Salamander Mussel Natural Diversity Section April 2015
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Species Action Plan Salamander Mussel Natural Diversity Section April 2015 Species Action Plan: Salamander Mussel (Simpsonaias ambigua) Purpose and Goals Salamander Mussel (Simpsonaias ambigua): Photo credit: Karen Little, Illinois State Museum. Purpose: This Species Action Plan is an initial Mussel in the Commonwealth, to ensure five-year blueprint for actions to address near- sufficient distribution, term and long-term goals for the conservation To adequately secure the species and, and recovery of the Salamander Mussel. Given Secure its populations and remove this the complexity of managing and recovering this species from the list of Pennsylvania species, as new information becomes available, endangered species (58 Pa. Code §75.1). this document plan will be updated to reflect progress toward these goals. This plan also Natural History supports the 2015 Pennsylvania Wildlife Action Plan (PA-SWAP) by specifically addressing the Taxonomy: Class Bivalvia, Order Unionoida, following goals: GOAL 1. Conserve Family Unionidae (unionids), Salamander Pennsylvania's native wildlife and its habitat by Mussel (Simpsonaias ambigua, Say, 1825). See implementing conservation actions in the Watters et al. (2009) for synonymy. Wildlife Action Plan. GOAL 2. Base wildlife Description: Parmalee and Bogan (1998) conservation decisions on the best available describe the shell characteristics as “thin, fragile, science, with an emphasis on Species of Greatest considerably elongated, and inflated, especially Conservation Need and its habitat, and GOAL 5. along the broadly rounded posterior ridge, which Develop a knowledgeable citizenry that supports is sometimes more swollen in females. This is a and participates in wildlife conservation. small species – individuals rarely exceed 50 mm Several Objectives and Strategies within these in length.” The shell noticeably lacks rays and is goals are also addressed. This Species Action differentiated from similar-looking Anodontine Plan (SAP) also includes a description of the genera Anodontoides, Pyganodon, and species natural history, its distribution and Strophitus by having rudimentary cardinal teeth threats that have led to its rarity or imperilment. (Watters et al. 2009). Goals: The goals of this Species Action Plan are Habitat: The Salamander Mussel is found in to: riverine conditions underneath flat shelter rocks Guide the maintenance and protection of where it typically co-occurs with its only known extant populations of Salamander host, the Mudpuppy salamander (Necturus maculosus). P a g e | 1 Species Action Plan Salamander Mussel Natural Diversity Section April 2015 Life History: The maximum age of Salamander Mussel is approximately 10 years, although most individuals collected have been around 4-5 years of age (Watters et al. 2009). The Salamander Mussel is a long- term brooder (bradytictic) and releases its glochidia (larvae) in the fall. The mechanism that triggers glochidial release onto its only known host, the mudpuppy, is unknown. The glochidia metamorphose into juveniles in the spring. The Salamander Mussel diet is unknown, but presumed to be bacteria, detritus, phytoplankton, and zooplankton. The Figure 1. National range and conservation status of Simpsonais Salamander Mussel is the only ambigua. North American unionid that uses an amphibian host. Pennsylvania Legal Status: Endangered Distribution and Status State Rank: S1 – Critically Imperiled Global Status: G3 – Vulnerable National Distribution: The Salamander Mussel is restricted to North American streams and rivers in the Great Lakes and the Mississippi River and Ohio River basins of the following states: 5 by D. Tanner (1968) and D. Stansbery (1970) Arkansas, Illinois, Indiana, Iowa, Kentucky, (Clarke 1985). Presently, the only extant Michigan, Minnesota, Missouri, New York, Salamander Mussel population occurs in the Ohio, Pennsylvania, Tennessee, West Virginia, Allegheny River. Since the first collections of Wisconsin and Ontario, Canada (NatureServe this species in Pennsylvania in the late 1960’s, a 2012) (Figure 1). total of three Allegheny River navigational pools (5, 6, and 8) are known to harbor Salamander Pennsylvania Distribution: Little is known Mussels (EnviroScience 2007; Aquatic Systems about the historical distribution of this species in 2008; USFWS 2008; Smith and Meyer 2010; Pennsylvania. Early surveys (e.g., Ortmann Swecker 2013). A shell of this species was 1919) did not detect this species. The first recently found in Pool 9 (D. Counahan, personal occurrence of this species in Pennsylvania are communication). specimens collected from Allegheny River pool The Salamander Mussel also occurs in the Great P a g e | 2 Species Action Plan Salamander Mussel