Australian Marine JVIammal Centre Final Report No. 13/45 Season 2004/15 • Title - Maintaining the monitoring of pup production at key Australian sea lion colonies in South Australia (2014/15). • Chief Investigator - Prof Simon Goldsworthy • Organisation - SARDI Aquatic Sciences Activity Period - April 2014 to May 2015 Table of contents 1. Activity Summary 2. The Outcomes/Objectives 3. Appropriateness 4. Effectiveness 1. Activity Summary A clear summary of approximately 500 words outlining the work undertaken and any significant findings (for publication on the Department's web site) This project undertook the first contemporaneous survey over 1-2 breeding seasons of Australian sea lion (ASL) pup abundance, providing the first base-line estimate ofpup abundance across the species South Australia (SA) range. In all, over 120 individual surveys across 54 known breeding sites were conducted over the 18 month period of the project. A total of 2,417 pups were recorded at 44 sites, including two newly identified breeding sites located at Curta Rocks (7 pups) and Williams Island (5 pups). For five sites, surveys were conducted outside the breeding season, so earlier survey estimates were used. For colonies along the Bunda Cliffs where cliff-top surveys underestimate pup production, adjustments based on verified cliff-top and ground surveys were incorporated. With these adjustments, the current total pup abundance for ASL breeding sites in SA was estimated to be 2,619. Based on available survey data available, primarily between 2004 and 2008 (although data for some colonies was from as early as 1990), Shaughnessy et al. (2011) estimated ASL pup abundance in SA to be 3,119. However, this figure did not include five newly identified breeding colonies and three sites which were poorly surveyed and have since been comprehensively surveyed. This adds a minimum of 175 pups to the assessment published in 2011 and leads to a total of 3,294. The 2014/15 estimate of 2,619 is therefore 20% lower (675 pups) than the 2011 assessment. For 54 ASL sites where current or previous historic pup production has been reported, a subset of 32 sites provide at least two comparable surveys undertaken at least six years apart (mean interval 14.5 years, range 6-44.5 years), enabling trends in abundance to be estimated. These sites account for 82% (2,157) of the estimated SA pup abundance in 2014/15, and include eight key ASL monitoring sites from four regions: Seal Bay and Seal Slide (Kangaroo Island); Dangerous Reef and English Island (Spencer Gulf); Olive and Jones Islands (Chain of Bays) and Lilliput and Blefuscu Islands (Nuyts Archipelago). Analyses of historic time-series indicates that pup numbers at most breeding sites (78%) and regions have declined between the comparable survey periods. The overall rate of decline is 3.7% per year, or 5.5% per breeding cycle, but the rate of decline varied considerably between sites and regions. Following IUCN Redlist assessment methods, and using a mean generation time of 12.6 years, the change in pup abundance over three generations (37.8 years) was extrapolated based on the observed change in pup abundance with the exponential rate of change assumed to be constant. Following this approach, the total percentage change in estimated pup abundance over three generations was estimated to be -69.7%. This global assessment approach based on 82% of the estimated SA ASL pup production, suggests the species has declined by -70% in 3 generations, meeting the IUCN Endangered category based on criteria A2(b) and (d). The regional analysis indicates that declines have occurred across the range of the species in SA. The extent of these declines at individual colonies over the last 3 generations is estimated to range between 22% and 85%. Western populations offEyre Peninsula (Nuyts Archipelago and Chain of Bays) and in the GAB (Bunda Cliffs) have shown the greatest rates of decline, including >50% decline in pup abundance over the last ten years for breeding sites in the western Nuyts Archipelago. Other major colonies off the western Eyre Peninsula at Olive, Nicolas Baudin and West Waldegrave Islands have undergone a -37% decline in pup abundance since surveys in the early to late 2000s. An evaluation of survey methodologies and strategies was undertaken and recommendations on future monitoring strategies have been proposed for the species. More details will be provided in a peer-reviewed SARDI report on the project, which is currently being drafted. 2. The Outcomes/Objectives List of the Project Objectives The objectives of the project were to: 1. Continue to provide data on the status and trends in abundance of Australian sea lions (ASL) at key monitoring sites in SA, as well as a number of other locations where information on breeding status and trends in abundance are poor. 2. Archive the first State-wide survey of all ASL breeding sites within an 18m period, providing a contemporary assessment of the species status, and analyse historic time-series data on all sites to provide an assessment of their trends in abundance. 