Oysters – Canaries of our Estuary

laurie-derwentLaurie Derwent spoke at our 24 October 2016 meeting on the rise, fall and eventual demise of the oyster industry along the Georges River.

The Derwent Family were involved in the oyster industry for the best part of 100 years. Lauries spoke from his personal experience as an oyster farmer in his youth and over 35 years experience working for various fisheries and maritime agencies until his retirement in 2013. During his lifetime, Laurie has seen the river change from an ideal oyster-growing environment to a “disaster”.

oysters-from-georges-river

He spoke of the rich history of the estuarine areas around the Georges River – home of the world’s best oyster: Saccostrea glomerata (Sydney Rock Oyster).

He spoke of its cultivation from the early days in 1880’s: when stone was cut, and laid around the estuary to capture spat; and the rack method where oysters were suspended above the mud to avoid the mud worm.

As the production and the demand for oysters increased, this sustainable industry supported many farmers for generations. Then the troubles began with E. coli infection from water pollution; TBT (antifouling paint) influence on shellfish; introduction of rogue Pacific oyster; and the death knell itself – QX in 1994. This parasite ruined the oyster industry in the Georges River and the livelihood of many local farming families.

The humble oyster spends its entire life protected by its sharp shell feeding on the nutrient provided by the healthy River. But as our city continues to grow unabated, and our sewerage and drainage infrastructure buckles, our precious river engorges on a toxic cocktail and the humble oyster is stuck between a rock and a hard place.

PLEASE CLICK HERE FOR FULL POWER POINT PRESENTATION

neverfail-bay-oyster-lease-remnants Neverfail Bay Oyster Lease Remnants oysters-on-shell-bed Lime Kiln Bay Oyster Shell Bed tray-cultivation-oatley-pk Oatley Park Tray Bed Cultivation oyster-trays Pulling up Oyster Trays

 

 

 

 

 

Central Asia

105Talk on Central Asia on 26th September by Julian Sheen

This presentation grappled with the complex history of Central Asia, sometimes known as the five Stans (Kazakhstan, Kyrgyzstan, Uzbekistan, Tajikistan and Turkmenistan).

71Culture, mixing history and geography, dealt with the nomadic tribes of the steppe and the limited influence of China. Stories of such exotic peoples and places as the Sogdians, the Parthians, and the Saminids with Samarkand, Bukhara and Ashkhabad were traced along the great artery of central Asia: the Amu Darya (or Oxus River).

27The backdrop was the towering mountains of the Pamir and Tienshan and the parchment dry of the Karakum desert.
Alexander the Great made his mark here in 320BC, later came the Islamic invasion of the Arabs, the contest with China and the growth of Persian influence leading to the golden age of the Islamic enlightenment (about 900-1200AD).

57Much of this was swept away by the crushing impact of the Mongols in 1220AD followed by the destruction brought about by Tamerlane. Threading though this vivid historical tapestry of beauty, delicate artistry, violence and terror were the Silk Road caravan routes to and from China, India, Persia and Europe.

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Finally, in the 19th century when the region was fragmented and in decay, the Imperial Russians moved in to face the British Empire active in India and Afghanistan; contestants in what became known as the Great Game. From Russian rule was spawned the Soviet Union which collapsed in 1991 bringing about the five republics we know today.

Flora and Fauna of Northern Alaska

BearsForestOn 22 August Rodger entertained us with another one of his adventures.

On this trip he travelled the notorious Dalton Highway from Fairbanks to Deadhorse, Alaska.

This road featured on the TV programWorlds Most Dangerous Roads”.  See below for video played during talk. Before  1996 it was only open to trucks supplying the Alaskan oilfields. Despite the harsh environment, plants and animals manage to survive.

Rodger talked about their life on the edge of the Arctic Circle . Life in the extreme temperatures at 70 degrees north is tough.

Last treeMost memorable photo from the night was the Northern most spruce tree (now chopped down!)

CLICK HERE TO SEE PRESENTATION

CLICK HERE TO SEE DALTON HIGHWAY VIDEO

 

 

Coal Mining & Water Pollution

River bed crackingAt the October meeting of Oatley Flora and Fauna Conservation Society, Dr Ian Wright from the University of Western Sydney (UWS) presented startling evidence of environmental damage caused by coal mining in the Sydney Region. Dr Wright worked as a scientific officer with Sydney Water investigating the impact of human activities on creeks and rivers in the Sydney basin before taking up a research fellowship at UWS in freshwater ecology and water pollution.

