基本情報

所属

• 北極域研究センター

職名

• 博士研究員

科研費研究者番号

• 20929608

ORCID ID

•  https://orcid.org/0000-0002-4336-6876

J-Global ID

• 202101004763896179

研究キーワード

• Environmental Science   Climate change   Satellite oceanography   Marine Ecology and Fisheries   

研究分野

• 環境・農学 / 生物資源保全学

職歴

• 2009年04月 - 2010年03月 University of the Philippines Diliman Physical Oceanography Laboratory, Marine Science Institute Philippine Harmful Algal Bloom: Ecology & Stratification of HABs in the tropics
• 2008年07月 - 2009年03月 University of the Philippines Diliman Marine Science Institute Upwelling and gyral circulation patterns in the Eastern & western areas of the Philippines
• 2006年01月 - 2008年06月 University of the Philippines Diliman Physical Oceanography Laboratory, Marine Science Institute Pacific Seaboard Program: Upwelling variability & Intrusion Into Coastal Waters
• 2005年10月 - 2005年12月 University of the Philippines Diliman Physical Oceanography Laboratory, Marine Science Institute Modeling for mitigating and prediction of Harmful Algal blooms

学歴

• 2012年04月 - 2015年03月   北海道大学   大学院水産科学院
• 2011年03月 - 2012年03月   北海道大学   大学院水産科学院
• 2005年06月 - 2009年03月   University of the Philippines
• 1999年06月 - 2003年03月   University of the Philippines Visayas

所属学協会

• 水産海洋学会   Nippon Foundation and the Partnership for Observation of the Global Oceans Alumni Network   

研究活動情報

論文

• Possible future scenarios in the gateways to the Arctic for Subarctic and Arctic marine systems: II. prey resources, food webs, fish, and fisheries

  Franz J Mueter, Benjamin Planque, George L Hunt, Irene D Alabia, Toru Hirawake, Lisa Eisner, Padmini Dalpadado, Melissa Chierici, Kenneth F Drinkwater, Naomi Harada, Per Arneberg, Sei-Ichi Saitoh

  ICES Journal of Marine Science 2021年10月08日 

  Climate change impacts are pronounced at high latitudes, where warming, reduced sea-ice-cover, and ocean acidification affect marine ecosystems. We review climate change impacts on two major gateways into the Arctic: the Bering and Chukchi seas in the Pacific and the Barents Sea and Fram Strait in the Atlantic. We present scenarios of how changes in the physical environment and prey resources may affect commercial fish populations and fisheries in these high-latitude systems to help managers and stakeholders think about possible futures. Predicted impacts include shifts in the spatial distribution of boreal species, a shift from larger, lipid-rich zooplankton to smaller, less nutritious prey, with detrimental effects on fishes that depend on high-lipid prey for overwinter survival, shifts from benthic- to pelagic-dominated food webs with implications for upper trophic levels, and reduced survival of commercially important shellfish in waters that are increasingly acidic. Predicted changes are expected to result in disruptions to existing fisheries, the emergence of new fisheries, new challenges for managing transboundary stocks, and possible conflicts among resource users. Some impacts may be irreversible, more severe, or occur more frequently under anthropogenic climate change than impacts associated with natural variability, posing additional management challenges.
• Marine biodiversity refugia in a climate-sensitive subarctic shelf

  Irene D. Alabia, Jorge García Molinos, Takafumi Hirata, Franz J. Mueter, Toru Hirawake, Sei Ichi Saitoh

  Global Change Biology 27 14 3299 - 3311 2021年07月 

  The subarctic shelf of the Eastern Bering Sea (EBS) is one of the world's most productive marine environments, exposed to drastic climate changes characterized by extreme fluctuations in temperature, sea ice concentration, timing, and duration. These climatic changes elicit profound responses in species distribution, abundance, and community composition. Here, we examined the patterns of alpha and temporal beta diversity of 159 marine taxa (66 vertebrates and 93 invertebrate species) from 29 years (1990–2018) of species observations from the NOAA bottom trawl surveys in the EBS. Based on these data, we identified geographically distinct refugial zones in the northern and southern regions of the middle shelf, defined by high species richness and similarity in community species composition over time. These refugial zones harbor higher frequencies of occurrence for representative taxa relative to the regions outside of refugia. We also explored the primary environmental factors structuring marine biodiversity distributions, which underpinned the importance of the winter sea ice concentration to alpha and temporal beta diversity. The spatial biodiversity distributions between high and low winter sea ice regimes highlighted contrasting signals. In particular, the latter showed elevated species richness compared to the former. Further, the temporal beta diversity between the high and low winter sea ice periods underpinned an overall increase in the compositional similarity of marine communities in the EBS. Despite these spatiotemporal differences in biodiversity distributions, the identified refugia represent safe havens of marine biodiversity in the EBS. Distinguishing these areas can help facilitate conservation and management efforts under accelerated and ongoing climatic changes.
• Influence of Spawning Ground Dynamics on the Long-Term Abundance of Japanese Flying Squid (Todarodes pacificus) Winter Cohort

