Pighead prickleback COSEWIC assessment and status report: chapter 8

Limiting Factors and Threats

Pighead pricklebacks may be especially vulnerable to artificial dredging of basins used to accommodate ships, and to oilrigs or pipelines carrying oil to ships from offshore oil wells if there is spillage of contaminants. Freshwater flooding in spring, or by human diversion of rivers, could be a threat to their habitat as pighead pricklebacks require access to salinity. In Tuktoyaktuk Harbour, pigheads are taken almost exclusively in otter trawls towed in deeper saline water; salinities may be near 0.5% at 0 to 6 m depths but 25 to 30% at the 10 to 20 m depths where they are captured (Hopky and Ratynski 1983). Fishing may also impact populations; Doug Chiperzak (pers. comm. Dec. 10, 2001) noted a gill net-caught specimen taken by a local fisherman in very shallow water in Tuktoyaktuk Harbour.

Long-term habitat issues of global warming (i.e., loss of nearby permafrost ice within pingos and beneath tundra eroding shorelines) and potential accidents of the oil industry (heavier oils sinking to becoming trapped in deeper basins) suggest potential vulnerability for localized pighead populations.

Page details

Date modified: