or 'spurdogs' as they are sometimes called, are relatively small
squaloid sharks, characterized by the presence of two dorsal fins
with spines on their leading edges and no anal fin. They often have
a light scattering of small white spots on their torso, especially
along their lateral lines.
Their slow rate of maturity (upwards of twenty
years) combined with extremely long gestation (more than two years),
leave them extremely vulnerable to overexploitation.
Spiny Dogfish have a wide but fragmented
range. The largest subpopulations
occur in coastal habitats on both sides of the North Atlantic. There
are smaller isolated
subpopulations in the Southwestern Atlantic and the Eastern Pacific
along the coastlines of South America as well as the southern tip
of Africa, Southern Australia and around New Zealand.
Spiny dogfish populations in the North
Pacific have recently been reclassified as a separate species
Squalus suckleyi - the North Pacific Spiny Dogfish. Although S.
suckleyi faces similar obstacles, it is not included in this
The principal threat to this species
worldwide is over-exploitation, by target and bycatch fisheries.
This is a valuable commercial species in many parts of the world,
caught in bottom trawls, gillnets, line gear, and by rod and reel.
France was the
largest importer of dogfish meat within the EU from 1990-1994,
importing an annual average of 5,000 tonnes (98% spiny) with the UK
as their top European supplier. During 1988-1994, Norway was the
largest of nine non-EU suppliers to the EU of fresh or chilled spiny
dogfish, followed by the US. As European stocks decline, demand is
being met by frozen imports from 25 countries, dominated by the US
the Food and Agricultural Organization (FAO), dogfish catches
reached a peak in 1972 (73,500 t) then declined and stabilized in a
range between 36,000 and 51,000 t in the 1990s. Most of the catch
reported to FAO comes from the North Atlantic, with minor amounts
reported from the Mediterranean and Black Seas. There are, however,
some data discrepancies: in 1999, the US landed nearly 15,000 t of
spiny dogfish and 9,800 t was landed from ICES areas, most of this
by the UK fleet (UK fisheries statistics report over 9,000 t
landed), yet FAO reports 1999 global catch at 22,756 t with the
largest catches coming from Canada (5,536 t) and Norway (1,461 t) (FAO
2000) (note that some statistics will include the North Pacific
Spiny Dogfish Squalus suckleyi).
biomass initially supports large catches, but most large-scale spiny
dogfish fisheries have depleted populations and collapsed (Ocean
Wildlife Campaign 1996). An aggregating habit makes it possible for
fishers to continue to target highest value mature females even
after stocks have been depleted to a few percent of baseline. The
species is also taken as a bycatch in mixed species fisheries,
meaning that fishing pressure can continue even after stocks have
been so seriously depleted that they can no longer support viable
potential impacts on spiny dogfish associated with habitat loss and
degradation. Coastal development, pollution, dredging and bottom
trawling affect coastal or benthic habitat on which spiny dogfish or
their prey rely (ASMFC 2002).
POORLY MANAGED FISHERIES AND
INEFFECTIVE CONSERVATION MEASURES
Despite several decades of warnings of
unsustainable fishing pressure and reported steep stock declines,
very few conservation or management measures are in place for spiny
dogfish; measures in place have not been effective in terms of
rebuilding populations. A notable exception may be New Zealand,
where quotas have been introduced to limit catches to sustainable
levels in response to the first signs of fishery development to meet
European demand for meat. Spiny dogfish were brought under the New
Zealand Quota Management System in October 2004 (M. Francis, pers.
Holden (1968) first warned that part of
the Northeast Atlantic stock was over-exploited, but there is still
no effective management in this region despite wide-spread
recognition that fishing levels are unsustainable and several parts
of the stock have collapsed. A minimum landing size established in
Norway in order to protect mature females is of limited value for a
migratory species that is intensively fished in other parts of its
range. Total Allowable Catches in EU waters, first established in
1998, have consistently exceeded recent landings and do not appear,
therefore, to have had any constraint upon current unsustainable
levels of fishing pressure. This fishery needs to be closed if the
stock is to recover, ICES recommended a zero quota in 2006, but this
advice was not heeded by the EU.