  Yang Liu, Xinmei Xia, Yongjun Tian, Irene D. Alabia, Shuyang Ma, Peng Sun, Sei Ichi Saitoh

  Frontiers in Marine Science 8 2021年05月26日 

  Japanese flying squid (Todarodes pacificus) is one of the most commercially important resources in the Pacific Ocean and its abundance is largely affected by environmental conditions. We examined the influence of environmental factors in potential spawning grounds of the winter cohort, approximated from Japanese and South Korean catch and catch per unit effort (CPUE) data of Japanese flying squid. Annual spawning ground dynamics were constructed using sea surface temperature (SST), submarine elevation and mean Kuroshio axis data from 1979 to 2018. Based on these information, we generated a suite of spawning ground indices including suitability SST-weighted area of potential spawning ground (SSWA), mean values (January–April) of suitable SST (MVSS), and the meridional position (MP) of SST isolines (18–24°C). Comparable interannual-decadal variability patterns were detected between the squid abundance and spawning ground indices, with abrupt shifts around 1990/1991 and in recent decades. In particular, the Pacific Decadal Oscillation is negatively correlated with spawning ground indices, suggesting its role in regulating the environmental dynamics in the area. Further, the gradient forest model underpinned the importance of SSWA, SSWA_Lag1 and MVSS_Lag1 on squid abundance. The CPUE is also shown to be a better abundance index than the annual catch in modeling the species’ response to environmental variability in its spawning grounds. Our findings suggest that it is imperative to pay more and timely attention to the relationship between the abundance of Japanese flying squid and environmental changes, especially under adverse environmental conditions.
• Response of Arctic biodiversity and ecosystem to environmental changes: Findings from the ArCS project

  Toru Hirawake, Masaki Uchida, Hiroto Abe, Irene D. Alabia, Tamotsu Hoshino, Shota Masumoto, Akira S. Mori, Jun Nishioka, Bungo Nishizawa, Atsushi Ooki, Akinori Takahashi, Yukiko Tanabe, Motoaki Tojo, Masaharu Tsuji, Hiromichi Ueno, Hisatomo Waga, Yuuki Y. Watanabe, Atsushi Yamaguchi, Youhei Yamashita

  Polar Science 27 2021年03月 

  Arctic ecosystems are altered profoundly by climate changes. However, the responses of Arctic marine and terrestrial ecosystems as well as their biodiversity to global warming remain largely unknown. This article provides comprehensive insights into the results and major findings from the Arctic Challenge for Sustainability (ArCS) Project – an Arctic region research program initiated in Japan, which aims to address and advance our understanding of these uncertainties. Marine ecosystem studies have identified several biogeochemical processes that are associated with sea ice decline and northward transport and shift of marine species across multiple trophic levels over the Bering and Chukchi Sea shelves. Studies of the terrestrial ecosystem have identified factors that are important for the understanding of terrestrial biodiversity and ecosystems, including Arctic lakes, under the presence of global warming. Novel fungal species from the Arctic terrestrial ecosystem have also been isolated and described. Overall, these results could contribute to the conservation and sustainable management of the Arctic ecosystem services.
• Environmental habitat mapping of green mussel: A gis-based approach for sustainable aquaculture in the inner gulf of Thailand

  Hathaichanok Kumgumpol, Yang Liu, Tanuspong Pokavanich, Irene D. Alabia, Zixu Yin, Sei Ichi Saitoh, Yongjun Tian

  Sustainability (Switzerland) 12 24 1 - 16 2020年12月02日 

  The green mussel (Perna viridis) is one of the most commercially-important cultured species along the coast of Thailand. In this study, a suitable aquaculture site-selection model (SASSM) was developed to identify the most suitable areas in the inner part of the Gulf of Thailand (InnerGoT) for green mussel culture. Satellite-derived chlorophyll-a (Chl-a) and hydrodynamic model outputs for sea surface temperature (SST), salinity, maximum water current (MWC), and bathymetry between 2018 and 2019 were used as input to the SASSM. The results show that suitability scores in mussel aquaculture areas were lowest (1–3) during the Southwest (SW) monsoon, rainy season (July–August), and highest (6–7) during the Northeast (NE) monsoon, cold season (November–December). Moderate suitability scores (4–5) were obtained during the monsoon transition from the NE monsoon to the SW monsoon, summer (April–May). The study area was further divided into three zones: the western, central, and eastern regions. The western and eastern parts showed high suitability scores (5–7) while the central zone exhibited low suitability scores (2–4). The model results show a similar pattern to the actual mussel production in the study area. Seasonal events (i.e., flood and dry seasons) were incorporated into the model to examine the seasonal effects on the suitable mussel aquaculture areas. The suitability scores during the SW monsoon in 2018 were more sensitive to changes in SST and salinity relative to 2019. The higher freshwater discharge and lower temperature in 2018 relative to 2019 resulted in the accrual of suitable aquaculture areas. This pattern is consistent with the productions of the green mussel, where higher production was recorded in 2018 (2002.5 t) than in 2019 (410.8 t). However, correlations among atmospheric (air temperature, rainfall, and wind) and oceanographic factors (SST and MWC) were significant in the western and central regions, suggesting that the suitability of green mussel aquaculture in these regions is vulnerable to environmental disturbances. Thus, the SASSM can be a powerful tool in providing useful information on spatial management for marine aquaculture in environmentally-dynamic coastal systems.
• Multiple facets of marine biodiversity in the Pacific Arctic under future climate

