Pendoley K.,Pendoley Environmental Pty Ltd |
Christian M.,PO Box 999
Memoirs of the Queensland Museum | Year: 2012
Nothing has been published in the modern literature on the status of marine turtles at Norfolk Island although their presence has been recognised since 1793 (Fidlon & Ryan 1980). This study brings together all the available published, anecdotal and field survey data on marine turtles at Norfolk Island so that the status of habitat usage could be established. The results confirm the Norfolk Island group is used for foraging by resident adult and juvenile Chelonia mydas (Green) turtles and adult Eretmochelys imbricata (Hawksbill) turtles. The natal beaches for these resident animals are thought to be Melanesian and Polynesian islands to the north and the beaches of north eastern Australia. While juvenile hawksbill turtles have not been recorded foraging at Norfolk Island they are the most common species and age class recorded in the island's strandings data. The confirmation of marine turtles at Norfolk means that any future development proposals must include assessment of project impacts on these listed threatened species under Australian Federal legislation and their marine bioregional processes. © Queensland Museum.
Scott R.,University of Exeter |
Scott R.,University of Swansea |
Hodgson D.J.,University of Exeter |
Witt M.J.,University of Exeter |
And 15 more authors.
Global Ecology and Biogeography | Year: 2012
Aim Tracking technologies are often proposed as a method to elucidate the complex migratory life histories of migratory marine vertebrates, allowing spatially explicit threats to be identified and mitigated. We conducted a global analysis of foraging areas of adult green turtles (Chelonia mydas) subject to satellite tracking (n= 145) and the conservation designation of these areas according to International Union for Conservation of Nature criteria. Location The green turtle has a largely circumtropical distribution, with adults migrating up to thousands of kilometres between nesting beaches and foraging areas, typically in neritic seagrass or algal beds. Methods We undertook an assessment of satellite tracking projects that followed the movements of green turtles in tropical and subtropical habitats. This approach was facilitated by the use of the Satellite Tracking and Analysis Tool (http://www.seaturtle.org) and the integration of publicly available data on Marine Protected Areas (MPAs). Results We show that turtles aggregate in designated MPAs far more than would be expected by chance when considered globally (35% of all turtles were located within MPAs) or separately by ocean basin (Atlantic 67%, Indian 34%, Mediterranean 19%, Pacific 16%). Furthermore, we show that the size, level of protection and time of establishment of MPAs affects the likelihood of MPAs containing foraging turtles, highlighting the importance of large, well-established reserves. Main conclusions Our findings constitute compelling evidence of the world-wide effectiveness of extant MPAs in circumscribing important foraging habitats for a marine megavertebrate. © 2012 Blackwell Publishing Ltd.
Pikesley S.K.,University of Exeter |
Maxwell S.M.,Stanford University |
Pendoley K.,Pendoley Environmental Pty Ltd |
Costa D.P.,University of California at Santa Cruz |
And 10 more authors.
Diversity and Distributions | Year: 2013
Aim: Knowledge and understanding of marine vertebrate spatial ecology are required to identify sources of threat and highlight areas for conservation. Olive ridley sea turtles Lepidochelys olivacea are in decline in some regions, and data for the Eastern Atlantic are sparse. Here, we seek to describe observed, and potential, post-nesting habitats for this species in the southeast Atlantic. We contextualize these with fisheries catch data to identify areas of potential threat from fisheries interaction for this species. Location: West coast of Africa, southeast Atlantic. Methods: We tracked 21 female olive ridley turtles, from two nesting sites, between 2007 and 2010. We used ensemble ecological niche modelling, integrated with knowledge on the physical and biological oceanographic environment, to identify regions where environmental variables exist that may be critical in defining post-nesting habitats for this species. We further integrate fisheries catch data to contextualize potential threat from fisheries. Results: We describe key areas of observed, and potential, olive ridley turtle occurrence at sea, and reveal that there was considerable overlap of these conspecifics, from two distinct nesting regions, within the Angolan exclusive economic zone (EEZ). With the inclusion of fisheries catch data for the region, we highlight areas that have the potential for conflict with fishing activities known to result in bycatch. Main conclusions: This study demonstrates that it is imperative that marine conservation policy recognizes the spatial extent of highly migratory species with expansive ranges. It also highlights that deficiencies exist in current knowledge of bycatch, both in gear specificity and in catch per unit effort. With integration of vessel monitoring system (VMS) data and those on fisheries catch, knowledge and understanding of bycatch may be improved, and this will ultimately facilitate development of appropriate management strategies and long-term sustainability of fisheries and their supporting ecosystems. © 2013 John Wiley & Sons Ltd.
