DFO's Aquaculture Action Plan — Interim Guide to the Application of Section 35 of the Fisheries Act to Salmonid Cage Aquaculture Developments

Table of Contents

1.0 INTRODUCTION

2.0 THE STRATEGY

• 2.1 Application of the Strategy
• 2.2 Anticipated Benefits
• 2.3 Assumptions

3.0 PROJECT ASSESSMENT

• 3.1 Determining Benthic Baseline Conditions
• 3.2 Risk Assessment

4.0 PROPOSED INSTRUMENTS

• 4.1 Letter of Advice
  • 4.1.1 Monitoring Results and LOAs
• 4.2 HADD Avoidance, Mitigation, and Monitoring Agreement
  • 4.2.1 Monitoring Results and Agreements
• 4.3 Subsection 35(2) Authorization
  • 4.3.1 Monitoring Results and Authorizations
• 4.4 Changes to Monitoring Cycle or Production Levels

APPENDIXES

• APPENDIX 1: Determining Benthic Baseline Conditions
• APPENDIX 2: Proposed instruments
• APPENDIX 3: Example of the use of PBS
• APPENDIX 4: Templates for regulatory instruments
• APPENDIX 5: Flowcharts
• APPENDIX 6: Identifying unacceptable HADDs

BIBLIOGRAPHY

GLOSSARY

1.0 INTRODUCTION

The federal Minister of Fisheries and Oceans Canada (DFO) is responsible for the administration and enforcement of Section 35 of the Fisheries Act. When reviewing project proposals, regional Habitat Management staff determines what effects the project may have on fish habitat. This is done in accordance with the Policy for the Management of Fish Habitat (DFO, 1986) and with Subsection 35(1) of the Fisheries Act which states that "no person shall carry on any work or undertaking that results in the harmful alteration, disruption or destruction (HADD) of fish habitat" except when authorized by the Minister, DFO, as contemplated in subsection 35(2) or through regulations under the Fisheries Act.

This document was developed in response to the rapid growth of the aquaculture industry to provide a practical and nationally consistent approach to the application of Section 35 to salmonid cage aquaculture developments. The determination by DFO Habitat Management assessors of whether a project has the potential to result in a HADD of fish habitat related to organic deposition is aided by the document, Decision Framework for the Determination and Authorizations of Harmful Alteration, Disruption or Destruction of Fish Habitat (DFO, 1998(a)). In the case of aquaculture, additional direction is required to assist assessors in determining whether an aquaculture project could cause a HADD of fish habitat.

The guide describes a strategy that incorporates:

• Performance-Based Standards (PBS) (Appendix 1) which are physical or chemical indicators that approximate and rank the quality of fish habitat in an area. The PBS approach advocated in this guide has been proven the most cost-effective method (Wildish, et al. 2001) in terms of speed and simplicity of use for monitoring benthic effects while providing sufficient information to assess the potential fish habitat effects relative to the section 35 requirements of the Fisheries Act. As scientific knowledge expands, these standards may be refined;
• risk assessment which combines knowledge of the existing pre-project site conditions and the operation itself to determine the appropriate instrument to ensure that mitigation and monitoring requirements are respected; and
• adaptive management which uses monitoring results to accommodate uncertainty with respect to the effectiveness of measures to prevent a HADD and ecosystem complexity to permit early intervention through additional mitigation or avoidance to control a potential HADD from developing.

The guide was developed from an in-depth examination of the issues by the National Habitat Management Working Group on Aquaculture (NHMWGA) and it captures many of the main concerns expressed in those discussions. In addition, it incorporates the experience of aquaculture monitoring in New Brunswick, British Columbia, and the work of DFO scientists.

It is an interim strategy which, over the longer term, may be replaced or complimented by other approaches such as: regulations under section 36 or 43 of the Fisheries Act, integrated management, ecosystem-based objectives, marine environmental quality (MEQ) criteria, class screenings, and siting guidelines, as the science associated with these develops. Therefore, DFO should review the guide after it has been in use for 24 months. The review should determine, among other things, the ongoing need for the document or specific sections of it.

There are several options available to DFO to ensure the mitigation, monitoring, and reporting requirements are met. They provide varying levels of assurance that these needs can be met. These options are discussed in Appendix 2.

