2019 AIRF Funding Round

​​​​Decadal re-survey of long-term lobster experimental sites to inform Centrostephanus control

Lead Agency: Institute for Marine and Antarctic Studies (IMAS)
Funding: $30,000
Start Date: 1 September 2019                          End Date: 31 December 2020
Status: IN PROGRESS

Aims and Objectives:

The proposed project will re-survey baseline sites established during a previous Fisheries Research Development Corporation project (FRDC#2007/045) that investigated the effectiveness of rebuilding large lobsters to mitigate risk of urchin overgrazing.
Changes observed from 2008-2014 show decline in urchin abundance inside the dedicated no-take Fisheries Research Areas of Elephant Rock Research Reserve (ERRR) and North Bay Research Reserve (NBRR). From this prior research, the rebuilding of large predatory-capable lobster stocks within intact kelp beds (but containing incipient barrens) was, after 6 years, much more effective at reducing risk of barrens formation than was rebuilding of lobster stocks in an attempt to recover widespread barrens.

Given the research areas have remained in effect but have not been surveyed for the past 5 years, the re-survey of these experimental sites therefore presents an important opportunity to understand decadal trajectories in the capacity of large lobsters to mitigate the risk of sea urchin overgrazing.

The re-survey of these baseline sites constitutes highly cost-effective research to refine understanding of the effectiveness of lobster rebuilding strategies as an approach to control urchin overgrazing; thus, promoting sustainability of abalone stocks in eastern Tasmania.

Co-investment from IMAS will enable this objective to be achieved and will further enable a related objective regarding decadal trends in the ability of lobster stocks to be rebuilt on urchin barren grounds to be achieved, which will also contribute towards the overall effectiveness of 'east coast rock lobster stock rebuilding strategy' towards achieving ecological control of sea urchins.

Progress:

Deliverable #1. Diver resurveys of size/ age and abundance of lobsters, urchins, abalone and kelp bed cover at North Bay Research Area and Elephant Rock Research Area (plus a total of 4 control sites).
Update: All diver surveys of size and abundance of lobsters, urchins, abalone and kelp bed cover have been completed for NBRA plus control sites (see attached example images). Urchin, abalone and kelp cover has been surveyed for ERRA plus control sites; with surveys of urchin size yet to be completed. The remaining fieldwork is scheduled for October/November. We hope COVID19 restrictions have sufficiently lifted to enable this to happen. At this stage we consider we are on track to complete this deliverable.

Deliverable #2. Lobster potting at ERRA and NBRA (plus a total of 4 control sites) to determine the capacity to rebuild lobster stocks (size and abundance of lobsters) on urchin barren grounds and within kelp beds containing incipient barrens.
Update: Lobster potting has been completed for NBRA and adjacent control sites (as of Feb 2020). ERRA scheduled to be sampled in November 2020 to achieve seasonally consistency of surveys with historical baseline sampling for this location. We hope COVID19 restrictions have
sufficiently lifted to enable this to happen. At this stage we consider we are on track to complete this deliverable.

Deliverable #3. Data entry and QA/QC September 2020.
Update: Data entry has been completed for all completed tasks associated with Deliverables #1 and #2 above. Completion of data entry will occur soon after all remaining activities for Deliverable #1 & #2 are completed. Based on sample schedule, at this stage we are on track to complete this deliverable by November 2020.


Centrostephanus Exhibition

Lead Agency: Institute for Marine and Antarctic Studies (IMAS)
Funding: $6,500
Start Date: 1 September 2019                          End Date: 30 November 2020
Status: IN PROGRESS

Aims and Objectives:

This project is for a 3-month Centrostephanus exhibition in the public space at the IMAS Salamanca between Nov 2019 and Jan 2020.

The display will tell the story of the urchin problem in Tasmania and inform about control options. The exhibition will contain live urchins, photographic exhibition, public art, infoposters and brochures on impacts, video display of barrens and fishing, 360 VR setup.

There would also be launch and finale events which would include talks, urchin tastings, interactive displays, VR.

Progress:

The Centro exhibit is primed and ready to go, with key components installed. It will run for 3 months once available to be opened to the public. In addition, there will be aquaria to show urchin barren and healthy reef, physical displays (urchin jaws, fishing equipment, waste products) and the 360 VR.


