Mexican mosquito fern (Azolla mexicana) in British Columbia, proposed recovery strategy: part 1

Part 1 – Federal addition to the Recovery Strategy for the Mexican Mosquito Fern (Azolla mexicana) in British Columbia, prepared by Environment and Climate Change Canada

Preface

The federal, provincial, and territorial government signatories under the Accord for the Protection of Species at Risk (1996) agreed to establish complementary legislation and programs that provide for effective protection of species at risk throughout Canada. Under the Species at Risk Act (S.C. 2002, c.29) (SARA), the federal competent ministers are responsible for the preparation of recovery strategies for listed Extirpated, Endangered, and Threatened species and are required to report on progress within five years after the publication of the final document on the SAR Public Registry.

The Minister of Environment and Climate Change is the competent minister under SARA for the Mexican Mosquito-fern and has prepared the federal component of this recovery strategy (Part 1), as per section 37 of SARA. To the extent possible, it has been prepared in cooperation with the Province of British Columbia as per section 39(1) of SARA. SARA section 44 allows the Minister to adopt all or part of an existing plan for the species if it meets the requirements under SARA for content (sub-sections 41(1) or (2)). The Province of British Columbia provided the attached recovery plan for the Mexican Mosquito-fern (Part 2) as science advice to the jurisdictions responsible for managing the species in British Columbia. It was prepared in cooperation with Environment and Climate Change Canada.

Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this strategy and will not be achieved by Environment and Climate Change Canada, or any other jurisdiction alone. All Canadians are invited to join in supporting and implementing this strategy for the benefit of the Mexican Mosquito-fern and Canadian society as a whole.

This recovery strategy will be followed by one or more action plans that will provide information on recovery measures to be taken by Environment and Climate Change Canada and other jurisdictions and/or organizations involved in the conservation of the species. Implementation of this strategy is subject to appropriations, priorities, and budgetary constraints of the participating jurisdictions and organizations.

The recovery strategy sets the strategic direction to arrest or reverse the decline of the species, including identification of critical habitat to the extent possible. It provides all Canadians with information to help take action on species conservation. When critical habitat is identified, either in a recovery strategy or an action plan, SARA requires that critical habitat then be protected.

In the case of critical habitat identified for terrestrial species including migratory birds SARA requires that critical habitat identified in a federally protected areaFootnotei be described in the Canada Gazette within 90 days after the recovery strategy or action plan that identified the critical habitat is included in the public registry.  A prohibition against destruction of critical habitat under ss. 58(1) will apply 90 days after the description of the critical habitat is published in the Canada Gazette.

For critical habitat located on other federal lands, the competent minister must either make a statement on existing legal protection or make an order so that the prohibition against destruction of critical habitat applies.

If the critical habitat for a migratory bird is not within a federal protected area and is not on federal land, within the exclusive economic zone or on the continental shelf of Canada, the prohibition against destruction can only apply to those portions of the critical habitat that are habitat to which the Migratory Birds Convention Act,, 1994 applies as per SARA ss. 58(5.1) and ss. 58(5.2).

For any part of critical habitat located on non-federal lands, if the competent minister forms the opinion that any portion of critical habitat is not protected by provisions in or measures under SARA or other Acts of Parliament, or the laws of the province or territory, SARA requires that the Minister recommend that the Governor in Council make an order to prohibit destruction of critical habitat. The discretion to protect critical habitat on non-federal lands that is not otherwise protected rests with the Governor in Council.

Additions and modifications to the adopted document

The following sections have been included to address specific requirements of the federal Species at Risk Act (SARA) that are not addressed in the Recovery Plan for the Mexican Mosquito Fern (Azolla mexicana) in British Columbia (Part 2 of this document, referred to henceforth as “the provincial recovery plan”). In some cases, these sections may also include updated information or modifications to the provincial recovery plan for adoption by Environment and Climate Change Canada.

Under SARA, there are specific requirements and processes set out regarding the protection of critical habitat. Therefore, statements in the provincial recovery plan referring to protection of survival/recovery habitat may not directly correspond to federal requirements. Recovery measures dealing with the protection of habitat are adopted; however, whether these measures will result in protection of critical habitat under SARA will be assessed following publication of the final federal recovery strategy.

1 Critical habitat

This section replaces “Section 7: Species Survival and Recovery Habitat” in the provincial recovery plan.

Section 41 (1)(c) of SARA requires that recovery strategies include an identification of the species’ critical habitat, to the extent possible, as well as examples of activities that are likely to result in its destruction. The provincial recovery plan for Mexican Mosquito-fern (2016) includes a written description of the biophysical attributes of survival/recovery habitat. This science advice was used to inform the following critical habitat sections in this federal recovery strategy.