This document is not intended to provide technical details of benthic monitoring. General guidance on this may be found in Wildish et al (1999). Specific details must be developed on a regional, ecosystem, or even a case-by-case basis.

Back to Top

2.0 THE STRATEGY

2.1 Application of the Strategy

The strategy focuses on the potential negative benthic effects of the project on fish habitat. Therefore, it will apply to all new projects, proposed expansions, and relocations of salmonid cage culture regardless of the size of the operation.

Cod grow-out sites, are not included in this strategy. It is believed that the risks associated with cod grow-out as presently conducted in Newfoundland and Quebec are substantially less than with more traditional types of operations such as salmonid cage aquaculture. This assumption is based on the type of feed used, the length of time the fish are held in cages, and the fact that the stock is captured wild instead of using hatchery stock. Cod grow-out may be included in subsequent versions of this strategy if research indicates the need.

Back to Top

2.2 Anticipated Benefits

This strategy is expected to have several benefits:

• It should encourage proponents to seek out sites where the effects of aquaculture on fish habitat will be minimised.
• It will enable the acquisition of data to enhance the knowledge of the effects of aquaculture operations on fish habitat. This will, in turn, allow for more comprehensive and permanent solutions such as scientifically defensible siting guidelines, class screenings, and possibly regulations. It will also aid in the development of new tools that will more accurately predict impacts and effects.
• It will address the proponent's section 35 responsibilities with respect to the near-field effects on habitats.

Back to Top

2.3 Assumptions

This strategy was developed around a number of assumptions.

The Habitat Conservation and Protection Guidelines (DFO, 1998) will be followed as appropriate with respect to assessing other options, such as project relocation and redesign, (3.0 and 3.1).

To make effective decisions on the likelihood of a HADD, it is necessary that the Guide to Information Requirements for Environmental Assessment of Marine Finfis Zquaculture Projects be followed to permit an accurate assessment of the risks to fish habitat as the result of the project as it includes requirements for baseline information.

Back to Top

3.0 PROJECT ASSESSMENT

This section describes the process to identify the appropriate instrument to ensure that the principle of no net loss of the productive capacity of fish habitat is respected. The instrument identification will be based on benthic baseline conditions combined with risk assessment and an adaptive management approach to ensure that the principle of no net loss of the productive capacity of fish habitat is respected.

Back to Top

3.1 Determining Benthic Baseline Conditions

The initial step is to determine the pre-development benthic baseline site conditions, using a variety of physical or chemical proxies that rank the quality of fish habitat in an area. The results of this analysis should characterize the benthos within the scope of the project as oxic, hypoxic, or anoxic. Appendix 1 provides a more detailed explanation of determining benthic baseline conditions.

Back to Top

3.2 Risk Assessment

Risk assessment integrates the results of the baseline conditions with the information on the project and its operation. This information is obtained from the proponent through the Guide to Information Requirements for Environmental Assessment of Marine Finfish Aquaculture Projects (DFO, 2001) which the proponent will complete. As decisions at this point are very much on a case-by-case basis, additional information, such as local knowledge and expertise within DFO should be used as the assessor determines necessary.

Decisions at this point should be guided by the hierarchy of conservation and protection preferences of project relocation, redesign, mitigation, and compensation as outlined in the Habitat Conservation and Protection Guidelines (DFO, 1998(b)).

The result of this analysis will enable DFO to conclude that:

• a HADD is not anticipated to result from this project;
• there is uncertainty with respect to the effectiveness of measures to prevent a HADD; or
• a HADD will result from this project.

This initial risk assessment then determines the appropriate instrument (Table 1) to ensure that the mitigation and monitoring requirements are respected.

Table 1: Risk assessment categories with proposed instrument

Back to Top

4.0 PROPOSED INSTRUMENTS

4.1 Letter of Advice

In the case of salmonid aquaculture proposals where a HADD of fish habitat is not anticipated to result from organic enrichment, the preferred instrument would be a Letter of Advice (LOA) (see Appendix 4, templates 1A and B; Appendix 5, chart 1).