Resetting urchin barrens: liming as a rapid widespread urchin removal tool

Lead Agency: Institute for Marine and Antarctic Studies (IMAS)
Funding: $65,309
Start Date: 1 September 2019                          End Date: 30 March 2021
Status: IN PROGRESS

Aims and Objectives:

The aim of this preliminary liming project is to determine the effectiveness and feasibility of quicklime on Centrostephanus in Tasmania, and determine if large scale investment and field trials and application technology are warranted.

Progress:

Experiments for this project were terminated due to Covid and animals disposed of. Trials can recommence late September post Centro spawning season.


Commercial upscaling of urchin fertiliser

Lead Agency: Institute for Marine and Antarctic Studies (IMAS)
Funding: $538,580
State Date: 1 September 2019                          End Date: 31 August 2023
Status: IN PROGRESS

Aims and Objectives:

The aim of this project is to establish commercial processing of urchin waste, and test two key waste streams as an agricultural product on commercial crops; dried solids as a soil conditioner/fertiliser, and liquids to use as a foliar spray to enhance frost resistance.

Progress:

There has been a delay in the project caused by a number of factors, not least of which is the COVID19 situation that has created a shipping backlog.

The culling program that was completed this month, if repeated, will be critical in providing RTSPauaco with sufficient (otherwise unusable) stock to ensure the viability of the project while at the same time improving abalone habitats.


Modelling the fine-scale dispersal of Centrostephanus rodgersii larvae

Lead Agency: Institute for Marine and Antarctic Studies (IMAS)
Funding: $76,371
Start Date: 1 September 2019                          End Date: 30 December 2022
Status: IN PROGRESS

Aims and Objectives:

  • Construct a robust model (based on previous work of Sean Tracey) of larval dispersal for Centrostephanus rodgersii around the east coast of Tasmania using existing oceanographic data (piecing together highand low resolution)

  • Calculate the most likely sources for large recruitment events to the east coast of Tasmania

  • Predict whether the Tasmanian population may be self-recruiting or what oceanic changes may lead to self-recruitment

  • Set model up to be capable of addressing management decisions, such as which Tasmanian reefs would be most likely to produce larvae that survive the winter, which reefs pose the greatest risk of further range extension
  • The model could be flexible to allow input data for abalone or rock lobster larvae

Centro Cull The Southern Front

Lead Agency: Jeremy Huddlestone
Funding: $28,400
Start Date: 1 September 2019                          End Date: 31 October 2019
Status: COMPLETED

Aims and Objectives:
  1. Protect viable abalone Reef and habitat
  2. Stop the spread and expansion of centro
  3. Remove the centro from 22a where they are not yet plentiful enough to be commercially viable to harvest
  4. Establish a real cost to Urchin culling with the hope to roll out to other areas
Final Report

Key observations/recommendations:

  • Divers observed a substantial increase in Centro population in Munro Bight compared with that observed in the same area only 12 months ago.

  • Divers noted substantive weed, abalone and lobster recovery in shallow bottom previously affected by the June 2016 storm event.

  • Divers observed a “healthy” degree of recruitment of abalone populations within and around incipient Centro barrens.
  • Divers noted almost zero population of lobster, abalone or scale fish within the larger extensive Centro barrens. • A follow-up cull is recommended in abalone block 22a within 12 months.

  Final Report   (366Kb)


Centrostephanus Response Strategy

Lead Agency: CSIRO
Funding: $138,000
Start Date: 1 December 2019                          End Date: 15 September 2020
Status: CURRENT

Aims and Objectives

The proposed centrostephanus response strategy will provide the formal instrument for guiding Centrostephanus management in Tasmania.  It may or may not be formally endorsed as a management plan under the Living Marine Resources Management Act 1995, but will guide State government response and inform and align with the response efforts of other governments, industry, researchers and communities in a manner similar to the Integrated Pest Management approach that underpins the Crown of Thorns Starfish strategy.

