Ocean Deoxygenation – Another Global Challenge

By Sylvia Earle1,2, Dawn J. Wright3,4, Samantha Joye5, Dan Laffoley6, John Baxter6, Carl Safina8, and Patty Elkus2

1 National Geographic Society Explorer-in-Residence, Washington, DC 20036, USA.

2 Mission Blue, Napa, CA 94581, USA.

3 Environmental Systems Research Institute, Redlands, CA 92373, USA.

4 College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA.

5 Department of Marine Sciences, University of Georgia, Athens, GA 30602, USA.

6 International Union for Conservation of Nature World Commission on Protected Areas, Gland, SWITZERLAND.

7 School of Marine and Atmospheric Sciences, Stony Brook University, Setauket, NY 11733, USA.

The ocean is facing unprecedented pressures that are causing massive ecosystem and nutrient cycle disruption the result of industrial-scale depletion of ocean wildlife and destabilization of steady-state ecosystems. This occurs not only on the seafloor by trawling, dredging, drilling, and mining (1) but also in the water column with nets, long lines, fish aggregating devices and other techniques; methods introduced in recent decades to extract with unprecedented speed and scale from ecosystems hundreds of millions of years in the making. Indeed, the carbon cycle/climate impacts of overfishing of the ocean biomass are tremendous (2), and restoring ocean life could have a huge impact, not just on ocean health but on CO2 accumulation in the atmosphere (3). Since more than half of the oxygen produced on Earth is derived from phytoplankton, decline of oxygen in the ocean concerns life on land as well.


Example of a visualization representing a new three-dimensional classification for the ocean known as ecological marine units (EMUs), www.esri.com/ecological-marine-units. The region shown is south of Tasmania, Australia [though we at Esri can re-create for any part of the world including the Baltic Sea or Indian Ocean highlighted in the Breitburg et al. paper]. Although the EMUs are mapped as a continuous surface, representing them in 3D is facilitated using columnar stacks (in this case dissolved oxygen), allowing visualization of EMUs beneath the ocean surface at evenly-spaced locations. In the coastal zone, EMUs are single or few, whereas offshore there are more and deeper EMUs. Visualization by Sean Breyer and Keith Van Graafeiland, both of Esri.

In their review “Declining oxygen in the global ocean and coastal waters” (05 January, p. eaam7240), D. Breitburg et al. summarize the evidence for the decline of oxygen in open ocean and coastal waters over the past half-century, yet another consequence of the human activities that have increased emissions of greenhouse gas, as well as nutrient discharges to coastal waters. While further studies are needed to help understand the long-term, global- and regional-scale changes in oxygen and their effect on ocean species and ecosystems, we suggest that new insights about the role and speed of microbial engagement, including how deoxygenation is altering microbial pathways and rates of processes within the water column and the deep ocean represent additional critically important data gaps. Breitburg et al. point out that oxygen is dropping faster than can be accounted for by physics, which suggests that respiration must be increasing. However, a good portion of this may in fact be microbial. And the extent to which the system is out of balance is becoming clear, exposed now to the point of crisp detection and quantification (4, 5). The pace of this change is alarming, as well as how widespread the impacts are (6). We cannot afford to wait before action is taken.


Interactive Atlas of Marine Protection. Marine Conservation Institute (2018), MPAtlas [Online]. Seattle, WA. Available at: www.mpatlas.org/map/mpas. [Accessed 15-Jan-2018].

In addition to an integrated framework that combines modeling, observations, and experiments among scientists, local governments, intergovernmental bodies, and industrial sectors, Breitburg et al. call for a “raised awareness” of the phenomenon of deoxygenation. We contend that such awareness must extend to all facets of society, beyond the pages of scientific journals, and most readily by way of intuitive, interactive, dynamic web maps and visualizations, such as the new Ecological Marine Units digital ocean project (7, 8), that drive the point home to a variety of audiences. These will be key to generating the societal and political will toward the effective management that will ultimately reverse deoxygenation, and its serious consequences for ocean life, ecosystems and habitats. As a companion to Explaining Ocean Warming: Causes, Scale, Effects and Consequences (3), the IUCN, in collaboration with world experts, is coordinating the production of Ocean Deoxygenation – Everyone’s Problem: Causes, Impacts, Consequences and Solutions (9), that will further summarize the challenges and implications we face. We must connect important discoveries about the nature of the world with public perception and current policies that shape the habitability of Earth. The global trend by nations of securing large areas of the ocean within national Exclusive Economic Zones (EEZs) or on the high seas as “blue parks” or safe havens for ocean life is also cause for hope, because protecting nature protects our existence.


