Passive acoustic analysis of vessel presence in Australian Marine Parks

Brief description

Monitoring compliance and enforcing laws are integral to ensuring the success of marine protected areas (MPAs), but traditional monitoring techniques are costly and resource demanding.

With the addition of many new marine parks to the Australian Marine Parks (AMPs) estate, there is a gap in the Director of National Parks’ understanding of use of AMPs by small vessels. This lack of ‘domain awareness’ creates a potentially high risk for marine park managers.

The objective of this project is to improve our understanding of use of AMPs by small vessels and to inform compliance risk planning and management. To do this, archival acoustic recorders have been deployed in high risk parks. The data is analysed to gain an understanding of the level of small vessel activity in the AMPs.

Further deployments will be detailed within this metadata record as they occur.

Cod Grounds and Solitary Islands Marine Parks - Deployment 1

Three SoundTrap 300 recorders were deployed for one month between 1 July and 12 September 2018 to collect acoustic data in two marine parks off south-eastern Australia: one recorder in Cod Grounds Marine Park (CGMP) and two in the Solitary Islands Marine Park National Park Zone (SIMP NPZ). Approximately 12.7 hr of vessel sounds were recorded within CGMP; approximately 3.8 hr of vessel noise were recorded within the SIMP NPZ.

Lineage

Cod Grounds and Solitary Islands Marine Parks - Deployment 1

Three bottom-mounted acoustic recorders (SoundTrap 300s) were deployed in two National Park Zones (NPZs) located off the south-eastern coast of Australia: one in Cod Grounds Marine Park (CGMP) at a depth of 37 m, deployed from 1 July 2018 to 4 August 2018, and two 140 m apart within the NPZ of Solitary Islands Marine Park (SIMP NPZ) at a depth of 42 m, deployed from 10 August 2018 to 12 September 2018. The two recorders in the SIMP NPZ were placed on opposite sides of a seamount, Pimpernel Rock, and are referred to as East (EP) and West Pimpernel (WP) respective to their positions. A popular fishing spot known as Banana Rock is also located 1.5 km northeast of the SIMP NPZ hydrophones, outside of the NPZ.

Each of the three hydrophones recorded acoustic data between 32 and 35 days. An instrument error resulted in the CGMP hydrophone losing 2 hr of data (07:00 and 08:00 AEST) on 18 July 2018. Aside from this malfunction, data were collected continuously over the study period for each recorder. All recorders were set to sample at 48 kHz with the high gain calibration setting, providing an effective recording bandwidth of 20 Hz to 24 kHz. The recorders were also programmed to measure and record an instantaneous temperature every 10 s.

During the deployment of the recorders in the SIMP NPZ on 10 August 2018, the New South Wales (NSW) Department of Primary Industries (DPI) Fisheries Patrol Vessel (FPV) Peter Angel (a 6.8- m rigid-hulled inflatable boat (RHIB) with twin F200 Yamaha 4-stroke engines, henceforth Peter Angel) conducted three circular passages at a nominal speed of 15 km/h at distances of approximately 200, 500, and 1000 m around the SIMP NPZ recorders. Timestamped GPS locations were provided for these tracks and used in transmission loss modelling.

Once acoustic files were extracted from each recovered recorder, the resulting recordings were analysed manually for vessel presence using the acoustic software Raven Pro 2.0 (Bioacoustics Research Program, Cornell University, Ithaca, NY). Full details of data analysis for vessel presence can be provided upon request and will be available upon publication of the data (manuscript currently under review).

Notes

Credit
Acoustic devices were deployed with the assistance of the New South Wales Department of Primary Industries.

Credit
This project was a collaboration between the Director of National Parks, Parks Australia, and the US National Oceanic and Atmospheric Administration, National Marine Fisheries Service and the Northeast Fisheries Science Center