Management Plan for the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth in Canada

Transcription

1 Species at Risk Act Management Plan Series Management Plan for the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth in Canada Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth October 2009 Fisheries and Oceans Canada Pêches et Oceans Canada

2 About the Species at Risk Act Management Plan Series What is the Species at Risk Act (SARA)? SARA is the Act developed by the federal government as a key contribution to the common national effort to protect and conserve species at risk in Canada. SARA came into force in 2003, and one of its purposes is to manage species of special concern to prevent them from becoming endangered or threatened. What is a species of special concern? Under SARA, a species of special concern is a wildlife species that could become threatened or endangered because of a combination of biological characteristics and identified threats. Species of special concern are included in the SARA List of Wildlife Species at Risk. What is a management plan? Under SARA, a management plan is an action-oriented planning document that identifies the conservation activities and land use measures needed to ensure, at a minimum, that a species of special concern does not become threatened or endangered. For many species, the ultimate aim of the management plan will be to alleviate human threats and remove the species from the List of Wildlife Species at Risk. The plan sets goals and objectives, identifies threats, and indicates the main areas of activities to be undertaken to address those threats. Management plan development is mandated under Sections of SARA ( A management plan has to be developed within three years after the species is added to the List of Wildlife Species at Risk. A period of five years is allowed for those species that were initially listed when SARA came into force. What s next? Directions set in the management plan will enable jurisdictions, communities, land users, and conservationists to implement conservation activities that will have preventative or restorative benefits. Cost-effective measures to prevent the species from becoming further at risk should not be postponed for lack of full scientific certainty and may, in fact, result in significant cost savings in the future. The series This series presents the management plans prepared or adopted by the federal government under SARA. New documents will be added regularly as species get listed and as plans are updated. To learn more To learn more about the Species at Risk Act and conservation initiatives, please consult the Species at Risk Public Registry (

3 Spotted Sucker and Warmouth in Canada October 2009

4 Recommended citation: Edwards, A.L. and S.K. Staton Management plan for the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth in Canada. Species at Risk Act Management Plan Series. Fisheries and Oceans Canada, Ottawa. viii + 43 pp. Additional copies: Additional copies can be downloaded from the SARA Public Registry ( Cover photographs: Clockwise from upper left: Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker, Warmouth. Blackstripe Topminnow, Pugnose Minnow and Spotted Sucker Konrad Schmidt. Également disponible en français sous le titre «Plan de gestion pour le fondule rayé, le petit-bec, le meunier tacheté et le crapet sac-à-lait au Canada [proposition]» Her Majesty the Queen in Right of Canada, represented by the Minister of the Environment, All rights reserved. ISBN Catalogue no. En3-5/5-2009E-PDF Content (excluding the illustrations) may be used without permission, with appropriate credit to the source.

5 PREFACE Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth are freshwater fishes and are under the responsibility of the federal government. The Minister of Fisheries and Oceans is a competent minister for aquatic species under the Species at Risk Act (SARA). Since Warmouth is located in Point Pelee National Park of Canada administered by the Parks Canada Agency (Parks Canada), the Minister of the Environment is also a competent minister under SARA for this species only. The Species at Risk Act (SARA, Section 65) requires the competent ministers to prepare management plans for species listed as special concern. The Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth were listed as species of special concern under SARA in The development of this management plan was led by Fisheries and Oceans Canada Central and Arctic Region, in cooperation and consultation with many individuals, organizations and government agencies, including the Government of Ontario, the Parks Canada Agency, the University of Windsor and the Upper Thames Rivers Conservation Authority. The plan meets SARA requirements in terms of content and process (SARA sections 65-68). Success in the conservation of these species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this plan and will not be achieved by Fisheries and Oceans Canada and Parks Canada or any other party alone. This plan provides advice to jurisdictions and organizations that may be involved or wish to become involved in activities to conserve this species. In the spirit of the Accord for the Protection of Species at Risk, the Minister of Fisheries and Oceans and the Minister of the Environment invite all responsible jurisdictions and Canadians to join Fisheries and Oceans Canada and Parks Canada in supporting and implementing this plan for the benefit of the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth, and Canadian society as a whole. The competent ministers will report on progress within five years. RESPONSIBLE JURISDICTIONS Fisheries and Oceans Canada Government of Ontario Parks Canada Agency AUTHORS This document was prepared by Amy L. Edwards and Shawn K. Staton on behalf of Fisheries and Oceans Canada and Parks Canada. ACKNOWLEDGMENTS Fisheries and Oceans Canada would like to thank the following organizations for their support in the development of this management plan: the Ontario Freshwater Fish Recovery Team, Parks Canada Agency, Ontario Ministry of Natural Resources, Ontario Ministry of the Environment, i

6 University of Windsor and the Upper Thames River Conservation Authority. Mapping was produced by Carolyn Bakelaar (DFO). ii

7 STRATEGIC ENVIRONMENTAL ASSESSMENT 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. Management planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that plans 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 on non-target species or habitats. The results of the SEA are incorporated directly into the plan itself, but are also summarized below. This management plan will clearly benefit the environment by promoting the conservation of the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth. The potential for the plan to inadvertently lead to adverse effects on other species was considered. The SEA concluded that this plan will clearly benefit the environment and will not entail any significant adverse effects. The reader should refer to the following sections of the document in particular: description of the species habitat and biological needs, ecological role, and limiting factors; effects on other species; and, the management implementation actions. iii

8 EXECUTIVE SUMMARY In Canada, the Blackstripe Topminnow (Fundulus notatus), Pugnose Minnow (Opsopoeodus emiliae), Spotted Sucker (Minytrema melanops) and Warmouth (Lepomis gulosus) all occur in southwestern Ontario. The Blackstripe Topminnow is found only in the Sydenham River and Lake St. Clair drainages and the Warmouth is found only in four areas of Lake Erie (Long Point Bay, Big Creek National Wildlife Area [Long Point region], Rondeau Bay and Point Pelee National Park). The Pugnose Minnow and Spotted Sucker are found in Lake St. Clair and its smaller tributaries, Lake Erie, the Detroit River, the Sydenham River and the Thames River. In addition, the Spotted Sucker is also found in the St. Clair River. All four species are listed as Special Concern and are on Schedule 1 of the federal Species at Risk Act. As such, the Act requires that management plans be developed that identify management approaches for each species. Fisheries and Oceans Canada and the Parks Canada Agency, in cooperation with the government of Ontario, have developed a single management plan to aid in the conservation and management of these four species. In recognition of the degree of overlap between these species in their distribution, as well as the commonality of threats, a multi-species approach was adopted for the management of these species. Little data are available regarding population sizes and trends, biology or ecology of these four species. All face similar known and suspected threats, which include: habitat loss and degradation; sediment and nutrient loading; toxic compounds; exotic species; altered coastal processes; climate change; incidental harvest; and, barriers to movement. This management plan defines the goal, objectives and recommended approaches believed to be necessary for the conservation and management of these four species in Canada. The long-term goal of this management plan is to maintain, or enhance, existing populations of the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth in Canada, and to improve the quality and quantity of their associated habitats. This will be accomplished primarily through the implementation of ecosystem recovery/management approaches, in cooperation with relevant single/multi-species and ecosystem-based recovery programs, to mitigate identified threats. The following short-term objectives (over the next 5-10 years) have been identified to assist in achieving the management goal: i. To understand the health and extent of existing populations; ii. To improve our knowledge of the species biology, ecology and habitat requirements; iii. To understand trends in populations and habitat; iv. To maintain and improve existing populations; v. To ensure the efficient use of resources in the management of these species; and, vi. To improve awareness of these species and engage the public in conservation of these species. Some measures have already been implemented for the management of these species. In Ontario, three ecosystem-based recovery strategies address two or more of the species (Essex- Erie region, Sydenham River, Thames River). Stewardship and awareness initiatives have been developed by the ecosystem-based recovery teams and are ongoing throughout the iv

9 species ranges. The development and implementation of management actions is being coordinated with species at risk recovery teams throughout the species ranges to facilitate information sharing. Coordination with other recovery teams will help to ensure that proposed management actions do not negatively impact upon other co-occurring species at risk; management actions may, in fact, enhance or facilitate recovery of other species at risk. v

