6 J
.C. Castilla J. Exp. Mar. Biol. Ecol. 250 2000 3 –21
Conservation is a term that has evolved in the past 150 years reviewed by Meffe and Carroll, 1994; Heywood and Watson, 1995. In its widest sense it refers to the
protection, use and sharing of benefits of the biosphere in a sustainable way IUCN UNEP WWF, 1980. In its narrowest sense, as used in the Convention of Biological
Diversity, it embraces only ’preservation’ or the maintenance of some or all components of biological diversity. Furthermore, definitions of conservation vary between countries
and agencies. For example, the Chilean legislation defines conservation as the ’adminis- tration management of the biosphere by the human being so that the greatest and
sustainable benefits for the present and future generations are achieved’ Castilla, 1996. On the other hand, conservation i.e. wildlife rehabilitation; Estes, 1998 may also be
perceived as ’a public demand’ and be interpreted as a major confrontation with the continued use of the resources.
3. Management and experimental marine ecology
3.1. Approaches to management of single and multispecies resources At the beginning of 1900, most management focussed on single species and
uncertainties about the dynamics of recruitment of fish Hjort, 1914. Later, the focus was moved to population ecology and the development of predictive modelling tools,
such as the logistic curve of population growth. This was used to represent the catch which could be sustained by a population of a given size. To use these procedures,
relationships between fishing effort and average yield, Maximum Sustainable Yield MSY were assumed Beverton and Holt, 1957; Gulland, 1982. This approach and
model were challenged by Larkin 1977, who thought that seeking an absolute MSY, assuming a lack of ecological interactions among populations of fish, was risky.
Nonetheless, the method was used to manage fish stocks from the end of the second World War well into the late 1980s Gulland, 1983. According to Hilborn and Walters
1992, these approaches gave the wrong signal to practitioners for assessment of stocks. They concentrated almost exclusively on two questions: what is the optimal effort? and,
what is the MSY? It was hoped that by this process the nature of the modelled relationship would be understood well enough to apply it properly to manage a fishery.
Meanwhile, ’the thing to do was to monitor fishing effort as it increases slowly and gradually, while monitoring yields, so as to eventually be able to plot a relationship
between them’ Hilborn and Walters, 1992. This is the basis of Adaptive Management Walters, 1986. Monitoring policies were considered too costly and or risky Walters,
1997. As a consequence, many fisheries have suffered over-exploitation due to the absence of long-term monitoring schemes, the use of inadequate estimates of parameters,
poor understanding of environmental variability and or the implementation of fish catch quotas as a response to short-term economic pressures National Research Council,
1999. There have, however, been some reports of the management procedures for fisheres used which have been more rational. For instance, according to McCaughran
1996 the 108-year-old fishery of the Pacific Halibut, Hippoglossus stenolepis, managed by the International Halibut Commission IHC, represents a case of sustainable fishery
J .C. Castilla J. Exp. Mar. Biol. Ecol. 250 2000 3 –21
7
but see Ketchen 1956, Fukuda 1962 and the experimental options discussed by Parma and Deriso, 1990. The scheme for management in that example is based on a
long-term monitoring program and it appears to contain some of the components of a research program Underwood, 1990; Hurlbert, 1994; but see Parma and Deriso, 1990.
According to McCaughran 1996, the IHC: 1 has control over short-term economic desires, 2 the Halibut fishermen tend to be conservative in their catches and 3 the
fishermen share IHC’s goals for conservation of the stocks. Another example refers to the management of the Australian western rock lobster, Panulirus cygnus, where 1 an
index of recruitment has been used for over 35 years, 2 there is on-going monitoring of the stocks, and 3 there exists an adaptive management program for the fishery. These
have resulted in the long-term sustainable management of the fishery Caputi et al., 1996. No obvious connection between EME findings and these two examples of
successful fisheries can be seen. At the other extreme are managerial schemes for single species fisheries in which the assessments of stock may have been wrong, resulting in
collapses of the fishery and in community cascading effects throughout the whole ecosystem National Research Council, 1999.
Multispecies Sissenwine and Dann, 1991 and ecosystem Sherman et al., 1993 approaches to modelling fisheries appear to be ecologically more sound. In some cases
Murawski, 1991, a degree of success in the understanding of interactions among species and the consequences of alternative forms of management have been reported.
Present trends in management of multispecies fisheries show the incorporation of modelling, including trophic interactions among the species. This allows inferences to be
drawn about possible responses by the whole ecosystem Pauly and Christensen, 1995; Christensen and Pauly, 1998; for a historical perspective, see Gulland, 1982. This opens
up an opportunity for the future integration of findings about trophic interactions from EME, modelling and management.
