Fujiwara Masami

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Last Name
Fujiwara
First Name
Masami
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2002 - 2009 1 2010 - 2020 2
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  • Dataset
    Gill Net Catch Data in Bays along Texas Coast from 1986 to 2018
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-12-18) Fujiwara, Masami ; Martinez-Andrade, Fernando
    Vertebrate caught with gill net in Sabine Lake, Galveston Bay, Matagorda Bay, San Antonio Bay, Aransas Bay, Corpus Christi Bay, Upper Laguna Madre, and Lower Laguna Madre from 1986 to 2018 (except in Sabine Lake sampling begun in 1986). For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/828794
  • Thesis
    Mark-recapture statistics and demographic analysis
    (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2002-06) Fujiwara, Masami
    Mark-recapture analysis of populations is becoming an important tool in population biology. Mark-recapture methods can be used to estimate transition probabilities among life-stages from capture histories of marked individuals for which stages can be determined at each sampling occasion. This method is called a multi-stage mark-recapture (MSMR) method. In this thesis, I describe advances I made in the MSMR method and present analyses that apply this method to actual data. The advances I made in the MSMR method are motivated by a need to provide a link between mark-recapture data and demographic models such as matrix population models and integrodifference models. I resolve some issues that are commonly encountered during sampling, such as the fact that the sex or life-stage of some individuals is unknown during some sampling occasions and that individuals become unobservable during some life-stages. I introduce a stage-structure that permits simple conversion of estimated transition probabilities into a matrix population model. I describe an algorithm to simplify programming for parameter estimation. I also introduce a method to estimate the distribution of dispersal displacements (a dispersal kernel) from mark-recapture data. I apply some of the methods described above to data of the North Atlantic right whale (Eubalaena glacialis) The right whales are considered one of the most endangered mammals. The current population size is about 300 in the northwestern Atlantic, and the number is declining. I applied the multi-stage mark-recapture statistics to the 17-year individual sighting history data. Using the estimated transition probabilities, I constructed a population projection matrix, which was used for further demographic analyses. I found that the population was slowly increasing in 1980, but it started to decline slowly around 1992. I show that (1) this change was caused by increased mortality of females that have just given birth, (2) protecting two females a year from the deaths is enough to prevent the declining trend, and (3) demographic stochasticity is a more important factor influencing their long-term viability than environmental stochasticity.
  • Dataset
    Bag Seine Catch Data in Bays along the Texas Coast from 1982 to 2016
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-09-23) Fujiwara, Masami ; Martinez-Andrade, Fernando
    Data on vertebrates and invertebrates caught by bag seine in Sabine Lake, Galveston Bay, Matagorda Bay, San Antonio Bay, Aransas Bay, Corpus Christi Bay, Upper Laguna Madre, and Lower Laguna Madre. Data were collected monthly from 1982 to 2016 (except in Sabine Lake sampling begun in 1986). Environmental data include oxygen, salinity, temperature, and turbidity. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/773137