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Publications (256)
The deep ocean is the last natural biodiversity refuge from the reach of human activities. Deepwater sharks and rays are among the most sensitive marine vertebrates to overexploitation. One-third of threatened deepwater sharks are targeted, and half the species targeted for the international liver-oil trade are threatened with extinction. Steep pop...
Aim
Climate change is driving biogeographic change globally, including poleward range shifts of species and the increasing abundance of rare species. We examine spatiotemporal patterns in the occurrences of tropical, subtropical and rare marine fishes in Aotearoa New Zealand to determine whether biodiversity change is occurring in this temperate re...
1. Substantial global population declines in pelagic sharks have led to the introduction of management and conservation measures, including gear restrictions and no-retention policies, to curb declines and encourage stock recovery. As the rate of discarding sharks increases, there is a growing need to understand prognostic factors that influence th...
The subtropical islands of the north Tasman Sea have a fascinating mix of tropical, subtropical and temperate marine fishes. Species diversity and the proportion of tropical species in the fauna decline from west to east (Lord Howe > Norfolk > Kermadec Islands) (Francis 1993, Francis & Duffy 2015). This checklist has been compiled as a resource for...
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first globa...
Blue shark (Prionace glauca) is amongst the most abundant shark species in international
trade, however this highly migratory species has little effective management and the need
for spatio-temporal strategies increases, possibly involving the most vulnerable stage or
sex classes. We combined 265,595 blue shark observations (capture or satellite ta...
In addition to conventional immunoglobulin, camelids and cartilaginous fish express a special class of antibody that consists only of heavy (H) chain (HCAbs). In the holocephalan elephantfish there are two HCAb classes, one of which has evolved surprising features. The H chain genes in cartilaginous fish are organized as 20–200 minigenes, or cluste...
Vector Autoregressive Spatio-Temporal (VAST) models were applied to research trawl survey and environmental data to provide updated information on stock status for seven deepwater sharks. Deepwater sharks were found to be ubiquitous around New Zealand, with each species shown to have a unique distributional pattern. Deepwater shark “hotspots” in Ne...
106,107 ✉ replying to A. V. Harry & J. M. Braccini Nature https://doi.org/10.1038/s41586-021-03463-w (2021) Our global analysis 1 estimated the overlap and fishing exposure risk (FEI) using the space use of satellite-tracked sharks and longline fishing effort monitored by the automatic identification system (AIS). In the accompanying Comment, Harry...
Our previously published paper1 provided global fine-scale spatiotemporal
estimates (1° × 1°; monthly) of overlap and fishing exposure
risk (FEI) between satellite-tracked shark space use and automatic
identification system (AIS) longline fishing effort. We did not assess
shark mortality directly, but in addition to replying to the Comment
by Murua...
This article is a response to Murua et al.'s Matters Arising article in Nature, "Shark mortality cannot be assessed by fishery overlap alone," which arose from arising from N. Queiroz et al. Nature https://doi.org/10.1038/s41586-019-1444-4 (2019).
Basking sharks (Cetorhinus maximus) were widely reported throughout New Zealand waters. Once commonly observed, and sometimes in large numbers, basking sharks are now infrequently reported. Basking shark observations are known to be highly variable across years, and their distribution and occurrence have been shown to be influenced by environmental...
Aim
Despite the unprecedented rate of species redistribution during the Anthropocene, there are few monitoring programmes at the appropriate spatial and temporal scale to detect distributional change of marine species and to infer climate‐ versus human‐mediated drivers of change. Here, we present an approach that combines citizen science with exper...
Overfishing is the primary cause of marine defaunation, yet declines in and increasing extinction risks of individual species are difficult to measure, particularly for the largest predators found in the high seas. Here we calculate two well-established indicators to track progress towards Aichi Biodiversity Targets and Sustainable Development Goal...
Whale sharks, Rhincodon typus, are found circumglobally in tropical and warm temperate seas, exhibiting a range of residency and movement patterns. To determine spatio-temporal habitat use by juvenile male whale sharks in Cenderawasih Bay, Indonesia, we collected data from June 2015 to November 2016 using 16 fin-mounted satellite tags that provided...
Migratory movements in response to seasonal resources often influence population structure and dynamics. Yet in mobile marine predators, population genetic consequences of such repetitious behaviour remain inaccessible without comprehensive sampling strategies. Temporal genetic sampling of seasonally recurring aggregations of planktivorous basking...
A recent risk assessment for chondrichthyans (sharks, rays, and chimaeras) found some deepwater sharks were at relatively high risk of adverse impacts from fishing. Quantitative data for these species is limited, and some available information has been found to be unreliable. With a better understanding of spatial distributions, our knowledge of th...
Spatial classifications of the environment have previously been used to characterise biodiversity and to facilitate management planning at large spatial scales. Such classifications are more likely to be adopted if they can demonstrate integration of real patterns in habitats or biotic assemblages, in addition to environment. A previous classificat...
Effective ocean management and the conservation of highly migratory species depend on resolving the overlap between animal movements and distributions, and fishing effort. However, this information is lacking at a global scale. Here we show, using a big-data approach that combines satellite-tracked movements of pelagic sharks and global fishing fle...
Fin spines from elephantfish Callorhinchus milii were sectioned and viewed with transmitted white light under a compound microscope. The sections displayed growth bands but their interpretation and significance were unclear. Three different methods were used for counting growth bands. The results were compared with reference growth curves based on...
Post release mortality of silky and mako sharks
• The national extinction risk of 103 New Zealand chondrichthyans (sharks, rays, and chimaeras), ~10% of the global chondrichthyan fauna, was evaluated for the first time using the International Union for Conservation of Nature Red List of Threatened Species Categories and Criteria. Across 32 families, 103 species were assessed.
