Garig Gunak Barlu National Park Green Sawfish (Pristis zijsron) aggregation surveys

Garig Gunak Barlu National Park Green Sawfish (Pristis zijsron) aggregation surveys

This report details two surveys of Green Sawfish (Pristis zijsron) at two sites in Garig Gunak Barlu National Park in the Northern Territory. Weather conditions and limited water clarity restricting usable video footage from drones at one site (Lidarnardi) during survey 2. The use of Baited Remote Underwater Videos were unsuccessful. Drones recorded Green Sawfish on 88% of survey days and 30% of transect flights. Sawfish numbers ranged from 1–8 individuals per transect and density from 3.8–30.5 per hectare (the highest density of sawfish ever reported). Sawfish ranged from 57–167 cm total length (TL), with most 60–100 cm TL, suggesting a nursery area. The surveys confirmed the presence of juvenile Green Sawfish in intertidal waters of the national park, suggesting the park waters represents critical habitat, and provides the species some refuge from major threats. However, similar inshore intertidal habitat is not well represented in northern Australian protected areas.

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Abundant corals and fishes emerge from the ancient contours of Arafura Marine Park

November 17, 2020

Corals and fish in Arafura Marine Park
A rich shallow coral reef community with diverse and colourful fish life in Arafura Marine Park. Image: Australian Institute of Marine Science

Scientists have collected the first fine-scale maps and imagery of reefs and submarine canyons in the rarely visited Arafura Marine Park, revealing seafloor environments with surprisingly diverse coral and fish communities.

Setting out to survey our southern-most coral reefs

January 22, 2020

A Marine Biodiversity Hub team has embarked on a voyage to survey marine life at Elizabeth and Middleton reefs in the bountiful Lord Howe Island Marine Park.

Ningaloo survey finds deep treasures worth protecting

September 10, 2019

A benchmark survey at Ningaloo Marine Park (Commonwealth waters), finds hidden treasures in the lesser-known depths of Ningaloo reef.

BRUVS and fishes (and spatially-balanced sampling): a recipe for monitoring at Flinders Marine Park

May 10, 2018

Meet the monitoring team for Flinders Marine Park . . . Striped Trumpeter, Reef Ocean Perch, Gummy Shark, Jackass Morwong, Tiger Flathead and Sand Flathead.

Exploring the status of Western Australia’s sea snakes

Exploring the status of Western Australia’s sea snakes

All sea snakes are listed marine species under the EPBC Act and three Australian endemic species are listed as Critically Endangered or Endangered, and as such are a national conservation priority. Recent findings of two Critically Endangered sea snake species (Aipysurus apraefrontalis and Aipysurus foliosquama) in locations outside of their previously defined ranges have highlighted the lack of information on species distributions along the North West coast of Australia. Data on sea snake sightings on previously collected baited remote underwater video surveys (BRUVS) and fisheries independent trawl surveys were used to assess the utility of these methodologies to accurately define relative abundance and distribution patterns of sea snakes in the North West Marine Region (NWMR), including within Commonwealth Marine Reserves (CMRs), to refine species’ status.

Presence/absence data from BRUVS were used to predict locations that are likely important habitats for sea snake populations within the NWMR, which included mid-shelf and oceanic shoals along the Kimberley and Pilbara coasts. Limited fisheries-independent trawl sampling data collected in Shark Bay and Exmouth Gulf highlighted patterns of interaction between sea snakes and trawl fishing, with survivorship curves indicating that most sea snake species encountered within these regions may be able to sustain low to moderate levels of trawl fishing. Trawl survey data also highlighted the need for additional fisheries interaction data to accurately assess the species-specific influence of fishing activities (e.g. trawl and trap fishing) on different life stages of sea snakes susceptible to incidental capture (bycatch). This project highlights the need for more data on sea snakes in regions lacking information (e.g. mid-shelf shoals of Kimberley coast, Pilbara coast and Rowley Shoals). In addition, further research is also required to assess the degree of connectivity between sea snake populations from offshore reefs that have seen recent declines, and those on adjacent mid-shelf and oceanic shoals.

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RV Bluefin gives young scientists a first taste of research at sea

October 18, 2016

Lainey James and Margot Delaporte have completed their first trip aboard the Australian Maritime College Research Vessel Bluefin. The Hub research team revisited reef systems in the Freycinet Commonwealth Marine Reserve.

Harasti, David

Partner Organisation 

Current activities



Senior Research Scientist for Fisheries NSW working on marine protected areas and threatened species

Academic qualifications


Membership of key national committees

NSW Fisheries Scientific Committee
IUCN Seahorse, Pipefish and Seadragon specialist group

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