Samantha Andrzejaczek
Basic Life Research Scientist
Oceans
All Publications
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A framework for optimising opportunistic collaborative syntheses to propel ecological conservation
BIOLOGICAL CONSERVATION
2024; 298
View details for DOI 10.1016/j.biocon.2024.110717
View details for Web of Science ID 001306648200001
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Improving Ocean Management Using Insights from Space.
Annual review of marine science
2024
Abstract
Advancements in space-based ocean observation and computational data processing techniques have demonstrated transformative value for managing living resources, biodiversity, and ecosystems of the ocean. We synthesize advancements in leveraging satellite-derived insights to better understand and manage fishing, an emerging revolution of marine industrialization, ocean hazards, sea surface dynamics, benthic ecosystems, wildlife via electronic tracking, and direct observations of ocean megafauna. We consider how diverse space-based data sources can be better coupled to modernize and improve ocean management. We also highlight examples of how data from space can be developed into tools that can aid marine decision-makers managing subjects from whales to algae. Thoughtful and prospective engagement with such technologies from those inside and outside the marine remote sensing community is, however, essential to ensure that these tools meet their full potential to strengthen the effectiveness of ocean management.
View details for DOI 10.1146/annurev-marine-050823-120619
View details for PubMedID 39159203
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Salmon shark seasonal site fidelity demonstrates the influence of scale on identifying potential high-use areas and vulnerabilities
MARINE ECOLOGY PROGRESS SERIES
2024; 735: 125-140
View details for DOI 10.3354/meps14565
View details for Web of Science ID 001214316400004
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Stomach eversion and retraction by a tagged tiger shark at Ningaloo Reef, Western Australia
FISHERIES RESEARCH
2024; 269
View details for DOI 10.1016/j.fishres.2023.106875
View details for Web of Science ID 001098548400001
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Connectivity between white shark populations off Central California, USA and Guadalupe Island, Mexico
FRONTIERS IN MARINE SCIENCE
2023; 10
View details for DOI 10.3389/fmars.2023.1210969
View details for Web of Science ID 001038228900001
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Seasonal and diel habitat use of blue marlin Makaira nigricans in the North Atlantic Ocean
ICES JOURNAL OF MARINE SCIENCE
2023
View details for DOI 10.1093/icesjms/fsad020
View details for Web of Science ID 000942749100001
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Diving into the vertical dimension of elasmobranch movement ecology.
Science advances
2022; 8 (33): eabo1754
Abstract
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 global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements.
View details for DOI 10.1126/sciadv.abo1754
View details for PubMedID 35984887
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Prey interactions in tiger sharks: Accounting for visual perception in animal-borne cameras
JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY
2022; 553
View details for DOI 10.1016/j.jembe.2022.151764
View details for Web of Science ID 000807753300003
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Elasmobranch diversity across a remote coral reef atoll revealed through environmental DNA metabarcoding
ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
2022
View details for DOI 10.1093/zoolinnean/zlac014
View details for Web of Science ID 000787042000001
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First insights into the movements and vertical habitat use of blue marlin (Makaira nigricans) in the eastern North Atlantic
ANIMAL BIOTELEMETRY
2022; 10 (1)
View details for DOI 10.1186/s40317-022-00284-0
View details for Web of Science ID 000776712100001
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Multi-Decadal High-Resolution Data Reveal the Cryptic Vertical Movement Patterns of a Large Marine Predator Along the Californian Coast
FRONTIERS IN MARINE SCIENCE
2022; 9
View details for DOI 10.3389/fmars.2022.835576
View details for Web of Science ID 000767596100001
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Emergent research and priorities for shark and ray conservation
ENDANGERED SPECIES RESEARCH
2022; 47: 171-203
View details for DOI 10.3354/esr01169
View details for Web of Science ID 000790066600013
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Regional movements of satellite-tagged whale sharks Rhincodon typus in the Gulf of Aden.
