Gurnards - Seafish

2 Species Guide – Gurnards. March 2011 v2.
Biology
Gurnards are able to grunt or growl by using
muscles associated with the swim bladder
and this is believed to aid in keeping schools
together. They feed on benthic crustaceans,
other invertebrates and bottom-dwelling
fishes.
Fisheries and gears
Red gurnard is mainly caught in a mixed
fishery by otter trawlers. Tub and grey
gurnard are mainly taken as a bycatch in
mixed demersal fisheries for flatfish and
roundfish.
However the market for gurnard is limited and
they are often thrown back into the sea as an
unwanted bycatch and subsequently
discarded. Surveys indicate that this species
is one of the most widely discarded (3).
Stock assessment and catches
There are no formal assessments or advice
on gurnards However, there are a number of
sources of information on these species and
their role in the ecosystem (4,5,6).
According to landings statistics the annual
catches in the North East Atlantic from 2006-
2009 have been (2):
Tonnes 2006 2007 2008 2009
Red 5171 5175 4778 4055
Tub 2995 3416 2510 3058
Grey 529 399 317 438
There are uncertainties in landings data and
some nations do not discriminate between
the species in the landings data.
Red gurnard – French fishing vessels land
the most red gurnard and it is data from these
and research vessels which provide the best
time series for this species. Information is
available for the Bay of Biscay, Celtic Sea,
Western Approaches, English Channel and
North Sea. Most of these time series indicate
fluctuations in abundance without trends, with
the exception of the North Sea where there
appears to have been an upward trend in the
last decade.
Tub gurnard – As for red gurnard, French
trawl fisheries and research vessel data
provide the best time series for this species.
Information is available for the Bay of Biscay,
Celtic Sea, Western Approaches, English
Channel and North Sea. Most of these results
indicate fluctuation in abundance without
trend with some evidence of increasing
numbers of tub gurnard overwintering in the
North Sea in recent years. This effect has
been observed with other species such as
red mullet which until recently did not
overwinter in the North Sea.
Grey gurnard – Due to their low commercial
value there is widespread discarding of this
species so only research vessel data can be
considered a valid source of information. The
research vessel surveys in the North Sea
show a marked increase in abundance over
the period 1987-2009, and relatively stable,
though fluctuating abundance in the
Skagerrak and Kattegat.
Ecological aspects
Gurnards are key predators in the North Sea
and their importance is considered to have
increased over recent years (4).
Sustainability
Taken together the information described
above suggests that gurnard populations are
relatively robust; that is current exploitation is
not likely to seriously affect their abundance.
Responsible Sourcing Services
This guide is one of a series of Seafish
Responsible Sourcing Guides.
See:
http://www.tinyurl.com/seafishrsg