Shortfin mako (Isurus oxyrinchus) COSEWIC assessment and status report: chapter 1

Assessment Summary – April 2006

Common name : Shortfin mako

Scientific name : Isurus oxyrinchus

Status : Threatened

Reason for designation : As a large (maximum length 4.2 m), relatively late-maturing (7-8 yrs) pelagic shark, the species has life-history characteristics making it particularly susceptible to increased mortality from all sources, including human activities. The species is circumglobal in temperate and tropical waters. Individuals found in Atlantic Canada are considered part of a larger North Atlantic population. There does not appear to be any reason to assume that the Canadian Atlantic "population" is demographically or genetically independent from the larger Atlantic population, so the status of the species in Atlantic Canada should reflect the status throughout the North Atlantic. Although there is no decline in an indicator of status for the portion of the species that is in Atlantic Canada, two analyses suggest recent declines in the North Atlantic as a whole (40% 1986-2001; 50% 1971-2003). The main causes of the species' decline (mortality due to bycatch in longline and other fisheries) are understood and potentially reversible, but these sources of mortality have not been adequately reduced. 

Occurrence : Atlantic Ocean

Status history : Designated Threatened in April 2006. Assessment based on a new status report.