Lepidochelys olivacea (Eschscholtz, 1829): Tortuga golfina , Olive ridley turtle,

Legislation is one of the fundamental tools used to protect wildlife and there is State legislation and regulations that apply to coastal dolphins in Western Australia (Chapter 1). The following sections discuss additional protective measures such as Marine Protected Areas (MPAs) and restrictions on vessel speed that are not currently used in Bunbury. These are appropriate given the findings of female sociality, seasonal calving, the area used for calving and breeding (Chapter 3) and home range size (Chapter 4) and habitat use (Chapter 5).

6.3.1.1 Marine protected areas

The Conservation and Land Management Act 1984 provides the legislative mechanism to create MPAs in Western Australia. MPAs can provide protection from human activities that are destructive or extractive, e.g. fishing and mining (Preen 1998, Marsh et al. 2003). There are numerous ways that MPAs can be zoned including prohibiting certain activities, e.g. no fishing in sanctuary zones (Westera et al. 2003, Babcock et al.

2007), prohibiting vessels through time-area closures (Danil et al. 2005, Notarbartolo- di-Sciara et al. 2009) or restricting vessel speeds in designated areas (Laist & Shaw 2006, Steckenreuter et al. 2012a).

As discussed in Chapter 1, MPAs are often best suited to conserving species that are resident or have a small home range. There are two approaches to MPA planning for marine mammals: identifying core home ranges or areas where critical activities occur, such as feeding (Ingram & Rogan 2002, Laran & Gannier 2008), breeding (Johnston et al. 2007) and calving or protecting a larger area to encompass the entire home range. Protecting adequate areas can be challenging when animals use large areas and migrate long distances, often across jurisdictions, e.g. whales (Hinch & De Santo 2011). MPAs can be effective in protecting dolphins in situations where they show strong site fidelity and have small home ranges. However, some flexibility in the MPA boundaries is required along with ongoing monitoring to detect changes in ranging patterns and distribution over time (Culloch & Robinson 2008, Rayment et al. 2010).

There are few examples of MPAs in Australia that are targeted at marine mammal conservation and that we can draw experience from. The Adelaide Dolphin Sanctuary was the first established in 2008 in South Australia and was implemented to conserve bottlenose dolphins in an urban setting. Threats in Adelaide are similar to those in Bunbury and include entanglements of dolphins in fishing gear, vessel strikes with dolphins, deliberate attacks on dolphins by people, and environmental contaminants (Steiner & Bossley 2008).

Another example is a small-scale sanctuary zone that was established on Carnac Island, Western Australia, in an attempt to reduce the impact of disturbance by humans on Australian sea lions (Neophoca cinerea) (Orsini et al. 2006). A fixed sanctuary zone was ineffective in this case because environmental conditions varied over time and sea lions hauled out outside of the sanctuary zone, therefore impacts were only reduced when conditions were suitable and the sea lions were inside the sanctuary zone (Salgado Kent & Crabtree 2008).

6.3.1.2 Population status and MPAs

Population Viability Analysis (PVA) and Potential Biological Removal (PBR) analyses (Chapter 1; Section 1.2.2) are recommended to determine the longer-term status and

sustainability of the Bunbury dolphin population. Data from this study, i.e. abundance estimates, could be used in these analyses. If the population is forecast to be stable or increase, then further management strategies may not be required. If the population is forecast to decline then management strategies such as MPAs or speed restricted areas should be considered. If a MPA is proposed, this study identified the eastern side of Koombana Bay near the mouth of the Leschenault Estuary as the most appropriate location (Figure 6.1) where dolphins are concentrated in high density during the warmer months and breeding and calving occurs predictably in this area during summer and autumn (Chapter 3; Figure 3.4). If a year-round MPA is impractical then a seasonal time-area closure could be considered for the warmer seasons (summer and autumn) when calving peaks and adult dolphins of both sexes aggregate in the Bunbury inner waters. If this strategy is pursued, similar considerations to the Carnac Island Sanctuary Zone above should be heeded for Bunbury. This includes protecting larger stretches of useable habitat either side of the area depicted in Figure 6.1 to be effective.

The creation of a MPA would require community support as well as political incentive for its creation, maintenance and management. Such support is likely given the iconic status of the dolphins to the Bunbury community and the dependent tourism industry. Data on mortalities are limited for this population and therefore a PBR may not be possible with the data currently available. When additional data are available PBR analysis should be used to determine measurable goals for population maintenance. Additional management strategies may be required to those recommended here, depending on the outcome of the PVA and PBR analyses.

6.3.1.3 Speed restriction areas

The National Guidelines for Whale and Dolphin Watching 2005 provide the overarching framework for regulating interactions with cetaceans in Australia (Department of Environment and Heritage 2005). These guidelines are incorporated in legislation and regulations for each State which prescribe approach type and speed, number of vessels permitted to interact, minimum distances of approach, and length and nature of interactions with dolphins (Orams 1997, Scarpaci et al. 2003, Scarpaci et al. 2004, Steckenreuter et al. 2011, Steckenreuter et al. 2012a). In Western Australia, the Wildlife Conservation Act 1950 and the associated Close Season Notice 1998 give legislative power for regulating interactions between people and dolphins and this is administered by DEC (Department of Environment and Conservation). However, the

Department of Transport (DoT) has the authority to limit the speed of vessels under the Western Australian Marine Act 1972.

If vessel strikes are determined to be impacting on the sustainability of the dolphin population then speed restrictions may be an appropriate strategy to reduce these incidents where boating activity cannot be excluded from areas (Laist & Shaw 2006) (Figure 6.1). Speed restrictions (approximately 15 km/h) would be best placed where important dolphin habitat (Chapter 3; Figure 3.4) was identified, specifically, the eastern end of Koombana Bay adjacent to the Leschenault Estuary (Figure 6.1). Additional strategies such as enforcement, education and on-water signage are important to achieve community understanding of and compliance with vessel speed regulations (Jett & Thapa 2010).

Some recreational activities, such as water and jet skiing, are performed at high-speed and can be detrimental to dolphins through disturbance and physical injury (Goodwin & Cotton 2004). Currently, the areas used for water skiing in Koombana Bay are adjacent to areas identified as important dolphin habitat (Chapter 4 and Figure 6.1). Existing designated ski areas (Figure 6.1) should be re-evaluated and careful planning of future areas where these activities are allowed in Bunbury, given the importance of this area for female sociality, calving and breeding.

Recommendation 1: undertake Population Viability Analysis to forecast the long-term status of the Bunbury dolphin population and evaluate the need for management strategies such as MPA, speed restricted areas and re-evaluation of location of existing ski areas.