Marine Policy 120 (2020) 104138 Contents lists available at ScienceDirect Marine Policy journal homepage: http://www.elsevier.com/locate/marpol Sleuthing with sound: Understanding vessel activity in marine protected areas using passive acoustic monitoring Logan R. Kline a,*, Annamaria I. DeAngelis b, Candace McBride c, Giverny G. Rodgers c, Timothy J. Rowell b, Jeremy Smith c, Jenni A. Stanley b,d, Andrew D. Read e, SofieM. Van Parijs b a Under Contract to Northeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 166 Water Street, Woods Hole, MA, 02543, USA b Northeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 166 Water Street, Woods Hole, MA, 02543, USA c Parks Australia, GPO Box 858, Canberra, ACT, 2601, Australia d Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA, 02543, USA e National Marine Science Centre, Southern Cross University, 2 Bay Drive, Coffs Harbour, NSW, 2450, Australia ARTICLE INFO ABSTRACT Keywords: Monitoring compliance and enforcing laws are integral to ensuring the success of marine protected areas (MPAs), Marine protected areas but traditional monitoring techniques are costly and resource demanding. Three SoundTrap 300 recorders were Marine parks deployed for one month between 1 July and September 12, 2018 to collect acoustic data in two marine parks off Passive acoustic monitoring southeastern Australia: one recorder in Cod Grounds Marine Park (CGMP) and two in the Solitary Islands Marine Compliance Park National Park Zone (SIMP NPZ). Extractive activities such as fishingare not permitted in these zones. Raven Enforcement Surveillance Pro 2.0 was used to analyze data for vessel presence. Transmission loss equations for each site were generated using patrol boat GPS tracks and used to predict if acoustically recorded vessels were inside park boundaries based on received sound levels. In CGMP, 41 vessels were predicted within the park during the recording period; 34 vessels were predicted within the SIMP NPZ. Thursdays and Saturdays were identifiedas peak days for vessel presence in CGMP while Thursdays were the peak day in the SIMP NPZ. Most vessel activity at both locations took place between 06:00 and 17:00 AEST. Peak vessel presence in CGMP occurred at 09:00 AEST while the peak vessel presence in the SIMP NPZ occurred at 16:00 AEST. Approximately 12.7 h of vessel sounds were recorded within CGMP; approximately 3.8 h of vessel noise were recorded within the SIMP NPZ. Passive acoustic monitoring of vessel patterns in Australian Marine Parks has provided valuable insight to redirect compliance decisions on how to focus surveillance efforts. 1. Introduction health [4], and protecting endangered or commercially viable species [5,6]) and are principal to international efforts to improve MPA man­ Marine protected areas (MPAs) are recognized global conservation agement [7–9]. This is particularly true of large and/or remote MPAs, tools developed with the goal of conserving natural and cultural oceanic which present considerable challenges for ensuring effective surveil­ resources.1 The quantity and size of these areas have grown considerably lance [10]. Australian waters contain a handful of the largest MPAs (e.g. over the last few decades; as of 2018, MPAs constituted approximately Coral Sea Marine Park and Great Barrier Reef Marine Park) and repre­ 6.6% of the global ocean, with 13,000 MPAs worldwide averaging 2.5 sent some of the most thoroughly monitored regions of ocean on the km2 in size [1]. Effective compliance and enforcement of management planet [7,9,11]. rules are essential for meeting the ecological goals of MPAs (e.g. In Australia, the management of MPAs is shared between state and conserving species diversity and richness [2,3], promoting ecosystem Australian government agencies. Australian Marine Parks * Corresponding author. 102 Kenduskeag Avenue, Apt 1, Bangor, ME, 04401, USA. E-mail addresses: [email protected] (L.R. Kline), [email protected] (A.I. DeAngelis), [email protected] (C. McBride), giverny. [email protected] (G.G. Rodgers), [email protected] (T.J. Rowell), [email protected] (J. Smith), [email protected] (J.A. Stanley), andrew. [email protected] (A.D. Read), [email protected] (S.M. Van Parijs). 