10 TABLE OF CONTENTS PREFACE... I RESPONSIBLE JURISDICTIONS... I AUTHORS... I ACKNOWLEDGMENTS... I STRATEGIC ENVIRONMENTAL ASSESSMENT... III EXECUTIVE SUMMARY...IV INTRODUCTION SPECIES INFORMATION BLACKSTRIPE TOPMINNOW Species Assessment Information from COSEWIC Description Populations and Distribution Needs of the Blackstripe Topminnow Habitat and biological needs Ecological role Limiting factors SPECIES INFORMATION PUGNOSE MINNOW Species Assessment Information from COSEWIC Description Populations and Distribution Needs of the Pugnose Minnow Habitat and biological needs Ecological role Limiting factors SPECIES INFORMATION SPOTTED SUCKER Species Assessment Information from COSEWIC Description Populations and Distribution Needs of the Spotted Sucker Habitat and biological needs Ecological role Limiting factors SPECIES INFORMATION WARMOUTH Species Assessment Information from COSEWIC Description Populations and Distribution Needs of the Warmouth Habitat and biological needs Ecological role Limiting factors THREATS Threat classification Description of threats Habitat Loss and Degradation Sediment Loading vi

11 5.2.3 Nutrient Loading Exotic Species Altered Coastal Processes Climate Change Toxic Compounds Incidental Harvest Barriers to Movement Changes to Trophic Dynamics Actions Already Completed or Underway Knowledge Gaps MANAGEMENT Goal Objectives Actions Background surveys Monitoring Research Coordination with recovery teams and other complimentary initiatives Outreach and communication Stewardship and habitat improvement (threat mitigation) Effects on Other Species IMPLEMENTATION SCHEDULE ASSOCIATED PLANS REFERENCES CONTACTS APPENDIX 1. RECORD OF COOPERATION AND CONSULTATION LIST OF TABLES Table 1. Canadian and U.S. national and sub-national ranks for Blackstripe Topminnow (NatureServe 2008)...5 Table 2. Canadian and U.S. national and sub-national ranks for Pugnose Minnow (NatureServe 2008)...11 Table 3. Canadian and U.S. national and sub-national ranks for Spotted Sucker (NatureServe 2008)...16 Table 4. Canadian and U.S. national and sub-national ranks for Warmouth (NatureServe 2008) Table 5. Threat classification table...24 Table 6. Existing ecosystem-based recovery strategies that include two or more of the four Special Concern species...29 Table 7. Summary of recent fish surveys throughout the range of the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth Table 8. Implementation schedule vii

12 LIST OF FIGURES Figure 1. Blackstripe Topminnow (Fundulus notatus, male)...2 Figure 2. North American distribution of the Blackstripe Topminnow...3 Figure 3. Canadian distribution of the Blackstripe Topminnow...4 Figure 4. Pugnose Minnow (Opsopoeodus emiliae)....7 Figure 5. North American distribution of the Pugnose Minnow...8 (Cudmore and Holm 2000)....8 Figure 6. Canadian distribution of the Pugnose Minnow Figure 7. Spotted Sucker (Minytrema melanops; male)...13 Figure 8. Global range of the Spotted Sucker (COSEWIC 2005a) Figure 9. Canadian range of the Spotted Sucker...15 Figure 10. Warmouth (Lepomis gulosus)...18 Figure 11. Global distribution of Warmouth (COSEWIC 2005b)...19 Figure 12. Canadian distribution of the Warmouth Figure 13. Location of watershed-based species at risk recovery programs...29 viii

13 INTRODUCTION The watersheds of southern Ontario support some of the richest communities of fishes in the country. More than half of the 230 species of fishes known to exist in Canada are found in the region. A high proportion of Canada s fish species at risk are also found in southwestern Ontario and 34 species have been assigned a conservation status (OMNR 2006). Staton and Mandrak (2006) identified priority watersheds for protecting freshwater species at risk in Canada, which included conservation hot spots within Carolinian Canada watersheds of southwestern Ontario. The Ontario Freshwater Fish Recovery Team (OFFRT) was formed to address the recovery planning obligations for freshwater fishes listed under Canada s Species at Risk Act (SARA). The national management plan for the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth was developed by the OFFRT using the best available information in an effort to conserve the species and reduce the threats to their populations. These four species are at the northern extent of their ranges and all have been impacted, to some extent, by habitat degradation. They have all been listed as Special Concern under SARA. In recognition of the degree of overlap between these species in their distribution, as well as the commonality of threats, the OFFRT has adopted a multi-species approach to the management of these species. 1

14 1.0 SPECIES INFORMATION BLACKSTRIPE TOPMINNOW 1.1 Species Assessment Information from COSEWIC Date of Assessment: May 2001 Common Name (population): Blackstripe Topminnow Scientific Name: Fundulus notatus (Rafinesque, 1820) COSEWIC Status: Special Concern Reason for Designation: This species has a limited distribution in southwestern Ontario where it is impacted by habitat degradation and loss from industrial, urban and agricultural development. Canadian Occurrence: Ontario COSEWIC Status History: Designated Special Concern in April Status re-examined and confirmed in May Last assessment based on an update status report. 1.2 Description The following description has been adapted from Mandrak and Holm (2001). The Blackstripe Topminnow (Fundulus notatus Rafinesque, 1820) (Figure 1) is a small fish with a maximum total length (TL) of 74 mm. This species has a protractile upper jaw (adapted for feeding at the water s surface), partially scaled head, spineless fins, rounded caudal fin, single dorsal fin at or behind the middle of the body, flattened area anterior to the dorsal fin and abdominal pelvic fins. It can be distinguished from the banded killifish (F. diaphanus) and mummichog (F. heteroclitus) by the prominent black lateral stripe and the origin of the dorsal fin behind the origin of the anal fin. Male Blackstripe Topminnow have crossbars on the lateral stripe, a deepened body, and elongated dorsal and anal fins that are bright yellow in colour. Females lack crossbars on the lateral stripe, have white fins, rounded dorsal and anal fins, and a distinctly fleshy sheath at the origin of the anal fin. Figure 1. Blackstripe Topminnow (Fundulus notatus, male). Joseph R. Tomelleri (1998). 1.3 Populations and Distribution Distribution: Global Range (Figure 2): The Blackstripe Topminnow is found in lowland areas of the southern Great Lakes drainages (lakes Erie and Michigan), in the Mississippi basin from Illinois to the Gulf of Mexico, and along the lower coastal plain from Texas to Alabama. It occurs in 16 states and southern Ontario (Mandrak and Holm 2001). 2

15 Figure 2. North American distribution of the Blackstripe Topminnow. Adapted from Page and Burr (1991) and Shute (1980). Canadian Range (Figure 3): The Canadian range of the Blackstripe Topminnow is primarily restricted to an area of approximately 60 km² in the Sydenham River watershed where it is found in the North Sydenham River basin (including Bear, Black, Booth, Crooked, East Otter, Fox, Ryan s and West Otter creeks) as well as the lower East Sydenham River, including Molly s Creek (Mandrak and Holm 2001, Dextrase et al. 2003). It was also recently found in Little Bear Creek, Maxwell Creek and Whitebread Drain (Lake St. Clair drainage; Mandrak et al. 2006). 3

