Dolphins and Boats : When Is a Disturbance, Disturbing?

Acknowledgments A draft of this manuscript was presented (manuscript SC66b/WW10) to the Whalewatching Sub-Committee at the 66th meeting of the Scientific Committee of the International Whaling Commission, 4–20 June 2016, in Bled, Slovenia. Funding RH supported in part by a Sitka Sound Science Centre Scientist in Residency Fellowship.Peer reviewedPublisher PD

Forecasting intraspecific changes in distribution of a wide-ranging marine predator under climate change

Globally, marine animal distributions are shifting in response to a changing climate. These shifts are usually considered at the species level, but individuals are likely to differ in how they respond to the changing conditions. Here, we investigate how movement behaviour and, therefore, redistribution, would differ by sex and maturation class in a wide-ranging marine predator. We tracked 115 tiger sharks (Galeocerdo cuvier) from 2002 to 2020 and forecast class-specific distributions through to 2030, including environmental factors and predicted occurrence of potential prey. Generalised Linear and Additive Models revealed that water temperature change, particularly at higher latitudes, was the factor most associated with shark movements. Females dispersed southwards during periods of warming temperatures, and while juvenile females preferred a narrow thermal range between 22 and 23 degrees C, adult female and juvenile male presence was correlated with either lower ( 23 degrees C) temperatures. During La Nina, sharks moved towards higher latitudes and used shallower isobaths. Inclusion of predicted distribution of their putative prey significantly improved projections of suitable habitats for all shark classes, compared to simpler models using temperature alone. Tiger shark range off the east coast of Australia is predicted to extend similar to 3.5 degrees south towards the east coast of Tasmania, particularly for juvenile males. Our framework highlights the importance of combining long-term movement data with multi-factor habitat projections to identify heterogeneity within species when predicting consequences of climate change. Recognising intraspecific variability will improve conservation and management strategies and help anticipate broader ecosystem consequences of species redistribution due to ocean warming

Consequences of global shipping traffic for marine giants

Shipping routes in the ocean are analogous to terrestrial roads, in that they are regularly used thoroughfares that concentrate the movement of vessels between multiple locations. We applied a terrestrial road ecology framework to examine the ecological impacts of increased global shipping on "marine giants" (ie great whales, basking sharks [Cetorhinus maximus], and whale sharks [Rhincodon typus]). This framework aided in identifying where such "marine roads" and marine giants are likely to interact and the consequences of those interactions. We also reviewed known impacts of shipping routes on these species, and then applied the road ecology framework to detect unknown and potentially threatening processes. In the marine environment, such a framework can be used to incorporate knowledge of existing shipping impacts into management practices, thereby reducing the detrimental effects of future expansion of shipping routes on marine giants

Chemical immobilization of adult female Weddell seals with tiletamine and zolazepam: effects of age, condition and stage of lactation

BACKGROUND: Chemical immobilization of Weddell seals (Leptonychotes weddellii) has previously been, for the most part, problematic and this has been mainly attributed to the type of immobilizing agent used. In addition to individual sensitivity, physiological status may play an important role. We investigated the use of the intravenous administration of a 1:1 mixture of tiletamine and zolazepam (Telazol(®)) to immobilize adult females at different points during a physiologically demanding 5–6 week lactation period. We also compared performance between IV and IM injection of the same mixture. RESULTS: The tiletamine:zolazepam mixture administered intravenously was an effective method for immobilization with no fatalities or pronounced apnoeas in 106 procedures; however, there was a 25 % (one animal in four) mortality rate with intramuscular administration. Induction time was slightly longer for females at the end of lactation (54.9 ± 2.3 seconds) than at post-parturition (48.2 ± 2.9 seconds). In addition, the number of previous captures had a positive effect on induction time. There was no evidence for effects due to age, condition (total body lipid), stage of lactation or number of captures on recovery time. CONCLUSION: We suggest that intravenous administration of tiletamine and zolazepam is an effective and safe immobilizing agent for female Weddell seals. Although individual traits could not explain variation in recovery time, we suggest careful monitoring of recovery times during longitudinal studies (> 2 captures). We show that physiological pressures do not substantially affect response to chemical immobilization with this mixture; however, consideration must be taken for differences that may exist for immobilization of adult males and juveniles. Nevertheless, we recommend a mass-specific dose of 0.50 – 0.65 mg/kg for future procedures with adult female Weddell seals and a starting dose of 0.50 mg/kg for other age classes and other phocid seals

Variability in prey field structure drives inter-annual differences in prey encounter by a marine predator, the little penguin