There is accelerating momentum and opportunity for designating very large marine protected areas. Research suggests large MPAs are much more cost-effective to implement and manage compared to smaller MPAs and in general larger areas will provide better protection from activities that occur outside the MPA. Marine Conservation Institute (2018), MPAtlas [Online]. Seattle, WA. Available at: www.mpatlas.org/protection-dashboard/very-large-mpas  [Accessed 15-Jan-2018].


  1. A. Boetius, M. Haeckel, Mind the seafloor. Science 359, 34 (2018). [link]
  2. C. B. Woodson, J. R. Schramski, S. B. Joye, A unifying theory for top-heavy ecosystem structure in the ocean. Nature Communications 9, 23 (2018). [link]
  3. D. Laffoley, J. M. Baxter, Eds., Explaining Ocean Warming: Causes, Scale, Effects, and Consequences, (International Union for Conservation of Nature and Natural Resources (IUCN), Gland, Switzerland), 456 pp., (2016). [link]
  4. Á. López-Urrutia, E. San Martin, R. P. Harris, X. Irigoien, Scaling the metabolic balance of the oceans. Proceedings of the National Academy of Sciences 103, 8739-8744 (2006). [link]
  5. L. Cheng et al., Improved estimates of ocean heat content from 1960 to 2015. Science Advances 3,(2017). [link]
  6. R. N. Glud et al., High rates of microbial carbon turnover in sediments in the deepest oceanic trench on Earth. Nature Geoscience 6, 284-288 (2013). [link]
  7. A. Witze, 3D ocean map tracks ecosystems in unprecedented detail. Nature 541, 10-11 (2017). [link]
  8. R. Sayre et al., A three-dimensional mapping of the ocean based on environmental data. Oceanography 30, 90-103 (2017). [link]
  9. D. Laffoley, J. M. Baxter, Eds., Ocean Deoxygenation – Everyone’s Problem: Causes, Impacts, Consequences and Solutions, (International Union for Conservation of Nature and Natural Resources (IUCN), Gland, Switzerland, in press 2018).

Esri Ocean GIS Forum Keynote Speaker Announced

Learn How GIS “Closes the Gap” Between MetOcean Science and Resilience

ksDr. Kathryn Sullivan will share her experiences as a former Astronaut, Undersecretary of Commerce for Oceans and Atmosphere, and National Oceanic and Atmospheric Administration (NOAA) administrator, in her Keynote Address at the 2017 Esri Ocean GIS Forum.

Currently a Lindbergh fellow in aerospace history at the National Air and Space Museum and a senior fellow at the Potomac Institute for Policy Studies, Sullivan is an authority on the growing role of science in education, weather, ocean economies, homeland security, and public safety. With the addition of MetOcean content to this year’s Forum, she is uniquely positioned to present a fascinating view of the future of GIS in ocean and atmospheric work.

Before her distinguished career at NOAA, Sullivan was a National Aeronautics and Space Administration (NASA) astronaut, flying three space shuttle missions between 1986 and 1992. During the first mission, on space shuttle Challenger, she performed the first spacewalk by an American woman. In 1990, on space shuttle Discovery, she and her crew deployed the Hubble Space Telescope. Sullivan’s last mission was in 1992 on space shuttle Atlantis, logging a total of 532 hours in space.

After leaving the NASA Space Program in 1993, she served as NOAA chief scientist, and in 1996, she became president and CEO of COSI in Columbus, Ohio, a hands-on center of science and industry serving nearly 900,000 people annually throughout Ohio and surrounding states. COSI also operates the largest outreach education program of any science museum in the United States.

In 2006, Sullivan was selected as the inaugural director of the Battelle Center for Mathematics and Science Education Policy at the John Glenn School of Public Affairs at Ohio State University. She returned to NOAA in 2011 as deputy administrator, chief scientist in 2012, and administrator in 2014.

Please join us at the Esri Ocean GIS Forum to learn how you can help “Close the Gap” between ocean and atmospheric science and a resilient community.

Register for the event.

Geostatistics and GIS to Analyze the Spatial Distribution of the Diversity of Fruit Flies: The Effect of Forest Fragments in an Urban Area

Environmental Entomology, Published 23 September 2017

By A G Garcia, M R Araujo, K Uramoto, J M M Walder, and R A Zucchi

“Fruit flies are among the most damaging insect pests of commercial fruit in Brazil. It is important to understand the landscape elements that may favor these flies. In the present study, spatial data from surveys of species of Anastrepha Schiner (Diptera: Tephritidae) in an urban area with forest fragments were analyzed, using geostatistics and Geographic Information System (GIS) to map the diversity of insects and evaluate how the forest fragments drive the spatial patterns.


