Pandanus Mapping 2003
TIN CAN BAY AND GREAT SANDY STRAITS REGION
(Stage 1 in the proposed project: Cooloola Coast Pandanus Palm Recovery) Preliminary Report by volunteer Doug Collins Cooloola Coastcare Association Inc.
The aims of stage one are:
- To discover the distribution of Pandanus Palms in the Tin Can Bay and Great Sandy Straits area.
- To discover the extent of Jamella australiae infestation within the area.
- To determine a time frame for the control and future monitoring of the infestation.
Surveys conducted from January to March 2003, by walking, car and boat have located a large number of pandanus palms in the Wide Bay area. The largest number of plants, some one hundred, exists in the delta and middle reaches of the Searys Creek area which is now national park. Teebar Creek mouth area has a large population of plants at various stages of development. Plants are then dotted throughout Tin Can Bay inlet which could be an indication that spreading has occurred from these initial areas.
It appears that plants strike from ripe seeds and then mature as single plants. The mature tree drops its fruit and clusters of plants develop within the immediate area. Where fruit are waterborne it appears that the prevailing south-east winds, when strong, will wash them high enough onto fertile soil where they may strike and develop.
Should Searys and Teebar creeks be largely the source of fruit, few seeds have been transported well into the Great Sandy Straits. The density of the mangrove barrier has prevented many seeds from washing into the higher fertile land throughout this region. Many of the detected plants here seem to have been planted. Exceptions exist, however, as on East Stewart Island in the Garys Anchorage area there are about ten mature,thriving plants well behind a large mangrove barrier.
There is no accounting for private plantings, however, as these have been recorded in Rainbow Beach township, Cooloola Cove, Boonooroo, Maroom, Tin Can Bay, Stewart Island, Kingfisher Bay Resort and could occur anywhere within the region. Hervey Bay has a large population of healthy plants but there have been indications from long term residents that these have been planted. Duck Island has been in private hands until recently and has a population of approximately a dozen plants. Little Woody Island also has many plants.
Jamella infestation has been discovered in the Tin Can Bay township area ranging from Mullens Creek in the south to just north of Teebar Creek in the north. Various stages of dieback is occurring, ranging from lightly infested to dead plants.
The south-east winds appear to be a factor in spreading the Jamella leafhopper. Assuming that the infestation began at Tin Can Bay township from imported domestic or nursery plants all the infestation has been confined to the northern banks of the inlet and has spread north and south, but no infestation has been recorded on the eastern shores where the leafhopper would have to fly against this wind to spread. Distance across water may be a factor in slowing infestation spread but it appears that the quite wide creeks, Snapper and Teebar have not prevented the spread of the leafhopper. Fraser Island does not appear to be at immediate risk from the Tin Can Bay infestation as the distance across water is considerable. However even though no infestation has been recorded on Fraser Island the risk and consequences are considerable.
The Jamella infestation can be contained temporarily using chemical innoculation and leaf stripping but with much difficulty as access is varied and limited. Sandfly and mosquito presence is high, making the work extremely uncomfortable and repellant essential.
Many of the plants are only accessible by boat, so a reasonably large dingy capable of transporting equipment and personnel is essential along with protective clothing and suitable footwear. Many plant heads can only be reached with the aid of a suitable ladder. Biological control is at the experimental stage with wasp lavae having been introduced to the area in a sheltered, infested spot at Tin Can Bay.Considering the difficulties and distance to be covered, control of the infestation will not be quick or easy, but rather lengthy and painstaking.
DISTRIBUTION – widely throughout the Tin Can Bay inlet and sparcely throughout the Great Sandy Straits.
INFESTATION – confined to the northern banks of the inlet as far north as Dinnies Gutter and south to Mullens Creek
CONTROL – temporarily by chemical means but long term by biological means.
EQUIPMENT - large dingy and motor, GPS (global positioning system), protective clothing and footwear, binoculars, ladder, insect repellant, gloves, sunscreen, sunglasses. Sidewinder tree injector (backpack model), tree plugs, Confidor systemic insecticide.
PERSONNEL - Three or four fit and agile persons with great enthusiasm, determination and resolve.
TIME FRAME - Initially fifty full working days with ongoing monitoring.