3.2. The ecological approach to management of fisheries It is interesting to note that where a single species is managed the most common
form of management during the past century and in management multispecies fisheries, no strong partnerships between fishery modellers, managers and experimental marine
ecologists seems to have occurred e.g. Paine, 1984. Partly, this is due to the different temporal and spatial scales at which most marine ecologists and fishery scientists
managers operate. In any case, it appears that the species managed usually ill-managed and over-exploited have been thought of as though they exist in empty ecosystems
where no other species matter. Recently, the assumption that ecological research is the most productive way to determine the limits of sustainability in natural resource
management, particularly in fisheries, has been challenged by Ludwig et al. 1993 and Hilborn and Ludwig 1993. Hilborn and Ludwig 1993 argued that: 1 ecological
experiments take too long; 2 replication a critical issue in the scientific method, control and randomization are harder to achieve; and 3 that ecological systems have
the nasty habit of changing over time. Problems in management of fisheries need to be answered today. Society must make decisions in the face of uncertainties. On the other
hand, McAllister and Peterman 1992 argued that constraints on experimental fisheries
8 J
.C. Castilla J. Exp. Mar. Biol. Ecol. 250 2000 3 –21
can be overcome if: 1 experimentation is small-scale; 2 fishers are compensated when cuts in fishing effort are required; 3 fishers believe that experimentation is in
their best interests and 4 control populations are held in reserve in case overharvesting occurs in a treated population. Controls are of course needed to evaluate the experi-
ments. Controversies about such issues have been present in management of fisheries for the past 120 years Huxley, 1884; Lankester, 1884.
In the future, according to Ludwig et al. 1993 and Hilborn and Ludwig 1993, the approach should be: 1 to continue fishing; 2 to monitor; 3 to get rid of frequentist
statistical methods; and 4 to be adaptive. The sad fact is that in the almost total absence of experimentation and or ecological advice although poor a large number of
marine resources have been overexploited or depleted Botsford et al., 1997. It is not known to what degree ecological inputs would have helped to avoid such a situation.
Nevertheless, one thing is clear: such ecological inputs would have required testing hypotheses and, therefore, some degree of experimentation. A large number of collapses
of fisheries have happened under the use of inappropriate management of single species mainly using production or yield-per-recruit models. Hilborn and Ludwig’s 1993
prescription seems to be to continue fishing in the vacuum of knowledge about interacting processes. Accepting the limitations of experimental ecological research, and
being myself much in favor of Adaptive Management, I do not completely agree with Hilborn and Ludwig’s 1993 suggestions. In fact, although ecological research may not
be the most productive way to determine the limits of sustainability of any fishery, such limits cannot continue to be approached without better knowledge about ecosystems.
Long-term experimentation in fisheries, despite its limitations, has to be done. There is a need to test hypotheses. Currently small-scale benthic invertebrate fisheries appear as the
best candidates. Nevertheless, McAllister and Peterman 1992 reviewed several experiments on management of fin-fish single species management of salmon and
halibut and multispecies fisheries, where improvements on their designs, regarding controls over temporal and spatial variability, randomization, interspeciation, contrasting
treatments and spatial replication, are needed, but possible. Furthermore, there are new managerial tools see later, Section 3.5 that will enhance our future ability to do
experiments on management of fisheries and to make bridges with findings from EME. Of course, to be able to develop experimentation in any fishery we will have to get rid of
the ’ratchet effect’. This is the problem that managers under constant socio-political and economic pressure for greater harvesting of fish, to maximze short-term benefits,
continue to allow catches to increase Ludwig et al., 1993; Mace, 1996.
3.3. Small-scale fisheries In small-scale fisheries, it is now recognized that for the fishers and not the fishes are
the most important species in need of consideration. If fishers’ behavior, needs, expectations, perceptions, traditional knowledge, property rights and equitable use of
marine resources are not considered in plans for management, the deterioration of resources, communities and ecosystems must continue. The depletion of marine
resources is just one of the consequences derived from mismanagement. Another appears to be the effects on marine biodiversity Casey and Myers, 1998; Roberts and Hawkins,
J .C. Castilla J. Exp. Mar. Biol. Ecol. 250 2000 3 –21
9
1999. What is being learned in small-scale fisheries, where small-scale and experimental ´
replication are becoming possible Castilla and Fernandez, 1999, may be applied in the future to large-scale fisheries. This is a major challenge ahead and limitations are
inevitable.
3.4. Large-scale perturbations Modificiations of major oceanic ecosystem due to large-scale human perturbations,
such as heavy exploitation and or coupling with changes in the physical environment, have been reported from different areas of the world. For example, the Bering Sea and
Newfoundland Sea Myers et al., 1997; National Research Council, 1999 and the Barents Sea Hamre, 1994 have suffered. Nevertheless, there are still too many
scientific uncertainties to understand relatively ’simple’ modifications to ecosystems and to ascribe causality to the observed patterns National Research Council, 1999.
Large-scale modifications to fisheries, seem not to be fully used in a progressive adaptive management so as to gain insights into the dynamics and resilience of large
ecosystems but see Estes et al., 1998.
3.5. Present trends and the possibility of linking EME and fishery management During the late 1980s and 1990s, new approaches to management of fisheries and new
legal tools have been implemented. These are challenging the old paradigms and provide opportunities for more rational management and the application of knowledge generated
through EME. I highlight three managerial tools which may facilitate the cross-linkage between EME and management of fisheries.