16 Figure 3. Canadian distribution of the Blackstripe Topminnow. 4

17 Percent of Global Distribution in Canada: Less than 5% of the species global distribution is currently found in Canada. Population Size and Status: Global Population Size and Status: Although there are no population estimates for the Blackstripe Topminnow in the United States, it is possible to make inferences from available information. This species is common to abundant in most parts of its range in the United States, and has expanded its range in some areas. In Ohio, recent surveys indicate a range expansion in the Portage River basin, and in Wisconsin, populations have expanded in the last 50 years, despite inhabiting heavily disturbed waters (Becker 1983, Mandrak and Holm 2001). The species is ranked as secure (N5) in the United States, imperilled (S2/S3) in Michigan, and vulnerable (S3) in Alabama and Iowa (NatureServe 2008). Complete national and sub-national ranks are listed in Table 1. Table 1. Canadian and U.S. national and sub-national ranks for Blackstripe Topminnow (NatureServe 2008). Canada and U.S. National Rank (NX) and Provincial/State Rank (SX) Canada (N2) Ontario (S2) United States (N5) Alabama (S3), Arkansas (S4), Illinois (S5), Indiana (S4), Iowa (S3), Kansas (S5), Kentucky (S4S5), Louisiana (S5), Michigan (S2S3), Mississippi (S5), Missouri (SNR), Ohio (SNR), Oklahoma (S5), Tennessee (S5), Texas (S5), Wisconsin (S4) Canadian Population Size and Status: The Blackstripe Topminnow is ranked as imperilled (N2) in Canada (NatureServe 2008), and has been listed as Special Concern by the Ontario Ministry of Natural Resources (OMNR) (NHIC 2008) and the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) (COSEWIC 2001). The species is also listed as Special Concern under the SARA and is included on Schedule 1 of the Act. There are little data on population size or trends for Blackstripe Topminnow in Canada. Sampling conducted in September of 2003 in the Lake St. Clair drainage yielded 593 Blackstripe Topminnow from seven locations: East Otter Creek (83 specimens); East Sydenham River (221); Little Bear Creek (24); Maxwell Creek (4); North Sydenham River (207); West Otter Creek (33); and, Whitebread Drain (21) (Mandrak et al. 2006). A comparison of sampling conducted in the 1970s and late 1990s indicates that a comparable number of specimens were captured at most sites and, although Blackstripe Topminnow were not detected at several sites where they were previously found, the species was found at several new sites (Mandrak and Holm 2001). Overall, Blackstripe Topminnow populations in Canada are believed to be stable. Nationally Significant Populations: The Sydenham River watershed, Little Bear Creek and Whitebread Drain support the only known populations of Blackstripe Topminnow in Canada and are, therefore, nationally significant. 1.4 Needs of the Blackstripe Topminnow Habitat and biological needs The Blackstripe Topminnow prefers small to large, low-gradient streams, sloughs and pools of intermittent tributaries, with moderate to high turbidity, and is apparently tolerant of a wide range in water quality (McAllister 1987, Dextrase et al. 2003). Substrates at capture sites include silt, sand, clay, rubble and boulder (Becker 1983, Mandrak and Holm 2001), and water clarity 5

18 ranged from 5 40 cm (Mandrak and Holm 2001). In Canada, McAllister (1987) found the species to be particularly abundant in pools of intermittent tributaries of Black Creek, where aquatic vegetation and riparian areas had not been destroyed by livestock. The species is highly associated with areas containing abundant riparian and aquatic vegetation that offer a source of food as well as cover. In Michigan, spawning occurred from May to the third week of August while in Wisconsin, spawning occurred from June to July (Mandrak and Holm 2001). Eggs are laid on filamentous algae or other types of aquatic vegetation (Becker 1983). In the absence of aquatic vegetation, the species will spawn over detritus and leaf litter (Smith 1979). Blackstripe Topminnow occupy deeper waters during the winter and migrate to shallow water in late March or early April where they are typically found in the top 2.5 cm of water (Carranza and Winn 1954). The diet of the Blackstripe Topminnow includes a large proportion of terrestrial insects but the species has also been known to consume aquatic insect larvae, molluscs, spiders and microcrustaceans (Mandrak and Holm 2001). The species also consumes filamentous algae, which some authors consider to be only incidentally ingested, while other authors consider it to be an important food item (Mandrak and Holm 2001) Ecological role The Blackstripe Topminnow plays an important role in the ecosystem in terms of the exclusivity with which it feeds on terrestrial insects in the summer (McAllister 1987); aside from the Redside Dace (Clinostomus elongatus), few other Canadian fish species feed on terrestrial insects to this extent. The Blackstripe Topminnow may also be an important prey fish where it is abundant (Dextrase et al. 2003) Limiting factors Population sizes of the Blackstripe Topminnow are limited by the amount of riparian vegetation, aquatic vegetation and riparian terrestrial insect fauna (Dextrase et al. 2003). 6

19 2.0 SPECIES INFORMATION PUGNOSE MINNOW 2.1 Species Assessment Information from COSEWIC Date of Assessment: May 2000 Common Name (population): Pugnose Minnow Scientific Name: Opsopoeodus emiliae (Hay, 1881) COSEWIC Status: Special Concern Reason for Designation: This species is limited to a small area of southwestern Ontario and is susceptible to aquatic plant removal and siltation. Canadian Occurrence: Ontario COSEWIC Status History: Designated as Special Concern in April Status re-examined and confirmed in May Last assessment based on an update status report. 2.2 Description The following description has been adapted from Cudmore and Holm (2000). The Pugnose Minnow (Opsopoeodus emiliae Hay, 1881) (Figure 4) is a small cyprinid with a maximum length of 64 mm TL. It has a small upturned mouth, a black lateral band extending from the tail to the snout, and a criss-cross pattern of scaling particularly evident on the upper body. Adult males have a dusky or black dorsal fin with a white bar in the middle that intensifies during the spawning season. The Pugnose Minnow usually has nine principal dorsal rays, unlike any other Canadian minnow. This species has five, ridged pharyngeal teeth in one row on each side. There may occasionally be a fleshy barbel at the posterior end of one or both sides of the lower lip. Spawning males develop patches of small tubercles on the snout and chin. The Pugnose Minnow can be distinguished from similar species such as the Pugnose Shiner (Notropis anogenus), and other blackline shiners (e.g., Blackchin Shiner [N. heterodon], Blacknose Shiner [N. heterolepis]), primarily by its nine principal dorsal rays; the Pugnose Shiner and other blackline shiners have eight. Additionally, the Pugnose Minnow can be differentiated from the Pugnose Shiner by the dark lateral band that extends onto the nose, but not the chin, as is seen in the Pugnose Shiner. Figure 4. Pugnose Minnow (Opsopoeodus emiliae). From Scott and Crossman (1998), with permission. 7

20 2.3 Populations and Distribution Distribution: Global Range (Figure 5): The Pugnose Minnow is relatively common and widespread in the southern United States where it is found from South Carolina and Florida, west to Texas. It is found in the Mississippi River drainage north to southeastern Wisconsin, and west to southwestern Ontario. It is less frequently encountered and possibly disappearing from the more northern areas of its range (Cudmore and Holm 2000). Figure 5. North American distribution of the Pugnose Minnow (Cudmore and Holm 2000). Canadian Range (Figure 6): In Canada, the Pugnose Minnow is known only from a small area in southwestern Ontario where it was first recorded in 1935 from Mitchell s Bay in Lake St. Clair. It has also been collected from several small tributaries of Lake St. Clair since 1980 (Channel Ecarte, East Otter Creek, Maxwell Creek, Little Bear Creek, McDougall Drain and an un-named agricultural ditch north of Walpole island), as well as the Detroit River (first recorded in 1940), western Lake Erie (1994), Sydenham River (1972 North Sydenham; 1979 lower East Sydenham) and Thames River (1968) (Cudmore and Holm 2000, Dextrase et al. 2003, EERT 2008). In 2003, the species was captured for the first time in Whitebread Drain (Lake St. Clair drainage) (Mandrak et al. 2006). Additionally, a single specimen was purportedly collected from Long Point Bay in 2003 (EERT 2008), representing the most easterly location for this species; however, the voucher specimen for this record cannot be located and verification is not currently possible. In 2007, a single specimen was captured on the south shore of Lake St. Clair by the 8

