Archives - Rock Lobster Fishery Updates October - December 2019
Rock Lobster Biotoxin Update - 4 December 2019
Storm Bay/Bruny Zone to open as scheduled
All the lobster samples from the Storm Bay/Bruny Zone collected on Sunday 1 December have paralytic shellfish toxin (PST) levels
below the maximum permitted level for safe human consumption.
Under the Rock Lobster Monitoring Program decision protocols, the Storm Bay/Bruny Island Biotoxin Zone can
open as scheduled on:-
Saturday 7 December for the recreational fishery; and
-
Tuesday 10 December for the commercial fishery.
As detailed in the 2 December biotoxin update, all other biotoxin zones in the East Coast Stock Rebuilding Zone will open as scheduled.
Rock Lobster Biotoxin Update - 3 December 2019
Additional lobster samples from the Storm Bay / Bruny Zone were collected on Sunday 1 December (sampling was brought forward by a day because of weather forecast). The samples have been processed by IMAS and are now at the Analytical Services Tasmania (AST) Hobart laboratory for analysis.
These results are anticipated on
Thursday 5 December in the afternoon.
Rock Lobster Biotoxin Monitoring Results up to and including 25 November
Find below summary rock lobster and sentinel sample results up until 25 November for the East Coast Stock Rebuilding Zone.
Rock Lobster Biotoxin Monitoring Program 2019 - Summary Lobster and Sentinel Samples PST results
(96Kb)
Rock Lobster Biotoxin Update - 2 December 2019
Majority of East Coast Stock Rebuilding Zone to open as scheduled
Storm Bay/Bruny Island returns high PST results - there may be a delay in opening
As part of the Rock Lobster Biotoxin Monitoring program, rock lobster samples have been collected by IMAS and an independent contractor from the Central East, Maria Island, Lower East and Storm Bay/Bruny Biotoxin Zones.
The paralytic shellfish toxin (PST) levels in all the lobster samples were either low or negligible in all zones except Storm Bay / Bruny Zone.
Based on these results, DPIPWE has determined that the recreational and commercial fisheries between Eddystone Point and Tasman Island can open as scheduled on
Saturday 7 December (recreational) and
Tuesday 10 December (commercial).
PST levels in lobsters collected from the Storm Bay / Bruny Zone exceeded the maximum permitted level for safe human consumption. Some harmful algal bloom activity had been detected in mussel samples from this zone during the winter and early spring. Data from previous blooms indicates that it can take an extended period of time for toxin levels in lobsters to reduce to low levels once the harmful bloom has finished.
Re-testing of the Storm Bay/Bruny Zone
Another round of lobster sampling for this zone is scheduled for this week subject to the weather. The results from these samples will be used to determine the open / closed status of this zone.
If PST levels remain above the maximum permitted level or results are not available by Friday 6 December, the part of the fishery between Tasman Island and Tasman head, Bruny Island, including Port Arthur, Storm Bay, and the Channel will remain closed.
Further updates will be provided on this webpage.
Read more about
Transiting through Closed Biotoxin Zones in the Eastern Region.
The majority of the East Coast Stock Rebuilding Zone will open as scheduled. There may be a delay to opening for the Storm Bay/Bruny Zone which requires re-testing.
Biotoxin Update - 11 November 2019
The IMAS research program investigating the linkage between rate of paralytic shellfish toxins (PST) uptake in rock lobster and the early warning bivalve shellfish has collected two sets of lobster samples from the Mercury Passage area since the last biotoxin update (14 October). These rock lobster samples are showing a decline in the levels of PST, however the PST levels are still above or very close to the maximum limit permitted for human consumption.
Further rock lobster and other species samples will be collected from the Maria Island biotoxin zone and adjacent zones to determine whether these zones can open on the scheduled dates for the rock lobster season in December.
The monitoring of PST levels in bivalve shellfish species as an early warning for the lobster fishery on the East Coast continues under the Rock Lobster Biotoxin Monitoring program. This monitoring program shows that PST levels continue to remain very low in all areas other than Mercury Passage.
Further updates will be provided on this webpage.
Biotoxin Update - 14 October 2019
Paralytic shellfish toxin (PST) levels above the maximum acceptable levels of biotoxins in shellfish for human consumption (the Australia New Zealand Food Standards Code) have been recorded in mussels in Mercury Passage.