In the Northwest Atlantic, the 1999/2000
US federal dogfish rebuilding plan has yet to reverse population
decline and fishing mortality targets continue to be grossly
Federal Fishery Management Councils in
the eastern US developed a spiny dogfish rebuilding plan in the late
1990s coincident with the stock being officially declared overfished.
Low priority and controversy over cuts led to serious delays.
Implemented in mid 2000, the plan aimed to rebuild the population
through a low fishing mortality target (F=0.03) and corresponding
quota (four million lbs) and trip limits (300 to 600 lbs for two
periods) that would discourage targeted fishing and yet allow some
landing of incidental catch. Once that the ten-year legal limit to
recover the population became impossible, federal law allowed the
rebuilding period to be extended, opening the plan up for relaxation
As Federal measures developed, the
dogfish fishery shifted into state waters (within three miles from
shore). Continued state fisheries have undermined the federal plan
ever since. Most notably, Massachusetts, the Atlantic state with the
largest directed dogfish fishery, adopted a 2000 state quota at
nearly twice the Federal allotment for the entire Atlantic and
excessive possession limits that allowed for continued directed
dogfish fishing. Under the federal plan, overages are not deducted
from the subsequent year?s quota.
In late 2002, the Atlantic States Marine
Fisheries Commission (ASMFC) adopted a federally compatible dogfish
rebuilding plan for state waters. In early 2003, however, the ASMFC
rejected scientific advice and accepted a Massachusetts proposal to
more than double the quota (to 8.8 million lbs) and increase trip
limits by an order of magnitude (to 7,000 lbs) to allow directed
dogfish fishing. The ASMFC did impose scientifically defensible
limits for the 2004 fishing year (beginning in May), but rejected
the 2005 advice for a 50% quota cut for 2006 in favour of the status
quo (4 million lbs). This advice, from a joint state and federal
technical committee, was also rejected by the New England Fishery
Management Council, but adopted by the Mid-Atlantic Fishery
Management Council (MAFMC). The decision on catch limits for the
2006 fishing season now lies with the NMFS, but pressure to relax
recovery efforts is increasing due to the movement of a larger
percentage of the population to nearshore waters and therefore
fishing gear. The ability to set catch limits for a multi-year
period (3 to 5 years) is currently being considered by both state
and federal authorities and may be realized as soon as this year.
Canada began restricting Atlantic
dogfish catch in May of 2002, following a significant increase in
landings in years just prior. The government capped 2002 commercial
landings at 2,500 metric tons for the fixed gear groundfish sector
off Nova Scotia and in the Bay of Fundy, based on landings history
at the time. In addition, bycatch caps for other fisheries
consistent with historical landings and an additional 700 mt for a
cooperative industry sampling program were granted. The Canadian
government has stated that the caps are aimed to limit harvest while
future sustainable catch levels are investigated. The Canadian
government intends to maintain dogfish catches at roughly 3,200 mt
for directed fishing and research while they collect data and
develop their own population assessment, expected by 2007 (Campana
2002, pers comm).
Citation: Fordham, S., Fowler,
S.L., Coelho, R.P., Goldman, K. & Francis, M.P. 2016. Squalus
acanthias. The IUCN Red List of Threatened Species 2016:
Downloaded on 22 September 2017.
THE BOTTOM LINE
After decades of mismanagement, almost
all governing bodies (with the exception of New Zealand) have proven
themselves completely incapable of protecting spiny dogfish stocks.
Organizations such as the Shark Alliance
continue to lobby for change. Please support their initiatives
Although the issues may seem too large
to tackle on a personal level, you can create change:
Never order dogfish. In British fish
and chip shops, spurdog is marketed under the name FLAKE or ROCK
Politely suggest that restaurants
remove shark from their menu and explain why.
Never buy medications or supplements
that contain shark cartilage.
Never buy cosmetics that contain
Encourage your friends to follow