INVESTIGADORES
IRIBARNE Oscar Osvaldo
artículos
Título:
Spatial heterogeneity and species responses to anthropogenic disturbance: A test for generality.
Autor/es:
GUTIERREZ, J.L; M.G. PALOMO; O. IRIBARNE
Revista:
FISHERIES RESEARCH
Editorial:
Elsevier
Referencias:
Lugar: Amsterdam; Año: 2004 vol. 67 p. 55 - 70
ISSN:
0165-7836
Resumen:
Small-scale artisanal fisheries of the stout razor clam Tagelus plebeius are currently developing in intertidal habitats of
several southwestern Atlantic estuaries (3639◦S) in many cases conflicting with habitat conservation. We evaluated the
effects of this harvesting on non-target benthic species with replicated experiments conducted simultaneously at six different
locations. Given the tendency of burrowing crabs Chasmagnathus granulata to rapidly colonize disturbed plots and excavate
new burrows, our a priori prediction was that local effects of clam harvesting would vary depending on the local density
of burrowing crabs because it may determine contrasting levels of burrowing disturbance after clam harvesting. To test this
hypothesis, experimental plots were distributed equally between habitats characterized by contrasting levels of burrowing
crab density. Contrary to our expectation, burrowing crabs recolonized all the disturbed plots at similar rates. The effects
of clam harvesting on burrowing crabs, however, varied temporally from positive at low-density mosaics to negative at
high-density mosaics, probably due to temporal variations in crab wandering behavior. Juveniles of the crab Cyrtograpsus
angulatus showed location-dependent positive responses to the clam harvesting treatment associated with increases in the
amount of shell material exposed at the surface during harvesting. Harvesting significantly affects the density of the polychaeteTagelus plebeius are currently developing in intertidal habitats of
several southwestern Atlantic estuaries (3639◦S) in many cases conflicting with habitat conservation. We evaluated the
effects of this harvesting on non-target benthic species with replicated experiments conducted simultaneously at six different
locations. Given the tendency of burrowing crabs Chasmagnathus granulata to rapidly colonize disturbed plots and excavate
new burrows, our a priori prediction was that local effects of clam harvesting would vary depending on the local density
of burrowing crabs because it may determine contrasting levels of burrowing disturbance after clam harvesting. To test this
hypothesis, experimental plots were distributed equally between habitats characterized by contrasting levels of burrowing
crab density. Contrary to our expectation, burrowing crabs recolonized all the disturbed plots at similar rates. The effects
of clam harvesting on burrowing crabs, however, varied temporally from positive at low-density mosaics to negative at
high-density mosaics, probably due to temporal variations in crab wandering behavior. Juveniles of the crab Cyrtograpsus
angulatus showed location-dependent positive responses to the clam harvesting treatment associated with increases in the
amount of shell material exposed at the surface during harvesting. Harvesting significantly affects the density of the polychaete◦S) in many cases conflicting with habitat conservation. We evaluated the
effects of this harvesting on non-target benthic species with replicated experiments conducted simultaneously at six different
locations. Given the tendency of burrowing crabs Chasmagnathus granulata to rapidly colonize disturbed plots and excavate
new burrows, our a priori prediction was that local effects of clam harvesting would vary depending on the local density
of burrowing crabs because it may determine contrasting levels of burrowing disturbance after clam harvesting. To test this
hypothesis, experimental plots were distributed equally between habitats characterized by contrasting levels of burrowing
crab density. Contrary to our expectation, burrowing crabs recolonized all the disturbed plots at similar rates. The effects
of clam harvesting on burrowing crabs, however, varied temporally from positive at low-density mosaics to negative at
high-density mosaics, probably due to temporal variations in crab wandering behavior. Juveniles of the crab Cyrtograpsus
angulatus showed location-dependent positive responses to the clam harvesting treatment associated with increases in the
amount of shell material exposed at the surface during harvesting. Harvesting significantly affects the density of the polychaeteChasmagnathus granulata to rapidly colonize disturbed plots and excavate
new burrows, our a priori prediction was that local effects of clam harvesting would vary depending on the local density
of burrowing crabs because it may determine contrasting levels of burrowing disturbance after clam harvesting. To test this
hypothesis, experimental plots were distributed equally between habitats characterized by contrasting levels of burrowing
crab density. Contrary to our expectation, burrowing crabs recolonized all the disturbed plots at similar rates. The effects
of clam harvesting on burrowing crabs, however, varied temporally from positive at low-density mosaics to negative at
high-density mosaics, probably due to temporal variations in crab wandering behavior. Juveniles of the crab Cyrtograpsus
angulatus showed location-dependent positive responses to the clam harvesting treatment associated with increases in the
amount of shell material exposed at the surface during harvesting. Harvesting significantly affects the density of the polychaeteCyrtograpsus
angulatus showed location-dependent positive responses to the clam harvesting treatment associated with increases in the
amount of shell material exposed at the surface during harvesting. Harvesting significantly affects the density of the polychaeteshowed location-dependent positive responses to the clam harvesting treatment associated with increases in the
amount of shell material exposed at the surface during harvesting. Harvesting significantly affects the density of the polychaete
Laeonereis acuta in a few particular locations and sampling dates. Location-dependent increases of this species in disturbed
plots were observed after recruitment events, suggesting recruitment enhancement by bottom roughness interacting with
differences among locations in larval supply. These results demonstrate that extrapolation of results from a single location
may be inaccurate even for nearby areas.We strongly advocate that the occurrence and nature of location-dependency should
be integrated in the design of management programs.
© 2003 Elsevier B.V. All rights reserved.in a few particular locations and sampling dates. Location-dependent increases of this species in disturbed
plots were observed after recruitment events, suggesting recruitment enhancement by bottom roughness interacting with
differences among locations in larval supply. These results demonstrate that extrapolation of results from a single location
may be inaccurate even for nearby areas.We strongly advocate that the occurrence and nature of location-dependency should
be integrated in the design of management programs.
© 2003 Elsevier B.V. All rights reserved.