The LOA should clearly outline the proposed work or undertaking and the manner of carrying it out which led DFO to conclude that the project is not anticipated to result in a HADD. The LOA could also recommend regular monitoring and, based on evaluation of the monitoring report, additional mitigation measures, or changes in the operation's location or production levels. Site remediation may also have to be considered.

In all cases, the LOA should state that the document is not a subsection 35(2) Authorization. It should also reserve DFO's rights to take any appropriate actions under the Fisheries Act.

Back to Top

4.1.1 Monitoring Results and LOAs

If subsequent monitoring during the operational phase indicates that a HADD could be a concern in the future in spite of the original assessment, the proponent may apply for a subsection 35(2) Authorization as outlined in this document and Appendix 5, Chart 3. It is important to note that this is not a retroactive Authorization. Whether the proponent carried out the work or undertaking in the manner described in the LOA will be a factor considered in the decision to issue or not issue a s.35(2) Authorization. DFO is not obligated to issue an Authorization and will be guided by the Decision Framework for the Determination and Authorization of Harmful Alteration, Disruption or Destruction of Fish Habitat (DFO, 1998(a)).

Back to Top

4.2 HADD Avoidance, Mitigation, and Monitoring Agreement

In the case of salmonid aquaculture proposals, where there is uncertainty with respect to the effectiveness of measures to prevent a HADD, the preferred option is a HADD Avoidance, Mitigation, and Monitoring Agreement developed between the proponent and DFO (see Appendix 4, template 2; Appendix 5, chart 2).

Aquaculture projects should be assessed and regulated in the same manner as projects in other industry sectors. However, there is often uncertainty about the effectiveness of measures to prevent a HADD. Marine ecosystems are complex and dynamic. Our understanding of them and our ability to predict how they might react to management actions especially on a larger scale is relatively limited. In addition, our experience with aquaculture perturbation in the far-field and cumulative effects is inadequate in many instances. It is necessary to address this uncertainty in a manner that will ensure that there is no net loss of the productive capacity of fish habitat.

To compound this uncertainty, it is necessary to address the effects of the operational phase of the project. Unlike many other industry sectors where the operation is a consideration, aquaculture inputs of organics can vary greatly and irregularly depending on such variables as the season, fish size and type, chemical use and market conditions.

In these situations, a Letter of Advice is not adequate to address concerns, and a more responsive instrument, a HADD Avoidance, Mitigation, and Monitoring Agreement will be used as an adaptive management approach to deal with this uncertainty. The use of such agreements is a formal, systematic, and rigorous approach to learning from the outcomes of management actions, accommodating change, and improving management.

The Agreement should outline mitigation, monitoring and reporting, agreed upon by DFO-Habitat Management and the proponent and the possible need for remediation measures. Monitoring requirements should be detailed in the Agreement and based on performance-based standards. The Agreement should also indicate the need for regular monitoring reports to be submitted to DFO along with the supporting data and state that the document is not a subsection 35(2) Authorization. It should provide for a security of costs should the proponent fail to comply with the terms and conditions. The Agreement should also contain a statement that reserves DFO's rights to take appropriate actions under the Fisheries Act.

If a proponent does not wish to enter into an agreement, the Authorization option may be considered if the proponent files an application in the form set out in Schedule VI to the Fisheries (General) Regulations.

Assessors are advised to consult with DFO Legal Services when drafting agreements.

Back to Top

4.2.1 Monitoring Results and Agreements

Based on the results of the operational phase monitoring reports, additional mitigation measures or remediation may be required. Additional recommendations arising from the evaluation of these monitoring reports might include further mitigation, site remediation, or changes in the operation's location and/or production.

If the results of the monitoring confirm that the site is operating within the conditions of the Agreement, the Agreement may be continued and the monitoring cycle repeated at the agreed-upon interval. If the results indicate a change from baseline conditions that has not resulted in a HADD where enforcement action would be warranted, but a HADD could be a concern in the future, two options may be considered:

• The Agreement may be modified to reflect changes required in mitigation and the cycle of monitoring. This contingency would be stated in the original Agreement.
• The proponent may apply for a subsection 35(2) Authorization as outlined in this document and Appendix 5, Chart 3 if a HADD is likely to occur. This is not a retroactive Authorization. Whether the proponent has respected the terms and conditions of the Agreement will be a factor considered in the decision to issue or not issue a s.35(2) Authorization. DFO is not obligated to issue an Authorization and will be guided by the Decision Framework for the Determination and Authorization of Harmful Alteration, Disruption or Destruction of Fish Habitat (DFO, 1998(a)).

