By Anne Crawford
The rebuilding of abalone stocks in south-western Victoria over the past decade provides a world-first model for the recovery of the species, combining painstaking data collection and careful management with fisher-led initiatives to preserve breeding stock.
A decade ago, predictions for the future of the state’s Western Zone Abalone Fishery, from Warrnambool to the South Australian border, were dire.
Abalone viral ganglioneuritis (AVG) had wiped out up to 80 per cent of the wild abalone in the zone after being detected in 2006; the herpes-like virus brought commercial harvesting to a standstill.
It attacked both Blacklip Abalone (Haliotis rubra rubra), the primary species harvested in the zone, and Greenlip Abalone (Haliotis laevigata), which makes up a small portion of the catch.
The virus is transmitted through mucus secreted from infected abalone and is therefore highly dependent on water currents and weather conditions to spread. The pattern of AVG’s infection in 2006 has been compared to that of spot fires, with pockets of intense infection while nearby areas were totally unaffected.
AVG lost much of its virulence as it moved east into the Central Zone fishery (Warrnambool to Hopkins River), but it had affected almost 300 kilometres of coast before petering out near Cape Otway.
The state’s Eastern Zone (Lakes Entrance to the NSW border) was not impacted by the virus.
In 2008, an FRDC-funded report (project 2007-066) evaluating the future of the fishery post-AVG warned that the Western Zone in particular was in “dangerous territory”.
While the assessment was grim, the report did provide information on biomass, modelling and predicted trajectories of recovery, which has helped inform industry and government responses.
There were no documented examples of other abalone populations recovering from similar catastrophic events. Worse still, there was no known or accepted approach to managing the reopening and rebuilding of abalone fisheries that had been successful.
But a decade later the affected reefs have seen a remarkable recovery, with breeding populations re-established, the decline in abalone stocks reversed and quotas climbing, albeit slowly.
The recovery has been attributed to a combination of extensive data collection and analysis, careful monitoring, use of cutting-edge technology, conservative fishing effort and increasing the minimum size limit for harvesting to protect spawning animals.
In the immediate wake of the virus, in 2008-09, the Western Zone’s total allowable commercial catch (TACC) was only 16 tonnes; it had been 270 tonnes pre-AVG. However, the recently announced
2018-19 TACC for Blacklip Abalone in the zone is 70 tonnes, up 6.8 tonnes on this year’s quota.
Global fishery expert Keith Sainsbury is the independent chair of the forum that recommends annual TACC levels in the Western Zone to the Victorian Government and says the partnership between the Western Abalone Divers Association (WADA) and the Victorian Government has helped the recovery to happen.
The Victorian Government allowed low levels of controlled fishing to continue once the virus had cleared, Keith Sainsbury says. “That was a very brave step – it would have been very easy to say ‘Leave it alone for 10 years’.” While infected reefs were closed divers were given temporary access to disease-free reefs that were not normally fished.
In addition to population counts gathered by government scientists, the TACC Forum began to consider data collected by WADA divers.
Fishery stakeholders supported fishing at less than the allowable quota – an approach they had already been using pre-AVG – and also agreed that divers would fish according to a scientific design developed by the TACC Forum. While the design was not the most commercially efficient harvesting pattern, the divers’ GPS loggers provided important information about abalone size and abundance to help gauge biomass.
CSIRO helped to verify the robustness of using both data sources to set catch limits as part of an FRDC project, which Keith Sainsbury also contributed to. “We were able to draft a harvest strategy using those methods for subsequent years and have been applying it ever since,” he says.
WADA’s executive officer Harry Peeters says prior to the virus outbreak the association had already begun fine-scale management of stocks, reef by reef, equipping divers with a GPS-fitted shellfish measurer that produced detailed data about the size of the fish and location of the resource on the reefs. WADA has since added to this with technology with sensor loggers attached to divers, and automatic uploading of information to the ‘cloud’.
“What we’re now getting is catch-per-unit-effort data along with time and location, which gives you a much better handle on the effort that goes into catching the fish and their abundance and biomass,” Harry Peeters says.
As part of the recovery process divers in the Western Zone also voluntarily increased the minimum size of the animals they harvested.
“Prior to the virus, the legal minimum length was 120 millimetres,” Harry Peeters says.
“The fishers made a voluntary decision to limit the size to 130 millimetres when the reefs reopened. That’s now been legislated,” he says. “That single act, we believe, is the most important thing in the recovery of fishing that we’re seeing.”
This allowed the shellfish extra breeding time after reaching sexual maturity and before they were harvested to spawn more abalone.
The virus outbreak has taken a huge toll on the local abalone industry and the regional communities. The loss of production since the outbreak began has exceeded $100 million, and the value of the licences plunged from $6.4 million before the outbreak to less than $1 million in 2009. Of the 14 licence holders in the Western Zone, two went bankrupt and left the industry. Port Fairy processor Sou’West Seafoods closed in 2013.
But a decade on, the future of the industry is looking up. The Victorian Minister for Agriculture, Jaala Pulford, recently announced the increase in Blacklip Abalone quota for the 2018-19 year to 70 tonnes and praised the industry for actively managing the stock’s recovery.
She also announced that commercial abalone fishers would no longer be required to obtain a PrimeSafe licence for food handling, which removes red tape and costs for the sector.
New opportunities are also opening overseas. Harry Peeters says abalone now being harvested average 137 to 141 millimetres, allowing the industry to venture into the live export of large abalone to China, attracting a premium price for their shellfish.
WADA is also exploring the possibility of selling live abalone in local restaurants. Harry Peeters says there could well be vibrant domestic demand for this as part of tourism initiatives to attract some of the millions of Asian tourists to Port Fairy and Portland where the catch is landed.
FRDC Research Codes: 2005-024, 2007-066, 2008-076, (TRF No.) 2012-236
Harry Peeters, firstname.lastname@example.org