Professional Education


  • Doctor of Philosophy, University of California Davis (2017)
  • Bachelor of Science, Cornell University (2010)

All Publications


  • Plastic ingestion by marine fish is widespread and increasing. Global change biology Savoca, M. S., McInturf, A. G., Hazen, E. L. 2021

    Abstract

    Plastic pollution has pervaded almost every facet of the biosphere, yet we lack an understanding of consumption risk by marine species at the global scale. To address this, we compile data from research documenting plastic debris ingestion by marine fish, totaling 171,774 individuals of 555 species. Overall, 386 marine fish species have ingested plastic debris including 210 species of commercial importance. However, 148 species studied had no records of plastic consumption, suggesting that while this evolutionary trap is widespread, it is not yet universal. Across all studies that accounted for microplastics, the incidence rate of plastic ingested by fish was 26%. Over the last decade this incidence has doubled, increasing by 2.4±0.4%per year. This is driven both by increasing detection of smaller sized particles as a result of improved methodologies, as well as an increase in fish consuming plastic. Further, we investigated the role of geographic, ecological, and behavioral factors in the ingestion of plastic across species. These analyses revealed that the abundance of plastic in surface waters was positively correlated to plastic ingestion. Demersal species are more likely to ingest plastic in shallow waters; in contrast, pelagic species were most likely to consume plastic below the mixed layer. Mobile predatory species had the highest likelihood to ingest plastic; similarly, we found a positive relationship between trophic level and plastic ingestion. We also find evidence that surface ingestion-deep sea egestion of microplastics by mesopelagic myctophids is likely a key mechanism for the export of microplastics from the surface ocean to the seafloor, a sink for marine debris. These results elucidate the role of ecology and biogeography underlying plastic ingestion by marine fish and point toward species and regions in urgent need of study.

    View details for DOI 10.1111/gcb.15533

    View details for PubMedID 33561314

  • Microplastics and microfibers in surface waters of Monterey Bay National Marine Sanctuary, California. Marine pollution bulletin Kashiwabara, L. M., Kahane-Rapport, S. R., King, C. n., DeVogelaere, M. n., Goldbogen, J. A., Savoca, M. S. 2021; 165: 112148

    Abstract

    Despite a recent report of high concentrations of microplastics and microfibers in the mesopelagic waters of Monterey Bay National Marine Sanctuary (MBNMS), little is known about these particles in surface waters. From 2017 to 2019, we sampled two nearshore and two offshore locations within MBNMS using a manta trawl and analyzed these samples for microplastics and microfibers. We found an average concentration of 1.32 ± 0.70 (SE) particles per m3. We found the highest concentration of particles closest to shore, and the lowest concentration above the remote Davidson Seamount. Fiber-like debris was more common in offshore, as compared to nearshore, sites. Overall, particles in our samples were primarily buoyant synthetic polymers, including polypropylene and polyethylene. Our results provide baseline data on the degree of microplastic and microfiber pollution in MBNMS surface waters and confirm that this pollution can be found in waters from the surface to at least 1000 m depth.

    View details for DOI 10.1016/j.marpolbul.2021.112148

    View details for PubMedID 33610108

  • Lunge filter feeding biomechanics constrain rorqual foraging ecology across scale. The Journal of experimental biology Kahane-Rapport, S. R., Savoca, M. S., Cade, D. E., Segre, P. S., Bierlich, K. C., Calambokidis, J., Dale, J., Fahlbusch, J. A., Friedlaender, A. S., Johnston, D. W., Werth, A. J., Goldbogen, J. A. 2020

    Abstract

    Fundamental scaling relationships influence the physiology of vital rates, which in turn shape the ecology and evolution of organisms. For diving mammals, benefits conferred by large body size include reduced transport costs and enhanced breath-holding capacity, thereby increasing overall foraging efficiency. Rorqual whales feed by engulfing a large mass of prey-laden water at high speed and filtering it through baleen plates. However, as engulfment capacity increases with body length (Engulfment Volume Body Length 3.57), the surface area of the baleen filter does not increase proportionally (Baleen Area Body Length1.82), and thus the filtration time of larger rorquals predictably increases as the baleen surface area must filter a disproportionally large amount of water. We predicted that filtration time should scale with body length to the power of 1.75 (Filter Time Body Length1.75 ) We tested this hypothesis on four rorqual species using multi-sensor tags with corresponding unoccupied aircraft systems (UAS) -based body length estimates. We found that filter time scales with body length to the power of 1.79 (95% CI: 1.61 - 1.97). This result highlights a scale-dependent trade-off between engulfment capacity and baleen area that creates a biomechanical constraint to foraging through increased filtration time. Consequently, larger whales must target high density prey patches commensurate to the gulp size to meet their increased energetic demands. If these optimal patches are absent, larger rorquals may experience reduced foraging efficiency compared to smaller whales if they do not match their engulfment capacity to the size of targeted prey aggregations.

