Shortfin Mako Atlantic population
Scientific Name: Isurus oxyrinchus
Taxonomy Group: Fishes
COSEWIC Range: Quebec, New Brunswick, Prince Edward Island, Nova Scotia, Newfoundland and Labrador, Atlantic Ocean
COSEWIC Assessment Date and Status Change: May 2019
COSEWIC Status: Endangered
COSEWIC Status Criteria: A2bd
COSEWIC Reason for Designation: This wildlife species has a single highly migratory population in the North Atlantic, a portion of which is present seasonally in Canadian waters. The primary threat is considered to be bycatch in pelagic longline fisheries in the North Atlantic. The 2017 stock assessment indicates that the population is depleted and overfishing above sustainable levels is continuing. Life-history characteristics such as slow growth, late age of maturity and low reproductive rates mean that this shark species has relatively low productivity when compared to other shark species. Thus, the susceptibility to continued decline is considerable and once the population is depleted, the capacity to recover is limited.
COSEWIC History of Status Designation: Designated Threatened in April 2006. Status re-examined and designated Special Concern in April 2017. Status re-examined and designated Endangered in May 2019.
SARA Status: No schedule, No Status
Date of Listing (yyyy-mm-dd):
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
Shortfin Mako (Isurus oxyrinchus) is one of two species in the genus Isurus (the other being the Longfin Mako, I. paucus) and one of five species in the family Lamnidae or mackerel sharks. Other lamnid sharks found in Canada include the White Shark (Carcharodon carcharias), Salmon Shark (Lamna ditropis), and the Porbeagle shark (L. nasus). Based on biogeographical separation, genetic differences with other global populations, and no evidence of structuring within the North Atlantic, Shortfin Mako in the North Atlantic are considered to be a population and the single Designatable Unit (DU) in Canada is part of the wider North Atlantic population Although this species is not directly targeted in Canada, it is caught and landed as bycatch in a limited number of Canadian fisheries. Due to its energetic displays and edibility, it is sought by sport anglers as a game fish in the United States and occasionally in Canada. [Updated 22/01/2018]
Distribution and Population
Shortfin Mako is widespread in temperate and tropical waters of all oceans from about 50°N (up to 60°N in the northeast Atlantic) to 50°S. Shortfin Mako are distributed throughout the North Atlantic in waters south of 60-N to the equator. In Canadian waters, Shortfin Mako is a highly migratory summer and fall visitor typically associated with warm Gulf Stream waters and represents the northern extension of the North Atlantic-wide population. It has been recorded from Georges and Browns Bank, along the continental shelf of Nova Scotia, the Grand Banks and even into the Gulf of St. Lawrence. For Canadian waters, a catch rate series from the Canadian pelagic longline fishery from 1996 to 2014 is the only available index of abundance. The most recent data show a non-significant decline in catch rates compared to earlier in the time series. Canadian waters represent the northern fringe of the Shortfin Mako range, and therefore changes in the Canadian index may reflect distributional shifts. Internationally there are six catch rate indices that are considered by the International Commission for the Conservation of Atlantic Tunas (ICCAT) to be the most representative of abundance. The combined interpretation is that these indices were fairly consistent in showing a decline during the 1990s followed by an increase after 2000. A stock assessment conducted by ICCAT in 2012 concluded that updated abundance indices showed increasing or flat trends. Despite large uncertainties, the Commission concluded that the probability of overfishing was low and that the status of the population is above the maximum sustainable yield.[Updated 22/01/2018]
Temperature appears to be the dominant factor defining Shortfin Mako distribution. Preferred water temperature is between 17-22°C and consequently it is unlikely that Shortfin Mako have extended residency in Canadian waters. A lack of data has prevented any identification of habitats necessary for critical life functions (e.g., mating, pupping) of this species in Canadian waters, while impeding investigation of whether Shortfin Mako habitat has changed over time.[Updated 22/01/2018]
Shortfin Mako are aplacental viviparous with developing embryos known to feed on unfertilized eggs during the 15-18 month gestation period. Females have 11 pups on average every three years. The estimated age at which half the individuals are mature is 8 years for males and 18 years for females. They are a low-productivity species compared with other shark species, and have a generation time of about 25 years. It appears as if females migrate to latitudes of 20°-30°N to give birth based on evidence that no pregnant females have been caught outside of this range. This species is likely adapted to withstand natural changes in its environment as adults can readily move long distances and prey upon a wide variety of species. Based on diet studies of adults, Shortfin Makos prey upon a wide variety of species, primarily fish including Bluefish, Butterfish, tunas, mackerels, bonitos, and Swordfish. [Updated 22/01/2018]
Bycatch in commercial longline fisheries targeting pelagic tunas and Swordfish is the main cause of mortality within Canadian waters and throughout the range of the Shortfin Mako. Post-release survival of Shortfin Mako shark caught by longline gear in Canada was recently estimated at 49% resulting in an historical average annual estimate of total Canadian mortality at about 69 t/year. In 2015 voluntary release of live Shortfin Mako in the Maritimes Region was supported by the longline fishing industry and is anticipated to reduce mortality in Canadian waters. Mature females comprise less than 1% of the observed Shortfin Mako caught in the Canadian Maritimes Region pelagic longline fishery with at-sea observer coverage averaging about 5% of the annual fishing effort. Total fishing mortality for the entire North Atlantic is uncertain due to poor catch reporting, particularly in years prior to 1996. From 1996-2010, average reported landings were around 2400 t but this number was considered to be an underestimate by a recent ICCAT study that estimated the average catch (landings and discards) during this time period at 3500 t. Due to their life-history characteristics such as relatively slow growth, late age of maturity and low reproductive rates, Shortfin Mako populations have relatively low productivity, thus the capacity to recover is limited once the population is depleted. [Updated 22/01/2018]
Provincial and Territorial Protection
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
9 record(s) found.
- COSEWIC Status Reports (3 record(s) found.)
- Response Statements (3 record(s) found.)
- Orders (1 record(s) found.)
- COSEWIC Annual Reports (2 record(s) found.)
COSEWIC Status Reports
Response Statements - Shortfin Mako (2006-11-29)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.
COSEWIC Annual Reports
COSEWIC Annual Report - 2006 (2006-08-30)2006 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
COSEWIC Annual Report 2016 to 2017 (2017-10-24)Over the past year COSEWIC re-examined the status of 40 wildlife species; of these, the majority (78 %) were reassessed at the same or lower level of risk. Of a total of 73 species assessed 11 were assigned the status of Not at Risk (8 re-assessments and 3 new assessments). To date and with the submission of this report, COSEWIC’s assessments now include 735 wildlife species in various risk categories including 321 Endangered, 172 Threatened, 219 Special Concern and 23 Extirpated (i.e. - no longer found in the wild in Canada). In addition 16 species have been assessed as Extinct, 58 have been designated as Data Deficient and 186 were assessed and assigned Not at Risk status.