Post by Melanie on Aug 11, 2009 14:04:15 GMT
still listed as extinct in the IUCN redlist but seems to be rediscovered
Based on recent collections in Wisconsin (Lillie et al. 1987, Lillie 1992, 1995), this species may be more abundant in sand bottomed rivers in the Midwest and Southeast than has been represented historically. This is probably due to the special methods required for sampling the rapid-swimming, sand dweller larvae of this species (see McCafferty 1991). The current global ranking appears warranted, and the species should continue to be considered potentially vulnerable to habitat alteration.
Global Abundance: Unknown
Global Abundance Comments: There are no estimations of abundance available.
Estimated Number of Element Occurrences: 1 - 5
Estimated Number of Element Occurrences Comments: Only three known exant occurrances in WI. The species is considered historical in IL. This species was also collected in 1983 from South Carolina and Georgia (McCafferty pers. comm. 1994; Sweeny pers. comm. 1994). McCafferty (1991) suggested that at least part of this species rarity is due to difficulty in sampling.
Global Short Term Trend: Unknown
Global Short Term Trend Comments: At this point, there is no data available on trends.
Global Inventory Needs: Surveys are urgently needed to determine population status where the species has been found and to attempt to locate other extant populations.
Global Protection: Few (1-3) occurrences appropriately protected and managed
Global Protection Comments: The lower Wisconsin River is designated as a Scenic and Wild State Riverway (Lillie pers. comm. 1994).
Global Protection Needs: The Wisconsin occurrences need to be protected from habitat degradation. Habitat alteration projects should be discontinued until impacts to the mayfly are better understood.
Degree of Threat: B
Threats: Little is known about this species, but degradation of river habitats and changes in hydrology are probably the main threats to its survival. Dredging may have contributed to the apparent extirpation from the Illinois sites (Lillie et al. 1987). Dams on the Wisconsin and Chippewa rivers, along with periodic droughts, can cause low flows and expose the species' sand-bottomed habitats and/or alter currents and food availability (Schmude pers. comm. 1994).
Fragility Comments: This species tolerance of environmental change is largely unknown. The species is probably vulnerable to hydrological changes and degradation of water quality. Dredging appears to have contributed to the extirpation of the species in Illinois (Lillie et al. 1987).
Other Considerations: In 1983, specimens were found in Georgia and South Carolina. The current status of these populations is unknown (Sweeny pers. comm. 1994).
www.natureserve.org
Based on recent collections in Wisconsin (Lillie et al. 1987, Lillie 1992, 1995), this species may be more abundant in sand bottomed rivers in the Midwest and Southeast than has been represented historically. This is probably due to the special methods required for sampling the rapid-swimming, sand dweller larvae of this species (see McCafferty 1991). The current global ranking appears warranted, and the species should continue to be considered potentially vulnerable to habitat alteration.
Global Abundance: Unknown
Global Abundance Comments: There are no estimations of abundance available.
Estimated Number of Element Occurrences: 1 - 5
Estimated Number of Element Occurrences Comments: Only three known exant occurrances in WI. The species is considered historical in IL. This species was also collected in 1983 from South Carolina and Georgia (McCafferty pers. comm. 1994; Sweeny pers. comm. 1994). McCafferty (1991) suggested that at least part of this species rarity is due to difficulty in sampling.
Global Short Term Trend: Unknown
Global Short Term Trend Comments: At this point, there is no data available on trends.
Global Inventory Needs: Surveys are urgently needed to determine population status where the species has been found and to attempt to locate other extant populations.
Global Protection: Few (1-3) occurrences appropriately protected and managed
Global Protection Comments: The lower Wisconsin River is designated as a Scenic and Wild State Riverway (Lillie pers. comm. 1994).
Global Protection Needs: The Wisconsin occurrences need to be protected from habitat degradation. Habitat alteration projects should be discontinued until impacts to the mayfly are better understood.
Degree of Threat: B
Threats: Little is known about this species, but degradation of river habitats and changes in hydrology are probably the main threats to its survival. Dredging may have contributed to the apparent extirpation from the Illinois sites (Lillie et al. 1987). Dams on the Wisconsin and Chippewa rivers, along with periodic droughts, can cause low flows and expose the species' sand-bottomed habitats and/or alter currents and food availability (Schmude pers. comm. 1994).
Fragility Comments: This species tolerance of environmental change is largely unknown. The species is probably vulnerable to hydrological changes and degradation of water quality. Dredging appears to have contributed to the extirpation of the species in Illinois (Lillie et al. 1987).
Other Considerations: In 1983, specimens were found in Georgia and South Carolina. The current status of these populations is unknown (Sweeny pers. comm. 1994).
www.natureserve.org