  Irene D. Alabia, Jorge García Molinos, Sei Ichi Saitoh, Takafumi Hirata, Toru Hirawake, Franz J. Mueter

  Science of the Total Environment 744 140913 - 140913 2020年11月20日 

  Climate change is triggering a global reorganization of marine life. Biogeographical transition zones, diversity-rich regions straddling biogeographical units where many species live at, or close to, their physiological tolerance limits (i.e., range distribution edges), are redistribution hotspots that offer a unique opportunity to understand the mechanisms and consequences of climate-driven thermophilization processes in natural communities. In this context, we examined the impacts of climate change projections in the 21st century (2026–2100) on marine biodiversity in the Eastern Bering and Chukchi seas within the Pacific Arctic, a climatically exposed and sensitive boreal-to-Arctic transition zone. Overall, projected changes in species distributions, modeled using species distribution models, resulted in poleward increases in species richness and functional redundancy, along with pronounced reductions in phylogenetic distances by century's end (2076–2100). Future poleward shifts of boreal species in response to warming and sea ice changes are projected to alter the taxonomic and functional biogeography of contemporary Arctic communities as larger, longer-lived and more predatory taxa expand their leading distributional margins. Drawing from the existing evidence from other Arctic regions, these changes are anticipated to increase the susceptibility and vulnerability of the Arctic ecosystems, as trophic connectance between biological components increases, thus decreasing the modularity of Arctic food webs. Our results demonstrate how integrating multiple diversity facets can provide key insights into the relationships between climate change, species composition and ecosystem functioning across marine biogeographic regions.
• Impact of Climate Change on Wintering Ground of Japanese Anchovy (Engraulis japonicus) Using Marine Geospatial Statistics

  Shuhao Liu, Yang Liu, Irene D. Alabia, Yongjun Tian, Zhenjiang Ye, Haiqing Yu, Jianchao Li, Jiahua Cheng

  Frontiers in Marine Science 7 2020年07月31日 

  The distribution and fluctuations in abundance of small pelagic species such as anchovy are largely affected by climate change. We hypothesized that the future projected rise in temperature will result to a northward shift of Japanese anchovy (Engraulis japonicus) habitat and a subsequent increase in relative abundance. To test this hypothesis, we explored the link between Japanese anchovy abundance and environmental conditions using machine-learning and statistical models. The models were fitted with catch per unit effort (CPUE) as the response variable and remotely sensed data of sea surface temperature (SST), sea surface chlorophyll-a (Chl-a), assimilated information of sea surface salinity (SSS), meridional and zonal ocean currents, and depth as environmental covariates. Our results showed that the abundance of E. japonicus was significantly influenced by environmental factors. In particular, salinity front and SST highlight strong relationships with winter CPUE distribution. Based on these models, the results reinforced our hypothesis and showed that the warming ocean will drive a substantial shift in Japanese anchovy habitat in the China seas. SST and CPUE showed negative correlations with the El Niño Southern Oscillation (ENSO) index. These findings underpin ramifications of the climate-driven habitat shift of small pelagic fish species on the regional marine ecosystem in the China seas.
• Spatial habitat shifts of oceanic cephalopod (Ommastrephes bartramii) in oscillating climate

  Irene D. Alabia, Sei Ichi Saitoh, Hiromichi Igarashi, Yoichi Ishikawa, Yutaka Imamura

  Remote Sensing 12 3 2020年02月01日 

  Short-and long-term climate oscillations impact seascapes, and hence, marine ecosystem structure and dynamics. Here, we explored the spatio-temporal patterns of potential squid habitat in the western and central North Pacific across inter-decadal climate transitions, coincident with periods of persistent warming and cooling. Potential habitat distributions of Ommastrephes bartramii were derived from the outputs of multi-ensemble species distribution models, developed using the most influential environmental factors to squid distribution and occurrence data. Our analyses captured the underlying temporal trends in potential squid habitat in response to environmental changes transpiring at each climatic transition, regulated by phase shifts in Pacific decadal oscillation (PDO) from 1999-2013. The spatial differences in environmental conditions were apparent across transitions and presumably modulate the local changes in suitable squid habitat over time. Specifically, during a cold to warm PDO shift, decreases in the summer potential habitat (mean rate ± standard deviation:-0.04 ± 0.02 habitat suitability index (HSI)/yr) were observed along the southern edge of the subarctic frontal zone (162°E-172°W). Coincidentally, this area also exhibits a warming trend (mean temporal trend: 0.06 ± 0.21 °C/yr), accompanied with the prevalence of cold-core mesoscale eddies, west of the dateline (mean temporal trend in sea surface height:-0.19 ± 1.05 cm/yr). These conditions potentially generate less favorable foraging habitat for squid. However, a warm-to-cold PDO transition underpins a northward shift of suitable habitat and an eastward shift of regions exhibiting the highest rate of potential squid habitat loss (170-160°W; mean temporal trend:-0.05 ± 0.03 HSI/yr). Nonetheless, the emergence of the areas with increasingly suitable habitat regardless of climate transitions suggests the ecological importance of these regions as potential squid habitat hotspots and climatic refugia.
• Impact of climate extremes on suitability dynamics for Japanese scallop aquaculture in Shandong, China and Funka bay, Japan