Ian is now a full-time lecturer teaching students in water quality and management, environmental planning and environmental regulation areas. Conducting his research on a limited budget and often faced with a hostile reception from mining interests in the Blue Mountains and Southern Highlands, Dr Wright and his students have persevered, comparing water samples taken upstream of mining activity with those down stream. They have found significant deterioration in water quality attributable to waste water discharge from mining operations. Toxic levels of salt, bicarbonate, zinc, nickel and other minerals have impacted on aquatic life and degraded the waters flowing through prized wilderness areas and World Heritage sites. yshattered_river_bed

Long-wall mining, in particular, is responsible for subsidence in the bedrock of some creeks and streams feeding into Sydney’s water catchments. Dr Wright showed photographic evidence of streams simply disappearing into cracks, only to re-emerge further ‘downstream’ polluted by mining waste. Dr Wright was critical of the Environmental Protection Agency, responsible for regulating the discharge of wastewater from mines. Pollution licence conditions need to be tightened requiring mining companies to meet higher standards, although he conceded the regulator had lifted its game recently but only under pressure from the community and, in turn, government.

Asked how Oatley Flora & Fauna Conservation Society members could help to stop mining companies from causing environmental damage, Dr Wright suggested the best way would be to keep the pressure on our politicians to introduce more stringent rules on mining activities. Dr Wright gave an undertaking to keep the Society informed of future developments in the regulation of the coal industry.

Ian Wright-OFF-presentation-Short-8-nov-2015

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Impact of a coal mine waste discharge on water quality and aquatic ecosystems in the Blue Mountains World Heritage area.

FOR MORE INFORMATION SEE DR WRIGHT’S PUBLICATIONS CLICK HERE FOR MORE ABOUT UPLAND SWAMPS

15 NOVEMBER 2015 – LEADER ARTICLE “Coal Mining Risk revealed at Conservation Society meeting”

Microbat Predation on Mosquitoes

MicrobatDr Leroy Gonslaves studied the diet of microbats that live on the Central Coast for his PhD. His study area in Empire Bay has large areas of saltmarsh, which can support huge numbers of mosquitoes at different times of the year. Apart from nuisance biting, these particular mosquitoes have the potential to spread diseases such as Ross River and Barmah Forest viruses – which can cause rashes, fever and rheumatic pains. To See Powerpoint of Talk Click Here ( 75MB) Dr Gonslaves has also surveyed 56 Sites across Sydney for Microbats. Click here to see Sydney Morning Herald article

Bhutan – the Dragon Kingdom

IMG_0061Graham Fry’s talk about this intriguing Himalayan country drew an audience of 57. In April 2013 Graham and Liz visited Bhutan during a tour of the ‘wrinkled edge of the sub-continent’. Their group flew into Paro near the capital Thimphu and drove east in a small bus. Their route traversed a series of high passes and deep valleys that challenge road builders and divide the largely rural population into many ethnic and linguistic groups. It was spring and rhododendrons and primulas were flowering in the montane forests, and apple and peach blossom was appearing on farms along the snow-fed river valleys. In the eastern lowlands lemongrass, mandarins and bananas were under cultivation. All tour groups must be accompanied by a licensed Bhutanese guide and theirs was a forester who was expert at locating rare and spectacular birds including Satyr Tragopan, Beautiful Nuthatch and Rufous-necked Hornbill. Bhutan is a biodiversity hotspot and the constitution requires sixty per cent of the country to remain forested. IMG_0012-001Bhutan is undergoing rapid development but strives to maintain its traditional cultural, spiritual, environmental and ethical values, with the goal of improving Gross National Happiness. The constitution states “it is the fundamental duty of every citizen to contribute to the protection of the natural environment, conservation of the rich biodiversity of Bhutan and prevention of all forms of ecological degradation …”. The major sources of income are export of hydroelectricity to India, and tourism. Tourism is controlled by limiting visas and setting a high threshold for daily expenditure; a tourism royalty contributes to social services for disadvantaged citizens. Of thirteen traditional crafts practised in Bhutan, the most famous is weaving; Graham and Liz displayed examples.  CLICK HERE  for website describes some of the techniques, equipment and fibres used: rhododendron 2 Bhutan_2013 India2 404

