Lake Galilee (Queensland)

This large lake has six major wetland habitats and include:[7]

1. Dry saline clay flats which are seasonally flooded;
2. Fringing saline flats on the edges of the lake floor covered by low samphire bushes;
3. Sandy beaches around the edge of the lake, supporting a woodland of beefwood, other grevilleas, sally wattle and ironwood (Acacia excelsa);[10]
4. Red dunes around the southern part of the lake with gidgee woodland;
5. Freshwater swamps behind the dunes, with coolabahs and;
6. Fringing areas of open wattle scrub in the saline flood zone.

Regional ecosystems are assigned a conservation status based on their current extent in a particular bioregion. This status affords the regional ecosystem a level of protection from vegetation clearing. Regional ecosystems are classified as endangered if the area of remnant vegetation for the regional ecosystem is less than 10% of the pre-clearing extent of the regional ecosystem or the area of remnant vegetation for the regional ecosystem is 10% to 30% of the pre-clearing extent of the regional ecosystem and less than 10,000 hectares.

Out of the 52 regional ecosystems represented in the Lake Galilee catchment, the eight (listed below), are considered endangered.

1. Palustrine wetland. Mostly water or bare ground. Scattered forbs and grasses including Sclerolaena spp. may occur during dry periods. Occurs on infrequently flooded alluvial plains or fringing sandy closed depressions. (BVG1M: 34d) (10.3.16d);
2. Ironwood +/- beefwood low open woodland on lake fringing dunes over a calcrete hardpan adjacent to lake (10.3.17a);
3. Gidgee woodlands on lakeside dunes (10.3.19). This ecosystem is an unusual occurrence, having significant geomorphic values indicative of past climates. It is endemic to Lake Galilee. The deep fine sandy topsoils have very low fertility and are extremely susceptible to wind erosion. It is largely cleared for pasture development. Remnants are heavy infested with buffel grass. In December 2006, remnant extent was < 10,000 ha and 10-30% of the pre-clearing area remained, endangered under the VMA (Vegetation Management Act)[11] and the Biodivstat;[12]
4. False sandalwood low open woodland on alluvial plains (10.3.25);
5. Brigalow and blackbutt low forests grassy or shrubby woodlands (10.4.3a);
6. Blackbutt open woodland on Cainozoic lake beds (10.4.3b);
7. Blackbutt open woodland on Mesozoic sediments (10.9.3a);
8. Brigalow woodland on Mesozoic sediments (10.9.3b).

The Regional Ecosystem Description Database (REDD) lists the Biodiversity Status and the Vegetation Management Class (VM class) of each regional ecosystem.[13]

A further 13 regional ecosystems are “Of Concern”[14][15]

Lake Galilee is registered on the Directory of Important Wetlands in Australia (DIWA). The criteria for determining these nationally important wetlands are agreed to by the Australian and New Zealand Environment and Conservation Council (ANZECC) Wetlands Network in 1994.

Lake Galilee fulfilled four of the six criteria for inclusion as follows. It is a good example of a seasonal/intermittent saline lake with seasonal/intermittent freshwater ponds and marshes on inorganic soils in the Desert Uplands Region. It plays an important role in the natural functioning of a major wetland complex. It plays an important role in the natural functioning of a major wetland complex. It is important habitat for animal taxa at a vulnerable stage in their life cycles, or provides a refuge when adverse conditions such as drought prevail. It supports native plants, animals and ecological communities considered endangered or vulnerable at the national level.

Birds are listed as migratory species under the Environment Protection Biodiversity Conservation Act 1999 (EPBC Act), if they are listed under the Japan - Australia (JAMBA) and China - Australia (CAMBA) Migratory Bird Agreements and the Bonn Convention.

Migratory waterbirds make round trip migrations of up to 26,000 km each year between their breeding grounds in the Northern Hemisphere and their non-breeding areas in the south. These trips are made in several weeks, with brief stops at staging sites along the way to rest and refuel for the next leg of their journey.[20]

The corridor through which these waterbirds migrate is known as the East Asian - Australasian Flyway (the Flyway) . It extends from within the Arctic Circle, through East and South-east Asia, to Australia and New Zealand.[21] Stretching across 22 countries, it is one of eight major waterbird flyways recognised around the globe.[21]

Sharp-tailed sandpipers were recorded in a survey at the lake

Roger Jaensch conducted an aerial bird survey by helicopter around the lake in August 1998 (unpublished) and recorded at least 56,000 individual waterbirds at a series of shallow water bodies in the southern bed of the lake.