21 OMNR (G. Yunker, OMNR, pers. comm. 2008), representing a new location for the species in the lake. 9

22 Figure 6. Canadian distribution of the Pugnose Minnow. 10

23 Percent of Global Distribution in Canada: Less than 5% of the species global range occurs in Canada. Population Size and Status: Global Population Size and Status: There are an estimated to more than 1 million Pugnose Minnow globally (NatureServe 2008) and the species is considered to be globally secure (G5) (NatureServe 2008). However, it is rare and may be declining in the northern part of its range (Cudmore and Holm 2000). It is ranked as presumed extirpated (SX) in West Virginia and critically imperilled (S1) in Michigan and Ohio (NatureServe 2008). Complete national and sub-national ranks for the species are listed in Table 2. Table 2. Canadian and U.S. national and sub-national ranks for Pugnose Minnow (NatureServe 2008). Canada and U.S. National Rank (NX) and Provincial/State Rank (SX) Canada (N2) Ontario (S2) United States (N5) Alabama (S5), Arkansas (S3S4), Florida (SNR), Georgia (S3), Illinois (S2S3), Indiana (S2), Iowa (S3), Kentucky (S4S5), Louisiana (S5), Michigan (S1), Minnesota (S4), Mississippi (S5), Missouri (S4), Ohio (S1), Oklahoma (S3), Pennsylvania (SNA), Tennessee (S5), Texas (S4), West Virginia (SX), Wisconsin (S3) Canadian Population Size and Status: The Pugnose Minnow is ranked as imperilled (N2) in Canada (NatureServe 2008), and is listed as Special Concern by the OMNR (NHIC 2008) and COSEWIC (COSEWIC 2000). It is also listed as Special Concern under the SARA and is on Schedule 1 of the Act. The number of Pugnose Minnow in Canada is unknown and there are insufficient data available to determine population trends (Cudmore and Holm 2000). The species is not common in collections, which suggests that numbers are relatively low; however, population sizes likely fluctuate from year to year. Recent captures of the Pugnose Minnow at most sites where it was captured previously, and at new sites, indicate that the species is maintaining itself in Canada (Cudmore and Holm 2000). Twenty-eight Pugnose Minnow were captured from six locations throughout the Lake St. Clair drainage in 2003 (Mandrak et al. 2006): East Otter Creek (1 specimen); East Sydenham River (3); Little Bear Creek (3); Maxwell Creek (2); North Sydenham River (1); and, Whitebread Drain (18). In 2007, one specimen was caught along the south shore of Lake St. Clair by the OMNR during a seine survey. Overall, Pugnose Minnow populations in Canada are believed to be stable. Nationally Significant Populations: None have been identified. 2.4 Needs of the Pugnose Minnow Habitat and biological needs It is believed that the Pugnose Minnow prefers clear, slow-moving waters with abundant vegetation (Scott and Crossman 1998). However, in Canada, this species has been collected from turbid environments with small amounts of aquatic vegetation. Other physical characteristics of capture sites included substrates of silt, muck and detritus, and the presence of other cover such as boulders and woody debris (Cudmore and Holm 2000). Therefore, it would seem that, in Canada, the species is found in turbid, slow-moving or still waters with or 11

24 without vegetation over clay, silt or sand substrates (Cudmore and Holm 2000). The spawning season for the Pugnose Minnow occurs in late May to mid-june (Cudmore and Holm 2000). Spawning is believed to take place at depths of 0 2 m in areas with submergent and emergent aquatic vegetation over substrates of silt, clay or sand (Lane et al. 1996c). However, Cudmore and Holm (2000) stated that males select and defend a flat surface, such as the underside of a rock, as a spawning site. Eggs are laid in clusters on the underside of the flat surface over a period of 6 7 days and are defended by the male (Cudmore and Holm 2000). Nursery habitat for the Pugnose Minnow is thought to occur in areas containing abundant aquatic vegetation and substrates of silt and sand, at depths of 0 2 m (Lane et al. 1996b). The Pugnose Minnow feeds on a variety of small insects (e.g., Diptera and larval Trichoptera), crustaceans, filamentous algae, and occasionally on larval fishes and fish eggs (Parker et al. 1987) Ecological role The species upturned mouth may be an adaptation to mid-water or surface feeding habits (Scott and Crossman 1998). Apparent low population levels likely reduce its value as a forage species (Cudmore and Holm 2000). The egg clustering and parental care behaviour of the Pugnose Minnow is a complex breeding strategy and, along with that of species in the Pimephales and Cyprinella genera, is unique to North American cyprinids (Cudmore and Holm 2000) Limiting factors Factors that limit the survival and health of the Pugnose Minnow in Canada are unknown (Cudmore and Holm 2000). During the spawning season, the male Pugnose Minnow has an elaborate courtship display, which may require clear water to be effective (Cudmore and Holm 2000). 12

25 3.0 SPECIES INFORMATION SPOTTED SUCKER 3.1 Species Assessment Information from COSEWIC Date of Assessment: May 2005 Common Name (population): Spotted Sucker Scientific Name: Minytrema melanops (Rafinesque, 1820) COSEWIC Status: Special Concern Reason for Designation: This species is restricted to southwestern Ontario. The greatest threat to it is habitat degradation through increased erosion and turbidity. The Spotted Sucker is also at risk in Pennsylvania but not at risk in Michigan (where it is S3-vulnerable), making rescue effect moderate at best. Canadian Occurrence: Ontario COSEWIC Status History: Designated Special Concern in April Status re-examined and confirmed in April 1994, November 2001 and May Last assessment based on an update status report. 3.2 Description The following description was adapted from COSEWIC (2005a). The Spotted Sucker (Minytrema melanops Rafinesque, 1820) (Figure 7) is a medium-sized sucker that ranges between 230 and 380 mm TL as adults. Specimens as large as 500 mm TL have been captured in the Canadian waters of the Detroit River (S. Staton, DFO, pers. obs.). Most individuals weigh less than 1000 g, although specimens over 1300 g have been reported. This species is distinguished from other catostomid species by the presence of 8-12 parallel rows of dark spots on the base of the scales. Juvenile Spotted Sucker are torpedo-shaped and resemble the White Sucker (Catostomus commersonii). Adult Spotted Sucker resemble redhorse suckers (Moxostoma spp.). The dorsal surface is brown to dark green, the sides silver to bronze and the ventral surface is white and silvery. Breeding males have two dark lateral bands separated by a pinkish band along the midside. Tubercles are present on the snout, anal fin and both lobes of the caudal fin of males. Fewer tubercles are present around the lower cheek and eye, and on the underside of the head. Figure 7. Spotted Sucker (Minytrema melanops; male). Joseph R. Tomelleri. 13

26 3.3 Populations and Distribution Distribution: Global Range (Figure 8): The Spotted Sucker is widely distributed in central and eastern North America (COSEWIC 2005a). It occurs in the drainages of lakes Huron, Michigan, Erie and St. Clair, as well as throughout much of the Mississippi River basin and along the coastal plain from Texas to North Carolina. It is known from 23 states and the province of Ontario (COSEWIC 2005a). Figure 8. Global range of the Spotted Sucker (COSEWIC 2005a). Canadian Range (Figure 9): In Canada, the Spotted Sucker is rare and found only in the extreme southwestern region of Ontario. Its first recorded capture was from Lake St. Clair in 1962 (Campbell 1994; cited in COSEWIC 2005a). Since then, the species has been recorded from Lake Erie, the Detroit River, the St. Clair River, the Sydenham River watershed and several associated tributaries, and the lower Thames River (COSEWIC 2005a). In 1996, a single specimen was caught in Maxwell Creek (Lake St. Clair drainage), which represented a new occurrence for the Spotted Sucker. Similarly, a new record for the species occurred when a single juvenile was captured from Bear Creek (North Sydenham River drainage) in 1997 (COSEWIC 2005a). In 2003, the species was caught for the first time in Whitebread Drain, a tributary of the St. Clair River (Mandrak et al. 2006). Collections in Lake Erie are restricted to the western basin, from the mouth of the Detroit River to Rondeau Bay (EERT 2008). 14

