Andrew Phillip Nosal

University of California, San Diego | UCSD · Scripps Institution of Oceanography (SIO)

This study presents the longest uninterrupted acoustic monitoring record available to date for the leopard shark Triakis semifasciata, providing novel insight into the fine-scale and long-term movement patterns of this species, and demonstrating that both sexes exhibit sitespecific aggregation behavior and seasonal philopatry. Twenty females and 13...

The demography, spatial distribution, and movement patterns of leopard sharks (Triakis semifasciata) aggregating near the head of a submarine canyon in La Jolla, California, USA, were investigated to resolve the causal explanations for this and similar shark aggregations. All sharks sampled from the aggregation site (n = 140) were sexually mature a...

Skin color aberrations are naturally occurring abnormal pigment patterns that are generally rare among chondrichthyans. In this study, we highlight different skin color aberrations from observations of four shark species native to southern California, USA. We report the first recorded instance of apparent leucism (regional pigmentation loss), in a...

The fisheries history of the Giant Sea Bass, Stereolepis gigas (Telostei: Polyprionidae), is closely linked to its spatial ecology. Its overharvest is directly associated with formation of spatially distinct spawning aggregations during summer, while its subsequent recovery is hypothesized to be the result of spatially explicit gear restrictions. U...

Over one-third of elasmobranch fishes (sharks, rays, and skates) are threatened with extinction, mostly due to overfishing, habitat loss, and habitat degradation. Understanding the daily and seasonal movement patterns of these species can inform when and where populations are most susceptible to these threats, but these data are often lacking for n...

Characterizations of shark-microbe systems in wild environments have outlined patterns of species-specific microbiomes; however, whether captivity affects these trends has yet to be determined. We used high-throughput shotgun sequencing to assess the epidermal microbiome belonging to leopard sharks (Triakis semifasciata) in captive (Birch Aquarium,...

Characterizations of sharks-microbe systems in wild environments have outlined patterns of species-specific microbiomes; however, whether captivity affects these trends has yet to be determined. We used high-throughput shotgun sequencing to assess the epidermal microbiome belonging to leopard sharks ( Triakis semifasciata ) in captive (Birch Aquari...

Barotrauma—injury induced by changes in pressure—is a widespread challenge for successfully releasing fishes following capture. We used acoustic telemetry to examine the long-term post-release survival and behaviour of four rockfish species (genus Sebastes) suffering from barotrauma following capture using recreational fishing techniques. We placed...

Background: Characterizations of sharks-microbe systems in wild environments have outlined patterns of species-specific microbiomes; however, whether captivity affects these trends has yet to be determined. We used high-throughput shotgun sequencing to assess the epidermal microbiome belonging to leopard sharks (Triakis semifasciata) in captive (Bi...

Background: The epidermis of Chondrichthyan fishes consists of dermal denticles with production of minimal but protein rich mucus that influence the attachment and biofilm development of microbes, facilitating a unique epidermal microbiome. Here, we use metagenomics to provide the taxonomic and functional characterization of the epidermal microbiom...

Background: The epidermis of Chondrichthyan fishes consists of dermal denticles with production of minimal but protein rich mucus that influence the attachment and biofilm development of microbes, facilitating a unique epidermal microbiome. Here, we use metagenomics to provide the taxonomic and functional characterization of the epidermal microbiom...

Globally, one quarter of shark and ray species are threatened with extinction due to overfishing. Effective conservation and management can facilitate population recoveries. However, these efforts depend on robust data on movement patterns and stock structure, which are lacking for many threatened species, including the Critically Endangered soupfi...

Background Sevengill sharks are common inhabitants of estuaries and coastal areas and particularly abundant in San Francisco Bay (SFB). There is limited knowledge about the level of residency and migratory movements of this species. We describe the degree of residence of sevengill sharks in SFB and nearby locations, using ultrasonic tags and automa...

Researchers have unpacked the ways in which students participate in democracy through voting and other forms of civic engagement. However, very little empirical work has delved into how students develop socially progressive values, despite their unprecedented importance to young people during their years in higher education. Rooted in a rich histor...

This paper presents a method for modeling and then tracking the 2D planar size, location, orientation, and number of individuals of an animal aggregation using Autonomous Underwater Vehicles (AUVs). It is assumed that the AUVs are equipped with sensors that can measure the position states of a subset of individuals from within the aggregation being...

Despite the ongoing need for shark conservation and management, prevailing negative sentiments marginalize these animals and legitimize permissive exploitation. These negative attitudes arise from an instinctive, yet exaggerated fear, which is validated and reinforced by disproportionate and sensationalistic news coverage of shark 'attacks' and by...

Spreadsheet containing the complete dataset for Experiments 1, 2a, 2b, and 3. (XLSX)

Additional details on experimental treatments, stimulus materials, sample demographics, and analyses on perception measures between video and audio-only treatments. (DOCX)

How animals navigate the constantly moving and visually uniform pelagic realm, often along straight paths between distant sites, is an enduring mystery. The mechanisms enabling pelagic navigation in cartilaginous fishes are particularly understudied. We used shoreward navigation by leopard sharks (Triakis semifasciata) as a model system to test whe...

Reusable tagging apparatus, showing the modified Vemco V16TP transmitter with a galvanic timed release (GTR) and syntactic foam float (spray-painted orange). A Floy Tag FIM-96 identification tag was glued to the syntactic foam float to facilitate sighting and recovery at the surface (right photo; tagging apparatus having detached from shark, shown...

Effect of current on leopard shark movements released from Site A. Mean current profiles over tracks of sharks released from Site A are shown on the left graph, with the zonal component as a solid black line (negative is west and positive is east) and the meridional component as a dashed black line (negative is south and positive is north). To the...

Mean swimming depths of anosmic (released from Site A; dashed red line), sham-control (released from Site A; dashed black line), and normal leopard sharks (released from Site B; dashed black line). Also shown is mean thermal profile along tracks of sharks released from Site A (solid black line) and Site B (solid blue line), as well as mean chloroph...

Final approaches to shore of two representative leopard sharks with “touch-down” onto the benthos after crossing over the continental shelf. Depth data (black dots connected by solid black lines) are shown at 1-min resolution, spanning a window of 60 minutes. Bottom depth is indicated by thick gray line. The sham-treated shark tracked on 8-Jul-2014...

Zoomed in view of box in California (CA) inset map. The extent of offshore and alongshore transport shown by small black dots, which indicate the simulated tracks of clusters of 100 virtual drifters released just offshore at a depth of 20 m (black arrow), directly east of release site A. Release site B is shown for reference. These drifters were re...

Mean weighted vector (MWV) bearings and lengths (r) for tracked ground paths of sham-treated (black arrows, n = 15) and anosmic (red arrows; n = 11) leopard sharks released from Site A and normal sharks released from Site B (blue arrows, n = 10). The bold arrow in each plot represents the grand MWV for the group. Shaded wedges in each plot represen...