  Yang Liu, Yongjun Tian, Sei Ichi Saitoh, Irene D. Alabia, Kan Ichiro Mochizuki

  Sustainability (Switzerland) 12 3 2020年02月01日 

  The assessment of extreme weather events on suitable sites for aquaculture could help in establishing sustainable coastal environmental resource management. Japanese scallop culture is an economically important marine farming activity in the coastal communities of Shandong, China and Funka Bay, Japan. In this study, we improved the suitable aquaculture site-selection model (SASSM) by using Geostationary Ocean Color Imager (GOCI) data instead of Moderate Resolution Imaging Spectroradiometer (MODIS) data, as a complementary source for higher temporal and spatial resolution data that are useful for monitoring fine-scale coastal and oceanic processes. We also applied the newly developed SASSM to the Japanese scallop production site along the Shandong coast. Finally, we analyzed the correlations between environmental factors (chlorophyll a concentration, sea surface temperature (SST), and total suspended sediment), meteorological factors (precipitation, temperature, and wind), and climatic events (winter East Asian monsoon (EAM) and El Nino/La Nina Southern Oscillation), and the impacts of climate events on suitable zones for scallop aquaculture. The new SASSM maps show that GOCI products have the potential for oceanographic investigations in Shandong, China and Funka Bay, Japan. Our results highlighted higher aquaculture site suitability for scallop in Funka Bay than in Shandong coast. During the winter with a strong EAM (2011), the suitable area for Japanese scallop aquaculture increased. Conversely, in the winter during a strong El Nino (2016), we found fewer areas that were highly suitable for scallop aquaculture in Funka Bay. SST was extremely low in Funka Bay during spring and summer 2017, which caused fewer highly suitable areas (scores of 7 and 8) for scallop aquaculture relative to other years. These findings suggest that extreme climatic events significantly impact the availability of suitable sites for marine farming and thus, should be considered in the development and design of coastal aquaculture sites.
• Distribution shifts of marine taxa in the Pacific Arctic under contemporary climate changes

  Irene D. Alabia, Jorge García Molinos, Sei Ichi Saitoh, Toru Hirawake, Takafumi Hirata, Franz J. Mueter

  Diversity and Distributions 24 11 1583 - 1597 2018年11月 

  Aim: To investigate the species-specific exposure and distributional responses of marine fish and invertebrate taxa to rapidly shifting climate in the Pacific Arctic, characterized by warming and cooling episodes, over the last 24 years. Location: Pacific Arctic region, eastern Bering Sea and Chukchi Sea. Methods: We examined the variations in the summer (June–July) habitat patterns of 21 marine fish and invertebrate taxa in the eastern Bering Sea using multimodel ensemble predictions of species distribution between 1993 and 2016. Using ensemble model outputs, we examined the rates of predicted (biotic velocities) and expected (bioclimatic velocities) distribution shifts across taxa under four consecutive time periods of distinct climatic regimes. We then compared these species-specific velocity metrics to the rates of local climatic shifts (climatic velocities) and quantified the potential lags in distributional responses relative to changes in climate across taxa and transitions. Results: Our analyses showed that individual taxa responded to climatic fluctuations at different paces and generally exhibited lags in their predicted distributional responses. Subarctic species revealed higher habitat sensitivity and exposure to climatic changes than Arctic taxa, as they expand their habitat ranges into suitable regions emerging in the north under warmer conditions. Importantly, the actual rates of climate shifts (climatic velocities) were poorly correlated with both the expected and observed shifts in species distributions across taxa. Main conclusions: Our findings underpin the importance of incorporating species-specific climatic sensitivity and exposure to changes in climatic conditions when predicting range shift responses and evaluating species vulnerability. These insights are critical for conservation and management of fisheries resources in the region.
• Detection of potential fishing zone for Pacific saury (Cololabis saira) using generalized additive model and remotely sensed data