Pendoley K.L.,Pendoley Environmental Pty Ltd |
Schofield G.,Deakin University |
Whittock P.A.,Pendoley Environmental Pty Ltd |
Ierodiaconou D.,Deakin University |
And 2 more authors.
Marine Biology | Year: 2014
The establishment of protected corridors linking the breeding and foraging grounds of many migratory species remains deficient, particularly in the world's oceans. For example, Australia has recently established a network of Commonwealth Marine Reserves, supplementing existing State reserves, to protect a wide range of resident and migratory marine species; however, the routes used by mobile species to access these sites are often unknown. The flatback marine turtle (Natator depressus) is endemic to the continental shelf of Australia, yet information is not available about how this species uses the marine area. We used a geospatial approach to delineate a coastal corridor from 73 adult female flatback postnesting migratory tracks from four rookeries along the north-west coast of Australia. A core corridor of 1,150 km length and 30,800 km2 area was defined, of which 52 % fell within 11 reserves, leaving 48 % (of equivalent size to several Commonwealth Reserves) of the corridor outside of the reserve network. Despite limited data being available for other marine wildlife in this region, humpback whale migratory tracks overlapped with 96 % of the core corridor, while the tracks of three other species overlapped by 5-10 % (blue whales, olive ridley turtles, whale sharks). The overlap in the distribution ranges of at least 20 other marine vertebrates (dugong, cetaceans, marine turtles, sea snakes, crocodiles, sharks) with the corridor also imply potential use. In conclusion, this study provides valuable information towards proposing new locations requiring protection, as well as identifying high-priority network linkages between existing marine protected areas. © 2014 Springer-Verlag Berlin Heidelberg.
Pendoley K.,Pendoley Environmental Pty Ltd |
Kamrowski R.L.,Pendoley Environmental Pty Ltd
Marine Ecology Progress Series | Year: 2015
Marine turtles are threatened globally by increasing coastal development. In particular, increased artificial lighting at the nesting beach has the potential to disrupt turtle breeding success. Few published data exist regarding the behaviour of the flatback turtle Natator depressus, a species endemic to Australia, in response to artificial light. Given the ongoing industrialisation of the Australian coastline, this study is a timely investigation into the orientation of flatback hatchlings exposed to light glow produced by lighting typically used in industrial settings. We recorded the orientation of hatchlings at the nesting beach on Barrow Island, Western Australia, exposed to 3 types of standard lighting - high-pressure sodium vapour (HPS), metal halide (MH), and fluorescent white (FW) - at 3 different intensities. The light array was positioned either behind a high dune (producing a high, dark silhouette; 16° elevation), or in a low creek bed (producing a low silhouette and bright horizon; 2° elevation). At medium and high light intensities of all 3 light types, hatchlings were significantly less ocean-oriented when exposed to light at 2° elevation compared to 16° elevation. This difference remained with glow from low-intensity MH light; however, there was no significant difference in orientation of hatchlings exposed to low-intensity HPS and FW light glow at either elevation. Our study emphasises the importance of horizon elevation cues in hatchling sea-finding. Since all species of marine turtles show similar sea-finding behaviour, our results have important implications for management of lighting adjacent to turtle nesting beaches in Australia and elsewhere, as coastal development continues. © Inter-Research 2015.