The strategy seeks to provide a comprehensive, integrated and action-oriented framework to achieve the following three strategic objectives:

  1. Stop growth of existing barrens;
  2. Prevent establishment of new barrens;
  3. Promote recovery of full barrens.

The strategy will address the full suite of potential management response options in the near and longer term.  It will bring together knoweldge, expertise and resources from a range of sources to address the threats posed by Centro.  It will emphasize the importance of results in the water that directly contribute to the strategic objectives.  The strategy would comprise the followng components:

  1. A review of existing knowledge;
  2. Reasonable and immediate management responses given the strategic objectives and the state of knowledge;
  3. Assessment of the feasibility of achieving stated objectives
  • Identification of the knowledge/ technology gaps that must be filled;
  • A medium-long term management and research strategy;
  • Identification of the knowledge/ technology gaps that must be filled;
  • Future control technologies

Key Considerations:

The strategy will consider, and to the extent feasible, address the following key dimensions of Centrostephanus management i) Biological and Ecological Dimensions, ii) social and economic dimensions, iii) management dimensions, iv) knowledge gaps.  These dimenstions and the assumptions underpinning them are considered more fully in the attachment.


Hit Them While They're Down 2020 Centro Cull

Lead Agency: Jeremy Huddlestone
Funding: $24,600
Start Date: 5 March 2020                          End Date: 31 May 2020
Status: COMPLETED

Aims and Objectives:

To cull areas of incipient barrens located but not culled last October. To extend range of cull, And to revisit gps location of previous Cull. Observe Seaweed and marine life recovery.

Final Report

Key project actions/outcomes:

  • 12 dive hours per dinghy was successfully completed over 3 days
  • Dives on previous sites revealed Seaweed and Abalone recovery, in all but one extremely cryptic area where urchins had returned to a est 50 percent of original population.
  • Seaweed is recovering quicker than expected, 1 area is recovering after only 5 weeks post a harvest Day
  • Harvest day completed in block 22a by Beau, Jeremy and Mic revealed a harvest rate of 140kgs per hour in a  specific non culled “virgin site" at a depth of 15-20meters
  • A total of 15100 Centro urchins were culled. Mostly in range extension areas
  • 30-40 percent of the Centro in Munroes Bight are below Market size

Key observations/recommendations:

  • Divers observed  almost night and day difference in original cull locations
  • Divers noted continued weed, abalone and lobster recovery in shallow bottom previously affected by the June 2016 storm event.
  • Divers observed a extremely “healthy" degree of recruitment of abalone populations within original cull sites and most productive areas of 22a
  • Divers noted almost zero population of lobster, abalone or scale fish within the larger extensive Centro barrens.
  • We believe additional culling and or harvesting will be required in this area particularity with the large number of small non marketable centros in the population .

Dive Specific Findings:

  • In this region, working depth is an important dive planning consideration. Divers were able to cull for up to 4.5 hours on the first day but as the trip went on, combined bottom time was a limiting factor in available dive time.
  • Moving to a 3 day cull was beneficial in managing crew fatigue and Dive profiles
  • Revised Crew renumeration of $1300 per diver per day and $500 per deckhand per day proved acceptable and the crew would be happy to participate on further projects on these rates
  • The crew was extremely buoyed by the recovery of productive abalone habitat, and abalone stocks are recovering extremely well, Whilst 22a is a work in progress we have made some large steps in returning this area into the fishery

Effects of Urchin fishing on Urchin populations and kelp recovery

Lead Agency: Institute for Marine and Antarctic Studies (IMAS)
Funding: $132,303
Start Date: 1 August 2020                          End Date: 30 August 2021
Status: IN PROGRESS

Aims and Objectives:

The overall aim of this project is to determine the impact of high intensity fishing pressure on urchin populations and the capacity of such pressures to restore kelp ecosystems on heavily fished reefs in NE Tasmania.

The specific objectives of this project are:

  • Assess changes in urchin population structure (urchin density, age and size) following high fishing pressure.
  • Quantify habitat (kelp recovery of reefs subjected to high fishing pressure.
  • Develop detailed spatial maps of urchin barrens in the greater St Helens region pre and post the 2018/19 period of high fishing intensity.
  • Assess the effectiveness of urchin fishing as an effective Centrostephanus control tool.

Risk Profile for the paralytic shellfish toxins (PST) from Alexandrium cantenella in Tasmanian sea urchins

Lead Agency: Institute for Marine and Antarctic Studies (IMAS)
Funding: $92,110
Start Date: 1 July 2020                          End Date: 1 April 2023
Status: IN PROGRESS

Aims and Objectives:
  • Determine PST levels in two species of commercially harvested urchins on the east coast of Tasmania during blooms of PST producing algae
  • Complete a risk profile on PST accumulation in Heliocidaris erythrogramma and Centrostephanus rodgersii on the east coast of Tasmania as a result of A.catenella blooms to support public health and market access risk management activities.












Back Home