“The results indicated a high diversity of species associated with large fragments, and a trend toward lower diversity in the more urbanized area, as the fragment sizes decreased. We concluded that the diversity of Anastrepha species is directly and positively related to large and continuous forest fragments in urbanized areas, and that combining geostatistics and GIS is a promising method for use in insect-pest management and sampling involving fruit flies.”

Read the paper

Spatial autocorrelation analysis of tourist arrivals using municipal data: A Serbian example

Geographica Pannonica • Volume 21, Issue 2, June 2017

By Uglješa Stankov, Tanja Armenski, Michal Klauco, Vanja Pavluković, Marija Cimbaljević, and Nataša Drakulić-Kovačević

“Spatial autocorrelation methodologies can be used to reveal patterns and temporal changes of different spatial variables, including tourism arrivals. The research adopts a GIS-based approach to spatially analyse tourist arrivals in Serbia, using Global Moran’s I and Anselin’s Local Moran’s I statistics applied on the level of municipalities. To assess feasibility of this approach the article discusses spatial changes of tourist arrivals in order to identify potentially significant trends of interest for tourism development policy in Serbia.


Moran significance map for international tourist arrivals in Serbia (without the territory of Kosovo and Metohija) in 2001 and 2013.
Metohija) in 2001 and 2013

“There is a significant spatial inequality in the distribution of tourism arrivals in Serbia that is not adequately addressed in tourism development plans. The results of global autocorrelation suggest the existence of low and decreasing spatial clustering for domestic tourist arrivals and high, relatively stable spatial clustering for international tourists. Local autocorrelation statistics revealed different of domestic and international tourism arrivals. In order to assess feasibility of this approach these results are discussed in their significance to tourism development policy in Serbia.”

Read the paper

Call for Presentations: GIScience Research Sessions at the 2018 Esri User Conference

GIScience Research Sessions
Esri International Users Conference
July 9‐13, 2018
San Diego, California

Esri invites you to present a peer‐reviewed paper in a series of GIScience research sessions that will be scheduled as part of the 2018 Esri International Users Conference. Presentations in these special sessions will focus on cutting‐edge research in GIScience and full papers will be included in a special issue of Transactions in GIS that will be published a few weeks ahead of the conference itself. For your work to be considered for inclusion in these special GIScience research sessions, extended abstracts (≤ 1,500 words) must be submitted to Dr. John Wilson, University of Southern California, by Wednesday, November 15, 2017.

The three editors of Transactions in GIS will review these extended abstracts based on the novelty and likely impact of their GIScience content and select 9‐12 abstracts to become full papers. Notice of acceptance will occur by Friday, December 8, 2017. Full papers (maximum 6,000 words plus figures, tables, and references in appropriate format for publication) must be submitted via the journal’s Scholar One portal for peer review by Friday, January 19, 2018. Reviewed papers will be returned to authors by Wednesday, February 28, 2018 and final manuscripts must be returned by Friday, March 30, 2018, to be included in the special issue of Transactions in GIS.

For questions and/or additional guidance on these GIScience research sessions, contact Michael Gould at mgould@esri.com.

Abstracts should be submitted via e‐mail with a subject line “Esri GIScience Abstract, Authors Last Name” no later than Wednesday, November 15, 2017 to:

Dr. John Wilson, jpwilson@usc.edu

High resolution global gridded data for use in population studies

Scientific Data, Published Online 31 January 2017

By Christopher T. Lloyd, Alessandro Sorichetta, and Andrew J. Tatem

“Recent years have seen substantial growth in openly available satellite and other geospatial data layers, which represent a range of metrics relevant to global human population mapping at fine spatial scales. The specifications of such data differ widely and therefore the harmonisation of data layers is a prerequisite to constructing detailed and contemporary spatial datasets which accurately describe population distributions. Such datasets are vital to measure impacts of population growth, monitor change, and plan interventions. To this end the WorldPop Project has produced an open access archive of 3 and 30 arc-second resolution gridded data.


An excerpt of selected WorldPop gridded datasets at 100 m resolution, in plan view and as pseudo 3d stacks.

“Four tiled raster datasets form the basis of the archive: (i) Viewfinder Panoramas topography clipped to Global ADMinistrative area (GADM) coastlines; (ii) a matching ISO 3166 country identification grid; (iii) country area; (iv) and slope layer. Further layers include transport networks, landcover, nightlights, precipitation, travel time to major cities, and waterways. Datasets and production methodology are here described. The archive can be downloaded both from the WorldPop Dataverse Repository and the WorldPop Project website.”