Natural Diversity Section April 2015 Lakes basin including Ohio tributaries to Lake analysis of occupied streams. Historical Erie (Watters et al. 2009). A specimen was populations can include yet-undiscovered recently found in the Ohio portion of Conneaut populations. Populations that contain at least Creek (Crail, personal communication). three distinct year classes and a minimum number of individuals will be considered viable. Two shell specimens were collected from A viable population is defined as a naturally French Creek in 1985 and 1995 by C. Bier reproducing population large enough to (Western Pennsylvania Conservancy). Despite maintain sufficient genetic variation to enable it intensive surveys of French Creek and its to evolve and respond to natural environmental tributaries (e.g., Smith and Crabtree 2010), no changes (Soule 1980). live Salamander Mussels have been collected from this watershed. Management Status The Salamander Mussel was known to occur in The Allegheny River, French Creek (Ohio River Dunkard Creek prior to a 2009 pollution event Basin), Dunkard Creek, and Conneaut Creek which destroyed the Dunkard Creek mussel have been surveyed in recent times. fauna (Zeto 1982; Wood 1994; PFBC unpublished data). Population trends: In the absence of other information, the status of the Allegheny River The Salamander Mussel will be considered for population is presumed stable. The status of the delisting when 80% of the historically-occupied French Creek population is presumed extirpated streams contain three distinct naturally- because evidence of this species occurrence in reproduced year classes (PABS Bivalve French Creek has not been observed since 1995 Committee listing criteria) and a minimum (see above). The Dunkard Creek mussel number of individuals in each stream. A population was destroyed by a 2009 toxic event. minimum number will be determined after No live specimens of this species have ever been collected from the Pennsylvania portion of Conneaut Creek. Threats Historical threats have resulted in a decline of Pennsylvania’s Salamander Mussel populations. Due to the historical and recent distribution of Salamander Mussels over a geologically and land-use diverse Pennsylvania landscape, qualitative uncertainty ranges were used to measure the scope of threats facing this species. Figure 2. Salamander Mussel historic and extant occupied watersheds in Pennsylvania. Existing and possible future threats (Salafsky et al. 2008) to the P a g e | 3 Species Action Plan Salamander Mussel Natural Diversity Section April 2015 Salamander Mussel include the following: industrial accident although the scope and severity of this particular risk is 1. Energy production and mining unpredictable. A single catastrophic pollution event could destroy a. Mining and quarrying Pennsylvania’s only remaining Despite the relocation of several Salamander Mussel population in the Salamander Mussels, commercial sand Allegheny River. and gravel dredging activities in Allegheny River pool 5 have recently resulted in loss of habitat for both Conservation and Salamander Mussel and Mudpuppies and Recovery Actions presumably some level of Salamander A. Allegheny River Mussel mortality may have occurred as a result of these activities. 1. Protect, conserve and enhance existing 2. Transportation and service corridors Salamander Mussel populations located in pools 5, 6, 8 and 9. a. Utility and service lines a. Gather baseline information Threats associated with pipeline crossings i. Characterize Salamander Mussel could be locally severe; however, severity populations. is reduced when stream crossings are 1. Collect the following quantitative accomplished using directional boring population demographic methods. Directional boring is preferred information: where feasible despite some risk a. Shell lengths, widths, depths. associated with bentonite spills that can be b. Determine gravidity period for associated with directional bores. These Pennsylvania. events can lead to the smothering of c. Ratio of gravid/nongravid (using mussels or the choking of interstitial non-lethal methods). spaces and/or shelter rock habitat. d. Number of individuals. Consultations for the recent discovery of e. Density, if practical. Rayed Bean (Villosa fabalis, a state and f. Number of individuals found federally threatened mussel species) in the under each rock structure that can Salamander Mussel-inhabited Allegheny be surveyed. River (pool 5) may also limit the risk of ii. Quantitatively and qualitatively pipeline crossings to freshwater mussels. characterize physical habitat. 1. Measure streamflow, water 3. Pollution chemistry at known locations. a. Industrial and military effluents. 2. Measure length, width, depth of Generally, freshwater mussels are occupied rock structures. vulnerable to point-source