TimiBoy
14-12-2009, 08:08 AM
A little propoganda for you all...
"Fisheries Queensland, part of the Department of Employment, Economic
Development and Innovation, started a comprehensive monitoring program for snapper in late 2006."
Hmmmm. Their definition of "comprehensive" may be a little off the mark...
FULL TEXT FOLLOWS - I couldn't attach the pdf?
Snapper
Results update
December 2009
Snapper (Pagrus auratus) is an iconic species in south-eastern Queensland
and are a prized catch for recreational and commercial fishers alike.
Peak fishing on offshore fishing grounds
occurs during the winter months; however,
they can be caught all year round.
Fisheries Queensland, part of the
Department of Employment, Economic
Development and Innovation, started a
comprehensive monitoring program for
snapper in late 2006. The program collects
biological information (length, sex and age)
from recreational, charter and commercial
catches from south-eastern Queensland
between Baffle Creek and the Queensland
– New South Wales border. The biological
information collected is of vital importance
to stock assessment models used to
determine the status of the snapper stock in
Queensland waters.
Length structure (frequency) is one such
data input, and is used to demonstrate
differences (if any) in the length of fish being
caught by different sectors of the fishery.
They may also be used to see if the length
of fish being caught changes over time.
Sex and age structure are also important
inputs into the fishery models, along with
estimates of total harvest.
What sex is your fish?
Determining the sex of snapper is easiest to do during spawning season (winter
months) when the reproductive organs significantly increase in size (they
will reduce after spawning). To determine the sex of your snapper, find the
reproductive organs located towards of the top of the gut cavity. The ovaries are
orange in a mature female fish and the testes are white in a mature male fish.
Gonads of a female snapper Gonads of a male snapper
Stock assessments will continue to be updated in the future, so it is important
that the best possible data continue to be collected. Every snapper examined
for the monitoring program helps us improve fishery assessments and also the
understanding of the species. We would like to thank everyone who has donated
samples to the monitoring program.
Find out more about fisheries monitoring
(including the detailed methods of the program and how to get involved)
Web: www.dpi.qld.gov.au
Phone: 13 25 23
Email: FisheriesMonitoring@deedi.qld.gov.au
PR09–4687
Orange ovaries
White testes
The length structure (see the graphs below) shows that the recreational
and charter sector catch a higher frequency of smaller sized fish.
Fish size — length frequency
Sampled recreational catches
Sampled commercial catches
Sampled charter catches
Note: Length measurements in
all graphs are displayed as total
length (as this is more often used
by fishers). Lengths have been
converted from fork length. The
number of snapper measured in 2006
is lower, as the monitoring program
only commenced in the second half
of that year.
How old is your fish?
Fisheries Queensland relies on the donation of fish frames to collect age information
for snapper. The fish are measured and the otoliths (ear bones) are removed from
the fish’s head. For snapper, otolith sections are examined under a microscope to
estimate the age of the fish. This information allows us to work out an age-at-length
relationship for snapper. By measuring the total length of your fish, you can estimate
its age by finding it on the age-at-length graph (below).
Removal of otoliths from underneath the skull of
a snapper—a small piece of bone is removed to
allow access to the otoliths underneath
A thin section cut from an otolith allows
biologists to interpret the structure and
estimate the age of the fish.
Age at length
Note: Length measurements are displayed as total length (as this is more often used by
fishers). Lengths have been converted from fork length.
Cheers,
Tim
"Fisheries Queensland, part of the Department of Employment, Economic
Development and Innovation, started a comprehensive monitoring program for snapper in late 2006."
Hmmmm. Their definition of "comprehensive" may be a little off the mark...
FULL TEXT FOLLOWS - I couldn't attach the pdf?
Snapper
Results update
December 2009
Snapper (Pagrus auratus) is an iconic species in south-eastern Queensland
and are a prized catch for recreational and commercial fishers alike.
Peak fishing on offshore fishing grounds
occurs during the winter months; however,
they can be caught all year round.
Fisheries Queensland, part of the
Department of Employment, Economic
Development and Innovation, started a
comprehensive monitoring program for
snapper in late 2006. The program collects
biological information (length, sex and age)
from recreational, charter and commercial
catches from south-eastern Queensland
between Baffle Creek and the Queensland
– New South Wales border. The biological
information collected is of vital importance
to stock assessment models used to
determine the status of the snapper stock in
Queensland waters.
Length structure (frequency) is one such
data input, and is used to demonstrate
differences (if any) in the length of fish being
caught by different sectors of the fishery.
They may also be used to see if the length
of fish being caught changes over time.
Sex and age structure are also important
inputs into the fishery models, along with
estimates of total harvest.
What sex is your fish?
Determining the sex of snapper is easiest to do during spawning season (winter
months) when the reproductive organs significantly increase in size (they
will reduce after spawning). To determine the sex of your snapper, find the
reproductive organs located towards of the top of the gut cavity. The ovaries are
orange in a mature female fish and the testes are white in a mature male fish.
Gonads of a female snapper Gonads of a male snapper
Stock assessments will continue to be updated in the future, so it is important
that the best possible data continue to be collected. Every snapper examined
for the monitoring program helps us improve fishery assessments and also the
understanding of the species. We would like to thank everyone who has donated
samples to the monitoring program.
Find out more about fisheries monitoring
(including the detailed methods of the program and how to get involved)
Web: www.dpi.qld.gov.au
Phone: 13 25 23
Email: FisheriesMonitoring@deedi.qld.gov.au
PR09–4687
Orange ovaries
White testes
The length structure (see the graphs below) shows that the recreational
and charter sector catch a higher frequency of smaller sized fish.
Fish size — length frequency
Sampled recreational catches
Sampled commercial catches
Sampled charter catches
Note: Length measurements in
all graphs are displayed as total
length (as this is more often used
by fishers). Lengths have been
converted from fork length. The
number of snapper measured in 2006
is lower, as the monitoring program
only commenced in the second half
of that year.
How old is your fish?
Fisheries Queensland relies on the donation of fish frames to collect age information
for snapper. The fish are measured and the otoliths (ear bones) are removed from
the fish’s head. For snapper, otolith sections are examined under a microscope to
estimate the age of the fish. This information allows us to work out an age-at-length
relationship for snapper. By measuring the total length of your fish, you can estimate
its age by finding it on the age-at-length graph (below).
Removal of otoliths from underneath the skull of
a snapper—a small piece of bone is removed to
allow access to the otoliths underneath
A thin section cut from an otolith allows
biologists to interpret the structure and
estimate the age of the fish.
Age at length
Note: Length measurements are displayed as total length (as this is more often used by
fishers). Lengths have been converted from fork length.
Cheers,
Tim