27 Figure 9. Canadian range of the Spotted Sucker. 15

28 Percent of Global Distribution in Canada: Less than 5% of the species global distribution is currently found in Canada (Dextrase et al. 2003). Population Size and Status: Global Population Size and Status: The Spotted Sucker is globally Secure (G5) (NatureServe 2008) but declines have been reported in the northern part of its range (Becker 1983). It is ranked as critically imperilled (S1) in Pennsylvania and vulnerable (S3) in Illinois, Iowa, Kansas, Michigan and Texas (NatureServe 2008). Complete national and sub-national ranks for the Spotted Sucker are listed in Table 3. Table 3. Canadian and U.S. national and sub-national ranks for Spotted Sucker (NatureServe 2008). Canada and U.S. National Rank (NX) and Provincial/State Rank (SX) Canada (N2) Ontario (S2) United States (N5) Alabama (S5), Arkansas (S4), Florida (SNR), Georgia (S5), Illinois (S3), Indiana (S4), Iowa (S3), Kansas (S3), Kentucky (S4S5), Louisiana (S5), Michigan (S3), Minnesota (SNR), Mississippi (S5), Missouri (SNR), North Carolina (S4), Ohio (SNR), Oklahoma (S4), Pennsylvania (S1), South Carolina (SNR), Tennessee (S5), Texas (S3), West Virginia (S4), Wisconsin (S5) Canadian Population Size and Status: The Spotted Sucker is ranked as imperilled (N2) in Canada (NatureServe 2008) and listed as Special Concern by the OMNR (NHIC 2008) and COSEWIC (COSEWIC 2005a). The species is also listed on Schedule 1 of the SARA as a species of Special Concern. Available information regarding population size or trends for the Spotted Sucker in Canada is limited. In 2002 and 2003, 27 Spotted Sucker were captured from 14 sites throughout the Sydenham River and nine were captured from six sites along the Detroit River (COSEWIC 2005a, Mandrak et al. 2006, Edwards et al. in press). One specimen was caught in Turkey Creek (tributary of the Detroit River) in 2003, and three specimens were caught in the Detroit River in 2004 (Edwards et al. in press). Seventeen Spotted Sucker were captured from five sites on the St. Clair River in 2004 (Edwards et al. 2006a). In 2002, nine specimens were collected from two locations along the Canard River (COSEWIC 2005a). A total of 51 Spotted Sucker have been caught in Lake St. Clair during annual OMNR trap-net surveys (surveys began in 1974), with the most recent records occurring in 2007 (three specimens caught) (M. Belore, OMNR, pers. comm. 2008). In the Thames River, Spotted Sucker was caught in 2003 at three sites located approximately 75 km upstream of historical records (COSEWIC 2005a). A single individual was caught in 2000 from western Lake Erie; it was the only record from over fish sampled during an 11-year sampling period (COSEWIC 2005a). Between 1962 and 1992, approximately 24 Spotted Sucker were captured from Canadian waters. Since 1992, approximately 67 individuals have been caught. Fifty-four of the 67 Spotted Sucker collected since 1992 were collected in 2002 and Almost all individuals collected have been adults (COSEWIC 2005a). Although Spotted Sucker captures have increased in recent years, this is believed to be a result of increased sampling effort using more efficient methods as well as improved species identification, rather than an actual increase 16

29 in species abundance. Overall, Spotted Sucker populations are believed to be stable in Canada. Nationally Significant Populations: None have been identified. 3.4 Needs of the Spotted Sucker Habitat and biological needs The Spotted Sucker typically inhabits long, deep pools of small- to medium-sized rivers over substrates of clay, gravel or sand. They have also been collected from a variety of other habitats including large rivers, oxbows and backwater areas, impoundments and small turbid creeks (COSEWIC 2005a). In Canada, Spotted Sucker has been collected from small- to medium-sized rivers such as the Thames and Sydenham rivers, large riverine habitats in the St. Clair and Detroit rivers, and along the shores of lakes Erie and St. Clair (COSEWIC 2005a). Substrates at capture sites in Ontario range from hard clays to sand, gravel and rubble (Parker and McKee 1984). Specimens have also been reported from areas with abundant aquatic macrophytes (COSEWIC 2005a) and almost all Spotted Sucker capture locations in the Detroit and St. Clair rivers in 2003 and 2004 had abundant macrophytes (Edwards et al. 2006a, Edwards et al. in press). It is believed that the species prefers clear, warm waters with low turbidity levels (Trautman 1981); however, in Canada, Spotted Sucker has been collected from rivers with moderate to high turbidity (COSEWIC 2005a). It is considered to be more tolerant of siltation than other sucker species, especially if the siltation is only intermittently heavy (Parker and McKee 1984). Spawning occurs in spring to early summer when water temperatures are between 12 and 19 C (McSwain and Gennings 1972). Spawning habitat of the Spotted Sucker is typically located in clean riffle areas (McSwain and Gennings 1972) at depths of 0 1 m over hard substrates such as rubble, gravel, sand and hard pan clay (Lane et al. 1996c). Nursery habitat is believed to be depths of 0 2 m in areas containing aquatic vegetation (Lane et al. 1996b). Juvenile and adult Spotted Sucker feed on a variety of benthic organisms such as molluscs, chironomids and small crustaceans (White and Haag 1977, COSEWIC 2005a). Larval Spotted Sucker (12 15 mm TL) feed at the surface and at mid-water on zooplankton and diatoms, and at mm TL, individuals feed over patches of sand and in the shallow backwater of creeks (White and Haag 1977) Ecological role The Spotted Sucker plays an important role in nutrient cycling it transfers energy from the benthic food web, where it feeds, to the pelagic food web, where it is preyed upon (COSEWIC 2005a). Juvenile Spotted Sucker are probably preyed upon by piscivorous birds and fishes (Parker and McKee 1984) Limiting factors As most of the range of the species is located in the United States, water temperature may be limiting its northern extent of distribution (COSEWIC 2005a). Dissolved oxygen and water temperatures may act as limiting factors to the Spotted Sucker but this has not been verified. 17

30 4.0 SPECIES INFORMATION WARMOUTH 4.1 Species Assessment Information from COSEWIC Date of Assessment: May 2005 Common Name (population): Warmouth Scientific Name: Lepomis gulosus (Cuvier, 1829) COSEWIC Status: Special Concern Reason for Designation: This species has a very restricted Canadian distribution, existing at only 4 locations along the Lake Erie shore between Point Pelee and Long Point. It is sensitive to habitat change which results in loss of aquatic vegetation. Canadian Occurrence: Ontario COSEWIC Status History: Designated Special Concern in April Status re-examined and confirmed in November 2001 and in May Last assessment based on an update status report. 4.2 Description The following description has been adapted from Trautman (1981) unless otherwise noted. The Warmouth (Lepomis gulosus Cuvier, 1829) (Figure 10) is a small to medium- sized fish that ranges from 100 to 240 mm TL (Eakins 2007). It is characterized by having a large mouth, with the posterior end of the upper jaw extending well beyond the anterior margin of the eye, usually to the centre, or beyond, in adults. Three to five dark grey or lavender bands radiate back from the snout and eye, the opercle flap is black with a red spot (adults only) on a yellow edge (Page and Burr 1991) and the pectoral fin is short, with a rounded tip. Tiny teeth are present on the tongue. Colouration is light yellow-olive to dark olive-green, with lighter vermiculations and dull bluish, purplish and golden reflections. Six to 11 chain-like, double bands of dark olive are present on the back and sides. The anal, caudal and dorsal fins are boldly vermiculated and the paired fins are unspotted and transparent or olive. A brilliant orange spot is present at the base of the posterior three dorsal rays in breeding males. The Warmouth can be distinguished from other sunfish species (Lepomis spp.) found in the Great Lakes basin by its large mouth and dark bands radiating backward from the eye. It is the only species in the genus Lepomis that has teeth on its tongue (Page and Burr 1991). The Warmouth has fewer anal fin spines (3) than crappies (Pomoxis spp., 5-7) and Rock Bass (Ambloplites rupestris, 5-7) (Trautman 1981). Figure 10. Warmouth (Lepomis gulosus). Joseph R. Tomelleri. 18

31 4.3 Populations and Distribution Distribution: Global Range (Figure 11): The Warmouth is widely distributed in the Mississippi, Atlantic and Great Lakes drainages of eastern North America. In the Mississippi drainage, it is found from the Gulf of Mexico north to Wisconsin, and from western New York in the east to New Mexico in the southwest. In the Atlantic drainage, it is found from Alabama and Florida north to North Carolina. Within the Great Lakes basin, disjunct populations are found in Illinois, Indiana, Michigan, New York, Ohio, Ontario and Wisconsin (COSEWIC 2005b). Figure 11. Global distribution of Warmouth (COSEWIC 2005b). Canadian Range (Figure 12): In Canada, Warmouth has been captured at only four main localities, all within the Lake Erie drainage. The species was first recorded in Canada in 1966 from Rondeau Provincial Park. It has subsequently been captured from Point Pelee National Park (first recorded in 1983), Long Point Bay (2004) and Big Creek National Wildlife Area (NWA; Long Point region) (2004) (Crossman and Simpson 1984, COSEWIC 2005b). In 2007, Warmouth was also detected for the first time at Turkey Point (Long Point region) (S. Staton, pers. obs.). Warmouth was also reported from Duck Creek (tributary of Lake St. Clair) (Leslie and Timmins 1998); however, the voucher specimen for this record has been lost and cannot be verified (COSEWIC 2005b). 19

