.  Biotic crises in ecological and evolutionary time , 1981 .

[55]  F. Castri,et al.  Biological Invasions: A Global Perspective , 1989 .

[56]  C. Townsend,et al.  Investigating anti‐predator behaviour in three genetically differentiated populations of non‐rnigratory galaxiid fishes in a New Zealand river , 1993 .