  Achmad Fachruddin Syah, Sei Ichi Saitoh, Irene D. Alabia, Toru Hirawake

  IOP Conference Series: Earth and Environmental Science 54 1 2017年02月11日 

  To evaluate the effects of oceanographic conditions on the formation of the potential fishing zones for Pacific saury in western North Pacific, fishing locations of Pacific saury from Defense Meteorological Satellite Program/Operating Linescan System (DMSP/OLS) and satellite-based oceanographic information were used to construct species habitat models. A 2-level slicing method was used to identify the bright regions as actual fishing areas from OLS images, collected during the peak fishing season of Pacific saury in the North Pacific. Statistical metrics, including the significance of model terms, and reduction in the Akaike's Information Criterion (AIC) were used as the bases for model selection. The selected model was then used to visualize the basin scale distributions of the Pacific saury habitat. The predicted potential fishing zones exhibited spatial correspondence with the fishing locations. The results from generalized additive model revealed that the Pacific saury habitat selection was significantly influenced by the SST ranges from 13-18°C, SSC ranges from 0.5-1.8 mg.m-3, SSHA ranges from 5-17 cm and EKE ranges from 700-1200 cm2s-2. Moreover, among the set of oceanographic factors examined, SST explained the smallest AIC and is thus, considered to be the most significant variable in the geographic distribution of Pacific saury.
• Seasonal habitat patterns of Japanese common squid (Todarodes pacificus) inferred from satellite-based species distribution models

  Irene D. Alabia, Mariko Dehara, Sei Ichi Saitoh, Toru Hirawake

  Remote Sensing 8 11 2016年11月 

  The understanding of the spatio-temporal distributions of the species habitat in the marine environment is central to effectual resource management and conservation. Here, we examined the potential habitat distributions of Japanese common squid (Todarodes pacificus) in the Sea of Japan during a four-year period. The seasonal patterns of preferential habitat were inferred from species distribution models, built using squid occurrences detected from night-time visible images and remotely-sensed environmental factors. The predicted squid habitat (i.e., areas with high habitat suitability) revealed strong seasonal variability, characterized by a reduction of potential habitat, confined off of the southern part of the basin during the winter-spring period (December-May). Apparent expansion of preferential habitat occurred during summer-autumn months (June-November), concurrent with the formation of highly suitable habitat patches in certain regions of the Sea of Japan. These habitat distribution patterns were in response to changes in oceanographic conditions and synchronous with seasonal migration of squid. Moreover, the most important variables regulating the spatio-temporal patterns of suitable habitat were sea surface temperature, depth, sea surface height anomaly, and eddy kinetic energy. These variables could affect the habitat distributions through their impacts on growth and survival of squid, local nutrient transport, and the availability of favorable spawning and feeding grounds.
• Ensemble squid habitat model using three-dimensional ocean data

  Irene D. Alabia, Sei Ichi Saitoh, Hiromichi Igarashi, Yoichi Ishikawa, Norihisa Usui, Masafumi Kamachi, Toshiyuki Awaji, Masaki Seito

  ICES Journal of Marine Science 73 7 1863 - 1874 2016年07月01日 

  Neon flying squid (Ommastrephes bartramii) is a large pelagic squid internationally harvested in the North Pacific. Here, we examined its potential habitat in the central North Pacific using an ensemble modelling approach. Initially, ten statistical models were constructed by combining the squid fishing points, selected vertical layers of the sea temperature and salinity, sea surface height (SSH), and SSH gradient from the multi-variate ocean variational estimation system for the western North Pacific from June to July 1999-2011. The variable selection analyses have captured the importance of vertical temperature and salinity layers at the upper 300 and 440 m, respectively, coinciding with the reported vertical ranges of diel migration for the squid's primary prey species in the North Pacific. The evaluation of the habitat predictions using the independent sets of the presence data from 2012 to 2014 showed significant variability in the predictive accuracy, which is likely reflective of the interannual differences in environmental conditions across the validation periods. Our findings from ensemble habitat model approach using three-dimensional oceanographic data were able to characterize the near- and subsurface habitats of the neon flying squid. Moreover, our results underpinned the possible link between interannual environmental variability and spatio-temporal patterns of potential squid habitats. As such, these further suggest that an ensemble model approach could present a promising tool for operational fishery application and squid resource management.
• Predicting potential fishing zones for pacific saury (Cololabis saira) with maximum entropy models and remotely sensed data

  Achmad F. Syah, Sei Ichi Saitoh, Irene D. Alabia, Toru Hirawake

  Fishery Bulletin 114 3 330 - 342 2016年06月02日 

  Fishing locations for Pacific saury (Cololabis saira) obtained from images of the Operational Linescan System (OLS) of the U.S. Defense Meteorological Satellite Program, together with maximum entropy models and satellite-based oceanographic data of chlorophylla concentration (chl-a), sea-surface temperature (SST), eddy kinetic energy (EKE), and sea-surface height anomaly (SSHA), were used to evaluate the effects of oceanographic conditions on the formation of potential fishing zones (PFZ) for Pacific saury and to explore the spatial variability of these features in the western North Pacific. Actual fishing regions were identified as the bright areas created by a 2-level slicing method for OLS images collected August-December during 2005-2013. The results from a Maxent model revealed its potential for predicting the spatial distribution of Pacific saury and highlight the use of multispectral satellite images for describing PFZs. In all monthly models, the spatial PFZ patterns were explained predominantly by SST (14-16°C) and indicated that SST is the most influential factor in the geographic distribution of Pacific saury. Also related to PFZ formation were EKE and SSHA, possibly through their effects on the feeding grounds conditions. Concentration of chl-a had the least effect among other environmental factors in defining PFZs, especially during the end of the fishing season.
• Elucidating the potential squid habitat responses in the central North Pacific to the recent ENSO flavors