3.5.1. Adaptive management AM AM was coined in the 1970s by Holling 1978 and mainly followed by Walters
1986 and co-workers and has been used in single species management schemes. At present, AM is a posture in fishery sciences. It states: let us use all the knowledge
scientific, traditional, other that is out there and start an active long-term process of management. In AM, the objectives for managing the fishery are jointly identified by the
resource users, scientists and managers. Targets are then set for the catch. The process is followed by monitoring, including feed-back mechanisms. The central premise of the
adaptive managerial strategy is ’learning and adaptiveness by doing’. Presently, numerous principles for managing fisheries and numerous policy documents refer
explicitly to AM as the future tool for management. In spite of its attractiveness, AM procedures have not been used in fisheries as frequently as might be expected.
Moreover, so far, the results have not been too successful Walters, 1997. This is because AM has been implemented on a short-term basis and under the ’ratchet effect’
Ludwig et al., 1993. The potential of AM relies in its adaptive philosophy and long-term monitoring. The challenge ahead is to introduce in AM not only monitoring
but also experimental protocols and to project it into perspectives about ecosystems. Cross-linkages between EME and AM should be aimed for in the future.
10 J
.C. Castilla J. Exp. Mar. Biol. Ecol. 250 2000 3 –21
3.5.2. Individual transferable quotas ITQs In fisheries, good management is bound to be hampered by the lack of private or
communal rights over the resource. This, under an open regime of access to the fishery, gives rise to the problem of common property or the ‘‘tragedy of the commons’’
Hardin, 1960. ITQs consider the allocation of a share of the total allowable catches under the management of single species either to individual or to communal users of
the resource. Quotas can be allocated for defined periods and constitute a quasi-right to property Dewes, 1998. ITQs vary according to the resource, legislation, ethnic group,
rental and the necessary mechanisms of adjusting and recovery by governments. They were among the first tools implemented to stop ’the race for the fish’. ITQs constrain the
participants from seeking only to maximize profits particularly in traditional fisheries. If the stake-holders in the resource have some degree of ownership in the stocks, they
may still seek to maximize profits, but they will also be more willing to work with scientists in schemes of Adaptive Management. Further, the design of experimental
fisheries implementation of ecosystem approaches and using ecological knowledge will be greatly enhanced. An alternative to ITQs, the Individual Non-Transferrable Quotas
INTQs, was experimentally used in Chile in the 1990s, with the management of the dive-fishery of the mollusc ’loco’, Concholepas concholepas Castilla, 1994. They were
implemented for the management of benthic resources jointly with the establishment of Territorial Use Rights in Fisheries TURFs, see below and under plans of co-
management. These tools have enhanced the possibility to do local benthic resource re-stocking, rotational extractions and extractive experiments. They have also permitted
the incorporation of knowledge from EME into the activities of small-scale fisheries
´ ´
Fernandez and Castilla, 1997; Castilla and Fernandez, 1998; Castilla et al., 1998; ´
Castilla, 1999; Fernandez et al., 2000. Above all, INTQs have permitted the incorpora- tion of fishers as active role-players in the processes of management.
3.5.3. Territorial ‘‘use rights’’ in fisheries TURFs ITQs and INTQs partially mitigate some of the adverse economic incentives in
fisheries. They do not, however, necessarily reduce completely the discount rates and do not ensure conservation of resources or ecosystems Mace, 1996. TURFs have been
implemented as another mitigating complement and used in different countries in the past decade Prince et al., 1998. They open the possibility for implementing schemes to
manage multispecies fisheries, although, so far, have been used mostly in single species fisheries. In Chile, TURFs have been allocated to communities having long-term
artisanal fishing traditions and organizational skills Castilla, 1994. These communities exercise collective responsibilities over a particular designated area and its resources by
developing a plan for management. This has served to develop community-based management of each fishery and has encouraged co-management. It has also permitted
the development of fishing experiments, monitoring the fisheries and adaptive local management, including participation by the resource users Castilla et al., 1998. The
’ownership’ of coastal areas by local communities does permit better communication between scientists and users of the resources. It also enhances the implementation of
monitoring schemes and the design of fishing experiments. Although these tools have been used mainly for management experimental management of single benthic species
J .C. Castilla J. Exp. Mar. Biol. Ecol. 250 2000 3 –21
11
and their application to pelagic fisheries is not easily foreseen, they have shown that critical constraints in the management of marine fisheries can be overcome. After all,
experimentation, although limited, can be approached in the sea and TURFs present a potential for suitable replication and control in the design of such experiments Castilla
´ and Fernandez, 1999. The challenges are to perfect and expand this direction, to include
the resource users in management, to be more holistic in the approach i.e. to use ecosystem approaches, to use schemes for managing multispecies fisheries and, thereby,
to bridge fisheries management and EME.
4. Conservation and experimental marine ecology
