My Giant Tale

I am proud to be the first person to study the life history of this amazing species for my PhD . The research I did from 1985 to 1992 layed the groundwork for the eventual total protection of this species in 1999. 

 COMPARATIVE REPRODUCTIVE BIOLOGY OF THE TASMANIAN FRESHWATER CRAYFISHES Astacopsis gouldi CLARK, Astacopsis franklinii, GRAY AND Parastacoides tasmanicus CLARK (DECAPODA: PARASTACIDAE).  Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy University of Tasmania January, 1990. 

My full PhD thesis can be dowloaded here: https://share.google/F72MrjuFkKaOLNorG

All photos are copyright ( P. Hamr)

My first encounter with the Giant Freshwater Crayfish in my then girlfiend's undergraduate zoology text.  I was doing my Masters thesis (on crayfish ofcourse!) at Trent University in Canada but had never seen or heard of this magnificent animal. There was one recent scientific paper on (the distribution only ) Astacopsis. I wrote a letter to the two authors, and luckily one of them (Dr Alastair Richardson) was interested in taking on a PhD candidate from the other side of thwecworld , and a year later I was on the plane to Tasmania! (I married the girlfriend and we went on a 7 year honeymoon).

Mr Ray Wescombe from Penguin, North West Tasmania (pictured above with his biggest catch - 65 cm long!) was a life-long Giant cray-fisherman  who preserved the shells of his biggest catches over the years. The Inland Fisheries purchased his collection in 1985 to prevent the trade in crayfish trophies.  Ray also directed me to my PhD sampling site where there was a good population but with few large crayfish (due to past fishing pressure).

Lee Hamr airbrushing a display specimen from Ray's collection, destined for the Inland Fisheries Commission. The finished product is pretty impressive!

Some highlights from my  7 years  of studying Astacopsis gouldi:    all pictures copyright PHamr

Measuring and marking:  the tagging was primitive those days consisting of punctures on the tail fan and scratching a number on the carapace. This was No 1 ! The pattern usually persisted trough 1 moult.

I used drop nets, snorkeling, baited "tangle" nets and single baited lines to catch crayfish.

My Last PhD sample: February 1988 with my supervisor Dr Alastair Richardson and Zoology head technician Mr Ron Mawbey:  Measuring and marking with Alastair, Ron photographing crays and one of his great underwater photos.

After finishing my PhD, I did a postdoc (on endangered fish!) but while at Inland Fisheries, I was also responsible for all things crayish. This is "Cedric" one of the biggest crayfish I caught in the 7 years.

My very last trip in February 1992 : stills  from the video by TasTV's Cassie O'connor (see video section for the complete story)

Selected Giant Crayfish Litterature

Hamr P (1996). A giant’s tale: the life history of Astacopsis gouldi (Decapoda: Parastacidae). Freshwater Crayfish 11:13–33.

https://www.researchgate.net/publication/284286938_A_giant's_tale_The_life_history_of_Astacopsis_gouldi_Decapoda_Parastacidae_a_freshwater_crayfish_from_Tasmania#fullTextFileContent

Walsh T. & B. Haller  (2013) A study of growth and moulting rates of Astacopsis gouldi Clark Freshwater Crayfish 19(1):97-101.

https://www.researchgate.net/publication/269664334_A_study_of_growth_and_moulting_rates_of_Astacopsis_gouldi_Clark

The Freshwater and Land Crayfishes of Australia.  a landmark scientific paper published by Australian Astacologist  Ellen Clark in 1936 describing A. gouldi for the first time. https://www.biodiversitylibrary.org/page/52382808#page/9/mode/1up

Lobster Tales, an  excellent series of articles by Prof Terry Mulhern about A. gouldi in Fourty South Magazine (Tasmania).  https://fortysouth.com.au/author/terry-mulhern/

Historical notes & Photos

The Tasmanian Aboriginals probably feasted on these when they travelled inland as they would have been abundant in the undisturbed catchments of all the rivers, though now there are very few remote creeks and rivers where they haven’t been fished to some degree.   Old bushman tales claim that there were giant ones that grew over 6 kilograms. These for all we know, could have lived to be a century old. Prior to mass forest clearance and habitat disturbance it was said that people came back from fishing trips with potato bags full that were caught within an hour, claiming to throw anything back in the water that was smaller than 2 kilograms.

Adapted rom Tasmanian Times.com

One of the first descriptions of Astacopsis comes from G. Smith's book in 1909:  "The northern Crayfish grows to nearly two feet in length, and may scale eight or nine pounds; it is dark green in colour, and studded on the claws and gill covers with blunt tubercles; the claws of the larger specimens are formidable weapons about the size of a man's hand. We obtained the largest specimens from Muddy Creek, a small rivulet that one could easily step across, and it seemed extraordinary to fish these huge monsters out of little pools in which one would expect to find nothing larger than a minnow." 

Geoffrey Smith, 1909  in his book  "A Naturalist in Tasmania".

Web Sites

This project by Mount Roland Landacre in NW Tasmania was inspired by Kentish Councillor Don Thwaites, who on several occasions has observed giant freshwater crayfish walking across Union Bridge Road in the Minnow Catchment. 

Videos

TasTV video I made about Astacopsis gouldi in February 1992 just before leaving Tasmania. This was the fist news story to raise the concern about the conservation of the species.  Nove of it was staged, they filmed me  while I was sampling in the Little Forester River in the North East of Tasmania. (The reporter is Cassie O'Connor who eventually became the Green Party leader and  member of fedral and state parliaments).  

Stories Lived/Wilderness Society video about further protection for A. gouldi . This is an older video but many of the concerns are still valid.

NRM North video on working with landholders and the community to recover populations of Tasmania’s giant freshwater crayfish, by restoring 15 km of high priority river reaches in the Pipers, Brid and Boobyalla catchments by June 2023. The project is supported by NRM North, through funding from the Australian Government.

Discovery Channel video with Jeremy Wade and Todd Walsh (a friend and crayfish researcher) about Tasmanian Giant Freshwater Crayfish (Astacopsis gouldi ). 

Beautiful footage by Daniel Costelloe of a  A. gouldi female  in the St. Pats River.  The species is thought to have been in troduced into this watershed but now appears abundant in the river.  I caught my biggest male there!

A Tasmanian Living video about the Lobster Ponds "sanctuary"  & tea room in Flowerdale, Northern Tasmania. Worth a visit if you want to see one the easy way and have a cuppa!