The aquatic fauna of King Island's streams and wetlands
Davies, PE and Brown, K and Sloane, T and Walker, Rodney and Cook, LSJ (2002) The aquatic fauna of King Island's streams and wetlands. Project Report. Freshwater Systems, Hobart.
|PDF - Requires a PDF viewer|
King Island has a wide range of freshwater aquatic environments including rivers and
streams and ephemeral and permanent wetlands (ponds, swamps, lagoons). The fauna
of these environments is not well known, and the writing of this chapter required
some new sampling to be done. As a result we now know that the island has many
species (more than 140) of aquatic macroinvertebrates, including burrowing crayfish,
aquatic insects, freshwater crabs and snails, as well as eight species of freshwater fish.
The island is highly seasonal in its rainfall, and, as a consequence most of the streams
and rivers have very low or no flow during the summer and autumn months. Some
sections have permanent water, especially near the coast or those associated with
springs or escarpments.
The landscape of the island has changed substantially since European settlement, and
significant changes have occurred to its freshwater habitats. Most of the catchments
no longer have their original vegetation cover, and that, coupled with intensive
agriculture, has undoubtedly led to changes in stream flows and water quality.
Changes to the bankside or riparian vegetation have been significant, with many
stream sections and wetlands now having no or limited areas of natural riparian
vegetation (1), and with many of these areas being accessed by stock, with effects on
bank erosion and water quality. There is evidence of higher levels of turbidity,
nutrients and salinity in several streams, as well as in some wetlands (2, K Brown
Before European settlement, most of the streams on the island were swamp-channel
complexes with shallow channels containing large amounts of woody and other
organic matter, often overlying sands. They were heavily shaded, slow flowing
(except for in the south east) and many sections probably experienced seasonal
(summer) drops in dissolved oxygen levels due to decomposition of organic material,
during periods of slow flow and higher temperatures. In some cases, surface waters in
swamps and lagoons and some stream sections were probably devoid of oxygen and
contained hydrogen sulphide (rotten egg gas). This can be seen today in places like
Collier's Swamp. Overall though, water quality was probably better than today, and
stream habitats were more uniform across the island.
Despite these changes and the highly seasonal rainfall, the majority of streams and
wetlands on the island still manage to maintain a reasonably diverse fauna, which in
many cases is highly abundant.
|Item Type:||Report (Project Report)|
|Keywords:||Aquatic fauna, stream, King Island, freshwater|
|Deposited By:||utas eprints|
|Deposited On:||24 Nov 2006|
|Last Modified:||18 Jul 2008 19:43|
|ePrint Statistics:||View statistics for this ePrint|
Repository Staff Only: item control page