Ecology and evolution
2021; 11 (9): 4920-4934
Abstract
To gain insight into whale shark (Rhincodon typus) movement patterns in the Western Indian Ocean, we deployed eight pop-up satellite tags at an aggregation site in the Arta Bay region of the Gulf of Tadjoura, Djibouti in the winter months of 2012, 2016, and 2017. Tags revealed movements ranging from local-scale around the Djibouti aggregation site, regional movements along the coastline of Somaliland, movements north into the Red Sea, and a large-scale (>1,000 km) movement to the east coast of Somalia, outside of the Gulf of Aden. Vertical movement data revealed high occupation of the top ten meters of the water column, diel vertical movement patterns, and deep diving behavior. Long-distance movements recorded both here and in previous studies suggest that connectivity between the whale sharks tagged at the Djibouti aggregation and other documented aggregations in the region are likely within annual timeframes. In addition, wide-ranging movements through multiple nations, as well as the high use of surface waters recorded, likely exposes whale sharks in this region to several anthropogenic threats, including targeted and bycatch fisheries and ship-strikes. Area-based management approaches focusing on seasonal hotspots offer a way forward in the conservation of whale sharks in the Western Indian Ocean.
View details for DOI 10.1002/ece3.7400
View details for PubMedID 33976859
View details for PubMedCentralID PMC8093710
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Regional movements of satellite-tagged whale sharks Rhincodon typus in the Gulf of Aden
ECOLOGY AND EVOLUTION
2021
View details for DOI 10.1002/ece3.7400
View details for Web of Science ID 000631682000001
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Reverse diel vertical movements of oceanic manta rays off the northern coast of Peru and implications for conservation
ECOLOGICAL SOLUTIONS AND EVIDENCE
2021; 2 (1)
View details for DOI 10.1002/2688-8319.12051
View details for Web of Science ID 000809441900021
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Behavior and Ecology of Silky Sharks Around the Chagos Archipelago and Evidence of Indian Ocean Wide Movement
FRONTIERS IN MARINE SCIENCE
2020; 7
View details for DOI 10.3389/fmars.2020.596619
View details for Web of Science ID 000600698800001
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A review of a decade of lessons from one of the world's largest MPAs: conservation gains and key challenges
MARINE BIOLOGY
2020; 167 (11)
View details for DOI 10.1007/s00227-020-03776-w
View details for Web of Science ID 000581775500001
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Depth-dependent dive kinematics suggest cost-efficient foraging strategies by tiger sharks
ROYAL SOCIETY OPEN SCIENCE
2020; 7 (8)
View details for DOI 10.1098/rsos.200789
View details for Web of Science ID 000565603500001
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Depth-dependent dive kinematics suggest cost-efficient foraging strategies by tiger sharks.
Royal Society open science
2020; 7 (8): 200789
Abstract
Tiger sharks, Galeocerdo cuvier, are a keystone, top-order predator that are assumed to engage in cost-efficient movement and foraging patterns. To investigate the extent to which oscillatory diving by tiger sharks conform to these patterns, we used a biologging approach to model their cost of transport. High-resolution biologging tags with tri-axial sensors were deployed on 21 tiger sharks at Ningaloo Reef for durations of 5-48 h. Using overall dynamic body acceleration as a proxy for energy expenditure, we modelled the cost of transport of oscillatory movements of varying geometries in both horizontal and vertical planes for tiger sharks. The cost of horizontal transport was minimized by descending at the smallest possible angle and ascending at an angle of 5-14°, meaning that vertical oscillations conserved energy compared to swimming at a level depth. The reduction of vertical travel costs occurred at steeper angles. The absolute dive angles of tiger sharks increased between inshore and offshore zones, presumably to reduce the cost of transport while continuously hunting for prey in both benthic and surface habitats. Oscillatory movements of tiger sharks conform to strategies of cost-efficient foraging, and shallow inshore habitats appear to be an important habitat for both hunting prey and conserving energy while travelling.
View details for DOI 10.1098/rsos.200789
View details for PubMedID 32968529
View details for PubMedCentralID PMC7481696
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Individual variation in residency and regional movements of reef manta rays Mobula alfredi in a large marine protected area
MARINE ECOLOGY PROGRESS SERIES
2020; 639: 137–53
View details for DOI 10.3354/meps13270
View details for Web of Science ID 000525359900009
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Tiger shark predation on large ocean sunfishes (Family Molidae) - two Australian observations
ENVIRONMENTAL BIOLOGY OF FISHES
2019
View details for DOI 10.1007/s10641-019-00926-y
View details for Web of Science ID 000492716100001
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Biologging Tags Reveal Links Between Fine-Scale Horizontal and Vertical Movement Behaviors in Tiger Sharks (Galeocerdo cuvier)
FRONTIERS IN MARINE SCIENCE
2019; 6
View details for DOI 10.3389/fmars.2019.00229
View details for Web of Science ID 000467919700001
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Cryptic habitat use of white sharks in kelp forest revealed by animal-borne video.
