Skip to main content

Ridge to Reef Management Implications for the Development of an Open-Source Dissolved Inorganic Nitrogen-Loading Model in American Samoa

Environmental Management volume 66, pages 498–515 (2020)Cite this article

Abstract

Excessive nutrient discharge to tropical island coastlines drives eutrophication and algal blooms with significant implications for reef ecosystem condition and provision of ecosystem services. Management actions to address nutrient pollution in coastal ecosystems include setting water-quality standards for surface waters discharging to the coast. However, these standards do not account for the effects of groundwater discharge, variability in flow, or dilution, all of which may influence the assessment of true nutrient impacts on nearshore reef habitats. We developed a method to estimate dissolved inorganic nitrogen (DIN) loads to coastal zones by integrating commonly available datasets within a geospatial modeling framework for Tutuila, American Samoa. The DIN-loading model integrated an open-source water budget model, water-sampling results, and publicly available streamflow data to predict watershed-scale DIN loading to the island’s entire coastline. Submarine groundwater discharge (SGD) was found to deliver more terrigenous DIN to the coastal zone than surface water pathways, supporting findings from other tropical islands. On-site wastewater disposal systems were also found to be the primary anthropogenic sources of DIN to coastal waters. Our island-wide DIN-loading model provides a simple and robust metric to define spatially explicit sources and delivery mechanisms of nutrient pollution to nearshore reef habitats. Understanding the sources and primary transport modes of inorganic nitrogen to nearshore reef ecosystems can help coastal resource managers target the most impactful human activities in the most vulnerable locations, thereby increasing the adaptive capacity of unique island ecosystems to environmental variation and disturbances.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

43,34 €

Price includes VAT (Finland)
Tax calculation will be finalised during checkout.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Data Availability

Recent advancements in cloud-computing technologies, particularly in open-source sharing of online projects, significantly increase methodological transparency and reproducibility of models. We provided dynamic open-source access to this project for managers, researchers, regulators, and others by developing the project with GitHub, which manages versioning and retains all necessary raw data files, model code, descriptive information, and output files in a public repository (Shuler and Comeros-Raynal 2019). We also archived the most recent version of the model for long-term storage in an open-access digital artifact repository (https://doi.org/10.5281/zenodo.3462869). Note that sensitive information or datasets not intended to be publicly available, are not posted in raw forms. The model code is licensed under the GNU General Public License v3.0, which is an open-access license designed to explicitly affirm any user’s unlimited permission to run, copy, and use the unmodified code from this repository. By designing the model as an interactive live-code document (Jupyter Notebook), it can be modified to potentially address new management questions that come up as we continue to work closely with stakeholders and managers toward the betterment of American Samoa’s terrestrial and marine environments. Most importantly, we hope that applying this open-source paradigm will provide a blueprint for others to improve upon and translate this method to other locations throughout Oceania.

References

  • Amato DW, Bishop JM, Glenn CR, Dulai H, Smith CM (2016) Impact of submarine groundwater discharge on marine water quality and reef biota of Maui. PLoS ONE 11:e0165825

    Article  CAS  Google Scholar 

  • AS-DOC—American Samoa Department of Commerce (2002) Tutuila minor watersheds [Data file]. http://portal.gis.doc.as. Accessed June 2014

  • AS-DOC—American Samoa Department of Commerce (2009) Buildings layer for Tutuila Island [Data file]. http://portal.gis.doc.as. Accessed June 2014

  • AS-DOC—American Samoa Department of Commerce (2013) The 2013 statistical yearbook for American Samoa. Amercan Samoa Department of Commerce, Pago Pago, AS. http://doc.as.gov/wp-content/uploads/2011/06/2013-Statistical-Yearbook-Final-Draft.pdf

  • AS-EPA—American Samoa Environmental Protection Agency (2005) American Samoa watershed management and protection program annual report. AS EPA report, AS EPA, Pago Pago, American Samoa

  • AS-EPA—American Samoa Environmental Protection Agency (2014) American Samoa watershed management and protection program annual report. AS EPA report, AS EPA, Pago Pago, American Samoa

  • AS-EPA—American Samoa Environmental Protection Agency. (2013) American Samoa water quality standards: 2013 revision. Administrative rule no. 001-2013. https://www.epa.gov/sites/production/files/2014-12/documents/aswqs.pdf. Accessed Jan 2019