Back to Top

4.3 Subsection 35(2) Authorization

In the case of salmonid aquaculture proposals, when the risk assessment predicts that a HADD will, or is likely to, result from organic enrichment, the only option is to determine if a subsection 35(2) Authorization can be issued (see Appendix 4, template 3; Appendix 5, chart 3).

DFO is not obligated to issue an Authorization and will be guided by the Decision Framework for the Determination and Authorization of Harmful Alteration, Disruption or Destruction of Fish Habitat (DFO, 1998(a)) especially in situations where adverse effects to fish habitat are judged to be unacceptable. Examples of unacceptable HADDs are outlined in Appendix 6. In addition, an Authorization will not be considered until the options outlined in the Habitat Conservation and Protection Guidelines (DFO, 1998(b)) have been adequately considered.

If a decision is made to issue the Authorization, the Authorization could include the following conditions:

• the specific mitigation measures to be undertaken by the proponent;
• the specific limits of organic enrichment and the compensation required to offset the loss of habitat that will result as per the Policy for the Management of Fish Habitat (DFO, 1986). Compensation options, other than those on-site may have to be considered. The proponent is responsible to undertake compensation;
• the specific monitoring required and monitoring cycle; and
• the need to provide security for costs should the proponent fail to comply with the terms and conditions of the Authorizations (e.g. letter of credit).

To provide some measure of security to the proponent, the Authorization validation period should not exceed the period of time of the NWPA approval, if such approval is required for the proposed work or undertaking. If an NWPA approval is not required, the Authorization period should not exceed 5 years, but may be of shorter duration.

Back to Top

4.3.1 Monitoring Results and Authorizations

Monitoring is vital to determine if mitigation is working and to ensure the terms of the Authorization are being respected. If the results of the operational phase monitoring confirm that the site is operating within the conditions of the Authorization, the Authorization will continue and the monitoring cycle will be repeated at the interval determined in the Authorization. If the monitoring results indicate that the operation has exceeded the conditions of its Authorization, then appropriate enforcement action will be considered.

Back to Top

4.4 Changes to Monitoring Cycle or Production Levels

In cases of LOAs and HADD Avoidance, Mitigation, and Monitoring Agreements, where monitoring has repeatedly indicated no change of concern from baseline conditions, increasing the time between monitoring cycles could be considered. Alternatively, an increase in the production levels could be considered. These changes would be at the discretion of the assessor on a case-by-case basis. They are based on DFO's assessment of productive capacity.

Back to Top

APPENDIXES

APPENDIX 1: DETERMINING BENTHIC BASELINE CONDITIONS

In determining benthic baseline conditions it is necessary to use a variety of physical and chemical proxies or indicators that approximate and rank the quality of fish habitat in a particular area. Indicators include parameters such as percent volatile organic solids in sediment, production of sulfides, and sediment redox potential. These are used to assess the quality (i.e. performance) of benthic receiving environments, rather than assessing what has been released into the environment and predicting the effects.

This information is then used in conjunction with information supplied on the operation of the site itself to determine the actual risk of a HADD occurring. It is based on the anticipated change in the benthic community at or near the site as defined by the presence of characteristic microfauna and/or geochemical measures of redox (Eh) or sulfides (S--). Janowicz and Ross (2001) and Ross (2000) describe how these are used to monitor the effects of aquaculture on fish habitat in New Brunswick. From this assessment it is possible to determine which of the three instruments described in the strategy should be used. A guide to information requirements is currently being developed to ensure that this baseline data is collected (DFO, 2001) to conduct both fish habitat and CEAA assessments.

Realistic performance-based standards (PBS) provide regulators with a fair, accurate, and objective method of ensuring compliance with regulatory requirements. They also provide site operators with the opportunity to better understand the environmental conditions near their site and the potential consequences these could have on their operations.

The PBS advocated in this guide have been determined by Wildish et al. (2001) to be the most cost-effective method, in terms of speed and simplicity of use, for monitoring benthic effects while providing sufficient information to address issues related to fish habitat. The PBS determined for New Brunswick are provided in Appendix 3 as an example of the standards in use in the Maritimes Region.

