Victor Peddemors | Macquarie University (original) (raw)

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Papers by Victor Peddemors

Ocean & Coastal Management, 2021

Journal of Fish Biology, 2019

Aquatic Conservation: Marine and Freshwater Ecosystems

Frontiers in Marine Science

Understanding the movement ecology of marine species and connectivity of populations is required ... more Understanding the movement ecology of marine species and connectivity of populations is required for effective fisheries management. This is especially the case for species with wide-ranging distributions for which movement can span across several jurisdictions with different management regulations. We used the Australian national network of acoustic receivers facilitated by the Integrated Marine Observing System (IMOS) to describe the extent and frequency of movements for two large epipelagic shark species, the bronze whaler (Carcharhinus brachyurus) and dusky shark (Carcharhinus obscurus). A total of 210 sharks (117 bronze whalers and 93 dusky sharks) were tracked for a 10-year period during which 21% and 9% of detected bronze whalers and dusky sharks, respectively, moved between Australian states. Bronze whalers showed more variable inter-state movements, mostly between Western Australia and South Australia but also eastwards to New South Wales (NSW). Although no dusky sharks tag...

J. Cetacean Res. Manage.

Between 1963 and 1998, 55 mortalities of southern right whales and a further three ‘possible righ... more Between 1963 and 1998, 55 mortalities of southern right whales and a further three ‘possible right whale’ mortalities were recorded on theSouth African coastline. Of the known right whale mortalities, 31 could be classified as ‘calves of the year’, 8 as juveniles and 14 as adults.Relatively few (6.5-16.1%) of the calf mortalities could be attributed to anthropogenic factors, compared to juveniles (25-50%) and adults(35.7-57.1%). Apparent causes of death included ship strikes (4 definite, 7 possible) and entanglement (4 definite, 1 possible), with oneharpooning incident. Five non-fatal ship strikes and 16 instances of non-fatal entanglement were also recorded. Whilst the gear mostcommonly involved in non-fatal entanglement was crayfish trap lines, three of the four entanglement fatalities involved longline gear. Theincidence of scars attributable to previous entanglement remained constant amongst mature females from 1979-1997, at 3-4%. Recordedmortalities increased over the period 19...

Biodiversity and Conservation

PloS one, 2018

The development of shark vertebrae and the possible drivers of inter- and intra-specific differen... more The development of shark vertebrae and the possible drivers of inter- and intra-specific differences in vertebral structure are poorly understood. Shark vertebrae are used to examine life-history traits related to trophic ecology, movement patterns, and the management of fisheries; a better understanding of their development would be beneficial to many fields of research that rely on these calcified structures. This study used Scanning X-ray Fluorescence Microscopy to observe zinc distribution within vertebrae of ten shark species from five different orders. Zinc was mostly localised within the intermedialis and was generally detected at levels an order of magnitude lower in the corpus calcareum. In most species, zinc concentrations were higher pre-birth mark, indicating a high rate of pre-natal zinc deposition. These results suggest there are inter-specific differences in elemental deposition within vertebrae. Since the deposition of zinc is physiologically-driven, these difference...

South African Journal of Zoology

Marine and Freshwater Research, 2016

Broad-scale acoustic telemetry networks are being established worldwide. The 10-year anniversary ... more Broad-scale acoustic telemetry networks are being established worldwide. The 10-year anniversary of the Integrated Marine Observing System’s Animal Tracking Facility provided the opportunity to assess the efficiency of one of the first national-scale acoustic telemetry networks. Acoustic networks are comprised of acoustic receiver arrays that detect high-frequency transmitters attached to animals that pass within detection range. Herein we assessed the efficiency of eight curtains to detect passing animals by calculating the standardised mean number of detections and transmitters detected at each station. The aim was to determine how many receivers could be decommissioned from each curtain while maintaining its integrity (i.e. detection of all species passing the array). Pivotal locations were defined as the furthest station at which all species would still be detected and where at least 75% of the detections and transmitters would still be detected. By applying these criteria, we w...

Scientific reports, Jan 18, 2016

Determining the age of sharks using vertebral banding is a vital component of management, but the... more Determining the age of sharks using vertebral banding is a vital component of management, but the causes of banding are not fully understood. Traditional shark ageing is based on fish otolith ageing methods where growth bands are assumed to result from varied seasonal calcification rates. Here we investigate these assumptions by mapping elemental distribution within the growth bands of vertebrae from six species of sharks representing four different taxonomic orders using scanning x-ray fluorescence microscopy. Traditional visual growth bands, determined with light microscopy, were more closely correlated to strontium than calcium in all species tested. Elemental distributions suggest that vertebral strontium bands may be related to environmental variations in salinity. These results highlight the requirement for a better understanding of shark movements, and their influence on vertebral development, if confidence in age estimates is to be improved. Analysis of shark vertebrae using...

Methods in Ecology and Evolution, 2015