(b) Identifying and assessing the impacts of the plan or project in view of the site's conservation objectives
The assessment must cover the impact of the entire plan or project in question, with all the activities it comprises, and during all phases (preparation, construction, operation and, where relevant, decommissioning or reconditioning). The assessment must identify and differentiate the various types of impact, including direct and indirect effects, temporary or permanent effects, short- and long-term effects and cumulative effects The assessment typically includes the analysis of the following possible impacts: Direct loss : reduction of habitat coverage as a result of its physical destruction (e.g. due to its removal or to the deposition of construction materials or sediments); loss of breeding, foraging, resting areas for species. Degradation : deterioration of habitat quality, leading to a reduced abundance of characteristic species or an altered community structure (species composition). This can be caused by changes in abiotic conditions (e.g. water levels or an increase in suspended sediments, pollutants or dust deposition); deterioration of breeding, foraging, resting areas for species. Disturbance : a change in existing environmental conditions (e.g. increased noise or light pollution, a greater frequentation of people and vehicles). Disturbance may cause, inter alia, the displacement of species individuals, changes in species behaviour, or the risk of morbidity or mortality. Fragmentation: leading to an alteration of distribution patches of relevant habitats and species, e.g. through the creation physical or ecological barriers in areas that are physically of functionally connected, or splitting them into smaller more isolated units. Other indirect effects: indirect change to the quality of the environment (resulting for example from a change in availability of nutrients and light, or an increase in the vulnerability of the site to other new threats such as invasive alien species, human and animal penetration). These effects should be analysed in view of the site-specific conservation objectives, which implies that the analysis needs to be done not only in relation to the current condition of the habitats and species significantly present within the site but also in relation to their desired condition as defined by the conservation objectives (e.g. an increase in population size or habitat coverage by x %). An analysis of effects in view of the site-specific conservation objectives must also therefore be done on the basis of the specific attributes or parameters that determine the conservation condition of the protected features (e.g. range, habitat, structure and function, population size, future prospects). Each aspect of the plan or project should be examined in turn and its potential effects considered against the site’s conservation objectives. Then the effects on all the affected habitats and species should be looked at together, and in relation to each other, so that the interactions between them can also be taken into account. Different methods can be used to predict the potential impact of plan or projects. Box 10 lists some examples of methods that can be used to predict the impacts as well as the scale of the impact. Table 5 gives an example of a systematic cross-analysis between project elements and the protected features in a Natura 2000 site. Table 5 Example of systematic cross-analysis between project components and protected features on a Natura 2000 site – simplified example for a fish farm The assessment must be based on the best available scientific knowledge in the field. This means that the information must be complete and up-to-date. For this reason, it is often necessary to carry out field surveys in order to fill information gaps and collect precise data. This may involve, for example, prospecting the area (using sampling methods, censuses, inventories, etc.) to identify or confirm the precise location and distribution of natural features in relation to the planned activities of the plan or project under assessment, and their conservation condition. A prior desk study may be useful to review available knowledge and identify the information needs that warrant further field survey work. For instance, this can be useful practice when the desk study indicates that there are vulnerable habitats present which have an associated rare assemblage of flora and/or fauna, or that the area to be affected hosts species critical for the conservation objectives of the site. Data obtained from field surveys should provide an objective basis for the assessment process, which has to be carried out in view of the site-specific conservation objectives. For the field data to be complete, a sufficient timeframe has to be set, e.g. a one or more-year study that covers a whole vegetation cycle, taking into account the seasonality of the wildlife, or faunal surveys that may need to be repeated to confirm populations and trends over a period of time. For major developments such as motorways, railways, windfarms, ports, waterways, etc., which due to their scale and nature are expected to have significant effects on a site, field studies are almost always required. They will need to include detailed mapping of protected habitats or of breeding or resting places of species etc. (unless some of these surveys and studies have already been carried out recently, for example during the preparation or updating of a management plan or while assessing another major development project in the area). The impact should be quantified or recorded using parameters that make it possible to assess the scale and severity of the impact on the specific conservation objectives of the habitats and species significantly present on the site (see also box 7 in section 3.1.4 for indicators of significance) . This could include, for instance, parameters such as: Area of the habitat or habitat of the species permanently lost (e.g. by clearing of vegetation or removal of suitable breeding/nesting sites) assessed against the habitat area on the site, at regional, national and biogeographical level (percentage of habitat area lost) and against the target set in the site-specific conservation objective (which may include a target for restoration); Area of the habitat or habitat of the species affected (e.g. by pollution, noise, deterioration of other ecological conditions) assessed against percentage of the habitat area on the site, at regional, national and biogeographical level (percentage of habitat area affected) and against the target set in the site-specific conservation objective (which may include a target for restoration); Size of resident and migratory species populations affected, assessed against the local, regional, national and international populations (percentage of population affected) and against the target set in the site-specific conservation objective (which may include a target for an increase in population size within the site); Scale of impact (e.g. by pollution, noise, deterioration of other ecological conditions) on the quality of the habitat or habitat of the species or the survival of species affected, in view of their ecological requirements in the site as defined in the site-specific conservation objective (which may include a target for restoration). As already mentioned in the points above, when assessing possible adverse effects, the assessment should not only consider negative changes in the current status, but also changes that can prevent the achievement of the conservation objectives in so far as they require improvement of the current conditions.
Source: EUR-Lex (Cellar) · retrieved 2026-09-25 · Text as adopted (Official Journal); later amendments are not incorporated in this text.