32 Figure 12. Canadian distribution of Warmouth. 20

33 Percent of Global Distribution in Canada: Less than 5% of the species global distribution is currently found in Canada. Population Size and Status: Global Population Size and Status: Population estimates for Warmouth in the United States are unavailable but the species is considered globally secure (G5) (NatureServe 2008). It is ranked as imperilled (S2) in Pennsylvania and West Virginia and as vulnerable (S3) in Illinois (NatureServe 2008). Complete national and sub-national ranks for Warmouth are listed in Table 4. Table 4. Canadian and U.S. national and sub-national ranks for Warmouth (NatureServe 2008). Canada and U.S. National Rank (NX) and Provincial/State Rank (SX) Canada (N1) Ontario (S1) United States (N5) Alabama (S5), Arizona (SNA), Arkansas (S4), Delaware (SNA), District of Columbia (SNA), Florida (SNR), Georgia (S4S5), Idaho (SNA), Illinois (S3S4), Indiana (S4), Iowa (SNR), Kansas (S4S5), Kentucky (S4S5), Louisiana (S5), Maryland (S3?), Michigan (S5), Mississippi (S5), Missouri (SNR), Nevada (SNA), New Jersey (SNA), New Mexico (SNA), New York (SNA), North Carolina (S5), Ohio (SNR), Oklahoma (S5), Oregon (SNA), Pennsylvania (S2), South Carolina (SNR), Tennessee (S5), Texas (S5), Virginia (S5), Washington (SNA), West Virginia (S2), Wisconsin (S4) Canadian Population Size and Status: Warmouth is ranked as critically imperilled in Canada (N1) and Ontario (S1) (NatureServe 2008) and is listed as Special Concern by the OMNR (NHIC 2008) and COSEWIC (COSEWIC 2005b). It is also on Schedule 1 and listed as a species of Special Concern under the SARA. There are few data available regarding the size of Warmouth populations in Canada. A fish community survey of Point Pelee National Park in 2002 and 2003 captured 657 Warmouth from 87 of 117 sites (Surette 2006). Most of the specimens were juveniles and many were likely recaptures. Larger individuals were PIT-tagged (93 specimens); however, too few fish were recaptured (three specimens) to estimate the population size (Surette 2006). Since it was first captured from Rondeau Bay in 1966, only 15 specimens have been caught, eight of them in the late 1960s, two in 1999, two in 2005 and three in 2007 (COSEWIC 2005b, Edwards et al. 2006b, A. Dextrase, unpubl. data). Until 2005, only four specimens had been caught from Long Point Bay (one juvenile in 2003, and three adults at the mouth of Big Creek NWA in 2004), making it difficult to determine if an established population exists (COSEWIC 2005b). However, in 2005, 11 specimens were caught within Big Creek NWA (Marson et al. in press), providing further support for the presence of an established population. A single specimen was also caught by the OMNR in 2007 (M. Belore, pers. comm. 2008); however, a voucher specimen is not available and the record cannot be verified. In 2007, a new Warmouth record was collected at Turkey Point (Long Point region). It is possible 21

34 that this record represents a stray from Long Point Bay, as only one specimen was captured, despite intensive sampling effort. Nationally Significant Populations: Long Point Bay, Big Creek NWA, Point Pelee National Park and Rondeau Bay support the only known populations of Warmouth in Canada and should therefore be considered nationally significant. 4.4 Needs of the Warmouth Habitat and biological needs The habitat requirements of the Warmouth appear to be similar to other members of the sunfish family. It is a warmwater species that prefers vegetated habitats in lakes, streams and wetlands (Crossman et al. 1996, Scott and Crossman 1998, Coker et al. 2001, COSEWIC 2005b). In Ontario, it is found only in three coastal wetlands of Lake Erie. Adults are found in areas having depths of m, with submergent and emergent vegetation over sand or silt substrates (Page and Burr 1991, Lane et al. 1996a), which was characteristic of Canadian Warmouth capture sites (e.g., Edwards et al. 2006b). Spawning occurs in the spring or summer, when water temperatures range between C, at depths of 0 2 m (Lane et al. 1996c, NatureServe 2008). Spawning habitat is characterized as having both submergent and emergent vegetation, along with stumps, rocks or clumps of vegetation. Nests are constructed on a soft, muddy bottom, often among algae or exposed roots of vascular plants. Eggs are guarded and fanned by the male (Lane et al. 1996c, Coker et al. 2001). Nursery habitat is typically found at depths of 0 2 m and is characterized by submergent vegetation over substrates of sand, silt or gravel (Lane et al. 1996b). The Warmouth feeds in both the pelagic and benthic zones, on crustaceans and aquatic insect larvae when small, and on fishes, crayfishes and molluscs when larger (COSEWIC 2005b) Ecological role Unlike most sunfish species, Warmouth exhibits a high degree of piscivory as adults (Coker et al. 2001) and may be an important mid-level predator as an adult. Warmouth is a naturalized Canadian species, having naturally colonized Canadian waters relatively recently (Crossman et al. 1996), and its presence here may be indicative of the effects of global warming and/or a continuing range expansion following the last period of glaciation (COSEWIC 2005b) Limiting factors The current distribution of Warmouth in Canada is limited by temperature (Crossman et al. 1996). Projected future climate warming scenarios may lead to an expansion in range (Mandrak 1989). 5.0 THREATS Blackstripe Topminnow The Blackstripe Topminnow is threatened by habitat destruction, including the damage or removal of riparian vegetation (e.g., damage to the riparian vegetation by livestock access has been noted in the Sydenham watershed) and the loss or disturbance of emergent and floating aquatic macrophytes (Dextrase et al. 2003). Channelization and wetland drainage will likely have a negative impact on the Blackstripe Topminnow, and seepage from oil wells in Black Creek has also been identified as a threat to this surface-feeding species (Mandrak and Holm 2001, Dextrase et al. 2003). Although the species can be caught at the 22

35 surface using dip nets and makes a hardy aquarium fish (Mandrak and Holm 2001), there is no evidence that the pet trade in Canada is a threat to the Blackstripe Topminnow. Pugnose Minnow Erosion and associated turbidity negatively affect the densely vegetated habitats that the Pugnose Minnow prefers, and filling or drainage of riparian wetland habitats would further limit the species. Cudmore and Holm (2000) suggest that turbid water would likely reduce the effectiveness of the male s courtship display. Other potential threats have been identified by the Essex-Erie recovery team and include nutrient loading, exotic species, climate change, altered coastal processes, harvesting pressure (incidental harvest by baitfishers) and barriers to movement (EERT 2008). Spotted Sucker Habitat degradation, pollution, siltation and dams are identified as the main threats to the Spotted Sucker (COSEWIC 2005a). The degree to which turbidity limits its distribution is uncertain as well the Spotted Sucker has been collected in Canada from waters with moderate to high turbidity, but the species is generally believed to prefer clear, warm waters with low turbidity (COSEWIC 2005a). Additional potential threats to the species have been identified in the Essex-Erie Recovery Strategy and include nutrient loading, exotic species, climate change, altered coastal process and harvesting pressure (incidental harvest in the commercial fishing industry) (EERT 2008). Warmouth The Warmouth is likely threatened by the loss of its preferred habitat calm, vegetated, shallow waters (COSEWIC 2005b). Any declines in water quality, due to siltation, turbidity and other factors, would likely have a negative effect on the species. Trautman (1981) indicated that the Warmouth appears to be less tolerant than the Green Sunfish (Lepomis cyanellus) to siltation and turbidity where their ranges overlap. The Warmouth is abundant at Point Pelee National Park but is absent from Hillman Marsh (adjacent to Point Pelee National Park), while the Green Sunfish is present at Hillman Marsh and absent from Point Pelee National Park. It is not clear if this is a result of interspecific competition (both species exhibit a high degree of piscivory as adults, unlike other species in the genus Lepomis), abiotic factors (e.g., turbidity levels) or different colonization histories (COSEWIC 2005b). Additional potential threats to the species have been identified in the Essex-Erie Recovery Strategy and include nutrient loading, toxic compounds, exotic species, climate change, altered coastal processes and barriers to movement (EERT 2008). As the Warmouth is found only in wetland habitats in Ontario, this has implications for the management of the nearshore areas of Lake Erie. Any management activities that result in the degradation of wetland habitats may have a negative impact on the Warmouth. 5.1 Threat classification Table 5 summarizes all known and suspected threats to the Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth in Canada. The threat classification parameters are defined as follows: Extent spatial extent of the threat in the waterbody (widespread/localized) Frequency the frequency with which the threat occurs in the waterbody (seasonal/continuous) Causal Certainty the level of certainty that it is a threat to the species (High H, Medium M, Low - L) Severity the severity of the threat in the waterbody (H/M/L) 23

