Effective ecosystem-based management requires estimates of abundance and population trends of species of interest. Trend analyses are often limited due to sparse or short-term abundance estimates for populations that can be logistically difficult to monitor over time. Therefore it is critical to assess regularly the quality of the metrics in long-term monitoring programs. For a monitoring program to provide meaningful data and remain relevant, it needs to incorporate technological improvements and the changing requirements of stakeholders, while maintaining the integrity of the data. In this paper we critically examine the monitoring program for the Australian fur seal (AFS) Arctocephalus pusillus doriferus as an example of an ad-hoc monitoring program that was co-ordinated across multiple stakeholders as a range-wide census of live pups in the Austral summers of 2002, 2007 and 2013. This 5-yearly census, combined with historic counts at individual sites, successfully tracked increasing population trends as signs of population recovery up to 2007. The 2013 census identified the first reduction in AFS pup numbers (14,248 live pups, -4.2% change per annum since 2007), however we have limited information to understand this change. We analyse the trends at breeding colonies and perform a power analysis to critically examine the reliability of those trends. We then assess the gaps in the monitoring program and discuss how we may transition this surveillance style program to an adaptive monitoring program than can evolve over time and achieve its goals. The census results are used for ecosystem-based modelling for fisheries management and emergency response planning. The ultimate goal for this program is to obtain the data we need with minimal cost, effort and impact on the fur seals. In conclusion we identify the importance of power analyses for interpreting trends, the value of regularly assessing long-term monitoring programs and proper design so that adaptive monitoring principles can be applied.
Penguins face a wide range of threats. Most observed population changes have been negative and have happened over the last 60 years. Today, populations of 11 penguin species are decreasing. Here we present a review that synthesizes details of threats faced by the world's 18 species of penguins. We discuss alterations to their environment at both breeding sites on land and at sea where they forage. The major drivers of change appear to be climate, and food web alterations by marine fisheries. In addition, we also consider other critical and/or emerging threats, namely human disturbance near nesting sites, pollution due to oil, plastics and chemicals such as mercury and persistent organic compounds. Finally, we assess the importance of emerging pathogens and diseases on the health of penguins. We suggest that in
Technical advances in monitoring devices, specifically drones, are allowing managers and scientists to obtain quality information on ecosystem health with minimal disturbance to ecosystems and the wildlife they support. Temporal and spatial indicators of ecosystem health, such as population size and/or abundance estimates of marine mammals are the basis for our understanding and prediction of ecosystem change. This is critical for the achievement of conservation goals and sustainable natural resources use. Performing surveys to obtain abundance estimates can be logistically demanding and expensive particularly in offshore marine environments, and can cause significant disturbance to wildlife. These constraints may lead to sub-optimal monitoring programs that reduce the frequency and/or precision of surveys at the cost of data quality and confidence in the resulting analyses. Using Remote Piloted Aircraft (RPA) can be a solution to this challenge. With appropriate testing and ethical consideration; for many situations, RPAs can perform surveys with increased frequency, higher data resolution and less disturbance than typical methods that involve people being present on the ground, thereby enabling more robust programs for monitoring. We demonstrate the process of testing images from RPAs for estimating the abundance of Australian fur seals (Arctocephalus pusillus doriferus) at one of their largest colonies on Seal Rocks, Australia. Two sizes of multirotor (1,400 and 350 mm) with different imaging equipment were tested at 40, 60, and 80 m altitude above sea level. We assessed wildlife disturbance levels and optimized a methodology for effective and economical monitoring of this site. We employed commercially available and open-source software for programming survey flights (Drone Deploy), image processing (Agisoft Photoscan and Autopano Giga), data collation and analyses (R and Python). An online portal "SealSpotter" was developed to facilitate data collection, with the ultimate goal being the engagement of the public as citizen scientists in fur seal counts from RPA images. Preliminary comparisons show that a small RPA at 40 m altitude can produce pup counts 20-32% higher than corresponding ground counts without observable disturbance. The benefits and disadvantages of the RPA trials are discussed, as well as important considerations for those looking to incorporate similar methodologies in their research.
