Recovery Strategy for the Eastern Sand Darter (Ammocrypta pellucida) in Canada: Ontario Populations [Proposed]: Recovery
The recovery of the Eastern Sand Darter is considered to be both biologically and technically feasible. The following feasibility criteriaFootnote 2 have been met for the species:
1. Are individuals capable of reproduction currently available to improve the population growth rate or population abundance?
2. Is sufficient suitable habitat available to support the species or could it be made available through habitat management or restoration?
3. Can significant threats to the species or its habitat be avoided or mitigated through recovery actions?
4. Do the necessary recovery techniques exist and are they demonstrated to be effective?
The above criteria indicate that recovery is biologically and technically feasible for Ontario populations. The level of effort required for the recovery of the Sydenham, Thames and Grand River populations would be moderate due to a focus on habitat restoration and protection (Dextrase et al. 2003). Where the Eastern Sand Darter has been extirpated from systems in Ontario, which may be the case in three river systems, the level of effort required for population recovery would be high, as it would entail both habitat restoration and repatriation (ARRT 2005). Management priorities should be given to high quality habitat areas currently supporting Eastern Sand Darter populations.
The long-term goal (>20 years) of this recovery strategy is to maintain self-sustaining, extant populations and to restore self-sustaining populations to formerly occupied habitats where feasible. In some locations, permanent changes in the fish community, as a result of the establishment of exotic species, may impact the feasibility of re-establishing Eastern Sand Darter populations.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed the Eastern Sand Darter as Threatened in 2000 and reassessed it as the same status in 2009, in part, because of its small area of occupancy, number of locations and the continuing decline in habitat quality. The Eastern Sand Darter is considered extant at six locations in Ontario, unknown at two locations and extirpated from three locations (Bouvier and Mandrak 2010). Currently, the total number of confirmed Eastern Sand Darter locations, both extant and extirpated, is 11.
An important factor to consider when determining population and distribution objectives is the number of populations that may be at a given location, as it is possible that a location may contain more than one discrete population. In this context, location does not refer to the locality of the discrete population, but rather a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of this species present (COSEWIC 2010).
To recover the species to a level lower than Threatened under COSEWIC criteria, a minimum of 11 extant locations with at least one self-sustaining population are required. Where present, multiple populations at a single location should be maintained. At present, the number of populations present at each Eastern Sand Darter location in Canada is unknown and further research is required to investigate this.
The population and distribution objective for Eastern Sand Darter is to ensure the survival of self-sustaining population(s) at the six extant locations (Sydenham River, Thames River, Lake St. Clair, Big Creek, Grand River, Lake Erie [Long Point Bay]) and restore self-sustaining population(s) at the following locations; Ausable River, Lake Erie (Rondeau Bay and Pelee Island), Catfish Creek and Big Otter Creek, where feasible.
Modelling results from the Recovery Potential Assessment conducted by Finch et al. (2011) indicated that the estimated minimum viable population size (MVP) for Eastern Sand Darter is 52 822 adults, given a 10% chance of a catastrophic event occurring per generation. However, the implementation of such a target is difficult without also having information on population(s) size, trends and spatial distribution, as well as habitat quality; this information is mostly lacking for the majority of Eastern Sand Darter locations in Ontario. Further research is required to validate the model results and to obtain the aforementioned information. More quantifiable objectives relating to MVP will be developed once abundance information can be obtained. This will also inform the refinement of the recovery goal.
Short-term recovery objectives (5 – 10 years)
In support of the long-term goal, the following short-term recovery objectives will be addressed over the next 5 -10 years:
- Refine population and distribution objectives;
- Ensure the protection of critical habitat;
- Determine long-term population and habitat trends;
- Evaluate and minimize threats to the species and its habitat;
- Investigate the feasibility of population supplementation or repatriation for populations that may be extirpated or reduced;
- Enhance efficiency of recovery efforts through coordination with aquatic and terrestrial ecosystem recovery teams and other relevant or complementary groups/initiatives; and,
- Improve overall awareness of the Eastern Sand Darter and the role of healthy aquatic ecosystems, and their importance to humans.
