GLADSTONE MANGROVE JACK 2018

Mangrove Jack are an iconic sportfishing species, prized for their aggressive fighting ability.

  • Overview

    Overview

    Crystal Bowl GBR is aiming to examine 3 core measures across a wide range of species in the region:

    • Fishing experience (how many fish per trip)
    • Quality of the fish (size of fish)
    • Community attitudes

     

    Fishing Experience

    • Boyne Tannum Hookup catch rate of 1.04 fish/fisher/day (reflective of limited targeting of Mangrove Jack in the BTH)
    • Gladstone sports fishing club reports catch rate of 0.29 fish/fisher/day 
    • Qld Fisheries Boat Ramp Surveys reports catch rate of 0.12 fish/fisher/day 
    • Gladstone ranked 7th in the state for Mangrove Jack Rates
    • Not a target species for commercial catch

     

    Quality of the Fish

    • Most of the  Mangrove Jack in Estuaries are Juvenile
    • 2017 Avg length in the Boyne Tannum Hookup was 424/6mm
    • 2017 Avg length for Gladstone Sportfishing Club was 358.3mm
    • 2017 Avg length in Qld Fisheries Boat Ramp Surveys was 430mm
    • Gladstone Ranked 10th in the State on length but given the low sample size this is not a reliable measure.
    • Gladstone Sportfishing caught 267 Mangrove Jack during the year as such their average length is more likely to be reliable

     

    Community Attitudes

    • Qld Fisheries Boat Ramp Surveys report that 82% of Mangrove Jack are released despite the high likelihood those fish will be legal.
    • 100% of fish caught by Gladstone Sportfishing Club were tagged and released.
    • 83% of fishers surveyed were locals.

     

  • Assessment

    Limited Take For Consumption Advised

    As this species is primarily a Sports Species, and given the high release rate amongst sport fishers, recommend maximum 1 fish taken in any one session.

  • Forecast

    Forecast

    • Catch rates will likely be down slightly for T20 fishers - 0.2 fish/fisher/day - 0.4 fish/fisher/day
    • Mangrove Jack average size will be similar to 2017.

     

  • Boyne Tannum Hookup

    Boyne Tannum Hookup Annual Event

    Summary

    The Boyne Tannum Hookup is the biggest single fishing event in Queensland. Gladstone Sportfishing Club has run a live weigh-in as part of the event since the beginning and over that time 191 Mangrove Jack have been weighed in. All fish weighed in are of legal size or above, though trophy bream are few and far between.

    Boyne Tannum Hookup 2016 Report
    • Catch rate at the hookup was 1.04 fish/fisher/day
    • Average length of fish at the Live weigh in was 424mm
    • Average weight of fish at the live weigh in was 0.43kg

     

    Detailed Examination of Size

    Over that time the condition of the Mangrove Jack has been consistent, with the fish tending to be average or above average condition. A summary of the event and condition of Mangrove Jack below.

    View All Years Length - Weight
    View All Years Condition Data

     

  • Sportfishers

    Mangrove Jack as a Sports Species

    Mangrove Jack are most commonly targetted by Sportfishers in Gladstone. They are a difficult species to target and represent a signficant challenge. Mangrove Jack are often found in similar habitat to Barramundi, though in Gladstone 2017, Barramundi were reported 3.5 times more often.

    • Gladstone Sportfishing Club catch rate of 0.3 fish/fisher/day
    • 2017 Gladstone Sportfishing Club average fish size was 358.2mm

    A detailed snapshot of tagging by the Gladstone Sportfishing Club and Suntaggers is available:

    Gladstone Suntag Results

     

  • Qld FIsheries Boat Ramp Surveys - General Fishers

    Monitoring of Recreational Catch by Qld Fisheries

    Queensland Fisheries monitors boat ramps up and down the coast as a part of the Sustainable Fisheries Strategy. General Fishers in Gladstone rarely report catching Mangrove Jack, with a 82% of fish being released in 2017. Monitoring is ongoing in 2018.

    • Only 11 Mangrove Jack were reported in Boat Ramp Surveys
    • 2017 Catch Rate of 0.12 fish/fisher/day
    • 2017 Average size fish 430mm

     

    Qld Fisheries Boat Ramp Surveys monitoring dashboard

     

  • Recruitment

    Monitoring of Mangrove Jack Recruitment

    While the lifecycle of the Mangrove Jack is understood, limited research has been conducted on environmental drivers for recruitment success.  Mangrove Jack recruits are detected during Bream Recruitment Surveys indicating they use similar habitat during their growth phase.

     

  • Monitoring

    Monitoring of Mangrove Jack

    Data for this assessment has been sourced from:

    • Bureau of Meterology
    • Boyne Tannum Hookup
    • Gladstone Sportfishing Club
    • Queensland Fisheries

     

    Here are links to all the monitoring pages for Mangrove Jack:

    Boyne Tannum Hookup 2016 Report

     

  • Fishing Area

    Area Assessed

    Mangrove Jack are caught throughout the Gladstone region.