Anela Choy

POSTDOCTORAL FELLOW

Monterey Bay Aquarium Research Institute

7700 Sandholdt Road

Moss Landing, CA 95039

Phone: (831) 775-2072

email: anela@mbari.org

Curriculum Vitae

Google Scholar profile

Education:

  • Ph.D. 2013, University of Hawaii, Oceanography
  • M.S. 2008, University of Hawaii, Oceanography
  • B.A. 2004, University of Hawaii, Interdisciplinary Studies

Select Recent Publications:

  • Choy CA, Wabnitz C, Weijerman M, Woodworth P, Polovina J. 2016. Finding the way to the top: how the composition of mid-trophic micronekton groups determines apex predator biomass in the central North Pacific. Marine Ecology Progress Series 549: 9-25. [Link]
  • Choy CA, Popp BN, Hannides CCS, Drazen JC. 2015. Trophic structure and food resources of epipelagic and mesopelagic fishes in the North Pacific Subtropical Gyre ecosystem inferred from nitrogen isotopic compositions. Limnology and Oceanography. 60: 1156-1171. [Link]
  • Sackett DK, Drazen JC, Choy CA, Popp BN, Pitz GL. 2015. Mercury sources and trophic ecology for Hawaiian bottomfish.Environmental Science & Technology 49(11): 6909-6918. [Link]
  • Bradley CJ, Wallsgrove NJ, Choy CA, Drazen JC, Hetherington ED, Hoen DK, Popp BN. In Press. Trophic position estimates of marine teleosts using amino acid compound specific isotopic analysis. Limnology and Oceanography: Methods. doi: 10.1002/lom3.10041. [Link]
  • Arthur KE, Kelez S, Larsen T, Choy CA, Popp BN. 2014. Tracing the biosynthetic source of essential amino acids in marine turtles using δ13C fingerprints. Ecology 95(5): 1285-1293. [Link]
  • Choy CA, Drazen JC. 2013. Plastic for dinner? Observations of frequent debris ingestion by large predatory fishes from the central North Pacific. Marine Ecology Progress Series 485: 155-163. [Link]
  • Choy CA, Drazen JC. 2013. The diets of five important mid-trophic mesopelagic fishes of the central North Pacific. Marine Ecology Progress Series 492: 169-184. [Link]
  • Blum JD, Popp BN, Drazen JC, Choy CA, Johnson MW. 2013. Evidence for methylmercury production below the mixed layer in the North Pacific Ocean. Nature Geoscience 6: 879-884. [Link]
  • Hannides CCS, Popp BN, Choy CA, Drazen JC. 2013. Midwater zooplankton and suspended particle dynamics in the North Pacific Subtropical Gyre: a stable isotope perspective. Limnology and Oceanography 58: 1931-1946. [Link]
  • Choy CA, Davison P, Drazen JC, Flynn A, Gier E, Hoffman JC, McClain-Counts J, Miller T, Popp BN, Ross S, Sutton T. 2012. Global trophic position comparison of two dominant mesopelagic fish families (Myctophidae, Stomiidae) using amino acid nitrogen isotopic analyses. PLoS ONE 7(11): e50133. doi:10.1371/journal.pone.0050133. [Link]
  • Choy CA, Popp BN, Kaneko JJ, Drazen JC. 2009. The influence of depth on mercury levels in pelagic fishes and their prey.Proceedings of the National Academy of Sciences USA 106(33): 13865-13869. [Link]

Background:

The deep sea is Earth’s largest living space. In addition to providing harvestable animal protein for global societies, the deep sea plays critical physical, biological, and chemical roles in climate regulation. Dark, cold waters seaward of continental shelves are filled with fish with flashlights on their heads, squids with different sized eyes, and jellyfish as long as a school bus. Midwater communities consisting of these diverse groups of animals are ultimately fed by plant-based production in the surface skin of the ocean, which slowly rains down as organic particles into the deep sea.

Collectively, the series of feeding interactions between deep sea animals produces food supply for large marine predators such as tunas, billfishes, and sharks. We refer to these predator-prey networks as food webs, whereby all animals within a shared living space are connected to one another through feeding. Understanding who the main food web players are illuminates overall energy flow and how deep sea ecosystems might change or are already changing in response to external pressures such fishing and climate.

Current research projects:

  1. Constructing Open Ocean Food Webs with MBARI’s Remotely Operated Vehicle Video Archives

    MBARI is one of the premier marine research institutes in the world that has been exploring the deep, mysterious waters of Monterey Bay with state-of-the-art remotely operated vehicles (ROVs). A continuous and long-standing scientific presence in the deep sea is a rare and difficult achievement. The high cost of equipment development and maintenance, as well as dedicated ship time required to use ROVs has left much of the deep ocean unexplored. At MBARI however, 25+ years of deep sea scientific expeditions are cataloged in the publicly-available Video Annotation and Reference System (VARS).

    In collaboration with Dr. Bruce Robison and Dr. Steven Haddock, we are working to construct the main predator-prey linkages and energy pathways of the deep sea food web of Monterey Bay. Historical ROV observations are being mined from VARs and will provide new, big picture insights of how the deep sea animals of Monterey Bay live together in the deep, dark ocean.

  2. Constructing Open Ocean Food Webs with Stable Isotopes

    Just like people, marine predators can have extremely complex diets that change depending on what and how much food is available, as well as whom they are adapted to hunt and capture. Describing the diets of members of an ecosystem is often logistically impossible for the deep sea, as large ships with specialized sampling equipment are often required to send large nets to great depths to obtain animal samples. Another approach to studying food webs is to examine the biochemical feeding history of animals by measuring their stable isotope compositions relative to one another. The predictable behaviors of stable isotopes in food webs make them highly useful for figuring out what position an animal is feeding at and what their main prey items are.