Areas that naturally receive a heavy load of organic matter will quite often have anoxic sediments, but these will invariably be covered with at least a veneer of oxidized sediment. The infaunal benthic community will be effected, but epifaunal organisms do not experience unnatural habitat. This natural condition indicates that this system is already at or near its loading capacity for organic input. Therefore the incremental effects of loading from fish culture will be extreme and the potential for negative feedback on the culture operation is high.

PBS Related Monitoring

PBS are used to understand the changes in the benthic conditions at a site as operations are underway. Based on the results of this monitoring, additional remediation may be required. The key to effectively conserving and protecting fish habitat from the effects of aquaculture operations is through the application of an adaptive management approach, closely monitor effects, and mitigate those effects of concern and the specifics would be included in the Agreement or Authorization

The effects that result from the operation of aquaculture sites clearly depend on the pre-development conditions in the area where the site is located and how the site is operated. There is a substantial body of knowledge that allows operators to manage husbandry and operational variables to mitigate a significant proportion of effects. Measures, such as fallowing, can be used to accelerate the restoration process. There are several mechanical measures available that have unproven results. These measures should not be considered as substitutes for good site location and may be considered for existing sites only where permitted.

Validating PBS

This technique must be validated for different geographic regions and ecosystems in areas where aquaculture is practised.

Adopting other PBS

Where individual provinces have developed PBS strategies for monitoring these may be considered for use by DFO provided the data obtained meets DFO's requirements and DFO has unrestricted access to, and use of, all the data.

Back to Top

APPENDIX 2: PROPOSED INSTRUMENTS

DFO-Habitat Management can use several instruments to pursue its section 35 requirements. These are discussed based on their relative ease-of-use; their appropriateness in a given situation; and the anticipated risks associated with the project.

Subsection 35(2) Authorization

Under subsection 35(1) of the Fisheries Act, any harmful alteration, disruption or destruction (HADD) of fish habitat is prohibited unless authorized under subsection 35(2). The Authorization can provide the means and conditions with which the proponent can cause a HADD. These conditions could include methods of operation, mitigation measures, monitoring and reporting requirements, and the requirement to undertake remediation and compensation if required. The proponent would be in contravention of subsection 35(1) if these conditions are not met.

Subsection 36 and 43 Regulations

Regulations can be enacted under the Fisheries Act for carrying out the purposes and provisions of the Act. Sections 36 and 43 provide the authority to make regulations for certain purposes. Under such regulations, DFO-Habitat Management could prescribe conditions to be followed for various fish and fish habitat related issues associated with the aquaculture operations.

Requests for Information

Sections 37 and 61 of the Fisheries Act have provisions that oblige individuals to provide DFO, in certain situations, with information, data, and/or reports when requested to do so.

A request for information under section 37 of the Fisheries Act may be made when a work or undertaking results or is likely to result in a HADD. This authority is exercised by the Minister to determine if the HADD would constitute an offence under the Act and what measures could, if any, prevent that result or mitigate the effects.

Section 61 of the Fisheries Act also creates the obligation to provide information requested by a fisheries officer if regulations, or the terms and conditions of a lease or licence issued under the Act, requires keeping this information on record.

Back to Top

APPENDIX 3: EXAMPLE OF THE USE OF PBS

The following are the redox and sulfide Performance-Based Standards (PBS) used in Maritimes Region to define benthic conditions under salmonid cages. This table is provided as an example only. Specific relationships between redox, sulfides, and biological resources must be developed to meet specific (e.g. site regional, geographic) conditions.

* EMG: Environmental Management Guideline (NBDAFA, 2000)

The following is from the EMG for salmonid aquaculture in New Brunswick. It describes unacceptable habitat concerns that would trigger some level of enforcement action. The EMG also describes additional requirements such as remediation, mitigation, etc. that would apply at other levels of impact.