3. Review and evaluate sites, survey methodologies and strategies developed over the last decade. Based on these analyses, provide options and make recommendations on future monitoring strategies for the species. The degree to which the Activity has achieved each of the objectives Obiective 1: Continue to provide data on the status and trends in abundance ofASL at key monitoring sites in SA, as well as a number of other locations where information on breeding status and trends in abundance are poor. This project continued monitoring pup production and trends in abundance at eight key ASL monitoring sites from four regions across SA. These include: Seal Bay and Seal Slide (Kangaroo Island); Dangerous Reef and English Island (Spencer Gulf); Olive and Jones Island (Chain of Bays) and Lilliput and Blefuscu Islands (Nuyts Archipelago). Monitoring of pup production for consecutive (or near consecutive) breeding seasons has been maintained at these sites since at least 2007. For this project, monitoring ofpup production at Seal Bay started in December 2014 when the breeding season commenced and was still underway at the time of writing this report (May 2015). As such, survey results for the previous (2013/14) breeding have been used here, but will be updated when the 2015 breeding season is completed. Surveys at the Seal Slide were undertaken between December 2014 and May 2015. At Dangerous Reef and English Island surveys were undertaken between March and October 2015; at Olive and Jones Islands between September and December 2014 and at Lilliput and Blefuscu Islands between December 2014 and April 2015. Ground and aerial surveys were undertaken ofpup numbers at another 46 ASL sites (and numerous non-breeding sites) in SA, many of which had not been surveyed comprehensively for many years (including two previously unknown breeding sites). Surveys also provide a comprehensive assessment of the timing ofASL breeding across all SA breeding sites and its asynchrony. Objective 2: Archive the first State-wide survey^fall ASL breeding sites within an 18m period, providing a contemporary assessment of the species status, and analyse historic time- series data on all sites to provide an assessment of their trends in abundance. Surveys were conducted at 54 ASL sites across SA, including a number ofnon-breeding sites. Pups were recorded at 44 sites. This is the first time that contemporaneous surveys have been undertaken across the species SA range over 2-3 breeding seasons, providing the first contemporaneous base-line in pup abundance for the species in SA. Time series data were available for 32 sites, with the maximum interval between 'good' surveys ranging between 6 and 44.5 years. The total quantum and rate of change in estimated pup abundance over time was calculated for these sites. Objective 3: Review and evaluate sites, survey methodologies and strategies developed over the last decade. Based on these analyses, provide options and make recommendations on future monitoring strategies for the species. An evaluation of survey methodology has been undertaken. Options for future monitoring strategies are discussed below. More detail will also be provided in a peer-reviewed SARDI report on the project, which is currently being drafted. 3. Appropriateness The appropriateness of the approaches used in the development and implementation of the Activity Survey methodology for ASL has progressively been developed and improved over the last 20 years. Given the asynchronous breeding pattern for the species, a critical aspect of the success of any ASL survey, irrespective of the methodology being used, is getting the timing of the survey right with respect to the breeding season. Fortunately with ongoing monitoring by SARDI scientists over the last decade there have been many opportunities to assess breeding schedules for many sites, which has increased the likelihood of survey success. However, for some sites that had not been surveyed for some time, there were issues with survey timing. Another critical approach has been the almost universal use of helicopters to access sites. With the exception of a few colonies with vehicle access or where boat access can be achieved reliably, all other surveys utilised helicopters for access. This meant that surveys could be planned and conducted at specific times that were not contingent on weather. The use of helicopters also increased efficiency within field trips, as multiple islands could be quickly assessed over a short time, providing essential information on the timing and progression of the breeding season at different sites. 4. Effectiveness The degree to which the Activity has effectively met its stated objectives Obiective 1: Continue.tQjirovide data on the status and trends in abundance ofASL at key monitoring sites in SA, as well as a number other locations where information on breeding status and trends in abundance are poor.