This study was funded by Australian Research Council Linkage Grants (grant nos. LP110200603 and LP160100162), with contributions from the Taronga Conservation Society Australia.Understanding how marine predators encounter prey across patchy landscapes remains challenging due to difficulties in measuring the three-dimensional structure of pelagic prey fields at scales relevant to animal movement. We measured at-sea behaviour of a central-place forager, the little penguin (Eudyptula minor), over 5 years (2015–2019) using GPS and dive loggers. We made contemporaneous measurements of the prey field within the penguins' foraging range via boat-based acoustic surveys. We developed a prey encounter index by comparing estimates of acoustic prey density encountered along actual penguin tracks to those encountered along simulated penguin tracks with the same characteristics as real tracks but that moved randomly through the prey field. In most years, penguin tracks encountered prey better than simulated random movements greater than 99% of the time, and penguin dive depths matched peaks in the vertical distribution of prey. However, when prey was unusually sparse and/or deep, penguins had worse than random prey encounter indices, exhibited dives that mismatched depth of maximum prey density, and females had abnormally low body mass (5.3% lower than average). Reductions in prey encounters owing to decreases in the density or accessibility of prey may ultimately lead to reduced fitness and population declines in central-place foraging marine predators.Publisher PDFPeer reviewe

The thin(ning) green line? Investigating changes in Kenya's seagrass coverage

Knowledge of seagrass distribution is limited to a few well-studied sites and poor where resourcesare scant (e.g. Africa), hence global estimates of seagrass carbon storage are inaccurate. Here, we analysed freely available Sentinel-2 and Landsat imagery to quantify contemporary coverage and change in seagrass between 1986 and 2016 on Kenya’s coast. Using field surveys and independent estimates of historical seagrass, we estimate total cover of Kenya’s seagrass to be 317.1 ± 27.2 km226 , following losses of 0.85% yr-1 since 1986. Losses increased from 0.29% yr-1 in 2000 to 1.59% yr-1 in 2016, releasing up to 2.17 Tg carbon since 1986. Anecdotal evidence suggests fishing pressure is an important cause of loss and is likely to intensify in the near future. If these results are representative for Africa, global estimates of seagrass extent and loss need reconsidering

Giardia duodenalis and Cryptosporidium occurrence in Australian sea lions (Neophoca cinerea) exposed to varied levels of human interaction

AbstractGiardia and Cryptosporidium are amongst the most common protozoan parasites identified as causing enteric disease in pinnipeds. A number of Giardia assemblages and Cryptosporidium species and genotypes are common in humans and terrestrial mammals and have also been identified in marine mammals. To investigate the occurrence of these parasites in an endangered marine mammal, the Australian sea lion (Neophoca cinerea), genomic DNA was extracted from faecal samples collected from wild populations (n = 271) in Southern and Western Australia and three Australian captive populations (n = 19). These were screened using PCR targeting the 18S rRNA of Giardia and Cryptosporidium. Giardia duodenalis was detected in 28 wild sea lions and in seven captive individuals. Successful sequencing of the 18S rRNA gene assigned 27 Giardia isolates to assemblage B and one to assemblage A, both assemblages commonly found in humans. Subsequent screening at the gdh and β-giardin loci resulted in amplification of only one of the 35 18S rRNA positive samples at the β-giardin locus. Sequencing at the β-giardin locus assigned the assemblage B 18S rRNA confirmed isolate to assemblage AI. The geographic distribution of sea lion populations sampled in relation to human settlements indicated that Giardia presence in sea lions was highest in populations less than 25 km from humans. Cryptosporidium was not detected by PCR screening in either wild colonies or captive sea lion populations. These data suggest that the presence of G. duodenalis in the endangered Australian sea lion is likely the result of dispersal from human sources. Multilocus molecular analyses are essential for the determination of G. duodenalis assemblages and subsequent inferences on transmission routes to endangered marine mammal populations

Deiksis Pada Novel Bulan Terbelah Di Langit Amerika Karya Hanum Salsabiela Rais Dan Rangga Almahendra (Deixis in the Novel of Bulan Terbelah Di Langit Amerika by Hanum Salsabiela Rais and Rangga Almahendra)