    Using the advanced ROV sampling capabilities of MBARI we are working to construct a stable isotope based food web of Monterey Bay. Doing so allows for the rare inclusion of soft-bodied, but highly abundant deep sea animals that are often missed in food web studies due to their fragile body forms.

    Past isotope studies in the subtropical waters of Hawaii have revealed the potential importance of organic matter to deep sea fish communities, and have also established the application of cross-ecosystem food web comparisons.

    Relevant publications:

    • Choy CA, Popp BN, Hannides CCS, Drazen JC. 2015. Trophic structure and food resources of epipelagic and mesopelagic fishes in the North Pacific Subtropical Gyre ecosystem inferred from nitrogen isotopic compositions. Limnology and Oceanography. 60: 1156-1171. [Link]
    • Bradley CJ, Wallsgrove NJ, Choy CA, Drazen JC, Hetherington ED, Hoen DK, Popp BN. In Press. Trophic position estimates of marine teleosts using amino acid compound specific isotopic analysis. Limnology and Oceanography: Methods. doi: 10.1002/lom3.10041. [Link]
    • Arthur KE, Kelez S, Larsen T, Choy CA, Popp BN. 2014. Tracing the biosynthetic source of essential amino acids in marine turtles using δ13C fingerprints. Ecology 95(5): 1285-1293. [Link]
    • Hannides CCS, Popp BN, Choy CA, Drazen JC. 2013. Midwater zooplankton and suspended particle dynamics in the North Pacific Subtropical Gyre: a stable isotope perspective. Limnology and Oceanography 58: 1931-1946. [Link]
    • Choy CA, Davison P, Drazen JC, Flynn A, Gier E, Hoffman JC, McClain-Counts J, Miller T, Popp BN, Ross S, Sutton T. 2012. Global trophic position comparison of two dominant mesopelagic fish families (Myctophidae, Stomiidae) using amino acid nitrogen isotopic analyses. PLoS ONE 7(11): e50133. doi:10.1371/journal.pone.0050133. [Link]
    • Drazen JC, Popp BN, Choy CA, Clement T, De Forest L, Smith Jr. KL. 2008. Bypassing the abyssal benthic food web: Macrourid diet in the eastern North Pacific inferred from stomach content and stable isotope analyses. Limnology and Oceanography 53: 2644-2654. [Link]
  3. Tracking Changes in Midwater Food Webs with the Longnosed Lancetfish (Alepisaurus ferox), a Cosmopolitan Marine Predator

    Lancetfish are fierce looking deep water fish abundantly captured by open ocean commercial fisheries. Very recently lancetfish topped the list as the most caught species by the Hawaiian Longline fishery working in the central North Pacific. The removal of large numbers of predators from a network of interacting species has been shown to incite series of changes within open ocean ecosystems. What are these changes and what do they mean for our ability to continue fishing our global oceans? How quickly do these changes occur and how far across the ecosystem do they extend?

    In collaboration with NOAA’s Pacific Island Fisheries Science Center’s Ecosystems & Oceanography Division in Hawaii we are examining the stomach contents of lancetfish as a way of monitoring the composition of midwater communities. Fishery observers from the Hawaii Longline Observer Program remove the stomachs of lancetfish at sea, bringing back detailed snapshots of prey communities across large oceanic areas and extended time periods. Predatory marine fish often feed upon whatever they are able to successfully catch and thus, their stomach contents can provide unique and detailed snapshots of midwater animal communities.

    We are examining historical changes in diet and midwater animals. In collaboration with graduate students at Stanford University we are also looking at environmental and ecological drivers of lancetfish diet (e.g., productivity, prey availability) and how these differ with lancetfish size. We are actively working with deep water fish and cephalopod taxonomists and ecologists to look at prey species distributions and population structures using genetics. Please contact us if you are interested in stomach samples of midwater animals.

    Relevant publications:

    • Choy CA, Drazen JC. 2013. Plastic for dinner? Observations of frequent debris ingestion by large predatory fishes from the central North Pacific. Marine Ecology Progress Series 485: 155-163. [Link]
    • Choy CA, Drazen JC. 2013. The diets of five important mid-trophic mesopelagic fishes of the central North Pacific. Marine Ecology Progress Series 492: 169-184. [Link]
  4. Assessing Human Fingerprints on Open Ocean Communities with Biochemical Tracers

    The human fingerprint on seemingly far-removed deep sea ecosystems can extend beyond commercial fishing and climate-induced change. Assessing human impact can go hand in hand with learning about the structure and function of marine food webs because some biochemical tracers of anthropogenic origin or influence are transferred through food webs when animals eat one another. We have looked specifically at mercury distribution and cycling patterns in Hawaiian food webs. Recent findings that deep sea fish ingest large amounts of plastic debris has spurned preliminary work to examine the transfer of plastic-derived toxins in marine food webs.

    Relevant publications

    • Sackett DK, Drazen JC, Choy CA, Popp BN, Pitz GL. 2015. Mercury sources and trophic ecology for Hawaiian bottomfish.Environmental Science & Technology 49(11): 6909-6918. [Link]
    • Blum JD, Popp BN, Drazen JC, Choy CA, Johnson MW. 2013. Evidence for methylmercury production below the mixed layer in the North Pacific Ocean. Nature Geoscience 6: 879-884. [Link]
    • Choy CA, Popp BN, Kaneko JJ, Drazen JC. 2009. The influence of depth on mercury levels in pelagic fishes and their prey.Proceedings of the National Academy of Sciences USA 106(33): 13865-13869. [Link]