vation

Sand whiting

lopment and Inno Monitoring update

mic Deve Biological monitoring whiting ( ciliata) is one of the key commercial and recreational monitored nt, Econo by . Biological information collected routinely from the commercial and recreational sectors of the include length,

sex and age of being caught. 45% Employme 2007 Commercial Fisheries Queensland uses this information to Recreational nt of rtmeaDep nt of help assess trends in the status of the sand 30% whiting stock to ensure the sustainability of the fishery and to evaluate the effectiveness of 15% fisheries management strategies.

are currently assessed as sustainably fished. 0% 45% 2008 The routine collection of length and age data for

sand whiting began in 2007, focusing on 30% commercial and recreational catches between Baffle Creek (north of Bundaberg) and the 15% Queensland– border. y Similar data were collected irregularly in 0% 45% Queensland during the1970s and early 1990s by Frequenc 2009 several short-term research projects. These studies were primarily designed to determine key 30% biological features of sand whiting, such as length and age at which fish mature. Biological 15% research and monitoring of sand whiting has also

been undertaken by other state agencies (e.g. 0% New South Wales). 45%

2010 The monitoring program is reliant on the 30% participation of stakeholders, who allow scientific staff to measure fish and collect frames. 15% Fish size – length 0% The length distribution of sand whiting harvested 15-16 17-18 19-20 21-22 23-24 25-26 27-28 29-30 31-32 33-34 35-36 37-38 39-40 41-42 43-44 by both sectors is generally alike: • similar length range Total Length Class (cm) • similar shaped length distributions with Length structure of harvested sand whiting (2007–10) by peaks around 23–24 cm, the minimum legal sector, showing the relative abundance of fish caught within size. each length class. Large sand whiting, over 29 cm, make up a larger percentage of the recreational catch than the Note: Length measurements in all graphs are displayed as commercial catch. total length, as this is more often used by fishers. Lengths have been converted from fork length.

Fish age How old is your fish? The age of most species of fish, including sand Measure the total length of your fish and estimate whiting can be estimated by examining otoliths the age using the graph below. For example, a (ear bones). 31 cm sand whiting is most likely four years of age but could be as young as two or as old as Fish are measured and the otoliths are removed five. from the fish’s head. A thin section is cut from No. of fish = 666 one of the otoliths which is then viewed using a Usual Spread of ages (90%) 12 microscope to identify banding. The age of the Estimate of age (median) fish can be estimated by counting the number of 10 bands present. Each year 300 to 400 sand 8 whiting otoliths are aged. 6 4 Age (years) A section of a sand whiting otolith, as viewed 2

through a microscope. Dots show the yearly 0 bands (or periods of slower growth), similar to 41-42 39-40 37-38 35-36 33-34 31-32 29-30 27-28 25-26 23-24 the growth rings of a tree. 21-22 Total Length (cm)

Thank you to all the recreational and commercial fishers, as well as the wholesalers and retailers who generously assisted with the \ monitoring of sand whiting by allowing scientific staff to access catches to measure fish and collect frames.

Sand whiting caught by both the commercial and Want to find out more? recreational fishery sectors are dominated by three and four year old fish. Since 2007, the Visit www.fisheries.qld.gov.au, phone 13 25 23, oldest sand whiting aged by the monitoring or email [email protected] program was 10. This fish had a total length of 39 cm. Follow us at www.twitter.com/fisheriesQLD or find us on Facebook under Fisheries Queensland. 50%

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20% Frequency

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0% 012345678910 Age Group (years)

A typical age distribution of the sand whiting harvest (all sectors combined) for a single year.