  Irene D. Alabia, Sei Ichi Saitoh, Toru Hirawake, Hiromichi Igarashi, Yoichi Ishikawa, Norihisa Usui, Masafumi Kamachi, Toshiyuki Awaji, Masaki Seito

  Hydrobiologia 772 1 215 - 227 2016年06月01日 

  The effects of the El Niño Southern Oscillation (ENSO)-mediated environmental changes to marine resources were long recognized; however, species-specific responses were also reported to vary, possibly more so, under the emerging event-to-event diversity of the ENSO conditions. Hence, the objective of this study is to characterize the potential impacts of the ENSO-regulated environmental variability to squid habitat in the central North Pacific under the different ENSO flavors, using habitat models developed from at least a decade of fishery-dependent dataset and environmental parameters. Our findings revealed that the potential squid habitats were largely influenced by ENSO-forced environmental changes during the squid’s spawning and nursery periods, resulting in substantial reduction/enhancement of available habitats in the succeeding summers of Central Pacific El Niño/La Niña, where the latter led to an expansion of favorable spawning and nursery grounds. However, the autumn–winter periods of weaker and short-lived Eastern Pacific El Niño showed elevated potential habitats due to minimal sea surface temperature drop and close proximity of spawning and nursery grounds to optimal feeding environments. The quick, albeit variable, squids’ responses to ENSO flavors accentuate their promising potential as ecological beacons under climate changes, aiding the development of adaptive management strategies for commercially exploited fisheries.
• Future projected impacts of ocean warming to potential squid habitat in western and central North Pacific

  Irene D. Alabia, Sei Ichi Saitoh, Hiromichi Igarashi, Yoichi Ishikawa, Norihisa Usui, Masafumi Kamachi, Toshiyuki Awaji, Masaki Seito

  ICES Journal of Marine Science 73 5 1343 - 1356 2016年05月01日 

  Climate-driven changes in the marine ecosystem largely influence the distribution, abundance, and the consequent availability of marine resources to the fishery. In this study, we examined the potential habitat distributions of the neon flying squid (Ommastrephes bartramii) under the projected impacts of ocean warming. We used the sea surface temperature (SST) from the three CMIP5 climate scenarios (RCP4.5, RCP6.0, and RCP8.5) with the low to high future emissions. Based on the squid habitat models, SST showed the highest effect on the present potential squid habitat distribution that accounted for at least 60% of the predicted spatial patterns from May to July 2000-2010. This result underpinned the species' high sensitivity to the temperature changes in its feeding environments. Moreover, the projected future potential squid habitats revealed pronounced differences in the spatial and temporal patterns relative to the present habitat distributions across the different regions of the western and central North Pacific. The future squid habitat predictions revealed a net reduction in the suitable squid habitat coupled with the corresponding northward habitat retreat. Moreover, the magnitude of the predicted habitat changes was proportional to the levels of warming for the representative periods from May to July 2025, 2050, and 2100. The highest decrease in the spatial extent and poleward retreat of the potential squid habitat were observed from May to July 2100 under the RCP 8.5 scenario. These trends could translate to shorter squid fishing periods and offshore shifts of the squid fishing grounds. Thus, insights into the future spatio-temporal patterns and trajectories of the potential squid habitats could lend important implications on the availability of squid resources to the fishery and subsequent evaluation of squid fishery management options under climate change.
• Shifts in chlorophyll α off eastern Luzon, Philippines, associated with the North Equatorial Current bifurcation latitude