Dietary remains recovered from Australian sea lion (Neophoca cinerea) digestive tracts and regurgitate samples from Seal Bay (Kangaroo Island, South Australia) were used to identify prey species consumed. Four of eight digestive tracts collected (50%) contained prey items located only in the stomach. On the basis of biomass reconstruction of cephalopod prey remains, octopus contributed 40% of the biomass in the samples, giant cuttlefish (Sepia apama) contributed 30% and ommastrephid squids contributed 14% biomass. The remains of several fish species were found in the samples: leatherjacket (Monocanthidae), flathead (Platycephalus sp.), swallowtail (Centroberyx lineatus), common bullseye (Pempheris multiradiata), southern school whiting (Sillago flindersi) and yellowtail mackerel (Trachurus novaezelandiae). Southern rock lobster (Jasus edwardsii) and swimming crab (Ovalipes australiensis) carapace fragments, little penguin (Eudyptula minor) feathers and bones and shark egg cases (oviparous species and Scyliorhinidae sp.) were also identified.
The Australian sea lion Neophoca cinerea is an endemic species listed as vulnerable under the Commonwealth 'Environment Protection and Biodiversity Conservation Act' and as Endangered by IUCN. Assessing its abundance is difficult because of its supra-annual (17 to 18 mo) breeding cycle, and pupping seasons that are extended (about 6 mo but varying between colonies) and asynchronous in their timing between colonies. Based mainly on surveys at most sites in South Australia (SA) between 2004 and 2008, and information from the literature, estimates of abundance are provided for 39 breeding colonies and 9 haulout sites where pups are recorded occasionally. From this study it is estimated that in SA, 3119 Australian sea lion pups are born per breeding cycle, an increase on former estimates by at least 16% resulting from recognition of new breeding colonies, targeting surveys to coincide with maximum pup numbers and using mark-recapture procedures at some colonies. With the addition of 503 pups in Western Australia, the overall estimate of pup abundance for the species is 3622. This leads to an estimate of 14 780 animals using the multiplier 4.08. Trend data for the Seal Bay colony on Kangaroo Island indicated that pup numbers decreased at 0.54% yr -1 in the 22 yr (16 pupping seasons) from 1985 to 2007. A cause of the decrease is believed to be bycatch in the demersal shark gillnet fishery, which overlaps with sea lion foraging areas nearby. Area closures declared during 2010 within several km of all Australian sea lion breeding sites in SA should reduce the incidence of bycatch mortality.
One of the most critical phases in the life of petrels (Procellariiformes) is at fledging when young birds pass from parental dependence on land to an independent life at sea. To mitigate mortality at this time, rescue programs are implemented near breeding sites around the world, especially for birds grounded by artificial lights. We evaluated the plumage and body condition of short‐tailed shearwater (Ardenna tenuirostris) fledglings captured at colonies just before departure in comparison to fledglings washed up on beaches and to fledglings attracted by artificial light along roads. We measured abundance of down, body mass, and body condition index as the standardized residuals of a regression of body mass on size, and employed linear models to test differences on body mass and body condition between locations. Beach‐washed birds were underweight and in poor condition, suggesting their future survival probabilities at sea were low. Birds rescued on roads as a consequence of light attraction had lower body weights and condition indices than fledglings captured at the colony. However, more than 50% of light‐attracted birds had attained similar weights to those of adults, suggesting they have higher probabilities of survival than beach‐washed birds. Water‐logged birds being washed onto beaches is a natural process, but birds grounded by lighting along roads is an increasing anthropogenic threat that requires management. Thus, management and conservation efforts should be directed to protect birds in the colonies and reduce light‐induced mortality, ideally through the strategic reduction of light sources and lateral light spillage. When resources for conservation are limited, rescue programs should focus on rescuing birds from roads rather than beach‐washed birds, which have a lower probability of survival. © 2017 The Wildlife Society.
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