• New Zealand holds...
The subtropical islands of the north Tasman Sea have a fascinating mix of tropical, subtropical and temperate marine fishes. Species diversity and the proportion of tropical species in the fauna decline from west to east (Lord Howe > Norfolk > Kermadec Islands) (Francis 1993, Francis & Duffy 2015). This checklist has been compiled as a resource for...
White sharks, Carcharodon carcharias, are often described as elusive, with little information available due to the logistical difficulties of studying large marine predators that make long-distance migrations across ocean basins. Increased understanding of aggregation patterns, combined with recent advances in technology have, however, facilitated...
Pelagic sharks are vulnerable to overfishing because of their low reproductive rates, generally low growth rates, and high catch rates in tuna and billfish fisheries worldwide. Pelagic sharks often migrate long distances, but they may also occur close to shore, making it difficult to classify their behaviour on the continuum from oceanic nomad to c...
In this paper we combine analyses of satellite telemetry and molecular data to investigate spatial connectivity and genetic structure among populations of shortfin mako (Isurus oxyrinchus) in and around Australian waters, where this species is taken in recreational and commercial fisheries. Mitochondrial DNA data suggest matrilineal substructure ac...
The conservation status of all known New Zealand chondrichthyan taxa (chimaeras, sharks and rays) was reassessed using the New Zealand Threat Classification System (NZTCS). Since the last assessment (in 2005), 9 new taxa have been added to the list, 6 have been removed from it and 30 have had name changes. Also, 1 previously Data Deficient taxon is...
New Zealand adopted a revised National Plan of Action for the Conservation and Management of Sharks (NPOA-Sharks 2013) in January 2014. Amongst other objectives, the NPOA-Sharks established a risk-based approach to prioritising management actions. An initial qualitative (level 1) risk assessment (RA) workshop in November 2014 assessed the risk to a...
New Zealand adopted a revised National Plan of Action for the Conservation and Management of Sharks (NPOA-Sharks 2013) in January 2014. Amongst other objectives, the NPOA-Sharks established a risk-based approach to prioritising management actions. An initial qualitative (level 1) risk assessment (RA) workshop in November 2014 assessed the risk to a...
Conservation concerns exist for many sharks but robust estimates of abundance are often lacking. Improving population status is a performance measure for species under conservation or recovery plans, yet the lack of data permitting estimation of population size means the efficacy of management actions can be difficult to assess, and achieving the g...
The conservation and protection of marine megafauna require robust knowledge of where and when animals are located. Yet, our ability to predict animal distributions in space and time remains limited due to difficulties associated with studying elusive animals with large home ranges. The widespread deployment of satellite telemetry technology create...
Background
International trade for luxury products, medicines, and tonics poses a threat to both terrestrial and marine wildlife. The demand for and consumption of gill plates (known as Peng Yu Sai , “Fish Gill of Mobulid Ray”) from devil and manta rays (subfamily Mobulinae, collectively referred to as mobulids) poses a significant threat to these...
Mobulid rays are protected in New Zealand, but the spinetail devilray Mobula japanica is caught as bycatch in skipjack tuna purse seine fisheries.
Between 2005 and 2014, rays were recorded in 8.2% of observed purse seine sets. Rays were caught during summer, with a ‘hotspot’ (24.3% of sets) near the shelf edge off North Island over seabed depths of...
The smooth hammerhead shark, Sphyrna zygaena, occurs in warm temperate waters around the northern North Island of New Zealand. Commercial fishing records and research trawl survey data were used to determine their distribution. Highest catch rates were recorded in relatively sheltered bays and coastlines along the northeast coast of North Island. N...
Manta and devil rays of the subfamily Mobulinae (mobulids) are rarely studied, large, pelagic elasmobranchs, with all eight of well‐evaluated species listed on the IUCN Red List as threatened or near threatened.
Mobulids have life history characteristics (matrotrophic reproduction, extremely low fecundity, and delayed age of first reproduction) tha...
Background. Increased interest in luxury products and Traditional Chinese Medicine, associated with economic growth in China, has been linked to depletion of both terrestrial and marine wildlife. Among the most rapidly emerging concerns with respect to these markets is the relatively new demand for gill plates, or Peng Yu Sai (?Fish Gills?), from d...
Background. Increased interest in luxury products and Traditional Chinese Medicine, associated with economic growth in China, has been linked to depletion of both terrestrial and marine wildlife. Among the most rapidly emerging concerns with respect to these markets is the relatively new demand for gill plates, or Peng Yu Sai (?Fish Gills?), from d...
Abstract The basking shark (Cetorhinus maximus) is the world's second largest fish and the subject of strong conservation concern. Minimal genetic assessment exists for this globally distributed but regionally endangered species. We describe the complete mitochondrial genome sequence of C. maximus, obtained via polymerase chain reaction-based Sange...
A wide range of pelagic predators survive in the open ocean, yet little is known about how they use that environment. Much of the current information on these species comes from studies in shelf waters, and it is not clear how representative the results are of their oceanic lifestyle. We used pop-up satellite tags to explore the horizontal and vert...
The Kermadec Islands coastal fish fauna is still incompletely known, and recent expeditions there
have added new fish records, and improved our understanding of its diversity and composition.
This study documents 18 new fish records, presents an updated checklist of coastal fishes, and
analyses the species biodiversity and biogeography. The coastal...
Five visits to the Kermadec Islands between 2004 and 2013 have increased the number of confirmed
fish species from the region. The most intensive survey of shore fishes from all island groups of the
Kermadec Islands was undertaken in May 2011. Additional fishes were recorded during surveys
undertaken in 2004, 2012 and 2013. The main method used was...