Castleguard Cave (100117)
Canada, North America
Site overview
KBA status: confirmed
Global KBA criteria: A1a, A1e, B1
Year of last assessment: 2022
National site name: Castleguard Cave
Central coordinates: Latitude: 52.0938, Longitude: -117.2265
System: subterranean, terrestrial, freshwater
Area of KBA (km2): 131.95198
Protected area coverage (%): 99.96
KBA classification: Global
Legacy site: No
Site details
Site description: Castleguard Cave is a limestone cave located in Banff National Park, AB. Featuring over 21.3 km of surveyed passages, it is currently Canada's longest known cave system (Ford DC, Smart CC. 2017. Castleguard Cave and Karst, Columbia Icefield, Alberta and British Columbia, in Slaymaker, O., ed., Landscapes and Landforms of Western Canada: Springer, Switzerland, 227–239.) and a globally significant solutional cave complex. Formed by glacial drainage from the overlying Columbia Icefield, the cave lies within the Cathedral Formation limestone with a portion in the overlying Stephen Formation (a shale-dominated rock formation with interbedded limestone). The entrance zone of the cave has a high risk of flooding. For safety reasons, expeditions are limited to early to mid winter and access typically requires a 20 km remote ski journey. Parks Canada has restricted access to the cave since the early 1970s (Vokáč, M. 2006. Castleguard Cave 2005. First ascent of the 200-foot aven. The Canadian Caver.).
Rationale for qualifying as KBA: The Castleguard Cave Stygobromid (Stygobromus canadensis) is a freshwater amphipod crustacean found only in the subterranean environment of Castleguard Cave, where it evidently survived glaciation of the surrounding landscape during the last ice age (the Wisconsinan glaciation) (Zacharda M, Pugsley CW. 1988. Robustocheles occulta sp.n., a new troglobitic mite (Acari: Prostigmata: Rhagidiidae) from North American caves. Can. J. Zool. 66, 646–650.). Entirely blind and unpigmented, the Castleguard Cave Stygobromid is a unique and special part of Alberta's invertebrate fauna, and lives in a very cold, nutrient impoverished aquatic environment fed by glacial melt waters. While its evolutionary history, life cycle, diet, and other habits are still poorly understood, chronological studies of speleothems (solutional features that include stalagmites and stalactites) demonstrate that the cave's interior has remained intact and ice-free for at least 700,000 years (Zacharda M, Pugsley CW. 1988. Robustocheles occulta sp.n., a new troglobitic mite (Acari: Prostigmata: Rhagidiidae) from North American caves. Can. J. Zool. 66, 646–650.), suggesting that its very long and stable geological history may have facilitated adaptation and speciation of its fauna. Protecting this species is important to preserve and augment our knowledge of Pleistocene refugia and glacial relics (Holsinger JR. 1980. Stygobromus canadensis, a new subterranean amphipod crustacean (Crangonyctidae) from Canada, with remarks on Wisconsin refugia. Can. J. Zool. 58, 290–297.). A potential national KBA trigger species, a cave obligate isopod (Salmasellus steganothrix), is suspected from the cave as well as several others in Canada (Greg Horne, pers. comm.). However, this taxon may actually be conspecific and further surveys of Castleguard and elsewhere would likely be necessary to clarify the situation and potentially elevate this cave obligate isopod to trigger species status (Jerry Lewis, pers. comm.).
Additional biodiversity: Although not known from within the precise proposed boundaries of this KBA, other noteworthy biodiversity reported from the vicinity of Castleguard Mountain and area includes the moss species Short-nerved Nodding Moss (Pohlia brevinervis) (G1/N1) and Porsild's Braya (Braya humilis ssp. porsildii) (T3/N3). Castleguard Cave is also one of only a handful of known sites of a troglobitic cave mite species, a cave obligate mite (Robustocheles occulta) (Zacharda M, Pugsley CW. 1988. Robustocheles occulta sp.n., a new troglobitic mite (Acari: Prostigmata: Rhagidiidae) from North American caves. Can. J. Zool. 66, 646–650.). Apart from its unique biological diversity, the cave also includes one of only four known examples in the world of highly unusual nearly cubical 'cave pearls' (Ford DC, Smart CC. 2017. Castleguard Cave and Karst, Columbia Icefield, Alberta and British Columbia, in Slaymaker, O., ed., Landscapes and Landforms of Western Canada: Springer, Switzerland, 227–239.). Taxa assessed against national KBA criteria in Canada, but that did not meet criteria: a cave obligate isopod (Salmasellus steganothrix)
Manageability of the site: The site is entirely managed by Parks Canada, and is generally well protected at least from local threats.
Other site values: Treaty 8 Territory
Delineation rationale: The delineation proposed has been developed through multiple rounds of discussion with Parks Canada staff. Initially, the proposed delineation followed a buffered outline of the actual cave footprint (digitized from available maps). Because of the cave's origin as a hydrological/solutional feature, it was decided to propose the KBA's outer boundaries based on the small watershed that includes it and ultimately provides the inflow of water to the area. The cave boundary shape itself (the best available proxy for the known habitat of all contained species) has also been incorporated in the KBA proposal as an internal site boundary. The boundary was further refined after consultation with Chris Smart, who suggested that it be expanded slightly to the north to incorporate the bedrock catchment of all known springs and add possible areas outside where the Cathedral Limestone may allow groundwater recharge into the cave catchment. A small additional modification was made to this proposal for simplicity of administration to clip the boundary to the BC and Banff/Jasper boundaries somewhat.
Habitats
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Caves & Subterranean Habitats (non-aquatic) | 50 | |
| Rocky Areas(e.g., inland cliffs, mountain peaks) | 50 |
Threats
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Climate change & severe weather | Storms & flooding | Ongoing | |
| Human intrusions & disturbance | Work & other activities | Ongoing | |
| Natural system modifications | Fire & fire suppression | Unknown | |
| Pollution | Air-borne pollutants | Unknown |