Recovery approaches have been organized into three categories: ‘Research and Monitoring' (Table 5), ‘Management and Habitat Protection' (Table 7), and ‘Stewardship, Outreach and Education' (Table 8). Table 6 identifies the survey needs for Eastern Sand Darter in specific waterbodies in Ontario as part of a strategy identified under the Research and Monitoring category. Although approaches have been prioritized, all are important to meet recovery goals and objectives. A narrative has been included where deemed appropriate.
| Priority | Objective addressed | Threats addressed | Broad strategy to address threats | Recommended approaches to meet recovery objective(s) | Outcomes or deliverables (identify measurable targets) |
|---|---|---|---|---|---|
| High | ii | all | Habitat requirements | Refine knowledge of seasonal habitat requirements for all life stages especially juvenile. | Will allow for refinement of critical habitat. Will assist with the development of a habitat model. |
| High | i, ii | all | Habitat surveys and mapping | Evaluate and map the distribution, quantity and quality of habitat in the vicinity of known populations. | Will allow for refinement of critical habitat. |
| High | i, iii, v | all | Background surveys and monitoring – extant, historic and potential new locations | Develop a long-term monitoring program that includes standardized sampling protocol to monitor for trends over time in distribution and abundance for all life stages. Incorporate findings into a routine population monitoring program. |
Will determine presence/absence, health, range, abundance and population demographics and contribute to the refinement of critical habitat. |
| High | iv | All habitat related threats (barriers to movement, altered flow regimes, shoreline modifications) | Threat clarification - habitat | Investigate and evaluate the significance of habitat threat factors that may be impacting extant populations. Take steps to mitigate immediate threats identified. | Will determine the severity of specific threats to individual populations and will direct stewardship activities to alleviate their impacts. |
| High | iv | Exotic species | Threat clarification – exotic species | Investigate the mechanisms of impact of Round Goby on Eastern Sand Darter. Monitor distribution of Round Goby in areas of Eastern Sand Darter populations. | Will identify the degree to which Round Goby may impact Eastern Sand Darter. |
| Moderate | v | all | Captive rearing and repatriations | Where repatriations are deemed appropriate for restoring populations (historical or degraded), develop a repatriation plan. | Determine the feasibility and appropriateness of repatriations in areas of suitable habitat. |
| Low | v | all | Conservation genetics | Examine the degree of genetic variation and isolation within (i.e., small populations and inbreeding concerns) and among populations across its North American range. | Will help to distinguish populations and determine if there is more than one population at a location. Will contribute necessary info should population enhancement through repatriations or captive rearing be required. |
| Low | i | all | Habitat modeling | Develop a predictive habitat model in order to identify the potential Eastern Sand Darter sites and significant habitat areas. | Will use model to further refine critical habitat and identify potential Eastern Sand Darter sites for additional survey investigation. |
Background surveys and monitoring (R3)
The Eastern Sand Darter is known from only a few locations in watersheds throughout its range. In some cases, such as in the Ausable River, only historical records exist. This species may be somewhat more widely distributed than currently known, due to its cryptic burrowing behaviour (Portt et al. 2007). Survey needs are provided in Table 6. In the vicinity of current and historical occurrence, surveys are required to:
- confirm the spatial distribution of extant populations;
- confirm the loss of historical populations;
- identify suitable habitat (distribution, quantity and quality of sandy patches);
- provide an index of abundance and trend over time data; and,
- detect the presence of Round Goby.
| Ontario watershed | Survey needs |
|---|---|
| Ausable River | To determine if populations are extant. |
| Catfish Creek | To determine if populations are extant. |
| Big Otter Creek | To determine if populations are extant. |
| Grand River | To determine if Wilkes dam is a barrier to fish passage and if populations are present between Brantford and Paris. |
| Thames River | Routine monitoring of population. |
| Sydenham River | To determine the extent and status of the populations. |
| Lake St. Clair | To determine the extent and status of the populations. |
| Lake Erie | To determine the extent and status of the populations. |
| Big Creek | To determine the extent and status of the populations. |
It is recommended that riverine populations be surveyed using a variety of methods during periods of low flow (e.g., summer and early fall). Field surveys should target shallow habitats with sand and/or mixed sand/gravel bed material.