  • ASPA—American Samoa Power Authority (2017) Groundwater extraction rates spreadsheet, [Dataset]. ASPA, Pago Pago, 1st Road Airport, AS 96799

  • Bassiouni M, Oki DS (2013) Trends and shifts in streamflow in Hawai‘i, 1913–2008. Hydrol Process 27(10):1484–1500

    Article  Google Scholar 

  • Bentley CB (1975) Ground-water resources of American Samoa with emphasis on the Tafuna-Leone Plain, Tutuila Island. US Geological Survey Report No. 75-29, US Geological Survey

  • Bishop JM, Glenn CR, Amato DW, Dulai H (2017) Effect of land use and groundwater flow path on submarine groundwater discharge nutrient flux. J Hydrol: Regional Stud 11:194–218. https://doi.org/10.1016/j.ejrh.2015.10.008

    Article  Google Scholar 

  • Caraco NF, Cole JJ (1999) Human impact on nitrate export: an analysis using major world rivers. Ambio 28(2):167–170

    Google Scholar 

  • Carlson RR, Foo SA, Asner GP (2019) Land use impacts on coral reef health: a ridge-to-reef perspective. Front Mar Sci 6:562

    Article  Google Scholar 

  • Comeros-Raynal MT, Lawrence A, Sudek M, Vaeoso M, McGuire K, Regis J, Houk, P (2019) Applying a ridge-to-reef framework to support watershed, water quality, and community-based fisheries management in American Samoa. Coral Reefs 1–16. https://doi.org/10.1007/s00338-019-01806-8

  • D’Elia CF, Webb KL, Porter JW (1981) Nitrate-rich groundwater inputs to Discovery Bay, Jamaica: a significant source of N to local coral reefs? Bull Mar Sci 31:903–910

    Google Scholar 

  • Daly C, Smith J, Doggett M, Halbleib M, Gibson W (2006) High-resolution climate maps for the Pacific basin islands, 1971–2000. Final report, National Park Service, Pacific West Regional Office

  • Delevaux JM, Whittier R, Stamoulis KA, Bremer LL, Jupiter S, Friedlander AM, Toonen R (2018) A linked land-sea modeling Framew Inf ridge-to-reef Manag high Ocean Isl c 13(3):e0193230. https://doi.org/10.1371/journal.pone.0193230

    Article  CAS  Google Scholar 

  • DiDonato GT (2004) Developing an initial watershed classification for American Samoa. Report from the American Samoa Environmental Protection Agency. Available online: https://www.researchgate.net/publication/253200186_DEVELOPING_AN_INITIAL_WATERSHED_CLASSIFICATION_FOR_AMERICAN_SAMOA. Accessed 31 May 2020

  • Evans C, Davies TD (1998) Causes of concentration/discharge hysteresis and its potential as a tool for analysis of episode hydrochemistry. Water Resour Res 34(1):129–137. https://doi.org/10.1029/97WR01881

    Article  CAS  Google Scholar 

  • Hawai’i Administrative Rules (2013) Amendment and compilation of chapter 11–54. State of Hawai’i Department of Health, Honolulu, HI

  • Hinsby K, Jørgensen LF (2009) Groundwater monitoring in Denmark and the Odense Pilot River Basin in relation to EU legislation. In: Quevauviller Ph, Fouillac AM, Grath J, Ward R (eds) Groundwater monitoring. Wiley, Hoboken, pp 207–224

  • Hirsch RM (2014) Large biases in regression‐based constituent flux estimates: causes and diagnostic tools. JAWRA J Am Water Resour Assoc 50(6):1401–1424

    Article  Google Scholar 

  • Hughes TP et al. (2007a) Phase shifts, herbivory, and the resilience of coral reefs to climate change. Curr Biol 17:360–365. https://doi.org/10.1016/j.cub.2006.12.049

    Article  CAS  Google Scholar 

  • Hughes TP, Bellwood DR, Folke CS, McCook LJ, Pandolfi JM (2007b) No-take areas, herbivory and coral reef resilience. Trends Ecol Evol 22:1–3. https://doi.org/10.1016/j.tree.2006.10.009

    Article  Google Scholar 

  • Izuka SK, Perreault JA, Presley TK (2007) Areas contributing recharge to wells in the Tafuna-Leone Plain, Tutuila. Report no. 2007-5167. Geological Survey (US), American Samoa, Honolulu, HI. https://pubs.er.usgs.gov/publication/sir20075167