36 Overall Level of Concern composite level of concern regarding the threat to the species (H/M/L) Table 5. Threat classification table (threat information comes from species-specific COSEWIC reports; additional information adapted from Dextrase et al. [2003] for the Blackstripe Topminnow, and the Essex-Erie Recovery Team [2008] for the remaining species). Specific Threat Extent (widespread/localized) Frequency (seasonal/continuous) Causal Certainty (high, medium, low) Severity (high, medium, low) Overall Level of Concern (high, medium, low) Blackstripe Topminnow Habitat Loss and Degradation Widespread Continuous High Unknown Medium Oil seepage Localized Seasonal Low Unknown Low Channelization Unknown Unknown Unknown Unknown Unknown Pugnose Minnow Habitat Loss and Degradation Widespread Continuous High High High Sediment Loadings Widespread Continuous High High High Nutrient Loadings Widespread Seasonal High High High Exotic Species Widespread Continuous Low High Medium Altered Coastal Processes Widespread Continuous Unknown Unknown Unknown Climate Change Widespread Continuous Low Medium Medium Incidental Harvest Unknown Unknown Unknown Unknown Unknown Barriers to Movement Unknown Unknown Unknown Unknown Unknown Spotted Sucker Habitat Loss and Degradation Widespread Continuous High High Medium Sediment Loadings Widespread Continuous Medium High Medium Nutrient Loadings Widespread Continuous High High Medium Exotic Species Widespread Continuous Low High Medium Barriers to Movement Localized Continuous Unknown Unknown Unknown Altered Coastal Processes Widespread Continuous Unknown Unknown Unknown Toxic Compounds Widespread Continuous Unknown Unknown Unknown Climate Change Widespread Continuous Low Medium Low Incidental Harvest Localized Seasonal Low Low Low Warmouth Habitat Loss and Degradation Widespread Continuous High Medium Medium Sediment Loadings Widespread Continuous High Medium Medium Nutrient Loadings Widespread Continuous High Medium Medium Exotic Species Widespread Continuous Low High Medium Altered Coastal Processes Widespread Continuous Unknown Unknown Unknown Climate Change Widespread Continuous Low Medium Medium Toxic Compounds Unknown Seasonal Low Unknown Low Barriers to Movement Localized Continuous Low Unknown Low Changes to Trophic Dynamics Localized Unknown Low Unknown Low 24

37 5.2 Description of threats The following descriptions have been adapted primarily from the Essex-Erie Recovery Strategy (EERT 2008) Habitat Loss and Degradation The loss of wetland and riparian forest habitats across southern Ontario has been dramatic since the late 1800s. Continued development of wetlands is a concern, primarily for those wetlands without protection from development pressures. Habitat loss in the form of lake and river shoreline modifications (e.g., shoreline stabilization projects, docks, marinas) along Lake St. Clair, the Detroit River and Lake Erie are also a significant and ongoing concern. Modification of inland watercourses through subsurface and surface drainage activities has also negatively affected hydrological networks, and reduced the extent and quality of aquatic habitat. Livestock access to watercourses in both the Sydenham and Thames watersheds has resulted in the destruction of important riparian habitats that provide cover and a source of food for many fish species, in particular the Blackstripe Topminnow (in the Sydenham River). Riparian strips have also been destroyed in recreational or urban areas, more so in the Thames River watershed, where the grass is often mowed to the edge of the waterway (TRRT 2005) Sediment Loading Sediment loading affects aquatic habitats through decreasing water clarity, increasing siltation of substrates, and may have a role in the selective transport of pollutants, including phosphorus. Increasing turbidity, as a result of sediment loading, can reduce the amount of aquatic vegetation present, as sunlight cannot penetrate far into the water. This can have detrimental impacts on species that rely on dense growths of submerged macrophytes, such as the Pugnose Minnow and the Warmouth. Sediment loading, and resulting turbidity and siltation, can impact species by affecting their respiration, vision and prey abundance, and smothering eggs deposited on the substrate Nutrient Loading Nutrients (nitrates and phosphates) enter waterbodies through a variety of pathways, including manure and fertilizer applications to farmland; manure spills; sewage treatment plants; and, faulty domestic septic systems. Nutrient enrichment of waterways can negatively influence aquatic health through algal blooms and associated reduced dissolved oxygen concentrations. Elevated nutrient concentrations may be contributing to the decline of aquatic species at risk, reductions in their distribution, or may be preventing them from expanding their distribution. The persistent, elevated concentrations of total phosphorus and apparent trend of increasing nitrate ion concentrations in waterbodies such as the Sydenham and Thames rivers suggest that this is an ongoing problem Exotic Species Exotic species may affect the four species through several different pathways, including: direct competition for space and habitat; competition for food; and, restructuring of aquatic food webs. There are now at least 182 exotic species that have invaded the Great Lakes basin since 1840 (Ricciardi 2006), and at least some of these species will affect populations of these four species at risk to some extent. Dextrase and Mandrak (2006) indicate that while habitat loss and degradation is the predominant threat affecting aquatic species at risk, exotic species are the second most prevalent threat, affecting 26 of 41 federally-listed species across Canada. The Common Carp (Cyprinus carpio), Round Goby (Neogobius melanostomus) and Zebra Mussel (Dreissena polymorpha) are three exotic species that have had a dramatic effect on many aquatic species at risk, and will continue to alter ecosystems and ecosystem processes. Exotic 25

38 species are also a concern for coastal wetlands in that they can significantly change marsh vegetation communities. Two species of particular concern include common reed grass (Phragmites australis) and purple loosestrife (Lythrum salicaria) Altered Coastal Processes Natural coastal processes that occur near the shorelines, along lakes and large rivers, include sediment erosion and deposition that provide and maintain habitat for fishes. Much of the shoreline habitat along Lake St. Clair and the Detroit River has been artificially hardened, filled, dredged and modified for human use. In addition, the Detroit River itself has been significantly altered through the creation of shipping lanes, which resulted in the deepening of the channel, the creation of artificially hardened shoreline walls, and the modification of flow patterns in the river. As a result, the natural processes of erosion and deposition along the St. Clair River - Detroit River corridor have been altered. The Pugnose Minnow (found in the Detroit River) and Spotted Sucker (Detroit and St. Clair rivers) could be negatively impacted by these alterations. Similarly, along the Lake Erie coastline, hardening of shorelines, the creation of artificial dykes for coastal wetlands, and the creation of marinas and infill developments have affected natural shoreline processes. This may have more of a negative impact on species that are found in coastal wetlands such as the Warmouth. Historical sand and gravel mining operations at various locations offshore in Lake Erie began over a century ago and may have affected coastal processes necessary for maintaining suitable, nearshore habitat conditions. Based on an extensive review of documents and permits, it was estimated that 3.9 million m 3 of sand and gravel was extracted between 1910 and 1984 in the immediate vicinity of Point Pelee National Park (Baird & Associates 2007). A review of the operations in this area was conducted to assess their significance to the stability of the shoreline of the Park and the nearshore and shoreline areas to the north (Baird & Associates 2005, 2007). The areas most affected by the sand mining have been the shoreline of the National Park and the historical sand spit. The mining of the historical sand spit, and, to a lesser degree the mining on the shoal have removed the underwater foundation for the beaches of Point Pelee National Park. The tip of the park is now surrounded by deep water, which allows large waves to erode the shoreline during storm events (Baird & Associates 2007). Little is known about the impacts of shoreline alteration on natural coastal processes in the Great Lakes basin (Goforth and Carman 2003) and, thus, additional research is required to clarify this threat Climate Change Climate change is expected to have significant effects on aquatic communities of the Great Lakes basin through several mechanisms, including increases in water and air temperatures; lowering of water levels; shortening of the duration of ice cover; increases in the frequency of extreme weather events; emergence of diseases; and, shifts in predator-prey dynamics (Lemmen and Warren 2004). Additionally, warming trends, as a result of climate change, may favour the establishment of potentially harmful exotic species that may currently be limited by cooler water temperatures. It is anticipated that the effects of climate change will be widespread and should be considered a contributing impact to species at risk and all habitats. In a recent assessment of the projected impacts of climate change on coastal wetland fish assemblages in the Lower Great Lakes, Doka et al. (2006) predicted that several fishes at risk would be the most vulnerable. The results indicated that two of the four Special Concern species ranked as highly vulnerable to climate-induced changes in coastal wetlands and nearshore temperatures: Pugnose Minnow (1 st out of 99 fishes assessed) and Warmouth (2 nd ); 26