Captive rearing and repatriation (R6)
Repatriation efforts need to consider the following:
- Many of the extirpations are presumed to be the result of habitat degradation. The success of repatriations will depend on an understanding of the species' habitat needs and on a sufficient quantity of suitable habitat being available at the repatriation site. Surveys need to be undertaken to characterize current habitat conditions and identify appropriate actions to improve degraded habitats. If habitat requirements are poorly understood, then studies of habitat use will need to be undertaken;
- Repatriations should not be considered until the factors for extirpation are understood and addressed or there is suitable habitat present to support a viable population;
- Source populations to support repatriations need to be identified. Ideally, source populations possess a high level of genetic diversity and genetic composition developed under similar historic conditions as the repatriation site. Genetic comparisons with populations from other parts of its North American range will determine the appropriateness of augmentation and selecting source populations when deemed necessary. Where possible, source populations within the same watershed are preferred;
- Removal of individuals from source populations should not negatively affect the status of these populations;
- The preferred method of introduction (i.e., adult transfer versus captive reared) needs to be determined. If captive rearing is the preferred option, propagation and rearing methods and an appropriate rearing facility will need to be identified;
- To successfully establish self-sustaining populations and preserve the genetic composition, the number of individuals, appropriate life stages, and the frequency and duration of supplemental stockings needs to be determined. Population Viability Analysis (PVA) or other population modeling approaches may help to provide this information. Proper application of PVA tools, however, may require improved information on the life history and demographics of the species targeted for repatriation;
- Monitoring is required to ensure that newly established populations are viable, that the stocking rate is appropriate and habitat conditions continue to be suitable; and,
- All proposed repatriations associated with this strategy will involve the preparation of a repatriation plan that will address the logistic and ecological aspects discussed above, as well as stakeholder issues.
Repatriations should follow the American Fisheries Society Guidelines for Introductions of Threatened and Endangered Fishes (Williams et al. 1988) and the National Code on Introductions and Transfers of Aquatic Organisms (Fisheries and Oceans, 2003).
| Priority | Objective addressed | Threats addressed | Broad strategy to address threats | Recommended approaches to meet recovery objective(s) | Outcomes or deliverables (identify measurable targets) |
|---|---|---|---|---|---|
| High | vi, vii | All | Coordination with other recovery teams and relevant organizations | Work with relevant organizations (e.g. CA's, MNR), First Nations, and ecosystem/single species recovery teams to share knowledge, and implement recovery actions. | Will combine resources, ensure information dissemination, help to prioritize most urgent actions across the species range and allow for a coordinated approach to recovery. |
| High | iii, iv | All habitat threats | Habitat management and policy | Ensure planning and management agencies, including local First Nations, recognize the importance of fluvial and long-shore processes and sources of sand bedload in the maintenance of Eastern Sand Darter habitats. Ensure that flow requirements of the Eastern Sand Darter are considered in the management of water supply and flow regimes. |
Will result in protection of important habitat from development activities. For example: consistent plan for reducing shoreline hardening or removal of obsolete dams. |
| High | vi | All threats | Assessment of watershed-scale stressors | In cooperation with relevant ecosystem recovery teams and First Nations, address watershed-scale stressors to populations and their habitat. | Will identify areas in which cumulative effects of threats may be significant |
| High | vi, vii | Exotics | Exotic species management plan | Develop a management plan addressing potential risks and proposed actions in response to the arrival or establishment of exotic species, such as the Round Goby. | Will ensure timely response should this threat fully materialize. |
| Moderate | vi, vii | Habitat threats | Municipal planning | Encourage municipalities and First Nations to include the concerns about Eastern Sand Darter habitat conservation in the municipal planning documents. | Will prevent further impairment of water quality and quantity. |
| Priority | Objective addressed | Threat addressed | Broad strategy to address threats | Recommended approaches to meet recovery objective(s) | Outcomes or deliverables (identify measurable targets) |
|---|---|---|---|---|---|
| High | v | all | Stewardship - awareness | Encourage and strengthen stewardship efforts with managers, stakeholders, First Nations and citizens aimed at protecting Eastern Sand Darter habitats. | Will address local concerns about implications of recovery of Eastern Sand Darter. |
| High | Turbidity and sediment loading, contaminants and toxic substances, nutrient loading, shoreline modifications | Stewardship – implementation of BMP's | Work with landowners and First Nations to implement BMP's in areas that will provide the most benefit. Encourage the completion and implementation of Environmental Farm Plans and Nutrient Management Plans | Will minimize threats from soil erosion, stream sedimentation and nutrient and chemical contamination. | |
| High | v, vi | all | Communication plan* | Develop a communication and awareness-raising plan that identifies partners and target audiences. Raise the awareness and develop information products, educational and outreach opportunities, stewardship resources and specific BMP's that will assist with the recovery of the Eastern Sand Darter. |
Will provide a strategic basis for improving public awareness of species at risk and promote ways in which community and public involvement can be most effectively solicited fro the recovery of Eastern Sand Darter. |
| Moderate | v, vi | all | Coordination with other groups* | Collaborate with relevant groups, including First Nations groups and recovery teams to address recovery actions to benefit Eastern Sand Darter | Will combine efficiencies in addressing common recovery actions, and ensure information is disseminated in a timely cooperative fashion. |
| Moderate | v, vi | Exotic species and disease | Exotic species - awareness | Increase public awareness of the impacts of invasive species on the natural ecosystem, encourage the use of the Ontario invasive species reporting system. | Will reduce the transport and release of exotics and prevent their establishment in new areas. |
| Moderate | All | Stewardship- financial assistance/incentives* | Facilitate access to funding sources for landowner and local community groups engaged in stewardship activities. | Will facilitate the implementation of recovery efforts. BMP's associated with water quality improvements, sediment load reduction, etc. |
*approaches currently being implemented by one or more ecosystem-based recovery programs.
