4 J
.C. Castilla J. Exp. Mar. Biol. Ecol. 250 2000 3 –21 Keywords
: Conservation; Experiment; Humans; Linkages; Marine ecology; Management; Nearshore; Rocky intertidal
1. Introduction
Ecology is the scientific study of the interactions among species and is concerned with the distributions and abundances of organisms Andrewartha and Birch, 1954. Im-
portant progress in answering ecological questions and testing alternative hypotheses has been achieved by the use of experimental work. Experimental marine ecology EME is
a subdiscipline of ecology, which focuses on the marine realm and related environments. Within this realm, intertidal and inshore coastal ecosystems and their benthic assem-
blages communities are readily accessible. It is less expensive to develop experimental approaches in such habitats than elsewhere. These ecosystems have served as the key
environments where EME originated and produced significant scientific advances. Paine 1994 has reviewed the progress of ecological marine studies since the beginning of the
last century and concluded that, during the first three decades, there was a notable development of quantitative methodologies, particularly in the case of marine soft
sediments, but experimentation was absent. During the 1940s and 1950s, intertidal rocky shore ecological studies were numerous. They dealt mainly with the description of
intertidal zonation patterns and demonstration of its universality Stephenson and Stephenson, 1949; Guiler, 1955, 1959; Morgans, 1957. The patterns were convincing
and causation strongly biased toward physical factors see Lewis, 1964; Stephenson and Stephenson, 1972. Nevertheless, EME approaches were embryonic. In the 1960s,
advanced technology was used to develop a series of descriptive deep-sea benthic studies Sanders, 1968 and experimental manipulative studies were also initiated,
mainly to demonstrate the role of biological interactions in intertidal rocky shores communities i.e. Connell, 1961; Paine, 1966; Paine and Vadas, 1969. Throughout the
1970s and 1980s, experimental marine ecological studies flourished, particularly in cold and temperate rocky intertidal, subtidal nearshore reefs and kelp communities. The
marine ecological literature was flooded with experimental studies usually developed within short spatial and temporal scales, which nowadays represent the corner-stone of
modern EME i.e. Paine, 1971, 1974, 1977, 1980, 1984; Dayton, 1971, 1985; Connell, 1974; Estes and Palmisano, 1974; Branch, 1975, 1984; Menge, 1976, 1978; Menge and
Sutherland, 1976, 1987; Lubchenco, 1978; Underwood, 1978, 1984, 1985, 1986; Estes et al., 1978; Sousa, 1979a,b; Santelices et al., 1980; Duggins, 1980; Castilla and Moreno,
1982; Fairweather et al., 1984; Moreno et al., 1984; Duggins and Dethier, 1985; Moran,
´ ´
´ 1985; Castilla and Duran, 1985; Chapman, 1986; Duran et al., 1986; Duran and Castilla,
1989. During the late 1980s and throughout the 1990s, manipulative marine experi- ments increased and emphasis was moved to linkages between pelagic and benthic
systems, larval transport, subtidal-intertidal biomass subsidy Bustamante et al., 1995; Bustamante and Branch, 1996 and the use of appropriate experimental protocols
Underwood, 1990, 1991, 1997. Furthermore, the ecological role played by humans was studied experimentally Castilla, 1999.
J .C. Castilla J. Exp. Mar. Biol. Ecol. 250 2000 3 –21
5
In the past 40 years, EME has peaked to the level of a solid scientific discipline and intertidal and nearshore hard substrata systems have provided the basis for classic
experiments to test hypotheses about competition, predation, succession, niche, facilita- tion, perturbation, resilience, environmental heterogeneity and species richness. A large
array of vertebrates, invertebrates and algae has been used in these endeavors and this represents one of the important contributions of modern EME. Furthermore, during the
last 40 years, major ecological paradigms, such as the concept of the key-stone species, community resilience and or ecologically alternative states and the influence of
carnivores and hervibores on patterns of biomass in aquatic systems species and community trophic cascades and on species biodiversity have evolved, linked to marine
systems Paine, 1966; Sutherland, 1974; Bond, 1993; Mills et al., 1993; Castilla et al., 1994; Power et al., 1996; Polis, 1999. Nevertheless, during the past century, little
scientific progress has been made using experimental approaches to study marine detrital webs and the role of pathogens.
An area that shows little progress, particularly in cold and marine temperate systems tropical ecosystems are not addressed here, is the cross-linkage between EME and
resource management. This has most probably been due to limitations in the design of fishery experiments Underwood, 1990; McAllister and Peterman, 1992 and issues of
large temporal and spatial scales. Nevertheless, there are stronger connections between EME and conservation issues i.e. Mills et al., 1993; Heywood, 1999 than have been
highlighted to date.
In this paper, I analyze EME studies to link them to conservation and management. I suggest that, EME, marine conservation and management should be approached through
the use of long-term monitoring schemes, taking into account the relevant spatial and temporal scales, adaptive strategies and, whenever possible, the use of experimental
protocols. Otherwise these activities will continue to be dissociated. Furthermore, I stress the need for the explicit incorporation of humans in EME protocols and urge scientists to
bridge communication barriers between ecology, conservation, management and social sciences.
2. Management and conservation: definitions