  • Izuka SK, Giambelluca TW, Nullet MA (2005) Potential evapotranspiration on Tutuila, American Samoa. U.S. Geological Survey Scientific Investigations Report 2005-5200, U.S. Geological Survey

  • Jørgensen LF, Stockmarr J (2009) Groundwater monitoring in Denmark: characteristics, perspectives and comparison with other countries. Hydrogeol J 17(4):827–842

    Article  CAS  Google Scholar 

  • Kimsey MB (2005) Implementation guidance for the ground water quality standards. Publication (96-02). Washington State Department of Ecology. Olympia, Washington. https://fortress.wa.gov/ecy/publications/documents/9602.pdf. Accessed 20 June 2019

  • Kluyver, T., Ragan-Kelley, B., Pérez, F., Granger, B.E., Bussonnier, M., Frederic, J., Kelley, K., Hamrick, J.B., Grout, J., Corlay, S. and Ivanov, P. (2016) Jupyter Notebooks-a publishing format for reproducible computational workflows. In: Proceedings of the ELPUB. p 87–90

  • Kumar V (2011) Hysteresis. In: Singh VP, Singh P, Haritashya UK (eds) Encyclopedia of snow, ice and glaciers. Encyclopedia of Earth sciences series. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-2642-2_252

  • Littler MM, Littler DS, Brooks BL (2006) Harmful algae on tropical coral reefs: bottom-up eutrophication and top-down herbivory. Harmful Algae 5:565–585. https://doi.org/10.1016/j.hal.2005.11.003

    Article  Google Scholar 

  • Lloyd CEM, Freer JE, Johnes PJ, Collins AL (2016) Using hysteresis analysis of high-resolution water quality monitoring data, including uncertainty, to infer controls on nutrient and sediment transfer in catchments. Sci Total Environ 543:388–404

    Article  CAS  Google Scholar 

  • McCook LJ (1999) Macroalgae, nutrients and phase shifts on coral reefs: scientific issues and management consequences for the Great Barrier Reef. Coral Reefs 18:357–367. https://doi.org/10.1007/s003380050213

    Article  Google Scholar 

  • Medalie L, Hirsch RM, Archfield SA (2012) Use of flow-normalization to evaluate nutrient concentration and flux changes in Lake Champlain tributaries, 1990–2009. J Gt Lakes Res 38:58–67

    Article  CAS  Google Scholar 

  • Menzi H, Oenema O, Burton C, Shipin O, Gerber P, Robinson T, Franceschini G (2010) Impacts of intensive livestock production and manure management on the environment, chap 9. In: Steinfeld H, Mooney HA, Schneider F, Neville LE (eds) Livestock in a changing landscape, vol 1: drivers, consequences, and responses. Island Press, Washington, DC, p 139–163

  • Meyer RA, Seamon JO, Fa’aumu S, Lalogafuafua L (2016) Classification and mapping of wildlife habitats in American Samoa: an object-based approach using high resolution orthoimagery and LIDAR remote sensing data. Report prepared for American Samoa Department of Marine and Wildlife Resources. Pago Pago, AS

  • Moore WS (2010) The effect of submarine groundwater discharge on the ocean. Annu Rev Mar Sci 2:59–88

    Article  Google Scholar 

  • Moosdorf N, Stieglitz T, Waska H, Dürr HH, Hartmann J (2015) Submarine groundwater discharge from tropical islands: a review. Grundwasser 20:53–67. https://doi.org/10.1007/s00767-014-0275-3

    Article  CAS  Google Scholar 

  • Morton SL, Shuler A, Paternoster J, Fanolua S, Vargo D (2011) Coastal eutrophication, land use changes and Ceratium furca (Dinophyceae) blooms in Pago Pago Harbor, American Samoa 2007–2009. Chin J Oceanol Limnol 29:790–794. https://doi.org/10.1007/s00343-011-0507-7

    Article  Google Scholar 

  • N.J.A.C.—New Jersey Administrative Code (2018) Ground water quality standards. https://www.nj.gov/dep/rules/rules/njac7_9c.pdf. Accessed 20 June 2019. https://doi.org/10.1002/dap.30613

  • Nakamura S (1984) Soil survey of American Samoa. U.S. Department of Agriculture Soil Conservation Service, Pago Pago, p 95

