GLADSTONE BARRAMUNDI MID SEASON REVIEW 2017

There were 11 forecasts made for Barramundi in size of fish, catch rates, trends in stocks, recruitment and commercial catch. Taggers catch rates do not reflect the catch rates of the total fishing population however as taggers are generally in the top 20% of fishers that catch most fish their catches are more sensitive to changes in fish stocks and are comparable from year to year. Forecasts are available at www.crystal-bowl.com.au.

Season 2017 forecasts versus actual – mid-season June 2017 review

Taggers/Avids

  • Of the 11 forecasts for taggers 4 (36%) were within the forecast range or with 10% of the forecast range
  • Forecast for size range of fish were affected by fish spilling from Lake Awoonga in Apr 2017 however there is no change proposed to the forecast
  • Catch rates were on track as forecast until the spilling of fish from Awoonga and forecasts have been revised to take account of this influx of fish
  • Forecast was for poor/moderate recruitment and is currently assessed as poor while recruitment in the adjacent Fitzroy River is assessed as strong in line with environmental conditions
  • The trend in stock levels was downward until fish spilled from Awoonga however it has not been possible to assess the overall effect on stocks

Commercial Fishers

  • For the commercial catch the data are only available for 2016 while data for 2017 is incomplete
  • There were no forecasts made for commercial catch in 2017 due to the uncertainty in effort shift results from the introduction of the Capricornia Net Free Zone
  • Commercial effort increased by 51% in 2016 compared with 2015
  • The increase in commercial effort is likely to reflect some of the effort displaced from the Capricornia Bay Net Free Zone

Environmental conditions

  • Dry conditions largely persisted through to Apr 2017 when the remnants of Cyclone Debbie brought flooding to much of coastal Central Queensland
  • Climate outlook is for neutral conditions through to Feb 2018
  • Rainfall forecasts are only available for 3 months and the forecast is for a 45-55% chance of exceeding median rainfall from Jun-Aug

Infofish Australia
June 2017

MEASURE FORECAST

ACTUAL

GRAPH

GLADSTONE 2017

Jun 2017

Fish sizes
Undersize fish 200-579mm
Legal - trophy fish 580-999mm
Trophy fish >1m


25% (15-35%
70% (65-85%)
5% (0-15%)

Taggers/Bounty
39.3%
51.1%
9.6%

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Percentage of fish in size ranges
2008-2017

Highest  Lowest
LEGAL-TROPHY
2013    2009
72.9    27.6

TROPHY
2017    2010
13.5    1.1

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Average length of fish 2008-2017

Fish/tagger/day
 

Highest   Lowest
2015   2009
755mm   524mm
Decrease 9.2% from 2016-2017

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Actual catch rates taggers and avid fishers
Fish/fisher/day
Revised

Taggers

Overall
2.5 (2.3-2.7)
Legal fish
1.1 (0.9-1.3)
2.0 (1.8-2.2)
Legal revised 0.8 (0.6-1.0)
1.5 (1.3-1.7)

Taggers

Overall
2.2
Legal fish
1.6

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Catch rates percentage change compared with 2016
Fish/fisher/day
Revised

Taggers

Overall
-15% (-5---25%)
+50% (+30-+70%)
Legal fish
-20% (-5---25%)
+50% (+30-+70%)

Taggers

Overall
+62.3%
Legal fish
+63.8%

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Actual catch rates taggers and avid fishers
Fish/fisher/day
2008-2017
Highest Lowest
ALL
2012    2008
3.4    0.6
LEGAL
2013    2009
2.5    0.2
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Barramundi tags in Gladstone indicator of trends in stock
Most likely and range
2009-2017
Revised
Tagged fish 2017 (Jan-Dec)
150 (50-250)
400 (300-500)
-30% (-20-40%)
+120% (+100-140%)
Tagged fish 2017 (Jan-Jun)
286
+57%
Compared with 2016
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Recruitment
Recruits/fisher/day
Poor/Moderate
0.1 (0.05-0.15)
Poor
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Gladstone Harbour and Barramundi
Low Numbers of Trophy Fish
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Calliope River flow and Barramundi
Low Numbers of Trophy Fish
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Boyne River flow and Barramundi (Flow data only to 2012)
Low Numbers of Trophy Fish
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Awoonga Dam Levels Did not spill in 2016
Spilled in Apr 2017
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Commercial catchGrids R29 and R30
Catch tonnes
Catch rate kg/day
Catch
30 (27-33)
Catch rate
100 (90-110)
Catch 2016
27.2
(Feb-Oct)
Catch rate
53.8
(Feb-Oct)
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Commercial effort
Grids S29/S30/S31
Days fished

No forecast Days
505
(Feb-Oct)
51% increase from 2015-2016
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Climate outlook to Feb 2018 BOM NINO34 Neutral conditions through to Feb 2018
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Rainfall Outlook to Jun-Aug 2017 BOM forecast 45-55% chance of exceeding median rainfall
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DATA SOURCES

Data used in the Gladstone Barramundi Crystal Bowl are: