1 INTRODUCTION

Knowledge of the broadscale movements of migratory species is essential for conservation and management (Berumen, Braun, Jesse, Skomal, & Thorrold, 2014; Costa, Breed, & Robinson, 2012; Lyon, Dwyer, Pillans, Campbell, & Franklin, 2017). However, movement patterns and migration paths of marine species are often poorly understood, due to the logistical challenges of surveying these highly mobile and often elusive animals throughout such extensive and complex environments (Heupel et al., 2015; Hussey et al., 2015). This paucity of data can lead to gaps in the protection of critical habitats for species along entire migratory routes or throughout entire life cycles (Beger et al., 2010, 2015; Block et al., 2011; Mazor, Beger, McGowan, Possingham, & Kark, 2016; McGowan et al., 2016; Runge, Martin, Possingham, Willis, & Fuller, 2014).

One migratory marine species whose distribution and movement patterns are poorly understood is the world's largest extant fish, the whale shark (Rhincodon typus). In 2016, the conservation status of R. typus was updated from “Vulnerable” to “Endangered” on the International Union for the Conservation of Nature's (IUCN) Red List (Pierce & Norman, 2016), because of anthropogenic threats including targeted fishing (Li, Wang, & Norman, 2012; Pierce & Norman, 2016), by‐catch (Lascelles et al., 2014; Pierce & Norman, 2016), pollution (such as oil spills and plastics; Lascelles et al., 2014), ship strike (Berumen et al., 2014; Graham, 2007; Pierce & Norman, 2016) and activities associated with oil and gas exploitation (Graham, 2007). Effective conservation of R. typus requires accurate information on their movements and distribution in order to understand their spatial and temporal exposure to these threats (Berumen et al., 2014). Whale sharks are known to aggregate at various coastal locations in the tropics in response to seasonal increases in productivity (Colman, 1997; Heyman, Graham, Kjerfve, & Johannes, 2001; Motta et al., 2010; Nelson & Eckert, 2007). However, sighting records of R. typus are generally limited to coastal areas during aggregation periods, because of improved access to animals (Rowat & Brooks, 2012). Sightings outside these periods and in pelagic waters are relatively rare (Rowat & Brooks, 2012; Sequeira, Mellin, Meekan, Sims, & Bradshaw, 2013). This paucity of information on long‐term movements and distributions of R. typus is hampering conservation efforts (Berumen et al., 2014; Sequeira et al., 2013).

In the Indian Ocean, R. typus aggregate in some coastal areas, including Ningaloo Reef in Western Australia (WA) during the austral autumn/winter (Anderson et al., 2014; Colman, 1997; Norman, Reynolds, & Morgan, 2016; Norman & Stevens, 2007; Wilson, Taylor, & Pearce, 2001). This aggregation supports a lucrative tourism industry (Catlin, Jones, Norman, & Wood, 2010), and most sighting records come from the northern area of Ningaloo Reef in which the industry operates (Anderson et al., 2014; Norman et al., 2016). Although R. typus exhibit long‐distance movements away from this region (Norman et al., 2016; Sleeman, Meekan, Wilson, et al., 2010; Wilson, Polovina, Stewart, & Meekan, 2005), and genetic studies suggest that some degree of broadscale mixing of Indo‐Pacific populations is occurring (Vignaud et al., 2014), movements outside this recognized aggregation period are relatively unknown (Norman et al., 2016).

While at Ningaloo Reef, R. typus are protected by a network of State and Commonwealth marine preserves. Although Marine Protected Areas (MPAs) are widely recognized as a key tool in the conservation of marine biodiversity (Klein et al., 2015; Lester et al., 2009), their effectiveness in conserving migratory species has been questioned (Hays, Mortimer, Ierodiaconou, & Esteban, 2014; Hooker et al., 2011; Laurel & Bradbury, 2006), and there is a lack of understanding of the extent to which existing protected areas cover the distributions of migratory species (Runge et al., 2015). The use of Australia's network of MPAs by R. typus has never before been quantified, and it is unclear how much of their preferred or suitable habitat is protected. This is because other areas in the Indian Ocean that could be important habitat for R. typus have yet to be identified (Norman et al., 2016).

Biotelemetry is a valuable tool for gathering spatial information, particularly for mobile marine species (Doherty et al., 2017; Hussey et al., 2015). However, there has been a long‐standing disconnect between animal migration ecology, and spatial conservation and management decision‐making (Beger et al., 2015; McGowan et al., 2016). Migratory animals tend to be ignored when planning MPAs, because large‐scale migration data are difficult and expensive to obtain, may far exceed the spatial scale of planning, and spatial planning tools to incorporate animal telemetry are in their infancy (McGowan et al., 2016). In addition, telemetry data are presence‐only, and limited by the number of animals tagged to adequately represent population patterns (Block et al., 2011; Mazor et al., 2016). Spatial planning requires ecological information from the entire planning area to avoid biasing prioritizations towards areas where data exist. Species distribution models (SDMs) serve to overcome this challenge by predicting suitable habitat for species for which distributions are unclear (Torres et al., 2015) and can give useful ecological insights (Elith & Leathwick, 2009). These models predict the potential distribution of a species based on statistical relationships between recorded occurrences and environmental predictor variables (Torres et al., 2015). Habitat selectivity models do this by identifying physical and environmental characteristics that influence known distributions of a species and finding other areas that share these characteristics (Raymond et al., 2015).

This study aims to identify important areas for, and understand the movement ecology of R. typus through biotelemetry. The evaluation of the use of existing MPAs off Australia's west coast by tagged R. typus will provide insight into how the species is protected by the existing network of Australia's MPAs. Habitat selectivity modelling based on satellite‐tracked movement data will help to reveal the potential distribution of R. typus throughout the south‐eastern Indian Ocean. The techniques used could be applied to R. typus populations worldwide, as well as other mobile marine species, to help inform future management and conservation efforts.