"For the purposes of salmonid aquaculture, unacceptable habitat concerns occur when the sediment becomes anoxic. This is defined by the absence of macrofauna, a change from aerobic to anaerobic microflora, or by geochemical measurements of sulfide in excess of 6000uM and a negative redox potential (Eh). Hypoxic conditions, as defined either by the presence/absence of macrofauna, microflora or by geochemical measurements of sulfide and redox potential, would be of concern to DFO. In cases where hypoxic conditions are demonstrated, remediation measures would be indicated to mitigate the situation and to prevent further progression to anoxia." (NBDAFA, 2000, p17)

Back to Top

APPENDIX 4: TEMPLATES FOR PROPOSED INSTRUMENTS

Back to Top

APPENDIX 5: FLOWCHARTS

• Application Of S35 Of The FIsheries Act To Salmonid Cage AQuaculture Developments (21 KB)
• Chart 1 (11 KB)
• Chart 2 (13 KB)
• Chart 3 (10 KB)

Back to Top

APPENDIX 6: IDENTIFYING UNACCEPTABLE HADDS

One of the first tasks as outlined in the Guide to the Application of S35 of the Fisheries Act to Salmonid Cage Culture Aquaculture Developments is to identify unacceptable HADDs or "showstoppers" for which DFO would not issue a subsection 35(2) Fisheries Act authorization. These can be defined as specific overriding concerns related to both ecosystem and site-specific variables that, if one or more were present, would prevent an aquaculture operation from proceeding in that specific area as proposed.

DFO is not obligated to issue an Authorization in situations where adverse effects to fish habitat are judged to be unacceptable (DFO, 1998(a)). The discussions of the National Habitat Management Working Group on Aquaculture (NHMWGA, 2001) and the work done be DFO scientists have led to the development of the following list of areas that should be considered when determining unacceptable HADDs:

• The presence of critical habitat such as spawning areas, restricted migration routes, etc. at the site, or sufficiently close to the site that the effects cannot be mitigated adequately.
• Prior history of the site such as failure of an operation due to environmental causes, etc., where the situation remains essentially unchanged.
• Potential significant contribution of the proposed development to cumulative effects on fish habitat.
• Low suitability of the proposed site for aquaculture as determined by baseline benthic conditions which could have negative effects on the culture operation and possible implications for the fish habitat as a result.

Note: Considering it is not possible to develop an exhaustive list of showstoppers, proponents are reminded that it is important to contact DFO early in the process to determine if they have a situation where adverse effects to fish habitat are unacceptable.

Back to Top

BIBLIOGRAPHY

DFO. 1996. The Department of Fisheries and Oceans Policy for the Management of Fish Habitat. Communications Directorate, DFO.

DFO. 1998(a). Decision framework for the determination and Authorization of harmful alteration, disruption or destruction of fish habitat. Communications Directorate, DFO.

DFO. 1998(b). Habitat Conservation and Protection Guidelines. Communications Directorate, DFO. 2nd Edition.

DFO. 2001. Guide to information requirements for environmental assessment of marine finfish aquaculture projects. Draft-May 30, 2001.

Janowicz, M. and Ross, J. 2001. Monitoring for benthic impacts in the southwest New Brunswick salmon aquaculture industry. ICES Journal of Marine Science, 58:2, pp453-459.

NBDAFA. 2000. Environmental management guidelines for the Atlantic salmon marine cage Aquaculture industry in New Brunswick. New Brunswick Dept. of Agriculture Fisheries and Aquaculture. Dec. 2000

NHMWGA. 2001. Workshop Proceedings Report. Halifax. Jan. 29-31, 2001.

Ross, J. 2000. Can the New Brunswick Experience advance the use of national performance-based standards to monitor impacts of aquaculture? Discussion Paper prepared for the National Habitat Management Working Group on Aquaculture. March 31, 2000.

Wildish, D.J., Akagi, N., Hamilton, N., and Hargrave, B.Y. 1999. A recommended method for monitoring sediments to detect organic enrichment from mariculture in the Bay of Fundy. Can, Tech. Rep. Fish. & Aqua. Sc. No. 2286. DFO.

Wildish, D., Hargrave, B., and Pohle, G. 2001. Cost-effective monitoring of organic enrichment resulting from salmon mariculture. ICES Journal of Marine Science, 58:2, pp469-476.