Stewardship and habitat initiatives (S1)
Basin-wide efforts to improve habitat quality will be required in all watersheds. This represents an important opportunity to engage land owners, local communities, First Nations and stewardship councils on the issues of Eastern Sand Darter recovery, ecosystem and environmental health, clean water protection, nutrient management, BMPs, stewardship projects and associated financial incentives. To accomplish this, the members of the Ontario Freshwater Fish Recovery Team (OFFRT) will work closely with the various aquatic ecosystem recovery teams, many of which have already established stewardship liaisons and activities that will benefit the Eastern Sand Darter.
Implementation of BMPs (S2)
The members of the OFFRT, together with watershed Recovery Implementation Groups (RIGs) (for stewardship, awareness and community outreach), will work with landowners, First Nations and stewardship groups to implement BMPs. Establishing riparian buffers reduces nutrient (nitrogen and phosphorus) and sediment inputs and overland run-off. Restriction of livestock from watercourses, where feasible and appropriate, leads to reductions in erosion and sediment and nutrient loadings. Nutrient and manure management will reduce nitrogen and phosphorus inputs into adjacent waterbodies, thereby, improving water quality for the Eastern Sand Darter and other aquatic organisms. The RIGs can work with landowners to mitigate the impacts of tile drainage, thereby, reducing sediment and nutrient inputs. No-till practices can reduce soil erosion and improve soil structure while reducing sediment loads in adjacent watercourses. Environmental Farm Plans prioritize BMP implementation at the level of the individual farm and are sometimes a pre-requisite for funding programs. Environmental Farm Plans are overseen by the Ontario Soil and Crop Improvement Associations. For more information on BMPs see Ministry of Agriculture and Food, Best Management Practices Series.
Coordination with other recovery teams (S4)
Many of the threats facing the Eastern Sand Darter are a result of habitat degradation that affects numerous aquatic species. Multi-species ecosystem recovery strategies, such as those for the Grand, Sydenham and Thames rivers and the Essex-Erie watershed, have incorporated the requirements of the Eastern Sand Darter in their basin-wide strategies. As well as species specific considerations, these ecosystem-based strategies employ basin-wide strategies to improve environmental conditions such as water quality, benefiting the Eastern Sand Darter and other species. A coordinated, cohesive approach between the OFFRT and multi-species recovery teams that maximizes opportunities to share resources, information and combine efficiencies is recommended. The members of the OFFRT should also coordinate efforts with recovery teams focused on the recovery of Spiny Softshell Turtle (Apalone spinifera) and Round Hickorynut (Obovaria subrotunda).
Measurable performance indicators have been identified for each recovery objective (Table 9). They will help determine the success obtained in achieving the eight listed objectives over the next five years.
| Recovery objectives | Performance indicators |
|---|---|
| Protect known populations and habitats. |
|
| Determine the extent, abundance and demographics of existing populations. | Existing populations and historical sites and potential habitats have been sampled. |
| Determine the extent, abundance and quality of existing habitat (sandy patches) in areas of occurrence through a focused sampling program. | Gained knowledge of currently occupied and potential of historical habitats. |
| Identify key habitat requirements to refine critical habitat and implement strategies to protect known habitat. | Complete description of Eastern Sand Darter critical habitat. |
| Establish a long-term population and habitat monitoring program. | Monitoring program has been developed. |
| Clarify threats and identify remedial actions to reduce their effects. | Research has been conducted to clarify number, extent and severity of threats to Eastern Sand Darter. |
| Examine the feasibility of translocations, repatriations and captive rearing. | Research has been conducted to evaluate feasibility of translocations, repatriations and captive rearing. |
| Increase awareness of the significance of this species and its status as an aquatic species at risk and indicator of ecosystem health. | Outreach program developed and materials distributed. |
| Develop linkages among partners, including watershed-based recovery teams, interest groups, industry, agencies and landowners interested in supporting the recovery of the Eastern Sand Darter. | Formalized partnerships developed to increase awareness and formulate action plans towards recovery. |