While five Asian-breeding shorebirds listed under the EPBC Act were recorded at Lake Galilee during a survey conducted by Jaensch and Reid (2008) for Wetlands International in collaboration with Australian National University.[17] They include godwit, marsh sandpiper, common greenshank, sharp-tailed sandpiper and pectoral sandpiper.

The survey in May 2008[17] also recorded 50 species and at least 20,000 individuals and confirming the international-level importance of Lake Galilee in terms of numbers of waterbirds supported. This survey also discovered internationally important numbers (at least 1% of the Flyway population) of sharp-tailed sandpiper across the four main wetlands of the Desert Uplands bioregion; Lakes Galilee, Buchanan and Dunn and Cauckingburra Swamp.[17]

The flowers of Parkinsonia aculeata, an invasive species in Northern Australia.

Parkinsonia and parthenium infestations pose the largest threat to the ecological integrity of this significant wetland.[6]

Parkinsonia forms dense, impenetrable thickets which restrict waterbird access to shoreline feeding and roosting sites, and provide a haven for feral pigs, which in turn disturb waterbird habitats.[27] It is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts.[28] Wetlands are particularly vulnerable because parkinsonia can invade watercourses, cause erosion, lower watertables and take over vast tracts of floodplain.[28] At Lake Galilee it germinates freely on the moist edges of the lake.

Parthenium is an annual herb with a deep taproot and an erect stem that becomes woody with age.[29] It is a vigorous species that colonises weak pastures with sparse ground cover and will readily colonise disturbed, bare areas along roadsides and heavily stocked areas around yards and watering points.[29]

Disturbance to the wetland areas from pest animals is mainly from pigs.[3] Feral pigs cause damage by disturbing nesting birds, predation on frogs and aquatic species (e.g. mussels) and uprooting lakebed and riparian vegetation.[8] Their role as a host or vector for diseases of cattle such as leptospirosis makes control of feral pigs particularly desirable for landholders and the wider community.[8]

Tree clearing, some overgrazing and the introduction of buffel grass has occurred near the lake in the past and has created some impacts on biodiversity, water quality, erosion and changes in sedimentation and substrate composition. The lake fringes are highly productive and are regularly used for grazing, particularly after spring or early summer rainfall. Constant grazing can damage forbs and grasses that grow naturally on the lake fringes and may create a buffel grass monoculture.[8]

More and more tourists are venturing into western Queensland and the most preferred campsites are on the edges of lakes and waterholes.[8] Visitors use the riparian timber for campfire fuel, especially hollow branches and logs and over a long period totally degrade habitat for hollow-dwelling fauna such as ducks, parrots, owls, bats and reptiles. Disturbance of nesting birds by human activity in the heat of a summer's day can result in the death of unhatched chicks. Unleashed pet dogs can also be devastating to ground-nesting waterbirds and can also disturb wading birds and ground-dwelling fauna. Some visitors also create new vehicle tracks, which tend to draw others to continually expand their presence and impact. Other issues include the inappropriate disposal of rubbish and human excrement.

Parkinsonia on the lake's edge

Invasive weeds are the biggest threat to the ecological values of Lake Galilee, which has the largest infestation of parkinsonia known in Australia. It covers approximately 5,000 hectares around the entire edge of the lake.[6] Parthenium is also an issue in and adjacent to the catchment. There are also small infestations of rubber vine and mother-of-millions that are being closely monitored and managed. Parkinsonia, parthenium and rubber vine are listed as Weeds of National Significance (WONS) and as declared Class 2 pest plants under Pest and Stock Route Management Act 2002. Management of weeds in the Lake Galilee catchment is a major priority for the landholders in the catchment.[6]

The current infestation possibly stems from one parkinsonia tree that was planted in the garden of the “Eastmere” homestead in the late 1800s. It has been spread around the lake's edge during various flood events (e.g. 1974, 1991, 2008, 2010), receding floodlines and prevailing winds.[6] The parkinsonia is currently in several stages of treatment and ranges in size of infestation from large, dense clumps of trees; to thickets of small trees; to isolated plants and mats of seedlings. Weed control is effective only in the summer (wet season) when the plants are growing and not in a stressed physiological state.