39 the Spotted Sucker ranked 42 nd (medium vulnerability). In this study, vulnerabilities were based on an assessment of climate change risk associated with coastal wetland and thermal preferences for different life-stages as well as species distributions. Not all of the effects of climate change will negatively affect species at risk. As all four species may be limited in their range by cool water temperatures (particularly Warmouth), it is possible that climate change may allow them to expand their distributions. The Blackstripe Topminnow may benefit the most as a result of warming trends as it is not a wetland species and it has a relatively high tolerance to impaired habitat conditions (e.g., low dissolved oxygen, high turbidity). However, a suite of reactions related to expected changes in evaporation patterns, vegetation communities, lower lake levels, increased intensity and frequency of storms, and decreases in summer stream water levels may offset the direct benefits of increased temperatures. Climate change will have wide reaching effects both directly to fishes and other aquatic and semi-aquatic species that depend on wetlands. Identifying mitigation measures to adapt to and prevent negative implications as a result of climate change will require coordination with other agencies for research, implementation of recommended mitigation measures, and monitoring Toxic Compounds Pesticides (e.g., herbicides, insecticides) associated with agricultural practices and urban areas enter the watershed through runoff and could have significant impacts on species at risk. Roads and urban areas can also contribute contaminants to watersheds, including oil and grease, heavy metals and chlorides (Dextrase et al. 2003). No specific information is available on the direct impact of any contaminants and/or pesticides on any of the four fishes at risk discussed here. The presence of at least one of a suite of chemicals found in excess of the provincial and/or federal guidelines for the protection of aquatic life within almost all watercourses sampled within the Essex-Erie region (three of the four Special Concern species are found in this region) is of concern (Nelson 2006). As well, several contaminants are widely distributed in sediments across the region in concentrations exceeding provincial and/or federal guidelines (Dove et al. 2002). The specific impacts of these chemicals on the life-history processes of each species at risk may not be a direct cause of the mortality of the individual, but cumulative impacts are of concern Incidental Harvest Fishery activities that indirectly impact species at risk can have a negative effect on their populations. Of concern are the incidental by-catch of fishes in recreational angling, commercial baitfish, and commercial fishery operations. Baitfish harvesting is regulated in Ontario and a list of legal baitfish is updated based on the current list of Schedule 1 species at risk (Cudmore and Mandrak 2005). The Blackstripe Topminnow, Pugnose Minnow, Spotted Sucker and Warmouth are not legal baitfishes in Ontario (OMNR 2008). Continued monitoring of commercial baitfish harvesting permits and operations, and commercial fishing operations in Lake St. Clair and Lake Erie by the OMNR is essential. Two of the four species may be impacted to some degree by incidental harvest: Pugnose Minnow (baitfish industry) and Spotted Sucker (commercial/recreational fishing). Additionally, the Warmouth may be mistaken for other Lepomis spp. by recreational fishermen; however, the extent to which this may occur and the impact on the species is not known Barriers to Movement Three types of barriers to fish movement are found in southwestern Ontario: (1) dams and weirs; (2) pumped watercourses; and, (3) dyked wetlands. Several watercourses that drain into Lake St. Clair have pumps to ensure proper drainage of inland tributaries and drains. It is not 27

40 clear to what degree these pumps restrict access to fishes in these watercourses. Site-specific conditions may afford protection for some species from competitors, exotic species and predators; however, the barriers may prevent access to suitable habitat and lead to fragmentation of populations. The only wetland with an artificially maintained barrier within the range of the four species is at Big Creek NWA (Long Point region), which has a dyked cell within the NWA. This may have a negative impact on the Warmouth, which has been caught within this cell (Marson et al. in press), by preventing immigration and/or emigration into and from the cell. The Blackstripe Topminnow and Pugnose Minnow have recently (2003) been captured from a pumped watercourse, Whitebread drain, and it is possible that the maintenance of water levels in the drain could have a negative effect on these species Changes to Trophic Dynamics Periodic breaches of the barrier beach between Point Pelee National Park marshes and Lake Erie may allow for the introduction of species that could lead to changes in trophic dynamics within the protected marsh complex (Surette 2006). Breaching may be more frequent now than in the past due to the amount and rate of erosion resulting from shoreline hardening north of the park boundaries. This could have a negative effect on the Warmouth population at Point Pelee National Park, which is the healthiest population in Canada. 5.3 Actions Already Completed or Underway Ecosystem-based recovery strategies Several ecosystem-based recovery strategies have been developed that include at least two of the four species (Table 6, Figure 13): Essex-Erie Recovery Strategy: The goal of the Essex-Erie Recovery Strategy is, to maintain and restore ecosystem quality and function in the Essex-Erie region to support viable populations of fish species at risk, across their current and former range (EERT 2008). Included in this strategy are recovery/management initiatives for the Pugnose Minnow, Spotted Sucker and Warmouth as well as 11 other fish species at risk. Through this initiative, recovery actions are directed towards five primary core areas based on the presence of multiple, extant, populations of high priority fishes at risk. These core areas include many populations of the four species discussed here, including all three coastal wetlands that contain Warmouth populations. Sydenham River Ecosystem Recovery Strategy: The primary objective of the Sydenham River Recovery Strategy is to, sustain and enhance the native aquatic communities of the Sydenham River through an ecosystem approach that focuses on species at risk (Dextrase et al. 2003). The recovery strategy focuses on the 16 aquatic species at risk within the basin, including the Blackstripe Topminnow, Pugnose Minnow and Spotted Sucker. Thames River Ecosystem Recovery Strategy: The goal of the Thames River Recovery Strategy is to develop, a recovery plan that improves the status of all aquatic species at risk in the Thames River through an ecosystem approach that sustains and enhances all native aquatic communities (TRRT 2005). Twenty-five aquatic species at risk are included in this strategy, including the Pugnose Minnow and Spotted Sucker. 28

41 Table 6. Existing ecosystem-based recovery strategies that include two or more of the four Special Concern species (check indicates species inclusion in recovery strategy). Species Essex-Erie Sydenham River Thames River Blackstripe Topminnow Pugnose Minnow Spotted Sucker Warmouth Figure 13. Location of watershed-based species at risk recovery programs. Adapted from the Essex-Erie Recovery Strategy (EERT 2008). Stewardship and Awareness Initiatives: There are a number of stewardship and awareness initiatives that are ongoing or have been completed by various ecosystem-based recovery teams, and their partners, in southwestern Ontario. These initiatives include habitat improvement projects and threat mitigation measures that are relevant to the conservation and management of the four species. Conservation authorities, provincial stewardship councils, Ontario Parks, local field naturalist and non-government groups, Environment Canada and Parks Canada Agency are all involved in local initiatives that have an impact on species at risk. Conservation authorities and stewardship councils have been, and continue to be, involved in a number of habitat restoration projects. The types of projects include: tree planting; wetland 29