Previous Page Table of Contents Next Page

6. Precautionary Approach to Species Introduction

6.1. Introduction

104. Because of the high probability that impacts of species introduction be of irreversible and unpredictable impacts, many species introductions are not precautionary. Therefore, a strictly precautionary approach would not permit deliberate introductions and would take strong measures to prevent unintentional introductions. Recognizing the difficulties with introductions, the objectives of a precautionary approach to species introductions in relation to capture fisheries should be to reduce the risk of adverse impacts of introductions on capture fisheries, to establish corrective or mitigating procedures (as in a contingency plan) in advance of actual adverse effects, and to minimize unintended introductions to wild ecosystems and associated capture fisheries.

105. In relation to aquaculture, experience has shown that animals will usually escape the confines of a facility. As a consequence, the introduction of aquatic organisms for aquaculture should be considered as a purposeful introduction into the wild, even though the quarantine/hatchery facility may be a closed system.

106. Introductions and transfers (hereafter referred to as introductions) are an effective means to increase protein, generate income and provide employment. However, some intended and many unintended introductions may result in significant and serious impacts on capture fisheries. The numbers of unintended introductions, for example by means of ballast water, greatly outnumber those purposefully introduced for capture fisheries. In the case of introduced species for fishery purposes, the risk to capture fisheries can be reduced by the use of internationally accepted codes, such as the 1994 ICES Code of Practice (see Annex A)4. This code forms a basis for a more precautionary introduction and should be widely circulated and explained.

107. For a precautionary approach to fishery management, irreversible changes in the time scale of human generations and other undesirable impacts should be avoided, taking into account uncertainty. Species introductions, either purposeful or unintended, may have such undesirable effects. Once a species has been introduced, it cannot usually be eradicated, although it may be possible to mitigate its undesirable effects.

108. The difficulty in reversing an introduction and its adverse effects should figure prominently in the decision process on whether to allow an introduction. Assessment of the risks of intentional introductions on fisheries is necessary for the precautionary approach; the ICES Code of Practice provides a procedure for such an assessment.

109. To encourage more compliance with the precautionary approach to introductions, the existing Code of Practice formulated for the ICES region can be modified and adapted to suit more national implementation of the codes by streamlining its procedures without weakening the rigour of the codes.

110. Unintended introductions are inherently unprecautionary because they can rarely be evaluated in advance. A precautionary approach would aim at reducing the risk of such unintended introductions and minimize their impact.

6.2. Main Issues and Objectives

111. Introductions are considered here from the perspective of the fishery sector. The main reasons for deliberate introductions include production of protein, employment, generation of foreign exchange, biological control and recreation. Species have been introduced through activities associated with transport (i.e., ballast water, ship and oil-rig fouling), trade in living organisms including aquarium species, aquaculture and fisheries (commercial, recreational, stock enhancement, organisms carried on fishing equipment, live bait fish). Many of these activities have increased over the last century and are expected to increase further in the future.

112. Potential impacts of some introductions on the fishery sector included changes in the distribution and abundance of fishery resources through disease, changes in predator-prey relationships, changes in competition, mixing of bad (maladapted) genes, and habitat modification. There may also be second and third order changes that affect the ecosystem. Changes in fishing strategy and the fishing community may also require changes in fishing gear and season to allow for a newly introduced species to establish itself or to avoid potential side issues associated with the new fishery. Climate changes may also have significant consequences that may modify the environment, making it more suitable for introductions of either useful or harmful species.

113. The use of introduced species, including genetically modified and genetically selected organisms, may allow for continued or increased production from habitats that have been so altered or degraded that native fisheries are no longer viable. Care should be taken not to use this potential productivity from introduced species as justification for further abuse of habitat or for delaying their restoration.

6.3. Research and Technology

Deliberate introductions

114. The ICES Code of Practice (Annex A) describes the research activities that should be conducted in advance of an introduction as follows: (1) desk assessment of the biology and ecology of the intended introduction; (2) preparation of a hazard assessment (detailed analysis of potential environmental impacts); (3) examination of the species within its home range. The results of the above research should be contained in a prospectus or proposal to be submitted to the competent authority for evaluation and decision.

115. Technological intervention can be used during and following the introduction; such technologies may include:

a. use of hatcheries and quarantine stations to reduce the chance of spread of disease to fishery resources, and to impart some control on numbers of exotic organisms released;

b. use of sterile organisms to reduce the chance of interbreeding with natural fish stocks;

c. genetic stock identification to reduce or prevent genetic changes in the fishery resource;

d. disease diagnostics to monitor the health of the introduced species, and

e. development of the use of limited (pilot) scale introductions to assess impacts and performance.