  Olivia C. Cabrera, Cesar L. Villanoy, Irene D. Alabia, Arnold L. Gordon

  Oceanography 28 4 46 - 53 2015年12月 

  The circulation pattern off the east coast of Luzon, Philippines, as observed during two oceanographic cruises conducted in May/June 2011 and April/May 2012, features a northward-flowing current (the nascent Kuroshio) bracketed by an anticyclonic eddy to its northeast and a cyclonic eddy to its southwest. A previous study showed that a more northerly location of the North Equatorial Current (NEC) bifurcation during the 2011 cruise resulted in entrainment of more subtropical water from the Kuroshio into upper thermocline waters, while a more southerly bifurcation location during the 2012 cruise injected more tropical NEC water into upper thermocline waters offshore of eastern Luzon. Here, we show that the change in source of upper thermocline waters in this region can also be recognized in the distribution pattern of chlorophyll a. Horizontally averaged chlorophyll a profiles showed higher concentrations in the upper 125 m of the water column during the 2011 cruise when the bifurcation latitude was 13°N–14°N than during the 2012 cruise when the bifurcation latitude was observed at 10°N–11°N. Chlorophyll a data overlain on regional currents show that the 2011 nascent Kuroshio had a higher chlorophyll a content, supplied by the Kuroshio recirculation from the north, while the increased NEC content of the 2012 nascent Kuroshio was accompanied by reduced chlorophyll a within the upper thermocline, supporting the notion that horizontal advection plays an important role in chlorophyll variability off eastern Luzon. Using sea surface height anomalies as a proxy for upper ocean heat content, we show that warmer waters from the NEC supply the nascent Kuroshio when the location of the NEC bifurcation is more southerly. Empirical orthogonal function analysis of Moderate Resolution Imaging Spectroradiometer chlorophyll a data from 2003 to 2013 shows that the primary mode of chlorophyll a variability offshore of eastern Luzon was positively correlated with the NEC bifurcation latitude, further establishing that warmer, oligotrophic waters from the NEC supply the nascent Kuroshio when NEC bifurcation is southerly.
• Identifying pelagic habitat hotspots of neon flying squid in the temperate waters of the central North Pacific

  Irene D. Alabia, Sei Ichi Saitoh, Robinson Mugo, Hiromichi Igarashi, Yoichi Ishikawa, Norihisa Usui, Masafumi Kamachi, Toshiyuki Awaji, Masaki Seito

  PLoS ONE 10 11 2015年11月01日 

  We identified the pelagic habitat hotspots of the neon flying squid (Ommastrephes bartramii) in the central North Pacific from May to July and characterized the spatial patterns of squid aggregations in relation to oceanographic features such as mesoscale oceanic eddies and the Transition Zone Chlorophyll-a Front (TZCF). The data used for the habitat model construction and analyses were squid fishery information, remotely-sensed and numerical model-derived environmental data from May to July 1999-2010. Squid habitat hotspots were deduced from the monthly Maximum Entropy (MaxEnt) models and were identified as regions of persistent high suitable habitat across the 12-year period. The distribution of predicted squid habitat hotspots in central North Pacific revealed interesting spatial and temporal patterns likely linked with the presence and dynamics of oceanographic features in squid's putative foraging grounds from late spring to summer. From May to June, the inferred patches of squid habitat hotspots developed within the Kuroshio-Oyashio transition zone (KOTZ; 37-40°N) and further expanded north towards the subarctic frontal zone (SAFZ; 40-44°N) in July. The squid habitat hotspots within the KOTZ and areas west of the dateline (160°W-180°) were likely influenced and associated with the highly dynamic and transient oceanic eddies and could possibly account for lower squid suitable habitat persistence obtained from these regions. However, predicted squid habitat hotspots located in regions east of the dateline (180°-160°W) from June to July, showed predominantly higher squid habitat persistence presumably due to their proximity to the mean position of the seasonally- shifting TZCF and consequent utilization of the highly productive waters of the SAFZ.
• Seasonal potential fishing ground prediction of neon flying squid (Ommastrephes bartramii) in the western and central North Pacific

  Irene D. Alabia, Sei Ichi Saitoh, Robinson Mugo, Hiromichi Igarashi, Yoichi Ishikawa, Norihisa Usui, Masafumi Kamachi, Toshiyuki Awaji, Masaki Seito

  Fisheries Oceanography 24 2 190 - 203 2015年03月01日 

  We explored the seasonal potential fishing grounds of neon flying squid (Ommastrephes bartramii) in the western and central North Pacific using maximum entropy (MaxEnt) models fitted with squid fishery data as response and environmental factors from remotely sensed [sea surface temperature (SST), sea surface height (SSH), eddy kinetic energy (EKE), wind stress curl (WSC) and numerical model-derived sea surface salinity (SSS)] covariates. The potential squid fishing grounds from January-February (winter) and June-July (summer) 2001-2004 were simulated separately and covered the near-coast (winter) and offshore (summer) forage areas off the Kuroshio-Oyashio transition and subarctic frontal zones. The oceanographic conditions differed between regions and were regulated by the inherent seasonal variability and prevailing basin dynamics. The seasonal and spatial extents of potential squid fishing grounds were largely explained by SST (7-17°C in the winter and 11-18°C in the summer) and SSS (33.8-34.8 in the winter and 33.7-34.3 in the summer). These ocean properties are water mass tracers and define the boundaries of the North Pacific hydrographic provinces. Mesoscale variability in the upper ocean inferred from SSH and EKE were also influential to squid potential fishing grounds and are presumably linked to the augmented primary productivity from nutrient enhancement and entrainment of passive plankton. WSC, however, has the least model contribution to squid potential fishing habitat relative to the other environmental factors examined. Findings of this work underpin the importance of SST and SSS as robust predictors of the seasonal squid potential fishing grounds in the western and central North Pacific and highlight MaxEnt's potential for operational fishery application.