Critical habitat for Mexican Mosquito-fern is identified in this document to the extent possible, based on the best available information for the species. Critical habitat has not been identified for two populations that are extirpated (Population #4 – Darfield, and Population #8 – Sicamous) because they have been in-filled and it is unlikely that suitable habitat for the species can be restored at these sites. A potentially new population at Kelowna – Michaelbrook Marsh was reported in 2014; however the species’ identification is still unverified despite multiple observations. As responsible jurisdictions and/or other interested parties conduct research to address knowledge gaps, the existing critical habitat methodology and identification may be modified and/or refined to reflect new knowledge.

1.1 Identification of the species' critical habitat

Geospatial location of areas containing critical habitat

Critical habitat is identified for the eight known extant populationsFootnote1 of Mexican Mosquito-fern (below); these are linked with the population identifier numbers provided in Table 1 of the provincial recovery plan. All of the populations occur within the Little Fort area, the Shuswap Lake area and at Vernon, in south-central B.C. (Figures 1-7):

Little Fort

  • Population #1: Little Fort, north of Mount Loveway (Figure 1)
  • Population #2: Little Fort, south of (Figure 2)
  • Population #3: Mount Loveway, 1.8 km southeast of (Figure 1)
  • Population #5: Chinook Creek (Figure 3)

Shuswap Lake

  • Population #6: Tappen, Shuswap Lake (Figure 4)
  • Population #7: Salmon Arm (Figure 5)
  • Population #9: Cambie, 2.7 km west of (Figure 6)

Vernon

  • Population #10: Vernon (Figure 7)

The areas containing critical habitat for Mexican Mosquito-fern are identified based on the (partially or entirely submerged) substrate area required by individual plants or patches of plants, including the associated potential location error from GPS units (ranging up to 25 m uncertainty distance), plus an additional 50 meters (i.e., critical function zone distanceFootnote2) to encompass immediately adjacent submerged or semi-submerged areas, and adjacent upland habitat within 30 m of the highest recorded water mark that provides context for the occurrence. These upland areas provide important shade, sediment, and erosion control necessary to maintain the species’ aquatic environment.

Ecosystem processes that occur in ponds, ditches, oxbow lakes and lakeshores that support Mexican Mosquito-fern are integral to the production and maintenance of suitable microhabitat conditions. Where these habitat features are apparent as a distinct ecological featureFootnote3 at the landscape scale, the entire portion of the shallow water body associated with the plant or patch of plants (plus the 30 m adjacent upland habitat, as described above) is identified as critical habitat. Where occurrences are in close proximity (i.e., less than 250 m apart), and/or where they occur in association with the same distinct ecological feature, showing continuous suitable habitat characteristics between them, connective habitat (i.e., waterways in-between occurrences, and associated terrestrial upland habitat) is also identified as critical habitat.

Biophysical attributes of critical habitat

Mexican Mosquito-fern requires aquatic and shoreline habitat. Within the areas containing critical habitat, the biophysical features and attributes that the species’ requires overlap geospatially, seasonally, and across all life history stages. The habitat requirements  for Mexican Mosquito-fern are outlined in the provincial recovery plan (section 3.3, “Habitat and Biological Needs of the Mexican Mosquito Fern”), and are summarized below (Table 1).

Table 1. Summary of essential biophysical features, functions, and attributes of Mexican Mosquito-fern habitat in British Columbia.
Habitat type Biophysical feature(s) Function Life stage(s) supported Attributes
Aquatic habitat Slow-moving, partially shaded, sheltered, shallow waters (ponds, ditches, oxbow lakes, lakeshores) Growing, reproduction, dispersal All life history stages

Depth: typically, but not exclusively, 50 cm or less; where the roots can touch the substrate in summer drawdown

Movement: sheltered, slow-moving to still

Chemistry: above pH 3.5, below pH 10 (optimal at pH 6.5-8.1); low salinity (≤1.3% salt); iron and phosphorous-rich, but otherwise nutrient-poor

Temperature: optimal at 18–28°C (cold tolerance dependent on pH)

Shoreline habitat Drawdown zone, band of vegetation associated with shoreline (within 30 m of highest waterline) Growing, reproduction, dispersal All life history stages Coverage: semi-shaded (typically, but not exclusively, with intermediate canopy coverage); optimally around 50%

The areas containing critical habitat for the Mexican Mosquito-fern (totalling 166 ha) are presented in Figures 1-7. The shaded yellow polygons (units) shown on each map represent identified critical habitat, excluding only those areas that clearly do not meet the needs of the species in any life stage, for example: (i) existing anthropogenic features and infrastructure (e.g. houses, buildings and residential or urban infrastructure including active roads or railways), and (ii) deep water (i.e., areas where substrates are submerged by water more than 1 m in depth at lowest recorded water level). These features do not possess any of the described biophysical features or attributes required by Mexican Mosquito-fern and they are not identified as critical habitat. The 1 km x 1 km UTM grid overlay shown on Figures 1-7 is a standardized national grid system that highlights the general geographic area containing critical habitat, for land use planning and/or environmental assessment purposes.