    View details for DOI 10.1242/jeb.224196

    View details for PubMedID 32820028

  • Comprehensive bycatch assessment in US fisheries for prioritizing management NATURE SUSTAINABILITY Savoca, M. S., Brodie, S., Welch, H., Hoover, A., Benaka, L. R., Bograd, S. J., Hazen, E. L. 2020
  • Odors from marine plastic debris elicit foraging behavior in sea turtles. Current biology : CB Pfaller, J. B., Goforth, K. M., Gil, M. A., Savoca, M. S., Lohmann, K. J. 2020; 30 (5): R213–R214

    Abstract

    Pfaller et al. report that sea turtles respond to odors from biofouled plastic debris with the same behavior that is elicited by food odors, providing a possible unifying explanation for why sea turtles interact with marine plastic.

    View details for DOI 10.1016/j.cub.2020.01.071

    View details for PubMedID 32155421

  • Why whales are big but not bigger: Physiological drivers and ecological limits in the age of ocean giants. Science (New York, N.Y.) Goldbogen, J. A., Cade, D. E., Wisniewska, D. M., Potvin, J., Segre, P. S., Savoca, M. S., Hazen, E. L., Czapanskiy, M. F., Kahane-Rapport, S. R., DeRuiter, S. L., Gero, S., Tonnesen, P., Gough, W. T., Hanson, M. B., Holt, M. M., Jensen, F. H., Simon, M., Stimpert, A. K., Arranz, P., Johnston, D. W., Nowacek, D. P., Parks, S. E., Visser, F., Friedlaender, A. S., Tyack, P. L., Madsen, P. T., Pyenson, N. D. 2019; 366 (6471): 1367–72

    Abstract

    The largest animals are marine filter feeders, but the underlying mechanism of their large size remains unexplained. We measured feeding performance and prey quality to demonstrate how whale gigantism is driven by the interplay of prey abundance and harvesting mechanisms that increase prey capture rates and energy intake. The foraging efficiency of toothed whales that feed on single prey is constrained by the abundance of large prey, whereas filter-feeding baleen whales seasonally exploit vast swarms of small prey at high efficiencies. Given temporally and spatially aggregated prey, filter feeding provides an evolutionary pathway to extremes in body size that are not available to lineages that must feed on one prey at a time. Maximum size in filter feeders is likely constrained by prey availability across space and time.

    View details for DOI 10.1126/science.aax9044

    View details for PubMedID 31831666

  • Extreme bradycardia and tachycardia in the world's largest animal PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Goldbogen, J. A., Cade, D. E., Calambokidis, J., Czapanskiy, M. F., Fahlbusch, J., Friedlaender, A. S., Gough, W. T., Kahane-Rapport, S. R., Savoca, M. S., Ponganis, K. V., Ponganis, P. J. 2019; 116 (50): 25329–32

    Abstract

    The biology of the blue whale has long fascinated physiologists because of the animal's extreme size. Despite high energetic demands from a large body, low mass-specific metabolic rates are likely powered by low heart rates. Diving bradycardia should slow blood oxygen depletion and enhance dive time available for foraging at depth. However, blue whales exhibit a high-cost feeding mechanism, lunge feeding, whereby large volumes of prey-laden water are intermittently engulfed and filtered during dives. This paradox of such a large, slowly beating heart and the high cost of lunge feeding represents a unique test of our understanding of cardiac function, hemodynamics, and physiological limits to body size. Here, we used an electrocardiogram (ECG)-depth recorder tag to measure blue whale heart rates during foraging dives as deep as 184 m and as long as 16.5 min. Heart rates during dives were typically 4 to 8 beats min-1 (bpm) and as low as 2 bpm, while after-dive surface heart rates were 25 to 37 bpm, near the estimated maximum heart rate possible. Despite extreme bradycardia, we recorded a 2.5-fold increase above diving heart rate minima during the powered ascent phase of feeding lunges followed by a gradual decrease of heart rate during the prolonged glide as engulfed water is filtered. These heart rate dynamics explain the unique hemodynamic design in rorqual whales consisting of a large-diameter, highly compliant, elastic aortic arch that allows the aorta to accommodate blood ejected by the heart and maintain blood flow during the long and variable pauses between heartbeats.