Biology letters
2019; 15 (4): 20190085
Abstract
Traditional forms of marine wildlife research are often restricted to coarse telemetry or surface-based observations, limiting information on fine-scale behaviours such as predator-prey events and interactions with habitat features. We use contemporary animal-attached cameras with motion sensing dataloggers, to reveal novel behaviours by white sharks, Carcharodon carcharias, within areas of kelp forest in South Africa. All white sharks tagged in this study spent time adjacent to kelp forests, with several moving throughout densely kelp-covered areas, navigating through channels and pushing directly through stipes and fronds. We found that activity and turning rates significantly increased within kelp forest. Over 28 h of video data revealed that white shark encounters with Cape fur seals, Arctocephalus pusillus pusillus, occurred exclusively within kelp forests, with seals displaying predator evasion behaviour during those encounters. Uniquely, we reveal the use of kelp forest habitat by white sharks, previously assumed inaccessible to these large predators.
View details for PubMedID 30940023
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Cryptic habitat use of white sharks in kelp forest revealed by animal-borne video
BIOLOGY LETTERS
2019; 15 (4)
View details for DOI 10.1098/rsbl.2019.0085
View details for Web of Science ID 000465405300017
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First Insights Into the Fine-Scale Movements of the Sandbar Shark, Carcharhinus plumbeus
FRONTIERS IN MARINE SCIENCE
2018; 5
View details for DOI 10.3389/fmars.2018.00483
View details for Web of Science ID 000457220700001
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Temperature and the vertical movements of oceanic whitetip sharks, Carcharhinus longimanus
SCIENTIFIC REPORTS
2018; 8: 8351
Abstract
Large-bodied pelagic ectotherms such as sharks need to maintain internal temperatures within a favourable range in order to maximise performance and be cost-efficient foragers. This implies that behavioural thermoregulation should be a key feature of the movements of these animals, although field evidence is limited. We used depth and temperature archives from pop-up satellite tags to investigate the role of temperature in driving vertical movements of 16 oceanic whitetip sharks, Carcharhinus longimanus, (OWTs). Spectral analysis, linear mixed modelling, segmented regression and multivariate techniques were used to examine the effect of mean sea surface temperature (SST) and mixed layer depth on vertical movements. OWTs continually oscillated throughout the upper 200 m of the water column. In summer when the water column was stratified with high SSTs, oscillations increased in amplitude and cycle length and sharks reduced the time spent in the upper 50 m. In winter when the water column was cooler and well-mixed, oscillations decreased in amplitude and cycle length and sharks frequently occupied the upper 50 m. SSTs of 28 oC marked a distinct change in vertical movements and the onset of thermoregulation strategies. Our results have implications for the ecology of these animals in a warming ocean.
View details for DOI 10.1038/s41598-018-26485-3
View details for Web of Science ID 000433291300054
View details for PubMedID 29844605
View details for PubMedCentralID PMC5974137
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The ecological connectivity of whale shark aggregations in the Indian Ocean: a photo-identification approach
ROYAL SOCIETY OPEN SCIENCE
2016; 3 (11): 160455
Abstract
Genetic and modelling studies suggest that seasonal aggregations of whale sharks (Rhincodon typus) at coastal sites in the tropics may be linked by migration. Here, we used photo-identification (photo-ID) data collected by both citizen scientists and researchers to assess the connectedness of five whale shark aggregation sites across the entire Indian Ocean at timescales of up to a decade. We used the semi-automated program I3S (Individual Interactive Identification System) to compare photographs of the unique natural marking patterns of individual whale sharks collected from aggregations at Mozambique, the Seychelles, the Maldives, Christmas Island (Australia) and Ningaloo Reef (Australia). From a total of 6519 photos, we found no evidence of connectivity of whale shark aggregations at ocean-basin scales within the time frame of the study and evidence for only limited connectivity at regional (hundreds to thousands of kilometres) scales. A male whale shark photographed in January 2010 at Mozambique was resighted eight months later in the Seychelles and was the only one of 1724 individuals in the database to be photographed at more than one site. On average, 35% of individuals were resighted at the same site in more than one year. A Monte Carlo simulation study showed that the power of this photo-ID approach to document patterns of emigration and immigration was strongly dependent on both the number of individuals identified in aggregations and the size of resident populations.
View details for DOI 10.1098/rsos.160455
View details for Web of Science ID 000389244400021
View details for PubMedID 28018629
View details for PubMedCentralID PMC5180127