The best ways to beat the bite of blood thirsty mosquitoes

Dr Cameron Webb was our first speaker for 2015 regaling the audience of 60+ members and guests with warm-blooded facts and anecdotes on mosquitoes and diseases associated with these pesky ankle biters. He has provided us some useful way to beat the bites.

cameronwebb_mosquitoes_theleaderMosquitoes found around the Georges River region are more than just nuisance-biting pests. Mosquito-borne pathogens, in particular Ross River virus, are regularly detected and there have been cases of human illness in the local area too. There is no mosquito control in the local wetlands so individuals need to take steps themselves to avoid mosquito bites. Long sleeved shirts, long pants and covered shoes will provide a physical barrier against mosquito but the use of topical insect repellents will be important too. There is a range of cheap, safe and effective repellents available in Australia. A repellents should be approved by the Australian Pesticides and Veterinary Medicines Authority (APVMA) who test for effectiveness and safety. There’s over 100 insect repellent formulations currently registered while dozens more unregistered repellents are commonly found for sale at various stores, markets and via online retailers. The best repellents contain either DEET or picaridin as these chemicals have been repeatedly demonstrated in testing to provide the longest lasting protection against a range of biting insects. Many reviews of the literature have shown that, considering the widespread international use of these repellents, there are very few adverse health impacts reported (keeping in mind that their use has probably saved many live from potentially fatal illnesses such as malaria or dengue).

By Paul Zanetti By Paul Zanetti

There are other types of repellents available. The most common are plant-based products such as tea-tree, eucalyptus, lavender, cat mint and peppermint oils. These repellents vary in their effectiveness but generally provide less protection than DEET or picaridin and if you prefer to use these types of repellent, it is important to remember that they’ll will need to be reapplied more frequently to provide comparable protection. mossie It isn’t all about choosing the right repellent, to prevent bites you’ve got to use it correctly. Regardless of formulation, there must be an even and complete cover of all exposed skin otherwise mosquitoes will find a way through. Reapplication is required after swimming or physical activity. Spraying repellent on clothes or giving a dab “here and there” isn’t going to provide protection. Although mosquito repellent patches and wrist bands have been registered they won’t “whole body” protection against mosquito bites. Using mosquito repellents is the best way to reduce the risks of mosquito-borne disease. If you’re out and about around the local wetlands and bushland areas, it is important to take measures to avoid mosquitoes so make sure you pack a tube of insect repellent in your bag this weekend. For more information see the recent article at The Conversation “Chemical or natural: what’s the best way to repel mozzies?” Dr Cameron Webb – Department of Medical Entomology, University of Sydney and NSW Health Pathology. Email: cameronn.webb@health.nsw.gov.au Twitter: @mozziebites  CLICK HERE TO SEE BLOG FOR MORE INTERESTING INFORMATION :

Dr Cameron Webb on Mozzie Menace

cameronwebb_mosquitoes_theleaderMosquitoes been bugging you this summer ? Stop those sleepless summer nights! Come hear Dr Cameron Webb, Medical Entomologist with the University of Sydney and Pathology Westmead Hospital, speaking on mozzies and mosquito-borne disease at the next  Oatley Flora and Fauna Society meeting Feb 23rd (Mon) 7.45pm  at Uniting Church Hall Fredrick St,  Oatley. For more information on Dr Cameron Webb see his blog at http://cameronwebb.wordpress.com  

Studying the Platypus

 

5651Dr Tom Grant of UNSW spoke on this subject at the April 28th meeting, a research interest in which he has been involved for 40 years. Click here for details of his publication

While the International Union for Conservation of Nature (ICUN) classifies the status of the platypus as a ’species of least concern’, he argued that it is more probable that it is vulnerable, due to its dependence on water in which to feed. Spread along eastern Australia from Cooktown and to Tasmania, more investigation is needed to determine the current platypus population. Large numbers were trapped and shot in the 19th century, and there are remaining threats to their continued conservation. They are no longer found in the streams of the Adelaide Hills, Mount Lofty Ranges, and Fleurieux Peninsula in South Australia, where they once occurred. platypusLg