116. Continued research and technological intervention on introduced species as part of a monitoring and evaluation scheme should be conducted to assess their impact, health and performance within their new habitat. In this regard, databases or registries of introductions of aquatic species, including their ecological and socio-economic impact, have been established and should be maintained by competent organizations with input from the fishery sector.

Unintended introductions

117. Although unintended introductions may arise from several sources, such as fouling organisms, removal of natural barriers and aquarium fish trade, ballast water is probably the most significant and troublesome for the fishery sector and, therefore, emphasized here. In the case of ballast water and sediment, desk studies may be undertaken to determine (1) main ballast water sources, (2) volumes of ballast introduced, and (3) likely “hot spots” as sources of introductions.

118. Active research should take place and continue on:

a. practical methods for treating organisms in ballast water and sediment;
b. study of dynamics of target species in voyage;
c. study of algal cysts in ships ballast sediment and in port areas;
d. effectiveness of reballasting activities;
e. design changes to ballast water tanks to kill or control harmful species in ballast water, and
f. vessel design that will facilitate the treatment and handling of ballast sediments and water.
119. Research into new effective non-biocidal antifouling materials should continue to reduce the risks of introductions on ships* hulls and to replace those biocidal applications detrimental for capture fisheries. Antifouling agents are designed to reduce drag and increase the fuel efficiency of a vessel and its long-term efficacy, but they should also be environmentally friendly. Consideration should also be given to those antifouling agents designed to control organisms that would be especially harmful to capture fisheries, even though they may not affect the performance of the vessel.

6.4. Management

120. The first step to managing introductions is to establish a management authority with responsibility for evaluation of proposed introductions, approval in accordance with these guidelines and assuring monitoring of the effects of the introduction. The management of species introductions will involve comparative risk assessment and choices between various options to increase productivity. Management options are limited here to those in the aquatic sector, although countries may be aware of broader issues, such as the development of other sectors (e.g., agriculture). International codes of practice, such as the ICES code, provide a good framework for the management of purposeful species introductions. These codes should not be seen as a hindrance to development, but rather as a tool to help importers make good choices with regard to introductions. Implementation of the code should increase the probability of success of an appropriate introduction.

Deliberate introductions

121. Intended introductions should be controlled. As a consequence, those making an introduction should follow the ICES or similar code of practice as appropriate and would be expected to demonstrate caution by preparing a proposal covering: (1) the purpose and objectives of the introduction in advance of the introduction, (2) all relevant biological, ecological, and genetic data of the species in the target area likely to be affected, (3) analysis of potential impacts at the introduction site, including potential ecological, genetic and disease impacts and consequences of its spread, and (4) a qualitative and, where possible, a quantitative risk assessment.

122. If this proposal is approved: (1) a brood stock should be established at a suitable quarantine site; (2) all effluents from facility should be appropriately sterilized; (3) isolated first generation individuals, free of disease, should be released to the wild in small numbers; and (4) studies of the introduction in the new environment should be continued.

123. A contingency plan should take account of negative effects should they become apparent and warrant intervention.

124. The code should also cover introductions that are part of current commercial practice (live trade in fish and shellfish) and recommend: (a) periodic inspection prior to exportation; (b) regular inspection; and (c) quarantine and control if appropriate.

125. The concern expressed in relation to the introduction of species for fisheries, using the ICES Code, should apply to those species under consideration for biological control, which may have implications for capture fisheries. Bio-control programmes should be weighed carefully against other control methodologies, such as physical and chemical techniques or through intensive fishing. It is likely biological control techniques will take some years to evaluate, through field trials. Much may be learned from the studies on biological control in other disciplines, such as entomology.

126. The proposal submitted by the potential importer of an exotic species and its review by the competent authority serve as precautionary measures to reduce the chance of a harmful introduction. Governments may wish to consider for national legislation that, if these elements of the code are not followed, the importer of an exotic species may be financially responsible and subject to liability, should significant negative effects arise.

127. Care should be taken to ensure that the introduced population has an adequate genetic resource base, i.e., genetic diversity, low inbreeding, etc. This may reduce the need for additional introductions, which might otherwise be necessary to increase the genetic resource base. In addition, consideration should be given to the use of gametes, e.g., eggs, cryopreserved sperm, as import material instead of whole organisms to reduce the risk of introducing disease or unintended organisms.

