Monitoring Coastal Estuarine Habitats for Biodiversity Along the Temperate Bioregion of South Africa.

Saved in:
Bibliographic Details
Title: Monitoring Coastal Estuarine Habitats for Biodiversity Along the Temperate Bioregion of South Africa.
Authors: Campbell, Anthony1,2 (AUTHOR) anthony.d.campbell@nasa.gov, Adam, Elhadi3 (AUTHOR), Adams, Janine B.4,5,6 (AUTHOR), Barrenblitt, Abigail1,7 (AUTHOR), Fatoyinbo, Temilola1,8 (AUTHOR), Jensen, Daniel9 (AUTHOR), Naidoo, Laven10,11 (AUTHOR), Riddin, Taryn4,5,6 (AUTHOR), Simard, Marc9 (AUTHOR), Smith, Kyle12 (AUTHOR), Thakali, Pati3 (AUTHOR), van Deventer, Heidi11,13 (AUTHOR), van Niekerk, Lara4,5,13 (AUTHOR), Stovall, Atticus1,7 (AUTHOR)
Source: Journal of Geophysical Research. Biogeosciences. Oct2025, Vol. 130 Issue 10, p1-18. 18p.
Subject Terms: *Coastal wetlands, *Salt marshes, *Ecological mapping, *Estuarine ecology, *Biodiversity, Remote-sensing images, Tidal forces (Mechanics), Machine learning
Geographic Terms: South Africa
Abstract: Coastal wetlands provide critical ecosystem services, including the enhancement of biodiversity, carbon sequestration, and flood protection. Although these ecosystems have been mapped for country‐level biodiversity typing, improved extent mapping is necessary to account for estuarine dynamics and improved reporting to the Kunming‐Montreal Global Biodiversity Framework (GBF) by 2030. We achieved an overall coastal wetland accuracy of 90.7% (95% confidence interval: 90.2%–91.4%) utilizing a dense time series of very high spatial resolution (3 m) PlanetScope satellite imagery to map coastal wetlands with a combination of Random Forest to develop training data, U‐Net convolutional neural networks, and a final decision tree to determine discrete ecosystem extents. Across the 84 mapped estuaries totaling 67,452 ha and 2,135 images, we mapped 9,131.1 ± 1,596.9 ha (13.5% of total estuarine functional zone extent) of salt marsh & reed beds and 1,718.6 ± 234.3 ha (2.5%) of Submerged Aquatic Vegetation (SAV). In addition to our earth observation analysis, we calculated tidal amplitudes and water level trends for 20 water level gauges across the region. We found tidal amplitude was a significant driver of salt marsh extent, explaining 33.6% of the variation (F (1,19) = 9.62, p = 0.005). We demonstrate a repeatable methodology for improved mapping of ecosystem zonation and utilize water level data to explore potential drivers of ecosystem distribution. Our method could be incorporated into a robust earth observation approach for reporting progress toward the goals of the/reporting to the GBF and Sustainable Development Goals (SDGs). Plain Language Summary: Coastal wetlands provide many benefits to humans, including as habitat for a variety of species, accumulation of carbon in their soils, and protection from flooding and storm events. Global and regional maps of these ecosystems exist, but they lack precision in their identification of ecosystem zones. Improved maps could be used for improved reporting to international agreements and inform coastal management. We mapped three coastal wetland habitats to a high degree of accuracy (90.7%) utilizing a time series of commercial satellite data and machine learning algorithms. Across the 84 mapped estuaries totaling 67,452 ha, we mapped 9131.1 ± 1596.9 ha (13.5% of total estuarine functional zone extent) of salt marsh & reed beds and 1718.6 ± 234.3 ha (2.5%) of Submerged Aquatic Vegetation (SAV). We conducted additional analysis on how tidal amplitude, water level, and impervious surface influence the distribution of habitats in the region, finding that higher tidal amplitudes correlated with more salt marsh extent. Our methodology is repeatable and could improve the monitoring of these ecosystems in South Africa. Key Points: We mapped coastal wetland habitats (salt marsh, reeds and sedges, and submerged aquatic vegetation) with a U‐Net approach at >90% accuracyWe identified tidal amplitude as a major driver of salt marsh habitat, explaining 33.6% of the variation (F (1,19) = 9.62, p = 0.005)Salt marsh was only 19.4% of coastal wetland extent, 40% of this extent was found within Knysna Estuary and Langebaan Lagoon [ABSTRACT FROM AUTHOR]