    View details for DOI 10.1073/pnas.1914273116

    View details for Web of Science ID 000502577500056

    View details for PubMedID 31767746

    View details for PubMedCentralID PMC6911174

  • Marine top predators as climate and ecosystem sentinels FRONTIERS IN ECOLOGY AND THE ENVIRONMENT Hazen, E. L., Abrahms, B., Brodie, S., Carroll, G., Jacox, M. G., Savoca, M. S., Scales, K. L., Sydeman, W. J., Bograd, S. J. 2019

    View details for DOI 10.1002/fee.2125

    View details for Web of Science ID 000493849500001

  • Memory and resource tracking drive blue whale migrations PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Abrahms, B., Hazen, E. L., Aikens, E. O., Savoca, M. S., Goldbogen, J. A., Bograd, S. J., Jacox, M. G., Irvine, L. M., Palacios, D. M., Mate, B. R. 2019; 116 (12): 5582–87
  • Quantifying marine debris associated with coastal golf courses. Marine pollution bulletin Weber, A. K., Weber, M. W., Savoca, M. S. 2019; 140: 1–8

    Abstract

    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

  • Scaling of swimming performance in baleen whales. The Journal of experimental biology Gough, W. T., Segre, P. S., Bierlich, K. C., Cade, D. E., Potvin, J. n., Fish, F. E., Dale, J. n., di Clemente, J. n., Friedlaender, A. S., Johnston, D. W., Kahane-Rapport, S. R., Kennedy, J. n., Long, J. H., Oudejans, M. n., Penry, G. n., Savoca, M. S., Simon, M. n., Videsen, S. K., Visser, F. n., Wiley, D. N., Goldbogen, J. A. 2019

    Abstract

    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.) Savoca, M. 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 Savoca, M. S. 2018; 138 (1): 1–21
  • Vertebrate prey in the diets of free-ranging kiwi (Apteryx spp.) NOTORNIS Savoca, M. S., Gardiner, J., Colbourne, R., Tennyson, A. D. 2018; 65 (4): 242–44
  • Odours from marine plastic debris induce food search behaviours in a forage fish PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES Savoca, M. S., Tyson, C. W., McGill, M., Slager, C. J. 2017; 284 (1860)
  • Marine plastic debris emits a keystone infochemical for olfactory foraging seabirds SCIENCE ADVANCES Savoca, M. S., Wohlfeil, M. E., Ebeler, S. E., Nevitt, G. A. 2016; 2 (11): e1600395

    Abstract

    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 Meek, M. H., Wells, C., Tomalty, K. M., Ashander, J., Cole, E. M., Gille, D. A., Putman, B. J., Rose, J. P., Savoca, M. S., Yamane, L., Hull, J. M., Rogers, D. L., Rosenblum, E., Shogren, J. F., Swaisgood, R. R., May, B. 2016; 194: 218–19
  • Fear of failure in conservation: The problem and potential solutions to aid conservation of extremely small populations BIOLOGICAL CONSERVATION Meek, M. H., Wells, C., Tomalty, K. M., Ashander, J., Cole, E. M., Gille, D. A., Putman, B. J., Rose, J. P., Savoca, M. S., Yamane, L., Hull, J. M., Rogers, D. L., Rosenblum, E., Shogren, J. F., Swaisgood, R. R., May, B. 2015; 184: 209–17
  • 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 Savoca, M. S., Nevitt, G. A. 2014; 111 (11): 4157–61

    Abstract

    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 Savoca, M. S., Bonter, D. N., Zuckerberg, B., Dickinson, J. L., Ellis, J. C. 2011; 113 (3): 565–71