Unintended introductions

128. Introduction of undesirable species via ballast water poses problems for fisheries worldwide. In addition to unintentional introductions by ballast water, there are many other mechanisms, including fishing and trade in live fish. Fishing can introduce species by transporting live or fresh bait, or biologically contaminated fishing gear between ecosystems. With trade in live organisms (for aquarium or human consumption), there is the risk of escape.

129. Authorities responsible for regulating fishing and trade in fish products should establish regulations to reduce these risks, commensurate with the severity of potential adverse impacts. However, the national and international competent authorities that deal with ballast issues are seldom also responsible for fishery management matters. Cooperation between these authorities would greatly aid the management of this problem.

130. In order to reduce the risk of introductions of organisms in ballast water on capture fisheries in or near deballasting areas, the following methods of prevention include, as recommended by the IMO (1994, Annex B): (a) non-release of ballast; (b) ballast water exchange(s) in or near approved areas; (c) preventing or minimizing uptake of contaminated water or sediment (in shallow water, near dredging operations, during algal blooms); (d) special ballasting facilities on shore; (e) education of crews about ballast-water management procedures, and (f) treatments of ballast water, including changes in temperature and salinity and use of biocides (chemicals).

131. Although the issues of ballast-water transport, fouling organisms and other unintentional introductions may fall outside the mandate of fishery ministries, the fishery sector could contribute to the management of such introductions, which impact upon the industry. This could be accomplished by promoting the establishment and maintenance in the appropriate institution, of an accessible database on ballast or fouling organisms that have a demonstrated impact on fisheries, by promoting a network of experts who would identify problems, assist with species identification, and delimit areas of impact. The fishery sector may be well placed to detect the spread of harmful ballast/fouling organisms and should, therefore, contribute to such databases and networks once established, and may take a lead in instigating action on environmental management.

132. Introduced organisms may cause major changes in ecosystems, especially in port and associated, partly enclosed or enclosed areas, such as lagoons. Such introductions may result in changes in the productivity of local harvested species. Monitoring of introduced organisms and fisheries in these areas may provide useful information as a basis for modifying management techniques and policy for harvested resources.

6.5. Implementation Guidelines

133. Those making introductions should consider the ICES code as a means to reduce introductions of harmful or nuisance species, including parasites and diseases, which may impact on capture fisheries:

134. To encourage a more precautionary approach, governments outside the ICES region should follow the principles or recommendations of the code according to their particular circumstances. Critical elements to be considered are a proposal, independent review by a scientific body, and subsequent protocols if an introduction is approved.

135. In addition to codes of practice issued by ICES and IMO, the following may be useful as a precautionary approach to introduced species:

a. establish clear and straightforward procedures and protocols on the mechanisms for the management of introduced species under the relevant competent government agencies with authority to address issues of compliance, responsibility, and liability;

b. promote cooperation between the fishery sector and other sectors dealing with the aquatic environment in order to coordinate policy and regulation of introduced species, especially the national shipping sector, and port authorities and international organizations, e.g., ICES, FAO, IMO and ICLARM, which have relevant expertise;

c. encourage relevant groups (e.g., importer and regulatory agencies) to consider the development of a contingency plan in the event that the introduced species does not fulfil expectations or causes adverse impacts;

d. promote education, training and awareness of harmful species introductions, disseminate as widely as possible the ICES and IMO codes of practice and advise responsible authorities within the fishery and other sectors on the procedures of these codes;

e. develop an international information system in appropriate institutions on ballast or fouling organisms, which have demonstrated impacts on fisheries, by promoting a network of experts who would identify problems, species identification, and areas of impact, arrange standardization of sampling methods (inter-calibration), and develop a monitoring system so that changes can be evaluated in high-risk areas. Should unwanted species be detected, an eradication programme should be considered;

f. encourage compliance with the code by the fishing industry and other users of aquatic resources; national governments could encourage self-policing and self-enforcing by fishing industry and other users of the resource in minimising the impacts of introducing species by unauthorised means, and

g. conduct research on the applicability of information gained from introductions of limited numbers of animals (e.g. pilot/experimental introductions).

136. Promotion and maintenance of databases on species deliberately introduced for capture fisheries is suggested. This would include the impact of these introductions. Importers or fishery managers may wish to consult such databases to assist in the proposal formulation and its evaluation.

137. The development of effective non-biocidal antifouling applications to reduce the risk of introduction from ship fouling is encouraged.

4 Editor’s note: The ICES Code of Practice originally drafted by ICES was subsequently finalized jointly by ICES and EIFAC for use by the FAO Regional Fishery Bodies. The Code is still being evolved and supplementary material is being produced by FAO to assist in its implementation mainly in developing countries

Previous Page Top of Page Next Page