Bifenthrin is a pyrethroid insecticide typically applied by pest controllers to protect against termites. It has a high toxicity to aquatic organisms. In July 2012 bifenthrin contaminated Jamison Creek, Wentworth Falls, NSW and caused a mass mortality event of freshwater crayfish and macroinvertebrates. As part of the Australian Crayfish Project we volunteered to conduct a follow up survey of Jamison Creek and similar creeks in the area to monitor the recovery of freshwater crayfish and fish in the creek after this catastrophic event.
Results of those surveys were included in a scientific paper which has been presented at 7th Australian Stream Management Conference held in July at Townsville, Queensland.
St Lawrence, A., Wright, I.A., McCormack, R.B., Day, C., Smith, G. and Crane, B. (2014). Bifenthrin pesticide contamination: impacts and recovery at Jamison Creek, Wentworth Falls, in Vietz, G; Rutherfurd, I.D, and Hughes, R. (editors), Proceedings of the 7th Australian Stream Management Conference. Townsville, Queensland, Pages 558-567.
AbstractIn July 2012, over 1000 dead Giant Spiny Crayfish (Euastacus spinifer) were found in a two kilometre reach of Jamison Creek, Wentworth Falls, including within the Greater Blue Mountains World Heritage Area. A multi-agency investigation discovered the crayfish were killed by a termiticide, Bifenthrin, and that the effects extended beyond the crayfish to the entire aquatic macroinvertebrate community. The contaminant entered the creek via a conventional stormwater drainage system of pits and pipes, which provided a direct connection between the property at which the pesticide was over-applied and the creek 300m away. The pest control operators involved were prosecuted.
Our paper is now available on the conference website:
The ACT Aquatic Team from the ACT Government’s Conservation Planning and Research Unit sent me this photo of a berried Euastacus rieki and I just had to share it with you all. It’s the first female with eggs recorded and a tremendous leap towards filling the huge knowledge gaps on this cryptic species.
The Aquatic Team from the ACT Government’s Conservation Planning and Research Unit have been surveying subalpine bogs as well as creeks and rivers in the ACT to determine potential methods for a broader distribution survey of two species of spiny crayfish.
The current project is stage 1 to test methods for a program to determine the distribution and relative abundance of Euastacus crassus and Euastacus rieki. Despite being the type location for Euastacus rieki, very little is known on the distribution or habits of these two species in the ACT or elsewhere.
Among the more than 50 crayfish collected the team discovered two berried E. rieki (42 & 53mm OCL) with 100, 3.5mm orange eggs. Both crays were collected in a subalpine bog (approximately 1600m a.s.l) in Namadgi National Park.
The project was directed by ecologists from the Environment and Sustainable Development Directorate of the ACT Government. The work has been supported through ACT Government climate change funding.
A new species of Gramastacus freshwater crayfish has been described by Rob McCormack resulting from research over the last eight years as a volunteer on the Australian Crayfish Project (ACP). The eastern swamp crayfish from the genus Gramastacus, was published in the open access journal ZooKeys.
Only one other species of Gramastacus crayfish is known and that occurs some 900 km away in the Grampians region of Victoria. This new species is found in lowland ephemeral habitats between 3 and 48 m a.s.l. surrounding coastal lakes and lagoons from Wamberal Lagoon, north along the coastal strip to Wallis Lake, a straight line distance of 165 km.
This new species “The eastern swamp crayfish Gramastacus lacus” is one of the world’s smallest freshwater crayfish species with specific habitat requirements, preferring ephemeral habitats (smaller creeks, swamps, wet areas and stump holes) that offer conditions that enable their survival and presumably limit threats from other predators, such as eels. Habitats in the same area that consist of permanent water invariably contain large numbers of freshwater eels (Anguilla reinhardtii) and native fish gudgeons (family Eleotridae) but not G. lacus. Many ephemeral swamps and creeks can revert from dry beds to water bodies several metres deep when flooded. Eels and fish may penetrate into and temporarily visit some habitat areas but G. lacus takes refuge in the periphery, protected within the thick reeds and flooded grasses along the shallow edges, well away from the deeper water.