Back to Top

GLOSSARY

Anoxic sediment. Benthic conditions characterized by very high sediment accumulation, depositional with a high silt/clay ration, O2 absent at sediment/water interface, anaerobic respiration and gas bubbles are released from sediments, high sulfide accumulation, extensive bacterial mat cover, sediment colour is black.

Benthos. The aggregate of animals and plants living on or at the bottom of a body of water. Within this context, benthos also includes the characteristics of the physical and chemical environment on the sea or lake bed. (Guide to Information Requirements for Environmental Assessment of Marine Finfish Aquaculture Projects)

Compensation. The replacement of natural habitat, increase in the productivity of existing habitat, or maintenance of fish production by artificial means in circumstances dictated by social and economic conditions, where mitigation techniques and other measures are not adequate to maintain habitats for Canada's fisheries resources. (Policy for the Management of Fish Habitat)

Critical habitat. Environmentally sensitive habitat. Areas that require an added degree of caution owing to features and characteristics that support protected species and/or unique habitats (e.g., rearing or spawning habitat, migration corridors, protected areas or proposed protected areas, location of salmon streams, sensitive migratory bird habitat, etc.). (Guide to Information Requirements for Environmental Assessment of Marine Finfish Aquaculture Projects)

Epifauna. Benthic fauna living on the substrate (as a hard sea floor) or on other organisms (Merriam-Webster Dictionary)

Fish. Includes parts of fish, shellfish, crustaceans, marine animals and any parts of shellfish, crustaceans or marine animals, and the eggs, sperm, spawn, larvae, spat and juvenile stages of fish, shellfish, crustaceans and marine animals. (Fisheries Act, sec. 2).

Fish habitat. Spawning grounds and nursery, rearing, food supply and migration areas on which fish depend directly or indirectly in order to carry out their life processes (Fisheries Act, sec. 34)

Hypoxic sediment. Benthic conditions with high sediment accumulation, high silt/clay ratio, high diversity of infauna, O2 penetration to a few millimetres, anaerobic respiration is greater than anaerobic respiration, unreleased gas bubbles, moderate sulfide accumulation, bacterial mats may occur in patches, sediment colour is brown to black.

Infauna. Benthic fauna living in the substrate and especially in a soft sea bottom (Merriam-Webster Dictionary)

Mitigation. Actions taken during the planning, design, construction and operation of works and undertakings to alleviate potential adverse effects on the productive capacity of fish habitats. (Policy for the Management of Fish Habitat)

No net loss. A working principle by which the department strives to balance unavoidable habitat losses with habitat replacement on a project-by-project basis so that further reductions to Canada's fisheries resources due to habitat loss or damage may be prevented. (Policy for the Management of Fish Habitat)

Oxic sediment. Benthic conditions with little sediment accumulation, erosional to variable seafloor, high diversity of epifauna and infauna, O2 penetration to several millimetres or several centimetres, aerobic respiration is equals or is greater than anaerobic respiration, no or little sulfide accumulation, sediment is light brown to dark grey in colour.

Productive capacity. The maximum natural capability of habitats to produce healthy fish, safe for human consumption, or to support or produce aquatic organisms upon which fish depend. (Policy for the Management of Fish Habitat)

Redox potential. A measure of oxidation and reduction reactions in water, measured as the loss or gain of electrons. Elements that donate electrons are oxidants while those that accept electrons are reductants (or de-oxidizers). In neutral, fully oxygenated water in equilibrium with air, redox potentials slightly greater than 500 mv are obtained. Redox measurements in natural waters should not be quantitatively interpreted or compared. Qualitative or relative comparisons, however, can be helpful in defining the degree of change within a system. Within an oxygenated water column, oxidative reactions predominate. As oxygen concentrations approach zero and anoxic conditions appear, as happens near the sediment-water interface, the redox potential drops significantly. Within the sediments, it is common for reducing conditions to prevail and the redox potential to approach zero or even a negative value. (Guide to Information Requirements for Environmental Assessment of Marine Finfish Aquaculture Projects)

Remediation (restoration of habitats). The treatment or clean-up of fish habitat that has been altered, disrupted or degraded for the purpose of increasing its capability to sustain a productive fisheries resource. (Policy for the Management of Fish Habitat)

Salmonid. Of the family Salmonidae.

Back to Top

Last Updated : 2006-06-27

Important Notices