Doctor of Philosophy, University of California Davis (2017)
Bachelor of Science, Cornell University (2010)
- Memory and resource tracking drive blue whale migrations PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2019; 116 (12): 5582–87
Quantifying marine debris associated with coastal golf courses.
Marine pollution bulletin
2019; 140: 1–8
Identifying terrestrial sources of debris is essential to suppress the flow of plastic to the ocean. Here, we report a novel source of debris to the marine environment. From May 2016 to June 2018, we collected golf balls from coastal environments associated with five courses in Carmel, California. Our 75 collections recovered 39,602 balls from intertidal and nearshore environments adjacent to, or downriver from, the golf courses. Combining our collections with concurrent efforts of the Monterey Bay National Marine Sanctuary and the Pebble Beach Corporation, we report the retrieval of 50,681 balls, totaling approximately 2.5 tons of debris. We also examined decomposition patterns in the collected balls, which illustrate that degradation and loss of microplastic from golf balls to the marine environment may be of concern. Our findings will help to develop and direct mitigation procedures for this region and others with coastal golf courses.
View details for PubMedID 30803622
- Quantifying marine debris associated with coastal golf courses MARINE POLLUTION BULLETIN 2019; 140: 1–8
Memory and resource tracking drive blue whale migrations.
Proceedings of the National Academy of Sciences of the United States of America
In terrestrial systems, the green wave hypothesis posits that migrating animals can enhance foraging opportunities by tracking phenological variation in high-quality forage across space (i.e., "resource waves"). To track resource waves, animals may rely on proximate cues and/or memory of long-term average phenologies. Although there is growing evidence of resource tracking in terrestrial migrants, such drivers remain unevaluated in migratory marine megafauna. Here we present a test of the green wave hypothesis in a marine system. We compare 10 years of blue whale movement data with the timing of the spring phytoplankton bloom resulting in increased prey availability in the California Current Ecosystem, allowing us to investigate resource tracking both contemporaneously (response to proximate cues) and based on climatological conditions (memory) during migrations. Blue whales closely tracked the long-term average phenology of the spring bloom, but did not track contemporaneous green-up. In addition, blue whale foraging locations were characterized by low long-term habitat variability and high long-term productivity compared with contemporaneous measurements. Results indicate that memory of long-term average conditions may have a previously underappreciated role in driving migratory movements of long-lived species in marine systems, and suggest that these animals may struggle to respond to rapid deviations from historical mean environmental conditions. Results further highlight that an ecological theory of migration is conserved across marine and terrestrial systems. Understanding the drivers of animal migration is critical for assessing how environmental changes will affect highly mobile fauna at a global scale.
View details for PubMedID 30804188
Scaling of swimming performance in baleen whales.
The Journal of experimental biology
The scale-dependence of locomotor factors have long been studied in comparative biomechanics, but remain poorly understood for animals at the upper extremes of body size. Rorqual baleen whales include the largest animals, but we lack basic kinematic data about their movements and behavior below the ocean surface. Here we combined morphometrics from aerial drone photogrammetry, whale-borne inertial sensing tag data, and hydrodynamic modeling to study the locomotion of five rorqual species. We quantified changes in tail oscillatory frequency and cruising speed for individual whales spanning a threefold variation in body length, corresponding to an order of magnitude variation in estimated body mass. Our results showed that oscillatory frequency decreases with body length (∝ length-0.53) while cruising speed remains roughly invariant (∝ length0.08) at 2 m s-1 We compared these measured results for oscillatory frequency against simplified models of an oscillating cantilever beam (∝ length-1) and an optimized oscillating Strouhal vortex generator (∝ length-1). The difference between our length-scaling exponent and the simplified models suggests that animals are often swimming non-optimally in order to feed or perform other routine behaviors. Cruising speed aligned more closely with an estimate of the optimal speed required to minimize the energetic cost of swimming (∝ length0.07). Our results are among the first to elucidate the relationships between both oscillatory frequency and cruising speed and body size for free-swimming animals at the largest scale.
View details for DOI 10.1242/jeb.204172
View details for PubMedID 31558588
The ecology of an olfactory trap.
Science (New York, N.Y.)
2018; 362 (6417): 904
View details for PubMedID 30467162
- Chemoattraction to dimethyl sulfide links the sulfur, iron, and carbon cycles in high-latitude oceans BIOGEOCHEMISTRY 2018; 138 (1): 1–21
Vertebrate prey in the diets of free-ranging kiwi (Apteryx spp.)
2018; 65 (4): 242–44
View details for Web of Science ID 000452190500008
- Odours from marine plastic debris induce food search behaviours in a forage fish PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES 2017; 284 (1860)
Marine plastic debris emits a keystone infochemical for olfactory foraging seabirds
2016; 2 (11): e1600395
Plastic debris is ingested by hundreds of species of organisms, from zooplankton to baleen whales, but how such a diversity of consumers can mistake plastic for their natural prey is largely unknown. The sensory mechanisms underlying plastic detection and consumption have rarely been examined within the context of sensory signals driving marine food web dynamics. We demonstrate experimentally that marine-seasoned microplastics produce a dimethyl sulfide (DMS) signature that is also a keystone odorant for natural trophic interactions. We further demonstrate a positive relationship between DMS responsiveness and plastic ingestion frequency using procellariiform seabirds as a model taxonomic group. Together, these results suggest that plastic debris emits the scent of a marine infochemical, creating an olfactory trap for susceptible marine wildlife.
View details for DOI 10.1126/sciadv.1600395
View details for Web of Science ID 000391267800007
View details for PubMedID 28861463
View details for PubMedCentralID PMC5569953
- We should not be afraid to talk about fear of failure in conservation BIOLOGICAL CONSERVATION 2016; 194: 218–19
Evidence that dimethyl sulfide facilitates a tritrophic mutualism between marine primary producers and top predators
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2014; 111 (11): 4157–61
Tritrophic mutualistic interactions have been best studied in plant-insect systems. During these interactions, plants release volatiles in response to herbivore damage, which, in turn, facilitates predation on primary consumers or benefits the primary producer by providing nutrients. Here we explore a similar interaction in the Southern Ocean food web, where soluble iron limits primary productivity. Dimethyl sulfide has been studied in the context of global climate regulation and is an established foraging cue for marine top predators. We present evidence that procellariiform seabird species that use dimethyl sulfide as a foraging cue selectively forage on phytoplankton grazers. Their contribution of beneficial iron recycled to marine phytoplankton via excretion suggests a chemically mediated link between marine top predators and oceanic primary production.
View details for DOI 10.1073/pnas.1317120111
View details for Web of Science ID 000333027900063
View details for PubMedID 24591607
View details for PubMedCentralID PMC3964091
- NESTING DENSITY IS AN IMPORTANT FACTOR AFFECTING CHICK GROWTH AND SURVIVAL IN THE HERRING GULL CONDOR 2011; 113 (3): 565–71