Poster

Populations of sawfishes and river sharks in the Northern Territory (NT) are thought to have declined dramatically in recent decades, raising concerns about their viability. Research under the National Environmental Research Program (NERP) has provided information on the distribution, ecology and population dynamics of sharks and rays of northern Australian rivers to assist in their conservation, management and recovery. This project has generated a better ecological understanding of the habitat use and habitat requirements, short and long-term movements, connectivity and spatial dynamics of these species and collected tissue samples for population structure and abundance estimation.

Fisheries-independent surveys in selected river systems were conducted using gillnets and rod and line. Captured sharks were tagged and monitored with acoustic telemetry. This uses networks of moored acoustic receivers to detect tagged fish when they pass within range of a receiver. Extensive arrays of acoustic receivers provide long-term monitoring of tagged animals. Mitochondrial genome sequencing of Speartooth Sharks and Largetooth Sawfish was used to help profile their population structure. The mitogenome, which is inherited through the mother, offers clues to how widely females disperse to breed (for example, between river systems).

This new two-sided poster now features indigenous artwork by Graham Rostrom, a cultural teacher, artist, dancer, musician and song man.

The Marine Biodiversity Hub works with indigenous communities and ranger groups in northern Australia to manage and recover threatened sawfishes and river sharks

• This poster supports the project "Supporting management of listed and rare species". 
• Visit the sawfish project webpages for resources such as videos, species information sheets and news stories
• Download a low resolution version of the poster at the Item link below.
• Request a copy of the poster and postcard (with information about artist, Graham Rostron)