    Google Scholar 

  • Nelder JA, Mead R (1965) A simplex method for function minimization. Comput J 7(4):308–313. https://doi.org/10.1093/comjnl/7.4.308

    Article  Google Scholar 

  • Pellerin BA, Bergamaschi BA, Gilliom RJ, Crawford CG, Saraceno J, Frederick CP, Murphy JC (2014) Mississippi River nitrate loads from high frequency sensor measurements and regression-based load estimation. Environ Sci Technol 48(21):12612–12619

    Article  CAS  Google Scholar 

  • Pendleton LH (1995) Valuing coral reef protection. Ocean Coast Manag 26:119–131. https://doi.org/10.1016/0964-5691(95)00007-O

    Article  Google Scholar 

  • Perreault JA (2010) Development of a water budget in a tropical setting accounting for mountain front recharge. Masters Thesis, University of Hawaii at Manoa, Honolulu, HI

    Google Scholar 

  • Polidoro BA, Comeros-Raynal MT, Cahill T, Clement C (2017) Land-based sources of marine pollution: Pesticides, PAHs and phthalates in coastal stream water, and heavy metals in coastal stream sediments in American Samoa. Mar Pollut Bull 116(1-2):501–507. https://doi.org/10.1016/j.marpolbul.2016.12.058

    Article  CAS  Google Scholar 

  • Richardson CM, Dulai H, Whittier RB (2017) Sources and spatial variability of groundwater-delivered nutrients in Maunalua Bay, Oʻahu, Hawai’i. J Hydrol Reg Stud 11:178–193

    Article  Google Scholar 

  • Rodgers KUS, Jokiel PL, Brown EK, Hau S, Sparks R (2015) Over a decade of change in spatial and temporal dynamics of Hawaiian Coral Reef communities. Pac Sci 69(1):1–13. 13p

  • Savoie DL, Prospero JM, Nees RT (1987) Washout ratios of nitrate, non-sea-salt sulfate and sea-salt on Virginia Key, Florida and on American Samoa. Atmos Environ 21(1):103–112

    Article  CAS  Google Scholar 

  • Shuler CK, El-Kadi AI, Dulai H, Glenn CR, Fackrell J (2017) Source partitioning of anthropogenic groundwater nitrogen in a mixed-use landscape, Tutuila, American Samoa. Hydrogeol J 25(8):2419–2434. https://doi.org/10.1007/s10040-017-1617-x

    Article  CAS  Google Scholar 

  • Shuler CK, Amato DW, Veronica Gibson V, Baker L, Olguin AN, Dulai H, Alegado RA (2019) Assessment of terrigenous nutrient loading to coastal ecosystems along a human land-use gradient, Tutuila, American Samoa. Hydrology 6(1):18. https://doi.org/10.3390/hydrology6010018

    Article  Google Scholar 

  • Shuler CK (2019) From recharge to reef: assessing the sources, quantity, and transport of groundwater on Tutuila Island, American Samoa. Doctoral dissertation, University of Hawaii Manoa, Honolulu, HI

  • Shuler CK, Comeros-Raynal M (2019) cshuler/R2R_DIN_Loading_Model: provisional release for DOI generation 2 (Version v1.0). Zenodo. https://doi.org/10.5281/zenodo.3462869

  • Shuler CK, El-Kadi AI (2019) cshuler/SWB2-Tutuila_fork: SWB2 water budget model for Tutuila: version for DOI generation (Version V1.2). Zenodo. https://doi.org/10.5281/zenodo.3466114

  • Shuler CK, Mariner MKE (2019) cshuler/ASPA-UH_Integrated_Modeling_Framework. V1.0.2, Zenodo. https://doi.org/10.5281/zenodo.3460214

  • Shuler CK, El-Kadi AI (2018) Groundwater recharge for Tutuila, American Samoa under current and projected climate as estimated with SWB2, a soil water balance model. WRRC project completion report, Water Resources Research Center University of Hawai’i at Manoa, Honolulu, Hawai’i. 96822

  • Smith SV, Kimmerer WJ, Laws EA, Brock RE, Walsh TW (1981) Kaneohe Bay sewage diversion experiment: Perspectives on ecosystem responses to nutritional perturbation. Pac Sci 35:279–395