The Platypus is mobile, reclusive and active throughout the night but most often seen around dawn and dusk. The male has a poisonous spur that it may use in its defence, but is predominantly used against other males during the breeding season. Capture can be risky as they drown if caught and trapped underwater for too long. Radio-telemetry has been used to investigate platypus biology. When foraging, the platypus’s main sensory organ is its bill, much more sensitive than its eyes and ears that are closed when underwater. It has receptors that detect touch, pressure, and electric fields from its prey.

imagesBecause platypus populations can be small or spread along rivers, and many animals are mobile, population numbers are difficult to determine accurately. The Australian Platypus Conservancy encourages the public to report sightings of platypus as a way of determining population sizes at particular places. The Platypus is protected, but threats to survival include mortality in illegally set nets and traps, and habitat degradation. Natural and regulated high and low flows ofwater through rivers and creeks can damage nesting and feeding sites.Fossils of ancient forms of platypus have been found in central Australia, but during the time when these species existed the areas were wet, not arid as they are now. The platypus is found in most areas where it was prior to European occupation of Australia, but its populations are probably lower.Platypus_in_its_habitat

Extreme weather events resulting from climate change are likely to decrease the size and distribution of platypus  populations. They depend on a stable supply of water, and droughts can reduce current, distribution and numbers. Floods have a detrimental effect on juvenile platypus survival. Foxes are predators and some populations in Tasmania have been prone to a potentially fatal fungal disease causing ulcers and lesions. Use of illegal fishing nets is also a serious problem, as Platypus need to surface regularly to breathe. http://www.platypus.asn.au & http://australianmuseum.net.au/Platypus

Hidden Treasures of Sutherland Shire

Bonna pointInterested in exploring Sutherland Shire? The list of Sutherland Shire’s hidden treasures from Christine Guthrie would be a helpful guide. Oatley Flora and Fauna members were presdarook pkented with an arm chair tour of these parks on 28 of October by Oatley local and former manager of Bushcare at Sutherland Shire Council Christine Guthrie. She shared her intimate knowledge of Sutherland Shire’s more interesting bushland with a strong emphasis on threatened vegetation and vulnerable habitat. Chris brought to our attention the salt marsh for migratory waders, pockets of littoral rainforest, remnants of turpentine/ironbark forest and an extremely rare beetle (the endangered Menippus fugitivus). The beetles feed on the rainforest tree Celtis paniculata at Grays Point Reserve.

These were only some of the gems discussed, proving yet again how important it is to ensure protection for what little remnant bushland we have. More on plants at: sutherland.austplants.com.au

Click here for full guide OFF Sutherland Hidden Treasures Locations.doc Bonna Point Reserve – Coastal Saltmarsh , Important fish breeding habitat

Marton Park -  Freshwater Wetlands
Charlotte Breen Reserve – Kurnell Dune Forest
Woolooware Cycle Track – Saltmarsh and mangroves. Taren Point Shorebird Reserve -  important feeding and roosting areas for wading birds
Bass & Flinders Point – Littoral Rainforest, endangered Ecological Community
 
Darook Park – Closed forest with predominantly rainforest specie
Shell Road Reserve – Remnants of saltmarsh and littoral rainforest on Gunnamatta Bay
Rutherford Reserve – Remnants of littoral rainforest and coastal heath, views to Maianbar and Bundeena
Burraneer Park – Remnants of littoral rainforest and access to the foreshore of Burraneer Bay
Beauford Park – Beauford Avenue, Caringbah. Coastal heath species and views to Royal National Park.
Lilli Pilli Point Reserve – Interesting selection of rainforest species not common in Shire, views to Royal National Park
Grays Point Reserve – Littoral Rainforest and endangered Population of the beetle Menippus fugitivus
Pollard Park – Sydney Turpentine Ironbark Forest
Port Hacking Road Reserve – River-Flat Eucalypt Forest on Coastal Floodplains
Paruna Reserve - Views across the Woronora River to Illawong.
The Glen and Koolangarra Reserves – Swamp Oak Floodplain Forest
Maandowie Reserve – Accessible via an extensive series of fire trails
Prince Edward Park – A large tract of bushland at the rear of the cemetery with extensive views over the Woronora River.
Menai Conservation Park – Shale/Sandstone Transition Forest in the Sydney Basin Bioregion
Lucas Heights Conservation Area – Extensive network of trails through ANSTO and council owned land. Click here for full guide OFF Sutherland Hidden Treasures Locations.doc