1 https://oceanservice.noaa.gov/facts/mpa.html. https://doi.org/10.1016/j.marpol.2020.104138 Received 22 November 2019; Received in revised form 2 July 2020; Accepted 13 July 2020 Available online 27 July 2020 0308-597X/Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). L.R. Kline et al. Marine Policy 120 (2020) 104138 (Commonwealth reserves proclaimed under the Environment Protection acoustic signature [42]. In lieu of satellite-derived spatial information, and Biodiversity Conservation Act 1999) are located at the outer edge of PAM can provide estimations of presence and characteristics of motor- state and territory waters, generally begin 3 nm from shore, and extend ized vessels with unknown spatial attributes, as well as continuous to the outer boundary of Australia’s exclusive economic zone (200 nm) monitoring of remote locations for months at a time. Additionally, PAM [12]. A total of 58 marine parks are currently managed by Parks can enhance management understanding and improve decision-making Australia, part of the federal environment portfolio, and were estab- by unveiling human and biological presence patterns in the acoustic lished with the objective of protecting and conserving biodiversity and soundscape (see Refs. [24,42,43] for examples). Given that vessels other natural, cultural, and heritage values whilst allowing for ecolog- without AIS technology comprise most anthropogenic noise contribu- ically sustainable use of natural resources. Characterized by large, tions to shallow water soundscapes [44], PAM has the potential to be a highly biodiverse, and often remote ocean habitat that is difficult to powerful management tool. monitor, Australian Marine Parks are susceptible to a host of non- We present the use of PAM to develop a replicable methodology by compliant activities, notably illegal fishing and pollution [13]. Strong which temporal patterns of unknown motorized vessels near or within enforcement of MPA laws has shown the potential to rapidly increase the two Australian Marine Parks, Cod Grounds and Solitary Islands Marine number and density of target species in protected areas [5,6], and Parks, could be characterized over a one month recording period. The compliance alone has a strong positive effect on species biomass [14]. primary aim of this study was to optimize the effectiveness of future Optimizing compliance programs to protect MPA values ensures surface and aerial patrols by presenting a novel, low-cost technique for enforcement activities are effective and targeted toward observed estimating and understanding vessel presence and implications for characteristics of noncompliance [9]. A major challenge facing Austra- compliance in these highly protected areas. lian Marine Park managers is establishing effective and efficient tech- niques to optimize enforcement activities. 2. Materials and methods Manned surface patrols are the most common method for monitoring and enforcement in coastal MPAs [11], however they are 2.1. Study sites cost-prohibitive and resource demanding [7]. Furthermore, surface pa- trols have limitations in their scope of coverage and cannot realistically Australian Marine Parks are divided into zones that determine where detect all noncompliant activities. Studies have shown success in using certain activities can occur. National Park Zones (International Union automated identification systems (AIS) to monitor noncompliance of for Conservation of Nature Category II; NPZs) offer a high level of pro- commercial vessels in MPAs [15]. However, AIS data are limited by tection, with the goal of protecting and conserving ecosystems, habitats, small fleet coverage, the inability to identify vessel type, lowered ca- and native species [12]. This designation prohibits all extractive activ- pacity for data analysis by management agencies, and the ability to turn ities, such as fishing, aquaculture, and mining, and only permits off AIS at any time, thus masking criminal activities [16]. Vessel non-extractive activities unless authorized for research and monitoring. monitoring systems (VMS) have also been utilized to successfully deter Three bottom-mounted acoustic recorders (SoundTrap 300s2) were noncompliance events and have been used to analyze fishingactivity in deployed in two NPZs located off the southeastern coast of Australia: one MPAs [17]. Yet, similar to AIS, VMS is limited by fleet coverage; in in Cod Grounds Marine Park (CGMP) at a depth of 37 m, deployed from Australia, less than 15% of the Australian commercial vessel fleet has July 1, 2018 to August 4, 2018, and two 140 m apart within the NPZ of access to VMS that alerts users to their presence in MPAs [7]. Notably, Solitary Islands Marine Park (SIMP NPZ) at a depth of 42 m, deployed recreational vessels are not equipped with VMS and are not required to from August 10, 2018 to September 12, 2018 (Fig. 1). The two recorders have AIS, creating a significant gap in MPA user understanding and in the SIMP NPZ were placed on opposite sides of a seamount, Pimpernel awareness for managers. Satellite imagery