Australian Aquatic Biological

Australian aquatic biodiversity research and consultancy

Conservation of Imperiled Crayfish, Euastacus dharawalus

 

The Fitzroy Falls Crayfish Euastacus dharawalus

The Fitzroy Falls Crayfish Euastacus dharawalus

Our conservation paper on Euastacus dharawalus has been published in the Journal of Crustacean Biology which is published by The Crustacean Society. This is the second conservation paper I’ve published with them and hopefully we will do many more in the future. For the last 30 years the Crustacean Society has published four journal issues per year, but since 2012 they are doing 6 issues per year. They are a non profit organisation and I’m a happy member who recommends if you have an interest in crustaceans you should join.  www.thecrustaceansociety.org/  The mission of the Crustacean Society is to advance the study of all aspects of the biology of the Crustacea by promoting the exchange and dissemination of information throughout the world. This latest paper is titled:

McCormack, R.B. 2013. Conservation of Imperiled Crayfish, Euastacus dharawalus(Decapoda: Astacidea:Parastacidae), from the southern highlands of New South Wales, Australia. Journal of Crustacean Biology, 33(3), 432-439, 2013.

Conservation of Imperiled Crayfish Euastacus dharawalus

Conservation of Imperiled Crayfish Euastacus dharawalus

Members receive online access to Ecdysiast plus online and print version of Journal of Crustacean Biology.

This was an important paper as the New South Wales Fisheries Scientific Committee has listed Euastacus dharawalus as Critically Endangered. This is the first Euastacus crayfish to be listed as critically endangered by any state or the federal Government. It is illegal to catch and keep, buy, sell, possess or harm Fitzroy Falls Spiny Crayfish (Euastacus dharawalus) without a specific permit, licence, or other appropriate approval, and significant penalties apply. For critically endangered species, these penalties can include fines of up to $220,000 and up to 2 years in prison (Fisheries NSW).

Fitzroy Falls plunging 80 m into the valley below

Fitzroy Falls plunging 80 m into the valley below

Euastacus dharawalus has a very restricted distribution only known to occur above the Falls. If you are one of the 300,000 visitors/year that visit the walks and viewing platforms above Fitzroy Falls then take the time to have a look in the creek. If you’re lucky you may see one of these critically endangered crayfish scavenging along creek bottom.

The Giant Spiny Crayfish (Euastacus spinifer) from the Blue Mountains

The early morning view from one of the lookouts at Wentworth Falls

The early morning view from one of the lookouts at Wentworth Falls

A quick survey of some of the mountain streams in collaboration with Blue Mountains City Council proved most enlightening. The local streams draining through suburban areas seemed to have abundant numbers of freshwater crayfish and fish. We were very satisfied with the aquatic health of the streams we surveyed and following is a precis of the main species we encountered in abundance.

Photo Euastacus spinifer

Photo Euastacus spinifer

Euastacus spinifer is a Giant Spiny Group Crayfish was abundant in the Wentworth Falls area. They are a giant species that grow to a huge size of 1 kg or more and can have spectacular colours. The adults prefer the permanent clear flowing sections of streams and rivers and are active both day and night and can generally be seen wandering the creeks during the day, especially mid-afternoon onwards. In the clear mountain streams if you are quiet and patient you will see them wandering along the creek bed forever in search of tasty morsels.

The Giant Spiny Crayfish Euastacus spinifer

The Giant Spiny Crayfish Euastacus spinifer

Also in the same stream were large numbers of native fish. Both the Mountain Galaxias Galaxias olidus and the Australian Smelt Retropinna semoni were abundant in the streams with schools of 100 fish very common.

The Mountain Galaxias Galaxias olidus

The Mountain Galaxias Galaxias olidus

The Australian Smelt Retropinna semoni

The Australian Smelt Retropinna semoni

 

 

 

 

Engaeus fultoni from the Otway Ranges Victoria

 

Adult Engaeus fultoni 3 g, 16.4 mm OCL

Adult Engaeus fultoni 3 g, 16.4 mm OCL

Early February 2013 saw an expedition through the Otway Ranges and the Great Otway National Park. This is a fantastic tourist destination with the park stretching from Torquay through to Princetown and up through the Otway’s hinterland towards Colac. The park has everything, featuring the rugged coastlines, sandy beaches, rock platforms, windswept heathland, tall forests, ferny gullies, magnificent waterfalls and tranquil lakes. Most of our time was spent along the ranges in the lush forests under the tree ferns.

