Chasing Ephemeral Lakes August 31, 2009
- Ephemeral beauty
It is quite remarkable how an innocuous bit of pindan bush, glimpsed as a blur from the window of your car, can in fact harbour a wetland wonderland. Ephemeral water systems (lakes, marshes, swamps, wetlands) are so called for their cycle of filling and drying with the seasons. These areas are incredibly important habitats for a host of plants and animals – some of which may not survive without this water.
SKIPAs and Broome TAFE went chasing ephemeral lakes in the central Dampier Peninsula on the last weekend in August ’09. We started east of Beagle Bay. A short walk through tall dry cane grass, startling a family of quail and donkeys on the way, revealed a wetland wonderland.
- As the Dry intensifies this marsh will retreat until the rains return
Creamy flowered marshworts speckled the silvery water, grasses and herbs thrived, paperbarks and freshwater mangroves were in bloom, while the air hummed with insects and bird-song. The claypan was alive. And by looking closely you could find tiny treasures growing in the spongy ground.
- Nymphoides beaglensis, an aquatic Marshwort, is limited in the Kimberley to waterholes close to Beagle Bay
The clumping herb Eriocaulon cinereum has small flower heads atop its narrow leaves making it look like it’s wearing Martian headgear.
Peppered through the grass were delicate flowers, which looked like they had escaped from an English meadow but in fact were deadly hunters; Byblis liniflora and Drosera petiolaris have sticky leaves perfect to catch and digest insects.
The best view of these beauties is up close on hands and knees and if you are lucky you might spot what they’re having for dinner. There were several different types of these plants, sometimes called Sundews for the way the light catches the sticky hairs.
- These sticky leaves trap ants and small flying insects for dinner
- Insect hunter Byblis liniflora
- Nectar laden blossoms on the Freshwater mangrove
- Red or lime green blossoms covered many Melaleuca nervosa. Their slender warped trunks showed signs of past fires.
The next lake we visited was much more substantial and permanent. Lake Louisa (will try to find the Aboriginal name) was as big as a footy field. At first glance it was as green and grassy as one, and in a trompe l’oeil it looked like small sheep were grazing too. It was in fact a lake of grassy water chestnut and grey-blue waterlillies above the green!
- Lake Louisa, looking like a paddock with its sea of grass
It didn’t take long for a few keen SKIPAs to pull off shoes and socks and wade into the cool clear water to a chorus of Red-Tail Black Cockatoos and flocks of ducks.
- Doc digging up water chestnut
- Carmel and Cupar enjoying the fresh water
River red gums, complete with tide marks and some with unusual aerial roots, paperbarks and Freshwater Mangrove Lophostemon grandiflorus dominated the lake edge, along with Nardoo Marsilea mutica, a fern masquerading as a four-leave clover which enjoys wet spots. There were messy stick nests in a number of trees, plenty of bird life from Flycatchers to Egret, and it’s probable that Brushtail possoms had hollows high up in the trees. This area would have been very important to Aboriginal people living off the land, as well as animals, during the hot dry season as it offers both refuge and sustenance. It was a perfect place to dry off and enjoy a cuppa.
- An unusual, and unidentified aquatic plant. Seems to have four bladders to hold flower head above water, but the black capsules in its root system were a mystery. Can you help?
- A vast area of aquatic plants cover Lake Louisa
We visited another two seasonal wetlands and enjoyed identifying the range of trees and small plants. The sheer amount of water still around at this time of year surprised us.
Donkeys are clearly prevalent in this region, judging by the amount of dung and animals we saw. On the way into Lake Louisa we saw two adults and a foal. Further south, towards Nillabubicca, wetland systems accessible to cattle showed significant signs of hoof damage. Some SKIPAs members expressed concerns about the damage feral pigs would cause in these fragile wetlands.
Unrelated to ephemeral lakes, was the big boab we came across, close to the coastal marsh that borders King Sound. And this boab was HUGE!!! It had a three pronged girth and wild branches as big as tree trunks, which sprawled in an ungainly manner to the ground.
- Ancient, massive and craggy. This big boab has seen a lot of Dry seasons
SKIPAs member, and author of The Boab Tree, Pat Lowe declared it the biggest boab she had seen in all her trips out bush, and she was very quick to scramble up inside, using the knobbly bark as hand holds.
- Looking up into the centre of the boab
- It took 19 people holding hands to encircle the boab in a big SKIPAs hug
Thankyou to Beau and Alison Bibby and Phil Docherty for planning and organising the trip.