For the past 12 months AABio has been surveying the coastal creeks, streams and swamps of the Coffs Harbour City Council’s local government area. The surveys are now complete and the final report has been issued to Coffs Harbour City Council.
The focus of the survey is freshwater crayfish and crustaceans but all aquatic organisms are surveyed and recorded. We were specifically surveying for Tenuibranchiurus crayfish which are a rare and cryptic species in the area. Typically we would catch 150 C. cuspidatus for only one tenuie. We found abundant Cherax cuspidatus and Euastacus dangadi in the region plus numerous other crustaceans. So far we have found five different species of freshwater shrimp. Most species found are common and expected in the area, however we did make some startling discoveries.
We found some unusual species like limpets but of significance was the discovery of an extremely unusual freshwater crab. We were surveying a coastal creek flowing through a suburban Coffs Harbour area and finding long finned eels (Anguilla reinhardtii), intermediate spiny crayfish (Euastacus dangadi), plague minnows(Gambusia holbrooki), empire Gudgeons (Hypseleotris compressa), riffle shrimps (Australatya striolata), glass shrimp (Paratya australiensis), eastern river prawns, (Macrobrachium tolmerum), toebiters (Stenosialis australiensis), which were all common, abundant and expected. What was not expected was finding a freshwater crab! Not just any ordinary freshwater crab but something quite unusual. It’s a first for the ACP we hadn’t found these before. If in doubt I always contact the expert in that particular field. In this case its Peter Davie from the Queensland Museum, he’s the man for crabs and I asked him, “what this!” He advised it’s a River Swimming Crab, Varuna litterata. A marine crab known to occur in freshwater, being excellent swimmers and able to move with the currents along the coast. In Australia they have only been recorded from south east Queensland and north into Northern Australia (Qld Museum). They are also known to occur in India, East Africa and Japan. The discovery of this species this far south greatly increases the known distribution of the species. A specific research projects to acquire new knowledge on this species has been started with The Australian Crayfish Project www.austcray.com Eventually we will submit a scientific paper on the range extension. For an article with more photos, site locations, water quality data, etc. Go to: River Swimming Crab Article. http://www.austcray.com/2014/08/river-swimming-crab-herring-bow-crab-varuna-litterata-2/
Our thanks to Coffs Harbour City Council and specifically to Rachel Binskin, their Biodiversity Officer for their support of the research project and patience awaiting its completion. The project dragged on longer than expected.
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.
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.
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.
In October 2012 we conducted a survey of the upper Clyde River with the priority being to determine the freshwater crayfish species present within the upper catchment. It is currently unknown which freshwater crayfish species occur in this pristine and mostly inaccessible area. Our survey aimed at filling this knowledge gap and also record the other species present within the upland creeks and swamps.
The survey was a team effort with a group of us getting together to find and survey as many watercourses in the area as possible. The team consisted of;
David Crass – Southern Rivers Catchment Management Authority
Hugh Jones – Office of Environment and Heritage
Rob McCormack – Australian Aquatic Biological and Australian Crayfish Project volunteer
Paul Van der Werf – Earthan Group and Australian Crayfish Project volunteer
The area of interest is entirely within the Morton National Park and with the aid of Libby Shields and Rob Perry who are the local National Parks and Wildlife Service rangers for the area we gained access to the whole park which has a series of maintenance roads through it. It was very fortuitous that we could gain access as it would have taken us ages to cover the area on foot. Libby told us some of the roads were currently impassable but we had Hugh Jones at the wheel of his Toyota troop carrier and though some of the roads proved extreme they were all passable for Hugh and his V8 diesel troop carrier.
Unfortunately, they were far too extreme for both Pauls and my Great Walls so we left them discarded along the side of the track and loaded into Hugh’s beast for an exciting 4 wheel drive adventure. We came within millimetres of rolling the troopy in a pothole at one point but Hugh ground us up and out of what we described as a bomb crater. Much of the area we were surveying was part of the old bombing range and there were signs up everywhere warning of unexploded ordinance.
The upland streams in the area were relatively cold being 9-12⁰C and very low pH (4-5) without much biodiversity. The upper streams were without fish though they did occur at lower altitudes. We were unable to find any shrimp, crabs, snails or mussels but both macro invertebrates and tadpoles were common and freshwater crayfish were abundant in many of the larger streams. The area was pristine and a tribute to the NSW National Parks for the management and protection of the area. This survey is part of a series of the area and a report on our findings will be submitted to the Southern Rivers Catchment Management Authority and we are thankful to them for assisting with funding for our surveys.
An Expedition into “The Myall Lakes National Park” – Gramastacus crayfish and Amphipods – and watching the dingo on my back trail!
I was surveying freshwater crayfish in the Myall National Park the other day and spent the day hiking by myself up the old Hawks Nest Seals Rocks Road and surveying the surrounding swamps. 20 years ago I used to drive this road and it was potholed then. Now it’s all a National Park and closed to vehicles and heavily overgrown in sections and still quite good in other sections. I think it’s an old mining road that is a raised, rocky road through the centre of the Myall swamps. Either side on the road is wet swampy areas that are impenetrable, reeds, saw grass, tee trees, paperbarks and swamp banksias, etc.
The procedure was to hike along the road and stop every kilometre or so, put on my waders and wander into the swamp to sample the aquatic fauna. I’d stop on the road, drop my pack, take off my hiking boots and put on my waders, grab my scoop net and bash my way through the scrub and scoop the underlying swamps. At the second site about 2 km in I noticed a large dingo about 50 metres up the track watching me. For the next several hours this large dingo just kept following me along the road always staying 50-100 m back. The track was alive with other life, mostly birds, the odd lace monitor and occasional snake. At the 7 km mark the dingo was still there and again I put on the waders, bashed about 6 mtrs off the road into the wetland and scooped the shallow water. All up less than 5 minutes scooping then back to the road to sort the catch, I would see what I had then take the tadpoles and macro inverts back and release them. As I climbed back onto the old road I looked back for my dingo and couldn’t see him, not a worry as he was a sneaky critter and liked to hide just peeping out to watch me. Anyway, I sat down on the road to sort the catch and glanced up the road in the direction I was heading and with a start there was my mate the dingo. The sneaky critter had passed me within 7 mtrs and I never saw or heard anything. It was a relief to have him in front as hiking along and watching my back trail was a hassle. For the next kilometre I followed him, then he disappeared and just before the 9km mark I saw him way in the distance heading north.
The crayfish were restricted to the smaller pools that still retained water as the swamps were drying out. Many of the Gramastacus crayfish were in berry. They are a small species and females with eggs weigh in at only 1.73 grams.
Much of the Myall freshwater swamps have large sphagnum moss areas and I was scooping the sphagnum looking for the freshwater crayfish that hide in it and was surprised by the large number of amphipods that were also hiding in the moss. Most of the larger female amphipods were also in berry with the eggs tucked up under the carapace between their legs. I don’t know the genus but they had very large gnathopods and very spiny legs. Perhaps sometime in the future I will identify the species. If anyone knows amphipods and can identify them please let me know.