    CAS  Google Scholar 

  • Swarzenski PW, Dulaiova H, Dailer ML, Glenn CR, Smith CG, Storlazzi CD (2013) A geochemical and geophysical assessment of coastal groundwater discharge at select sites in Maui and O’ahu, Hawai’i. Groundwater in the Coastal Zones of Asia-Pacific. Springer, Dordrecht, p 27–46

    Chapter  Google Scholar 

  • SWRCB—State Water Resources Control Board (2015) 2015 California ocean plan water quality control plan ocean waters of California. State of California State Water Resources Control Board, Sacramento, CA. https://www.epa.gov/sites/production/files/2017-01/documents/ca-cop2012.pdf. Accessed May 2019

  • Thornthwaite CW, Mather JR (1955) The water balance. Publ Climatol (Lab Climatol) 8(1):1–86

    Google Scholar 

  • Wahl KL, Wahl TL (1995) Determining the flow of comal springs at New Braunfels, Texas. In: Proceedings of Texas Water’95, American Society of Civil Engineers, San Antonio, Texas, p 77–86, August 16–17 1995

  • Waterhouse J, Schaffelke B, Bartley R, Eberhard R, Brodie J, Star M, … Kroon F (2017) 2017 Scientific Consensus statement: land use impacts on Great Barrier Reef water quality and ecosystem condition. Department of the Environment and Energy. Queensland, Australa. https://www.reefplan.qld.gov.au/__data/assets/pdf_file/0029/45992/2017-scientific-consensus-statement-summary.pdf

  • Westenbroek SM, Engott JA, Kelson VA, Hunt RJ (2018) SWB Version 2.0—a soil-water-balance code for estimating net infiltration and other water-budget components (No. 6-A59). US Geological Survey. Reston, VA. https://doi.org/10.3133/tm6A59

  • Whitall D, Holst S (2015) Pollution in surface sediments in Faga’alu Bay, Tutuila, American Samoa. NOAA Technical Memorandum NOS NCCOS 201, Silver Spring, MD. p 54. https://doi.org/10.7289/V5/TM-NOS-NCCOS-201

  • Wong MF (1996) Analysis of streamflow characteristics for streams on the island of Tutuila, American Samoa. US Geological Survey Water Resources Investigations Report No. 95-4185, Honolulu, HI

Download references

Acknowledgements

We would like to express our appreciation for the many individuals and agencies who made this work possible by generously providing their time, expertise, and assistance with data collection and field support. These people and agencies include The American Samoa Department of Marine and Wildlife Coral Reef Advisory Group Staff, specifically Alice Lawrence, Motusaga Vaeoso, and Kim McGuire. The National Marine Sanctuary of American Samoa, especially Dr. Mareike Sudek. The American Samoa Environmental Protection Agency, specifically, Fa’amao Asalele, Jr, Christianera Tuitele, Jewel Tuiasosopo and Josephine Regis, and University of Guam—Dr. Peter Houk. This is contributed paper WRRC-CP- of the Water Resources Research Center, University of Hawai‘i at Manoa.

Funding

Funding for this work was provided by the United States Environmental Protection Agency Region IX Wetland Program Development Grant, through the American Samoa Environmental Protection Agency and NOAA’s Pacific Regional Integrated Sciences and Assessments Program (Pacific RISA) [grant number NA15OAR4310146].

Author information

Affiliations

  1. Department of Earth Sciences, Water Resources Research Center, University of Hawaii at Manoa, 1680 East West Road, Honolulu, HI, 96822, USA

    Christopher K. Shuler

  2. ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4810, Australia

    Mia Comeros-Raynal

Authors
  1. Christopher K. Shuler
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Mia Comeros-Raynal
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

All authors contributed to the study conception and design. Model development was performed by CS. The first draft of the paper was written by CS and MC-R contributed considerably to the betterment of subsequent drafts, with significant additions to the text. All authors read and approved the final paper.

Corresponding author

Correspondence to Christopher K. Shuler.

Ethics declarations

Conflict of Interest

The authors declare that they have no conflict of interest.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Shuler, C.K., Comeros-Raynal, M. Ridge to Reef Management Implications for the Development of an Open-Source Dissolved Inorganic Nitrogen-Loading Model in American Samoa. Environmental Management 66, 498–515 (2020). https://doi.org/10.1007/s00267-020-01314-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00267-020-01314-4

Keywords

  • Nutrient loading
  • Geospatial model
  • Dissolved inorganic nitrogen
  • Water quality
  • Island management