The monitoring of PST levels in bivalve shellfish species as an early warning for the lobster fishery on the East Coast will continue under the Rock Lobster Biotoxin Monitoring program. Over winter and spring, the levels detected along the East Coast have been low and the data from areas other than the recent Mercury Passage results, have not been elevated or of concern.
Coincidentally, an IMAS research program investigating the linkage between rate of PST uptake in rock lobster and the early warning bivalve shellfish also sampled lobster from Mercury Passage area on Monday 7 October. These rock lobster samples have returned PST results well above the maximum acceptable levels of biotoxins in shellfish for human consumption.
Further rock lobster and other species samples will be collected from the Maria Island biotoxin zone and adjacent zones to determine whether these zones can open on the scheduled dates for the rock lobster season in December.
Background Information
Under the current rock lobster biotoxin monitoring plan, paralytic shellfish toxin (PST) levels in mussels are used as an early warning alarm to decide when to close a zone to sample rock lobster. Previous tank studies suggest there could be a 14 day lag period between high PST levels in mussels and high PST levels in lobsters. A more recent study indicates that if the lobster is eating prey items with very high PST levels, the resulting lobster PST levels could reach 0.8mg/kg within a much shorter timeframe.
To answer this is a critical management question, the IMAS project team is proposing to track PST uptake in lobsters before, during and after a bloom.
The research project will collect 5 lobsters from the southern half of the Maria Island Zone (Maria Island revised zone) once a month in June, July, and August. If a harmful algal bloom (HAB) event occurs, the sampling may increase to fortnightly and continue during the closed season, reverting back to monthly when the bloom declines.
The zone will be closed to commercial lobster fishing for sampling and will reopen as soon as the results are available. It is anticipated that the closure will be 3 – 4 days for each sampling round. The lobster samples will be analysed by the AST Labs in Hobart. If the preliminary screen results are below 0.4 mg/kg, the zone will be reopened immediately, otherwise the confirmatory results will be used to determine the status of the zone in line with the Biotoxin decision protocols.
The rock lobster biotoxin monitoring program and response plan will continue to operate as normal and independently of the project sampling.
If you require any further information on the closure please email Hilary Revill at
hilary.revill@dpipwe.tas.gov.auFor further information on the research project
FRDC 2017-086 Improved risk management of paralytic shellfish toxins in Southern Rock Lobster go to the
IMAS website.
Indicative map illustrating the proposed trial division of the Maria Island Biotoxin Zone
Biotoxin zones and boundary maps
How do toxic algal blooms affect the rock lobster fishery?
Toxic algal blooms
Some species of naturally occurring algae that produce toxins have been present in eastern and southern Tasmanian waters over the past few years.
These algae can produce
paralytic shellfish toxins (PSTs) that accumulate in shellfish feeding on the algae. Humans can ingest these toxins when eating shellfish such as oysters, mussels, scallops and clams.
Abalone, scallop roes and the intestines and livers of rock lobster can also be affected when toxic algal blooms are present.
How do they affect the rock lobster fishery?
Extensive algal blooms affecting the rock lobster fishery have occurred off the east coast periodically since 2012. Rock lobster feed on shellfish and can become contaminated with PSTs. Toxins build up in specific organs (rarely in the flesh) and can be dangerous to humans when eaten. When biotoxin levels are above the prescribed minimum limit, the affected zones may be closed to fishing.
How to stay informed
Web: This webpage -
Biotoxin Fishery Events
Email alerts: Recreational Fishing News e-newsletter
Facebook page: www.facebook.com/FisheriesTasmania
Phone: Recreational - 6165 3233 or 1300 720 647
Commercial - 6165 3045
Email:
fishing.enquiries@dpipwe.tas.gov.au
Public health alerts:
www.publichealthalerts.tas.gov.au
Biotoxin decision making protocols
DPIPWE Wild Fisheries has developed the
Rock Lobster Biotoxin Plan and Decision Protocol in consultation with the Tasmanian Rock Lobster Fisherman's Association, the Commonwealth Department of Agriculture and other stakeholders. It is used to determine management responses in relation to a Paralytic Shellfish Toxin (PST) event. The policy for the
Recreational Rock Lobster Fishery for Biotoxin Events is also below.
Rock Lobster Biotoxin Monitoring Program and Decision Making Protocols 2020 (595Kb)
Recreational licence refunds
Please note that recreational licence refunds
will not be granted if you are unable to fish in some waters due to biotoxin closures. Licences grant access to all Tasmanian waters and biotoxin closures apply only to specific zones within those waters. Licence holders can still fish outside any closed areas.