Figure 1. Critical habitat for Mexican Mosquito-fern is represented by the shaded yellow polygons where the criteria and methodology set out in Section 1.1 are met. The detailed polygons show the area containing critical habitat at Population #1: Little Fort, north of Mount Loveway (88.3 ha) and Population #3: Mount Loveway, 1.8 km southeast of (3.8 ha). The 1 km x 1 km UTM grid overlay shown on this figure is part of a standardized national grid system that is used to indicate the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 1

Figure 1 shows a critical habitat map for Mexican Mosquito-fern in Little Fort, British Columbia using standardized 1 km x 1 km UTM grid squares. Six grid squares are placed around the area of Dunn Peak protected area and just north of this site near Round Top Rd.

Figure 2. Critical habitat for Mexican Mosquito-fern is represented by the shaded yellow polygons where the criteria and methodology set out in Section 1.1 are met. The detailed polygons show the area containing critical habitat at Population #2: Little Fort, south of (20.1 ha). The 1 km x 1 km UTM grid overlay shown on this figure is part of a standardized national grid system that is used to indicate the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 2

Figure 2 shows a critical habitat map for Mexican Mosquito-fern in the area of Little Fort, British Columbia using standardized 1 km x 1 km UTM grid squares. Three grid squares are placed in the area of Little Fort and Nekalliston 2 just south of Spokane Creek.

Figure 3. Critical habitat for Mexican Mosquito-fern is represented by the shaded yellow polygons where the criteria and methodology set out in Section 1.1 are met. The detailed polygon shows the area containing critical habitat at Population #5: Chinook Creek (0.8 ha). The 1 km x 1 km UTM grid overlay shown on this figure is part of a standardized national grid system that is used to indicate the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 3

Figure 3 shows a critical habitat map for Mexican Mosquito-fern in the area of Little Fort, British Columbia using standardized 1 km x 1 km UTM grid squares. There is one grid square depicting the critical habitat of Chinook Creek right off of McDougall Rd.

Figure 4. Critical habitat for Mexican Mosquito-fern is represented by the shaded yellow polygons where the criteria and methodology set out in Section 1.1 are met. The detailed polygons show the area containing critical habitat at Population #6: Tappen, Shuswap Lake (5.2 ha). The 1 km x 1 km UTM grid overlay shown on this figure is part of a standardized national grid system that is used to indicate the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 4

Figure 4 shows a critical habitat map for Mexican Mosquito-fern in the area of Shuswap Lake, British Columbia using standardized 1 km x 1 km UTM grid squares. Four grid squares were placed around Tappen and North Bay Reserve #5.

Figure 5. Critical habitat for Mexican Mosquito-fern is represented by the shaded yellow polygons where the criteria and methodology set out in Section 1.1 are met. The detailed polygons show the area containing critical habitat at Population #7: Salmon Arm (31.1 ha). The 1 km x 1 km UTM grid overlay shown on this figure is part of a standardized national grid system that is used to indicate the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 5

Figure 5 shows a critical habitat map for Mexican Mosquito-fern in the area of Shuswap Lake, British Columbia using standardized 1 km x 1 km UTM grid squares. Four grid squares were placed just east of Switsemalph Reserve #3 encompassing the south most border of Shuswap Lake until 16 St NE.

Figure 6. Critical habitat for Mexican Mosquito-fern is represented by the shaded yellow polygons where the criteria and methodology set out in Section 1.1 are met. The detailed polygons show the area containing critical habitat at Population #9: Cambie, 2.7 km west of (5.2 ha). The 1 km x 1 km UTM grid overlay shown on this figure is part of a standardized national grid system that is used to indicate the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 6

Figure 6 shows a critical habitat map for Mexican Mosquito-fern in the area of Shuswap Lake, British Columbia using standardized 1 km x 1 km UTM grid squares. One grid square was placed just south of Leaf Rd.