Youngs Creek, Great Otway National Park

Youngs Creek, Great Otway National Park

I met up with Steve Chara a well-known yabby farmer from the Torque area and we headed off together to chase a few crayfish along the Otway Ranges and into the Great Otway National Park.

Juvenile Engaeus fultoni 1 gram, 11.5 mm OCL

Juvenile Engaeus fultoni 1 gram, 11.5 mm OCL

The subject of our quest was the burrowing crayfish Engaeus fultoni that is well known in the area with local residents and park rangers commenting on its bright red colouration and nocturnal habits.

We had little difficulty locating this animal and it was locally abundant in all the higher wet areas we searched. Though you cannot actually see the animals you can identify their burrows by the excavated material they have pushed to the surface that is mounded into a small chimney/mound. It seemed an extremely robust species being found along the edges of watercourses and well up the mountain sides in seemingly dry areas throughout the forests.

Engaeus fultoni burrow entrances

Engaeus fultoni burrow entrances

It was an interesting species with large established burrow systems being exceptionally deep. We excavated to approximately 1.4 m without determining the bottom of the burrow complex. These large “traditional” burrows would have 6-8 surface entrances with relatively vertical burrows down to chambers and then more burrows continuing down. These large burrow systems contained large numbers of juveniles and that was all we were able to extract. We expect the large adult/s were deeper beyond our reach.

Most of our adult crayfish were captured by excavating relatively new burrow systems. These consisted of freshly excavated material with a single surface entrance and down 500-700 mm to a small water filled chamber. Invariable we would capture a single adult from these newly constructed burrows.

Engaeus fultoni female, 5 gram, 19.37 mm OCL with 93 eggs

Engaeus fultoni female, 5 gram, 19.37 mm OCL with 93 eggs

We encountered female Engaeus fultoni with eggs during our surveys and we observed this 5 gram, 19.37 mm OCL female with 93 eggs. (If you look closely they are actually hatchlings, stage 1 juveniles)

Steve at our campsite for the night

Steve at our campsite for the night

It was great survey with exceptional results but camping sites were at a premium and we ended up camping in the forest  along the top of the range well away from the creeks. But even here on top of the mountain, there are Engaeus burrows only 1 m behind our vehicle.

 

 

Juvenile Euastacus hystricosus

Juvenile Euastacus hystricosus

This is a picture of a juvenile Conondale Spiny Crayfish (Eustacus hystricosus). It’s about 25 mm long and snapped by Chris Van Wyk in January 2013. These newly released giant spiny crayfish have the white bands typical of the spiny group and this is a great photo showing those bands. As the crayfish grows the bands will fade, so they only have them for the first 4 months or so.

Springbrook National Park, Gold Coast Hinterland, Queensland.

Late December 2012 we had an expedition along the McPherson Range and into Springbrook National Park in Queensland. This was the first of a series of surveys in south eastern Queensland and northern NSW. We are specifically surveying for Cherax and Euastacus crayfish but are recording all crustaceans captured. Paul and I surveyed all the popular tourist areas within Springbrook National Park as well as some of the more unusual areas.

Paul and I camped at The Settlement campground which was quite pleasant.

Paul and I camped at The Settlement campground which was quite pleasant.

The weather was less than perfect and finding our way through the forest was less than easy.

The weather was less than perfect and finding our way through the forest was less than easy.

 

Paul catching Euastacus sulcatus in Purling Brook.

Paul catching Euastacus sulcatus in Purling Brook.

Photo Euastacus sulcatus

The streams in Springbrook national park were full of Euastacus sulcatus. This E. sulcatus from the Tallebudgera Creek drainage had juveniles under her tail.

Photo the Lamington Crayfish Euastacus sulcatus

This male Euastacus sulcatus from the Little Nerang River was out at night and we spotlighted large numbers of Euastacus during our night time surveys.

Photo Sphagnum Frog (Philoria sphagnicola)

Frogs were common throughout the area, not sure what this is. Perhaps a Loveridge’s Mountain Frog (Philoria loveridgei) from Tallebudgera Drainage at 800m. If anyone can let me know what it is that would be great.

 

Frog photo

Larger frogs liker this were common at night in the Little Nerang Drainage at 750 m.

Photo Dragonfly

Dragonflies were also common around the streams and rainforest.

Photo Euastacus maidae

Paul with an adult Hinterland crayfish Euastacus maidae.

Our surveys of Springbrook National Park and the McPherson Range was extremely enlightening and we will revisit the area for more intensive surveys in the future. Our thanks to the Queensland National Parks and Wildlife Service for all their help and assistance with our preliminary surveys.