Being dependent on regular natural flooding and drying cycles, only lowland, swampy areas are suitable for this tiny crayfish. Each crayfish digs a small rounded cross-section burrow up to one metre deep into the water table to survive the drying cycle. Some areas are riddled with these small burrows as they are a prolific species and can occur in very high numbers in small habitat areas.
They are found in one of Australia’s, most developed and fastest developing regions, unfortunately, this means that much of their habitat has been lost in the past, these ephemeral areas are the first to be drained or reclaimed to make way for agriculture, industry, housing developments, golf courses and infrastructure, etc. Now, with this species description, this crayfish must be considered in any future developments and hopefully future habitat loss will be reduced.
The scattered populations of Gramastacus seem highly fragmented and many are increasingly threatened by a range of threats other than human development. Invasive crayfish, pest fish species like plague minnows and swordtails, rising sea levels and falling water tables all are increasing threats. Luckily, the large number of National Parks and Reserves along the coastal strip provides safe refuges for some populations.
“The eastern swamp crayfish Gramastacus lacus sp. n. (Decapoda, Parastacidae) a new species of freshwater crayfish from coastal New South Wales, Australia” was published in Issue 398 of ZooKeys. This is a free access journal and if you would like a copy of the paper in full go to: http://www.pensoft.net/journals/zookeys/article/7544/abstract/the-eastern-swamp-crayfish-gramastacus-lacus-sp-n-decapoda-parastacidae-a-new-species-of-freshwater-crayfish-from-coasta
We have finally finished our aquatic surveys of the lower Clyde River, NSW. It’s an exciting area with mostly pristine clear flowing streams full of aquatic life. The results of the survey have been extremely interesting and have resulted in some significant findings. We have identified 3 different freshwater crayfish species in the lower Clyde River and they all match the known descriptions for all three species. Interestingly, the specimens of Euastacus crayfish previously collected from the upper Clyde are generally morphologically different to those in the lower Clyde. Eventually we will get the genetics done on all the specimens collected and then work out whether the upper Clyde specimens are a morphological variation or a separate species. Stay tuned for further updates. The full results of the aquatic biological surveys will be complied into a report and issued to the Southern Rivers Catchment Management Authority.
We surveyed 57 sites and at 43 of those we captured freshwater crayfish. A total of 149 Euastacus yanga were captured, examined, weighed, measured, and released during this survey. Euastacus yanga has the third largest distribution of any Euastacus species in Australia after E. spinifer and E. armatus. Found in south-eastern New South Wales from Robertson all the way south to north-eastern Victoria. It’s distribution extends from the Shoalhaven River in the north, then south through the Clyde, Deua, Tuross, Brogo, Murrah, Bega, Towamba, Womboyn, Wallagaraugh and Genoa rivers, as well as all the smaller coastal rivers and creeks running into all the inlets, lakes and bays down the coast. Found from 50 m to 895 m a.s.l it is a widespread and abundant species.
We observed Euastacus yanga to commence breeding in mid May in water temperatures between 11.3-12.1°C. The berried females nurtured their eggs and young till mid November to mid December when they released their brood into the streams. A huge amount of information was gathered as part of the surveys and this will be compiled into a peer reviewed scientific manuscript.
Membership to the Crustacean Society in now due. I’m a member and recommend if you have an interest in Crustaceans you should also join up. The mission of the Crustacean Society is to advance the study of all aspects of the biology of Crustacea by promoting the exchange and dissemination of information throughout the world.The Crustacean Society publishes The Journal of Crustacean Biology with free access to members. For the last 30 years they have published four issues per year, but since 2012 they have been publishing six issues per year. Check out the website http://www.thecrustaceansociety.org/ and join up.