書籍

• Future Oceans2 IMBeR Open Science Conference: Thoughts and perspectives from early career attendees

  Irene D Alabia, Xin Guo, Patricia Angkiriwang, Andrés Beita-Jiménez (担当:共著)
  North Pacific Marine Science Organization 2019年07月
• Detection of potential fishing zone for Pacific saury (Cololabis saira) using generalized additive model and remotely sensed data

  (担当:共訳)
  Achmad Fachruddin Syah, Sei-Ichi Saitoh, Irene D Alabia, Toru Hirawake IOP Conference Series: Earth and Environmental Science 2017年
• Investigating the roles of intrinsic and extrinsic factors in the blooms of Pyrodinium bahamense var. compressum using an individual-based model

  AT Yñiguez, A Cayetano, CL Villanoy, I Alabia, I Fernandez, JD Palermo, GA Benico, FP Siringan, RV Azanza (担当:共著)
  Procedia Environmental Sciences 2012年01月

講演・口頭発表等

• Future biogeographic shifts of marine biodiversity in the Pacific Arctic.

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Toru Hirawake, and Franz J. Mueter

  JpGU 2021年06月 口頭発表（一般）
• Multiple facets of marine biodiversity in the Pacific Arctic under future climate  [通常講演]

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Toru Hirawake, and Franz J. Mueter

  PICES Annual Meeting 2020年10月 口頭発表（一般）
• Multifaceted biodiversity distributions in the Eastern Bering Sea over the recent decades, 1990-2020

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Toru Hirawake, and Franz J. Mueter

  AGU Ocean Sciences Meeting 2020年02月 口頭発表（一般）
• Modeling abundance of demersal taxa in the Pacific Arctic under climate change: implications on future resource availability to fisheries  [通常講演]

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Takafumi Hirata, Toru Hirawake, and Franz J. Mueter

  IMBER Open Science Conference, Future Oceans 2019年06月 口頭発表（一般）
• Biogeographic patterns of marine communities in the Pacific Arctic under a warming ocean  [通常講演]

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Takafumi Hirata, Toru Hirawake, Franz J. Muete

  PICES Annual Meeting 2018年11月 口頭発表（一般）
• Projected distribution and diversity patterns of marine taxa in the Pacific Arctic under future climate  [通常講演]

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Takafumi Hirata, Toru Hirawake, and Franz J. Mueter

  Effects of climate change on the world’s ocean (ECCWO) 2018年06月 口頭発表（一般）
• Biodiversity patterns of marine taxa in the Eastern Bering Sea under extant climatic stanzas

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Takafumi Hirata, Toru Hirawake, Franz J. Muete

  AGU Ocean Science Meeting 2018年02月 ポスター発表
• Distribution shifts of marine taxa in the Pacific Arctic under contemporary climate changes

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Takafumi Hirata, Toru Hirawake, and Franz J. Mueter

  International Symposium on Arctic Research 2018年01月 口頭発表（一般）
• Habitat distribution patterns of demersal fish in the Eastern Bering and Chukchi Seas: comparing multivariate climatic and bioclimatic velocities

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, Takafumi Hirata, Toru Hirawake

  ESSAS Open Science Meeting 2017年06月 口頭発表（一般）
• Bioclimatic velocity for walleye pollock in the Bering Sea

  Irene Alabia, Jorge Garcia Molinos, Sei-Ichi Saitoh, and Toru Hirawake

  PICES Annual Meeting 2016年 口頭発表（一般）

受賞

• 2022年03月 水産海洋学会 水産海洋学会奨励賞
   気候変動下の極域・亜寒帯海域におけるハビタットモデルを用いた海洋生態学的研究
• 2010年02月 SAFARI International Fisheries and Remote Sensing Symposium Best Poster Presentation
   Interaction of Kuroshio with the Northern Bicol Shelf: Implications on Primary Productivity

大学運営

メディア報道

• 海の生き物たちが環境変動を避けて逃げ込む「退避海域」

  報道 : 2021年05月

  発行元・放送局 : The University of Tokyo

  Tokyo, Japan　インターネットメディア
• Two biodiversity refugia identified in the Eastern Bering Sea

  報道 : 2021年05月

  発行元・放送局 : Hokkaido University Research Press Release

  　インターネットメディア
• Marine biodiversity reshuffles under warmer and sea ice-free Pacific Arctic

  報道 : 2020年09月

  発行元・放送局 : Hokkaido University Research Press Release

  　インターネットメディア
• Mapping species range shifts under recent climatic changes

  報道 : 2018年11月

  発行元・放送局 : Hokkaido University Press Release

  　インターネットメディア

学術貢献活動

• Guest Associate Editor in Frontiers in Marine Science (Toward an Integrated Understanding of Ecological Responses to Variable Climate Changes and Marine Environments)

  期間 : 2020年10月 - 2021年09月

  役割 : 監修

  種別 : 査読等

その他

• 2011年04月 - 2015年03月  MEXT Monbusho Scholarship Recipient 

  Recipient of the MEXT Monbusho Scholarship (Doctoral Course)
• 2008年07月 - 2009年04月  DOST (Philippines) Thesis Grant Recipent