Bass Groper Polyprion americanus exPloitation status undeFined

I & I NSW
Wild Fisheries research Program
Bass Groper
(Polyprion americanus)
Exploitation Status
UNDEFINED
No detailed stock assessment available. Species has a worldwide distribution, local status has not
been determined.
Scientific name
Standard name
Polyprion americanus
bass groper
comment
Polyprion americanus
Image © Bernard Yau
Background
The bass groper (Polyprion americanus) is a large,
cosmopolitan species found in the northern and
southern Atlantic Ocean, the Mediterranean Sea,
southern Indian Ocean and in the south-western
Pacific. Genetic studies have revealed that there
are at least three distinct stocks of this species:
the North Atlantic and Mediterranean group,
Brazil group and the South Pacific (Australia and
New Zealand) group.
Adult bass groper mostly live in depths between
100 and 600 m, and typically inhabit deepwater
rocky reefs and caves. Juveniles (< 50 cm total
length (TL)) occur in surface waters around
floating objects or pieces of wreckage giving
rise to the name ‘wreckfish’ in other parts of
the world. In Australia bass groper have been
recorded around the south-east of the continent
and Tasmania where they are usually caught
deeper than 300 m. They also occur on offshore
seamounts.
A study of bass groper in the South Atlantic
(Brazil) found that males mature between
75 and 80 cm TL (9-11 years of age) and females
between 80 and 90 cm (10-15 years) and their
maximum life span exceeds 60 years. Off south
eastern Australia bass groper reach a maximum
length of 160 cm and weight of about
60 kg.
Apart from the occasional capture by trawlers, all
bass groper landed in NSW commercial fisheries
are by deepwater dropline fishers in the Ocean
Trap and Line Fishery. Bass groper are often
taken in association with blue-eye trevalla and
hapuku. Since 1997/98, bass groper catches
have been reported separately from hapuku and
annual catches have been between 2 and 10 t.
s t a t u s o f f i s h e r i e s r e s o u r c e s i n n s w , 2 0 0 8 / 0 9 B A S S G R O P E R | p 21
wild fisheries research program
Additional Notes
Landings by Commercial Fishery of Bass Groper
• There is a combined recreational bag limit
of 5 hapuku, banded rockcod, bass groper,
gemfish and blue-eye trevalla. Additional
restrictions apply to gemfish.
12
10
8
6
Landings (t)
4
2
• Local data could be compared with New
Zealand and American studies for additional
insights into harvesting pressure.
Ocean Trap and Line (Key Secondary Species)
0
• Historical length frequency data for the
mid 1990s do not suggest the population
was under heavy fishing pressure, however
catches and catch-rates off NSW have
declined since the early years of the
deepwater fishery in the 1970s.
97/98
99/00
01/02
03/04
05/06
07/08
Financial Year
Reported landings of bass groper by NSW commercial
fisheries from 1997/98. Fisheries which contribute less
than 2.5% of the landings are excluded for clarity and
privacy.
Catch
Recreational Catch of Bass Groper
The annual recreational harvest of bass groper in
NSW is likely to be less than 10 tonnes.
Length Frequency of Bass Groper
6
4
0
2
Landings (t)
8
10
Historical Landings of Bass Groper
98/99
00/01
02/03
04/05
06/07
08/09
Financial Year
Commercial landings (including available historical
records) of bass groper for NSW from 1997/98 to 2008/09
for all fishing methods. Note that before 1997/98, bass
groper were reported in combination with hapuku.
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The length distribution of bass groper landed by
NSW commercial fishers in the 1990s comprised fish
between 60 cm and 140 cm total length (TL), with a high
proportion of large fish (>100cm TL) present in the catch.
There are no recent length data for bass groper, which
does not have a minimum legal length in NSW.
s tat u s o f f i s h e r i e s r e s o u r c e s i n n s w, 2 0 0 8 / 0 9
Fur ther Reading
Ball, A.O., G.R. Sedberry, M.S. Zatcoff, R.W. Chapman
and J.L. Carlin (2000). Population structure of the
wreckfish Polyprion americanus determined with
microsatellite genetic markers. Marine Biology 137
(5-6): 1077-1090.
Deudero, S. and B. Morales-Nin (2000). Occurrence
of Polyprion americanus under floating objects in
western Mediterranean oceanic waters, inference
from stomach contents analysis. Journal of the
Marine Biological Association of the United Kingdom
80 (4): 751-752.
Machias, A., S. Somarakis, N. Papadroulakis, M.T.
Spedicato, M. Suquet, G. Lembo and P. Divanach
(2003). Settlement of the wreckfish (Polyprion
americanus). Marine Biology 142 (1): 45-52.
Rowling, K.R. (1996). Assessment of the NSW Dropline
Fishery, Progress Report - 1993 to 1995. Sydney
Cronulla, NSW Fisheries Research Institute: 37 pp.
Sedberry, G. R., C. A. Andrade, et al. (1999). Wreckfish
Polyprion americanus in the North Atlantic: fisheries,
biology, and management of a widely distributed
and long-lived fish. American Fisheries Society
Symposium 23: 27-50.
Please visit the CSIRO website,
http://www.marine.csiro.au/caab/ and search for the
species code (CAAB) 37 311170, common name or
scientific name to find further information.
Papandroulakis, N., M. Suquet, M.T. Spedicato, A.
Machias, C. Fauvel and P. Divanach (2004). Feeding
rates, growth performance and gametogenesis of
wreckfish (Polyprion americanus) kept in captivity.
Aquaculture International 12 (4-5): 395-407.
Paul, L. (2002). Size structure of hapuku (Polyprion
oxygeneios) and bass (P. americanus) populations
in New Zealand. N.Z. Fisheries Assessment Report
2002/16: 17 pp.
Peres, M.B. and M. Haimovici (2004). Age and growth
of southwestern Atlantic wreckfish Polyprion
americanus. Fisheries Research 66 (2-3): 157-169.
Peres, M.B. and S. Klippel (2003). Reproductive biology
of southwestern Atlantic wreckfish, Polyprion
americanus (Teleostei: Polyprionidae). Environmental
Biology of Fishes 68: 163-173.
Roberts, C. D. (1989). Reproductive mode in the
percomorph fish genus Polyprion Oken. Journal of
Fish Biology 34 (1): 1-9.
© State of New South Wales through Industry and Investment NSW 2010. You may copy, distribute and otherwise freely deal with this publication for any purpose, provided that you attribute Industry and Investment NSW as the owner.
Disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing (April 2010). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of Industry and Investment NSW or the user’s independent adviser.
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