As the prevailing wind is from the south-eastern edges of the lake towards the north and west, the “Friends of Lake Galilee” group decided it was best to control the southern and eastern infestations first as they are “source infestations”. Some landholders have spent years controlling parkinsonia with some properties now being relatively clean. Of the “Friends of Lake Galilee” group six landholders have parkinsonia on their properties and two of the six also have parthenium.

Parkinsonia Field Day at Lake Galilee

Six are implementing five-year pest management plans. Their aim is to eradicate parthenium and to contain and eradicate, if possible, the source infestations of parkinsonia around the lake. As well as funded weed projects, landholders have carried out additional control works from their own resources. Chemical methods of control have included:[6]

• nonselective, broad spectrum herbicides for larger trees where there are no native trees;
• trialling aerial applications of herbicides for thick infestations;
• cut-stump and basal barking with a mix of herbicide and diesel for less dense thickets; and
• foliar spraying for seedlings.

The 2011-2012 Caring For Our Country funding has enabled the participating landholders to tackle 620 hectares of parkinsonia, which is approximately twelve per cent of the total mapped infestation area around the lake. Combined with the additional control works carried out by landholders it is estimated that the parkinsonia infestation is now down to half its original mapped area. Other control methods and chemicals are being used and trialed with varying degrees of success and the best methods for different circumstances are yet to be determined.

Fungus inoculation trials are being conducted on “Eastmere” and other properties further north. Capsules containing a fungus that causes dieback in parkinsonia are inserted into a hole drilled into the base of the tree.[6] Early results have been mixed, but Desert Channels Queensland and researchers are working with landholders to assess the potential of using fungus inoculation to control parkinsonia.[30]

Parthenium weed at Lake Galilee (Queensland)

Parthenium was transported into the Lake Galilee area from the north with cattle during drought times. About 430 hectares of parthenium exists on one property and one hectare on another property about 10 km upstream (north) of the lake. Because of its potential to spread around the lake edge and across the lakebed, the main aim is to prevent parthenium reaching the lake and to have the infestation completely controlled within five years.[6] The 2011-2012 Caring For Our Country funding has also enabled landholders to control 12 kilometres of parthenium along streambanks using a selective herbicide for the control of broadleaved weeds.[6]

Hunting, trapping and baiting activities reduce the numbers of pigs to some degree and all property managers surrounding the lake are actively engaged in pest management.[6] Some landholders have found that the extreme drought years have the biggest effect on reducing pig numbers.[8]

The grazing properties surrounding Lake Galilee manage grazing pressure through stocking rates. Some fencing has been erected and alternative watering points have been placed adjacent to the lake to provide better quality water for stock and reduce trampling impacts at the lake edge.

Fencing of the whole lake area at this stage is not considered an economic proposition or a high priority for protection of the ecological values of the area; especially given the saline nature of the water and its corrosive effect on fencing materials.

Grazing management practices are already promoted in the Desert Uplands via a number of initiatives including a group of graziers using the International Standards for Environmental Management (ISO 14001) and a Natural Heritage Trust project sponsored through the Desert Uplands Development and Build-up Strategy group promoting on-ground nature conservation.[15]

Other management actions carried out by the ‘Friends of Lake Galilee’ include signage for a tourist information centre (to control public access to the lake from stock route adjacent to Hazelmere Station); construction of bollards; a parking area; an information shelter and erosion control work.[6]

To help look after Lake Galilee and its important waterbird habitats, tourists are encouraged to camp at Lake Dunn (commonly known as “The Lake”); it lies about 30 km to the southwest of Lake Galilee and is a popular bird watching and tourist spot.

It is a much smaller lake with facilities such as powered and unpowered camping sites and two small chalets available for hire. Water activities include swimming, water skiing, windsurfing and fishing.

Because of the presence of a caretaker and Lake Dunn's smaller size and more accessible shoreline, it is easier to manage tourism impacts.