Copyright of Journal of Geophysical Research. Biogeosciences is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: GreenFILE
FullText Text:
  Availability: 0
Header DbId: 8gh
DbLabel: GreenFILE
An: 188962301
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Monitoring Coastal Estuarine Habitats for Biodiversity Along the Temperate Bioregion of South Africa.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Campbell%2C+Anthony%22">Campbell, Anthony</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> anthony.d.campbell@nasa.gov</i><br /><searchLink fieldCode="AR" term="%22Adam%2C+Elhadi%22">Adam, Elhadi</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Adams%2C+Janine+B%2E%22">Adams, Janine B.</searchLink><relatesTo>4,5,6</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Barrenblitt%2C+Abigail%22">Barrenblitt, Abigail</searchLink><relatesTo>1,7</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Fatoyinbo%2C+Temilola%22">Fatoyinbo, Temilola</searchLink><relatesTo>1,8</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Jensen%2C+Daniel%22">Jensen, Daniel</searchLink><relatesTo>9</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Naidoo%2C+Laven%22">Naidoo, Laven</searchLink><relatesTo>10,11</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Riddin%2C+Taryn%22">Riddin, Taryn</searchLink><relatesTo>4,5,6</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Simard%2C+Marc%22">Simard, Marc</searchLink><relatesTo>9</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Smith%2C+Kyle%22">Smith, Kyle</searchLink><relatesTo>12</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Thakali%2C+Pati%22">Thakali, Pati</searchLink><relatesTo>3</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22van+Deventer%2C+Heidi%22">van Deventer, Heidi</searchLink><relatesTo>11,13</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22van+Niekerk%2C+Lara%22">van Niekerk, Lara</searchLink><relatesTo>4,5,13</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Stovall%2C+Atticus%22">Stovall, Atticus</searchLink><relatesTo>1,7</relatesTo> (AUTHOR)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Geophysical+Research%2E+Biogeosciences%22">Journal of Geophysical Research. Biogeosciences</searchLink>. Oct2025, Vol. 130 Issue 10, p1-18. 18p.
– Name: Subject
  Label: Subject Terms
  Group: Su
  Data: *<searchLink fieldCode="DE" term="%22Coastal+wetlands%22">Coastal wetlands</searchLink><br />*<searchLink fieldCode="DE" term="%22Salt+marshes%22">Salt marshes</searchLink><br />*<searchLink fieldCode="DE" term="%22Ecological+mapping%22">Ecological mapping</searchLink><br />*<searchLink fieldCode="DE" term="%22Estuarine+ecology%22">Estuarine ecology</searchLink><br />*<searchLink fieldCode="DE" term="%22Biodiversity%22">Biodiversity</searchLink><br /><searchLink fieldCode="DE" term="%22Remote-sensing+images%22">Remote-sensing images</searchLink><br /><searchLink fieldCode="DE" term="%22Tidal+forces+%28Mechanics%29%22">Tidal forces (Mechanics)</searchLink><br /><searchLink fieldCode="DE" term="%22Machine+learning%22">Machine learning</searchLink>
– Name: SubjectGeographic
  Label: Geographic Terms
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22South+Africa%22">South Africa</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Coastal wetlands provide critical ecosystem services, including the enhancement of biodiversity, carbon sequestration, and flood protection. Although these ecosystems have been mapped for country‐level biodiversity typing, improved extent mapping is necessary to account for estuarine dynamics and improved reporting to the Kunming‐Montreal Global Biodiversity Framework (GBF) by 2030. We achieved an overall coastal wetland accuracy of 90.7% (95% confidence interval: 90.2%–91.4%) utilizing a dense time series of very high spatial