Congolli (Pseudaphritis urvillii) discovered in five freshwater rivers across Kangaroo Island

December 6, 2017 | Posted in: Bony fishes, Coastal species, Freshwater systems, Research

Environment Minister Ian Hunter issued a Press Release on 5th December 2017 concerning the recent discovery of 27 congolli in 5 rivers on KI.

It announced that a fish species known as congolli had been discovered in freshwater rivers across Kangaroo Island for the first time.

The presence of congolli on Kangaroo Island suggests that the island’s rivers are providing healthy and essential ecosystem functions.

During a recent freshwater monitoring programme on Kangaroo Island, 27 congolli were found in five of the island’s rivers including Eleanor, Harriet, Cygnet and Middle Rivers and Deep Creek.

“This is an exciting discovery as species like congolli are important indicators of the health of freshwater systems and provide a baseline to inform how catchments on the island are managed in the future,” said Minister Hunter.

“Thank you to the Kangaroo Island volunteers, whose assistance was influential in making this discovery. With community support we aim to learn how we can balance the benefits to landholders who rely on access to water and provide for water dependent ecosystems.”

Background

Congolli are native to south-eastern Australia, but until 2017 had never been recorded on Kangaroo Island. The fish spends most of its adult life at sea, but the juveniles move to healthy freshwater habitats to grow. The greatest threat to the species is the installation of barriers which prevent migration.

The freshwater monitoring programme was funded by Kangaroo Island Natural Resources Management Board, Department of Environment, Water and Natural Resources (DEWNR) and carried out with community volunteers. The monitoring recorded baseline information about Kangaroo Island’s freshwater dependent ecosystems.

The baseline information will be used by DEWNR to identify issues relating to catchment connectivity and flow regimes on Kangaroo Island.

Further background

The agenda of the KI NATURAL RESOURCES MANAGEMENT BOARD MEETING 137 held on Friday 24 November 2017 provides some more background on the discovery.

It notes that “through this [freshwater catchment] monitoring a diadromous fish species congolli (Pseudaphritis urvillii) was discovered on Kangaroo Island for the first time.”

“Key outcomes or issues: A pilot project to assess diadromous fish communities in 10 freshwater catchments across KI was completed as part of the ‘Environmental Assessment of Water Management Options for KI’ project. Diadromous fish move between fresh and salt water over the course of their lives. The highlight of the monitoring was discovering the diadromous species congolli (Pseudaphritis urvillii) for the first time on Kangaroo Island (Figure 3).

The project worked closely with land managers to raise awareness of water dependent ecosystems requirements and identified diadromous fish as key indicators and a species deserving protection. This preliminary work forms a baseline from which a freshwater and estuarine monitoring program can be developed to identify issues relating to catchment connectivity and flow regimes. Historical monitoring on KI and mainland Australia shows a decline in water dependent species due to the construction of artificial barriers, such as dams, and reductions in flow from drought and over extraction.”

Steve Reynolds is the current President of MLSSA and is a long-standing member of the Society. Steve is a keen diver, underwater explorer, photographer and is chief author of the Society’s extensive back catalogue of newsletters and journals.

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