Figure 7. Critical habitat for Mexican Mosquito-fern is represented by the shaded yellow polygons where the criteria and methodology set out in Section 1.1 are met. The detailed polygons show the area containing critical habitat at Population #10: Vernon (10.9 ha). The 1 km x 1 km UTM grid overlay shown on this figure is part of a standardized national grid system that is used to indicate the general geographic area within which critical habitat is found in Canada. Areas outside of the shaded yellow polygons do not contain critical habitat.
Image of map (see long description below)
Long description for Figure 7

Figure 7 shows a critical habitat map for Mexican Mosquito-fern in the area of Vernon, British Columbia using standardized 1 km x 1 km UTM grid squares. Two grid squares were placed around Priest’s Valley Indian Reserve No. 6 and Okanagan Landing East.

1.2 Activities likely to result in destruction of critical habitat

Understanding what constitutes destruction of critical habitat is necessary for the protection and management of critical habitat. Destruction is determined on a case by case basis. Destruction would result if part of the critical habitat were degraded, either permanently or temporarily, such that it would not serve its function when needed by the species. Destruction may result from a single or multiple activities at one point in time or from the cumulative effects of one or more activities over time. The provincial recovery plan provides a description of the association between threats and habitat of Mexican Mosquito-fern (section 4.2). Activities described in Table 3 include those likely to cause destruction of critical habitat for the species; destructive activities are not limited to those listed.

Table 2. Examples of activities likely to result in the destruction of critical habitat for Mexican Mosquito-fern. Associated threat numbers are in accordance with the IUCN-CMP a unified threats classification system ( CMP 2010).
Description of activity Rationale Additional information
Conversion of natural landscape for human use and development (e.g., residential areas and transportation corridors) Results in direct habitat loss due to in-filling of aquatic habitat and/or alteration or destruction of associated microhabitat features needed by Mexican Mosquito-fern (shade, nutrients, pH).

Related IUCN-CMP Threat # 1.1, 4.1.

Many locations are adjacent to roads, highways and railways that could be subject to construction or widening.

Housing and urban development is a threat in the Shuswap and Vernon areas.

Activities (e.g., ditching, trenching, diversion of water, operation of water control devices that result in rapid water level changes or  premature drying) that cause alteration in local hydrological characteristics such that there is any loss of natural habitat and any net loss of anthropogenic habitat (e.g. ditches, dugouts) Results in habitat loss or degradation of critical habitat for Mexican Mosquito-fern by altering drainage patterns thereby disrupting natural ecological processes and destroying contextual habitat for growth

Related IUCN-CMP Threat # 4.1.

Many locations are adjacent to roads, highways and railways and are subject to roadside maintenance activities.

Any deposition of pollutants into occupied bodies of water including road-salting, herbicide application, chemical and oil spills, and agricultural run-off Pollutants may degrade critical habitat through residual effects, wind drift, incidental application, and altering the composition and structure of the water quality and/or native plant communities

Related IUCN-CMP Threat # 4.1, 9.1

Many locations are adjacent to roads, highways and railways and are subject to associated run-off and/or spills.

Does not need to occur within the bounds of critical habitat to cause destruction (e.g. upstream run-off).

a International Union for Conservation of Nature – Conservation Measures Partnership

2 Statement on action plans

This section replaces the “Statement on Action Plans” section in the provincial recovery plan.

One or more action plans for the Mexican Mosquito-fern will be posted on the Species at Risk Public Registry by 2022.

3 Effects on the environment and other species

A strategic environmental assessment (SEA) is conducted on all SARA recovery planning documents, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals. The purpose of a SEA is to incorporate environmental considerations into the development of public policies, plans, and program proposals to support environmentally sound decision-making and to evaluate whether the outcomes of a recovery planning document could affect any component of the environment or any of the Federal Sustainable Development Strategy’s (FSDS) goals and targets.

Recovery planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that strategies may also inadvertently lead to environmental effects beyond the intended benefits. The planning process based on national guidelines directly incorporates consideration of all environmental effects, with a particular focus on possible impacts upon non-target species or habitats. The results of the SEA are incorporated directly into the strategy itself, but are also summarized below in this statement.

The provincial recovery plan for Mexican Mosquito-fern contains a section describing the effects of recovery activities on other species (i.e., Section 9). Environment and Climate Change Canada adopts this section of the provincial recovery plan as the statement on effects of recovery activities on the environment and other species. Recovery planning activities for Mexican Mosquito-fern will be implemented with consideration for co-occurring species, such that impacts to these species or their habitats will be none or minimal.

4 References

CMP (Conservation Measures Partnership). 2010. Threats Taxonomy.

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