Spatial Analysis of Chinese Grain Production for Sustainable Land Management in Plain, Hill, and Mountain Counties

Sustainability 2017, 9(3), 348

By Jinlang Zou and Qun Wu

“In the context of China’s food security, spatially explicit information on grain production is an important asset to achieve the sustainable management of cultivated land. Previous studies have shown that spatial mismatches exist between grain production and water and cultivated land resources. In this paper, county-level data are used to investigate the degree of spatial (mis)match between grain output and the geographical distribution patterns of plain, hill, and mountain counties.


County-level dominant landform classification into plain counties, hill counties, or mountain counties based on the China County Statistical Yearbook.

“We estimate the difference in grain output between these different types of counties with a Spatial Autoregression Model. The results indicate that plain counties have the highest grain output, followed by hill counties and mountain counties subsequently. The reasons for the higher production in plain counties lie in the presence of more cultivated land, as well as a higher degree of irrigation and agricultural mechanization. The current pattern of Chinese total grain production follows the law of substituting labor with mechanization. Improving efficiency in the use of water resources and chemical fertilizer is both urgent and crucial. In this paper, we propose that the future roles for total grain production in relation to landforms should be: increased production and competitiveness in plain counties, a stabilization of capacity in hill counties, and a decrease in grain production in mountain counties.”

Neighbourhood Walkability and Daily Steps in Adults with Type 2 Diabetes

PLOSone, published online March 18, 2016

By Samantha Hajna, Nancy A. Ross, Lawrence Joseph, Sam Harper, and Kaberi Dasgupta

“There is evidence that greater neighbourhood walkability (i.e., neighbourhoods with more amenities and well-connected streets) is associated with higher levels of total walking in Europe and in Asia, but it remains unclear if this association holds in the Canadian context and in chronic disease populations. We examined the relationships of different walkability measures to biosensor-assessed total walking (i.e., steps/day) in adults with type 2 diabetes living in Montreal (QC, Canada).

Materials and Methods

Participants (60.5±10.4 years; 48.1% women) were recruited through McGill University-affiliated clinics (June 2006 to May 2008). Steps/day were assessed once per season for one year with pedometers. Neighbourhood walkability was evaluated through participant reports, in-field audits, Geographic Information Systems (GIS)-derived measures, and the Walk Score®. Relationships between walkability and daily steps were estimated using Bayesian longitudinal hierarchical linear regression models (n = 131).



Participants who reported living in the most compared to the least walkable neighbourhoods completed 1345 more steps/day (95% Credible Interval: 718, 1976; Quartiles 4 versus 1). Those living in the most compared to the least walkable neighbourhoods (based on GIS-derived walkability) completed 606 more steps per day (95% CrI: 8, 1203). No statistically significant associations with steps were observed for audit-assessed walkability or the Walk Score®.


Adults with type 2 diabetes who perceived their neighbourhoods as more walkable accumulated more daily steps. This suggests that knowledge of local neighborhood features that enhance walking is a meaningful predictor of higher levels of walking and an important component of neighbourhood walkability.”

Exploring Spatiotemporal Trends in Commercial Fishing Effort of an Abalone Fishing Zone: A GIS-Based Hotspot Model

PLOSone, published online May 20, 2015

By M. Ali Jalali, Daniel Ierodiaconou, Harry Gorfine, Jacquomo Monk, and Alex Rattray

“Assessing patterns of fisheries activity at a scale related to resource exploitation has received particular attention in recent times. However, acquiring data about the distribution and spatiotemporal allocation of catch and fishing effort in small scale benthic fisheries remains challenging. Here, we used GIS-based spatio-statistical models to investigate the footprint of commercial diving events on blacklip abalone (Haliotis rubra) stocks along the south-west coast of Victoria, Australia from 2008 to 2011. Using abalone catch data matched with GPS location we found catch per unit of fishing effort (CPUE) was not uniformly spatially and temporally distributed across the study area.


“Spatial autocorrelation and hotspot analysis revealed significant spatiotemporal clusters of CPUE (with distance thresholds of 100’s of meters) among years, indicating the presence of CPUE hotspots focused on specific reefs. Cumulative hotspot maps indicated that certain reef complexes were consistently targeted across years but with varying intensity, however often a relatively small proportion of the full reef extent was targeted. Integrating CPUE with remotely-sensed light detection and ranging (LiDAR) derived bathymetry data using generalized additive mixed model corroborated that fishing pressure primarily coincided with shallow, rugose and complex components of reef structures. This study demonstrates that a geospatial approach is efficient in detecting patterns and trends in commercial fishing effort and its association with seafloor characteristics.”