Human exclusion from the rocky intertidal zone of central Chile: the effects on Concholepas concholepas (Gastropoda)

The ecological role played by man as a top predator in a rocky intertidal environment of central Chile was studied. Human exclusion from a rocky intertidal stretch of coast (non-harvested area) at Punta El Lacho, for nearly two years, resulted in a substantial density increase of the economically important high trophic level predator muricid Concholepas concholepas. This was followed by a dramatic decline in the cover of the competitive dominant intertidal mussel Perumytilus purpuratus. According to current ecological theory the removal of the competitively superior primary space dominant species led to a pattern of increasing species diversity. We conclude that in the absence of human interference C. concholepas plays the role of a key species in central Chile rocky intertidal environments. We suggest that the interpretation of the structure and dynamics of intertidal landscapes should include the key role played by man. Comparison of monitoring programs between intertidal areas with and without human interference will prove critical to our understanding of such environments.

[1]  C. Peterson.  Does a Rigorous Criterion for Environmental Identity Preclude the Existence of Multiple Stable Points? , 1984, The American Naturalist.

[2]  S. Hurlbert.  Pseudoreplication and the Design of Ecological Field Experiments , 1984 .

[3]  C. Guisado,et al.  Aspects of the ecology and growth of an intertidal juvenile population of Concholepas concholepas (Mollusca: Gastropoda: Muricidae) at Las Cruces, Chile , 1983 .

[4]  J. Connell,et al.  On the Evidence Needed to Judge Ecological Stability or Persistence , 1983, The American Naturalist.

[5]  J. Sutherland.  The Fouling Community at Beaufort, North Carolina: A Study in Stability , 1981, The American Naturalist.

[6]  J. Castilla,et al.  Comparative ecology of Lessonia nigrescens and Durvillaea antarctica (phaeophyta) in Central Chile , 1980 .

[7]  R. Paine.  Food webs : linkage, interaction strength and community infrastructure , 1980 .

[8]  R. Paine.  A Note on Trophic Complexity and Community Stability , 1969, The American Naturalist.

[9]  R. Paine.  Food Web Complexity and Species Diversity , 1966, The American Naturalist.

[10]  C. Moreno,et al.  Man as a predator in the intertidal zone of southern Chile , 1984 .

[11]  G. M. Branch,et al.  Notes on the Ecology of Patella Concolor and Cellana Capensis, and the Effects of Human Consumption on Limpet Populations , 1975 .

[12]  J. Harper.  The role of predation in vegetational diversity. , 1969, Brookhaven symposia in biology.

[13]  R. Paine,et al.  Trophic Relationships of 8 Sympatric Predatory Gastropods , 1963 .