Migratory birds environmental assessment guideline

Environmental effects

1. General considerations
2. Specific considerations
3. Cumulative effects
4. Mitigation
5. Residual effects
6. Monitoring
7. Methods

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1. General considerations

A careful assessment of the environmental effects of the proposed project should be undertaken prior to consideration of any mitigation. The extent, both spatial and temporal, and the degree, quantified where possible, of the effects should be outlined in the environmental effects section of the EIS.

The types of factors that contribute to environmental effects will vary depending on the project and the types of habitats that are potentially affected. Additionally, the effects will depend on the intensity, duration, timing, and frequency of impacts. Cumulative effects should also be considered (see Cumulative Effects section). All the above should be incorporated into the impact analysis in view of the habitat needs and population dynamics of potentially affected species.

The baseline information needs that were identified in the previous section identify the parameters and ecological concepts that should be considered in the impact analysis. As in the baseline information section, the specific focus of the environmental effects section of the environmental assessment should be on maintaining viable habitats — especially sites with high concentrations of migratory birds, priority species, COSEWIC-listed species, and other species at risk.

If the proponent undertakes to classify the effects (e.g., as negligible, minor, major or significant, and either positive or negative), then explanations and justifications for the ranking system and designation of impacts should be presented. Quantification of environmental effects provides a good basis for determining the degree of impact. In particular, comparison to similar migratory bird habitats in the same or nearby similar landscape provides an opportunity to examine effects in a relative manner (see Monitoring section).

When considering potential impacts on habitat, include the degree of fragmentation/connectivity expected from the proposed project relative to the degree before the proposed project. This assessment should address fragmentation/connectivity within and between habitat types (e.g., within nesting habitat or between nesting and feeding habitat).

Consideration should also be given to habitat modifications that appear beneficial. Care should be taken to ensure that large-scale diversity is not reduced by local changes and that priority species are not negatively affected. For example, forest fragmentation can increase diversity at a local level but reduce diversity at a larger scale; it can also reduce abundance of priority species that require interior forest habitat. Similarly, although removal of one type of habitat may result in the creation of another type of habitat (for example, during hay-making), the change should not be considered beneficial if the replacement habitat supports smaller populations of priority species.

2. Specific considerations

Environmental effects, whether direct impacts or due to the modification of habitat, should:

• be considered at individual species and community levels;
• consider any potential increase in competition with other species of birds or other animals as a result of habitat change;
• consider increased potential for predation or brood parasitism; and
• consider any quantitative or qualitative (e.g., contaminants, species shifts) changes to food sources.

When determining impacts, proponents should consider disturbances, such as:

• noise (i.e., frequency, duration, and intensity);
• structures that could become obstructions (e.g., hydro towers and lines);
• visual changes (e.g., lighting); and
• use by humans.

Proponents should determine impacts on the following:

• abundance;
• density;
• distribution; and
• reproductive success of migratory birds.

The effects on Aboriginal or local subsistence users of migratory birds should be considered.

The degree of confidence with which these impacts can be accurately predicted throughout the EIS should be described.

3. Cumulative effects

CEAA specifically requires an environmental assessment to consider the cumulative environmental effects of a project. These are effects that are likely to result from the project in combination with other projects or activities that have been or will be carried out. (CEAA ss.16(1)(a)).

Because cumulative effects encompass changes resulting from past, proposed, and potential future projects, proponents need to take the dynamic nature of ecosystems into consideration. More specifically, the baseline information should describe the environment without any development, and elucidate and quantify the natural changes inherent in ecosystems. For previously developed locations, the use of unmodified control sites may provide approximate baseline information.

In many cases, migratory bird populations and their habitats have already been affected by human activities, locally, regionally, nationally, and internationally. An understanding of how the population responded to stresses in the past may be useful in the prediction of the effects of a particular stress associated with the proposed project. However, some species may have threshold population levels below which reproductive capacity and immigration are not able to overcome stresses from adverse environmental effects. These considerations should be addressed in the cumulative effects section of the EIS.

4. Mitigation

Mitigation is defined by CEAA as follows:

"mitigation" means, in respect of a project, the elimination, reduction or control of the adverse environmental effects of the project, and includes restitution for any damage to the environment caused by such effects through replacement, restoration, compensation or any other means.

The basic premise for any mitigation technique or strategy should be avoidance. The proponent should carefully consider the need for any component of the project that would affect migratory birds or their habitat. Relocating a project may provide the least disruptive approach. Consideration should be given to the timing of construction and/or project activities that contribute to disturbance. Activities should be avoided during critical periods of the migratory birds' life cycles (e.g., nesting, staging). Failing adequate avoidance, mitigation techniques and strategies should focus on minimization of impacts.

Mitigation should be considered for each of the environmental effects predicted in the previous section. Although addressing each environmental effect individually is a good starting point, an understanding of mitigation techniques or strategies that take into consideration the complex nature of ecosystems is required. For example, although use of a nonnative species in restoration may provide some habitat characteristics, such as food, it may negatively affect the natural ecological balance in the community. Consideration should be given to the effects of the technique on nontarget species and their habitat. Care should also be taken to ensure that mitigation for migratory bird species does not compromise other wildlife, or that mitigation for effects on other wildlife does not compromise migratory birds, important ecosystem components, or ecological processes.

The expected degree of effectiveness of proposed mitigation techniques or strategies should be identified and explained.

5. Residual effects

The proponent should describe what environmental effects would remain after mitigative measures have been conducted. If attempts are made by the proponent to classify the effects (e.g., as negligible, minor, major, or significant), explanations and justifications for the designation of impacts should be presented.

Particular attention should be paid to residual effects because they play a large role in the determination of whether the adverse environmental effects are acceptable or are significant enough to require mediation, panel review, or nonapproval.

6. Monitoring

Monitoring regimes are needed to determine whether impacts are more than predicted, and to allow for appropriate changes in mitigative measures, if they are required. The proponent should describe proposed monitoring methods. Generally, they should conform to accepted monitoring practices for the different bird types, but particular methods may be requested by Environment Canada, depending on the specific situation and species in the impact area.

When using habitat as an indicator, proponents should conduct ground truthing to ensure that habitat monitoring is a reliable way to track changes in migratory bird abundance and diversity as predicted in the EIS. The amount and detail of the ground truthing required will depend on the project and its projected impacts.

Monitoring, in general, should be conducted at specified intervals to determine the range of variation. To determine which effects are the result of the project and which are the result of natural variation, proponents are encouraged to monitor control sites that contain habitats and migratory bird populations similar to those found in the proposed impact area.

Monitoring requirements may be imposed as a condition of project approval.

7. Methods

It is beyond the scope of this guideline to identify methods of collecting information. There are standardized, quantitative data collection techniques for different bird types and species, as well as habitat description methodologies. The methods to employ will vary depending on the bird species, season, habitat type, and purpose of the data collection, which may be in part determined by the type of project and predicted impacts. Use of standardized techniques provides for the collection of data that will be comparable to other regional or national data, which in the long term will provide a more comprehensive database for more accurate impact predictions.

The EIS should clearly indicate the method used to collect the data and any existing information sources that were used in its preparation. The proponent may be required to justify the methods chosen. For all the above reasons, the proponent is encouraged to consult with the regional environmental assessment practitioner to determine what data may already be available and to discuss appropriate methods for data collection.

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