Deiksis pada Novel Bulan Terbelah di Langit Amerika karya Hanum Salsabiela Rais dan RanggaAlmahendra. Penelitian ini bertujuan untuk mendeskripsikan (1) deiksis persona, (2) deiksis tempat,(3) deiksis waktu, (4) deiksis wacana, dan (5) deiksis sosial yang terdapat dalam novel BulanTerbelah diLangit Amerika karya Hanum Salsabiela Rais dan Rangga Almahendra. Pendekatan yang digunakandalam penelitian ini adalah pendekatan kualitatif. Adapun jenis penelitian ini adalah penelitianpragmatik. Metode penelitian yang digunakan adalah metode deskriptif. Sumber data yang digunakanberasal dari novel BulanTerbelah di Langit Amerika karya Hanum Salsabiela Rais dan RanggaAlmahendra. Data pada penelitian ini berupa kata-kata dan kalimat yang bersifat deiksis. Teknikpengumpulan data yang digunakan adalah studi pustaka. Teknik analisis data yang digunakan adalahteknik analisis isi. Hasil dari penelitian ini menunjukkan bahwa dalam novel BulanTerbelah di Langit299Amerika terdapat lima macam deiksis, yaitu (1) deiksis persona, (2) deiksis tempat, (3) deiksis waktu,(4) deiksis wacana, dan (5) deiksis sosial. Deiksis persona terbagi menjadi tiga yaitu, orang pertama,seperti: aku, saya, kami, dan kita, orang kedua seperti: kamu, Anda, engkau, kau, kalian, kaliansemua, dan Anda semua, sedangkan orang ketiga seperti: ia, dia, nya, dan mereka. Deiksis tempatseperti: ini, di sini, ke sini, dari sini, itu, di situ, dari situ, dari sana, dan ke sana. Deiksis waktu seperti:tadi, dulu, kemarin, sekarang, saat ini, sedang, kini, besok, akan,dan nanti. Deiksis wacana berupaanafora dan katafora. Deiksis sosial seperti:eufemisme, honorifiks, profesi, dan gelar. Penelitian ini jugamenunjukkan bahwa deiksis memiliki keterkaitan dengan unsur intrinsik novel, yaitu tokoh, latar, dangaya bahasa. Hal ini terlihat dengan adanya deiksis persona maka memudahkan pembaca mengetahuikepada tokoh siapakah pronomina persona merujuk. Selain itu, dengan adanya deiksis tempat danwaktu pembaca dapat mengetahui seperti apakah latar tempat dan waktu yang ada dalam novel ini.Adapun keberadaan deiksis wacana dan sosial dapat memudahkan pembaca mengetahui gaya bahasayang digunakan.Kata

Big data analyses reveal patterns and drivers of the movements of southern elephant seals

The growing number of large databases of animal tracking provides an opportunity for analyses of movement patterns at the scales of populations and even species. We used analytical approaches, developed to cope with big data, that require no a priori assumptions about the behaviour of the target agents, to analyse a pooled tracking dataset of 272 elephant seals (Mirounga leonina) in the Southern Ocean, that was comprised of >500,000 location estimates collected over more than a decade. Our analyses showed that the displacements of these seals were described by a truncated power law distribution across several spatial and temporal scales, with a clear signature of directed movement. This pattern was evident when analysing the aggregated tracks despite a wide diversity of individual trajectories. We also identified marine provinces that described the migratory and foraging habitats of these seals. Our analysis provides evidence for the presence of intrinsic drivers of movement, such as memory, that cannot be detected using common models of movement behaviour. These results highlight the potential for big data techniques to provide new insights into movement behaviour when applied to large datasets of animal tracking.Comment: 18 pages, 5 figures, 6 supplementary figure

Speaking Power to ‘Post-Truth’:Critical Political Ecology and the New Authoritarianism

Given a history in political ecology of challenging hegemonic “scientific” narratives concerning environmental problems, the current political moment presents a potent conundrum: how to (continue to) critically engage with narratives of environmental change while confronting the “populist” promotion of “alternative facts.” We ask how political ecologists might situate themselves vis-à-vis the presently growing power of contemporary authoritarian forms, highlighting how the latter operates through sociopolitical domains and beyond-human natures. We argue for a clear and conscious strategy of speaking power to post-truth, to enable two things. The first is to come to terms with an internal paradox of addressing those seeking to obfuscate or deny environmental degradation and social injustice, while retaining political ecology’s own historical critique of the privileged role of Western science and expert knowledge in determining dominant forms of environmental governance. This involves understanding post-truth, and its twin pillars of alternative facts and fake news, as operating politically by those regimes looking to shore up power, rather than as embodying a coherent mode of ontological reasoning regarding the nature of reality. Second, we differentiate post-truth from analyses affirming diversity in both knowledge and reality (i.e., epistemology and ontology, respectively) regarding the drivers of environmental change. This enables a critical confrontation of contemporary authoritarianism and still allows for a relevant and accessible political ecology that engages with marginalized populations likely to suffer most from the proliferation of post-truth politics