resolution (3 m) PlanetScope satellite imagery to map coastal wetlands with a combination of Random Forest to develop training data, U‐Net convolutional neural networks, and a final decision tree to determine discrete ecosystem extents. Across the 84 mapped estuaries totaling 67,452 ha and 2,135 images, we mapped 9,131.1 ± 1,596.9 ha (13.5% of total estuarine functional zone extent) of salt marsh & reed beds and 1,718.6 ± 234.3 ha (2.5%) of Submerged Aquatic Vegetation (SAV). In addition to our earth observation analysis, we calculated tidal amplitudes and water level trends for 20 water level gauges across the region. We found tidal amplitude was a significant driver of salt marsh extent, explaining 33.6% of the variation (F (1,19) = 9.62, p = 0.005). We demonstrate a repeatable methodology for improved mapping of ecosystem zonation and utilize water level data to explore potential drivers of ecosystem distribution. Our method could be incorporated into a robust earth observation approach for reporting progress toward the goals of the/reporting to the GBF and Sustainable Development Goals (SDGs). Plain Language Summary: Coastal wetlands provide many benefits to humans, including as habitat for a variety of species, accumulation of carbon in their soils, and protection from flooding and storm events. Global and regional maps of these ecosystems exist, but they lack precision in their identification of ecosystem zones. Improved maps could be used for improved reporting to international agreements and inform coastal management. We mapped three coastal wetland habitats to a high degree of accuracy (90.7%) utilizing a time series of commercial satellite data and machine learning algorithms. Across the 84 mapped estuaries totaling 67,452 ha, we mapped 9131.1 ± 1596.9 ha (13.5% of total estuarine functional zone extent) of salt marsh & reed beds and 1718.6 ± 234.3 ha (2.5%) of Submerged Aquatic Vegetation (SAV). We conducted additional analysis on how tidal amplitude, water level, and impervious surface influence the distribution of habitats in the region, finding that higher tidal amplitudes correlated with more salt marsh extent. Our methodology is repeatable and could improve the monitoring of these ecosystems in South Africa. Key Points: We mapped coastal wetland habitats (salt marsh, reeds and sedges, and submerged aquatic vegetation) with a U‐Net approach at >90% accuracyWe identified tidal amplitude as a major driver of salt marsh habitat, explaining 33.6% of the variation (F (1,19) = 9.62, p = 0.005)Salt marsh was only 19.4% of coastal wetland extent, 40% of this extent was found within Knysna Estuary and Langebaan Lagoon [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Geophysical Research. Biogeosciences is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=8gh&AN=188962301
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1029/2025JG008833
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 18
        StartPage: 1
    Subjects:
      – SubjectFull: Coastal wetlands
        Type: general
      – SubjectFull: Salt marshes
        Type: general
      – SubjectFull: Ecological mapping
        Type: general
      – SubjectFull: Estuarine ecology
        Type: general
      – SubjectFull: Biodiversity
        Type: general
      – SubjectFull: Remote-sensing images
        Type: general
      – SubjectFull: Tidal forces (Mechanics)
        Type: general
      – SubjectFull: Machine learning
        Type: general
      – SubjectFull: South Africa
        Type: general
    Titles:
      – TitleFull: Monitoring Coastal Estuarine Habitats for Biodiversity Along the Temperate Bioregion of South Africa.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Campbell, Anthony
      – PersonEntity:
          Name:
            NameFull: Adam, Elhadi
      – PersonEntity:
          Name:
            NameFull: Adams, Janine B.
      – PersonEntity:
          Name:
            NameFull: Barrenblitt, Abigail
      – PersonEntity:
          Name:
            NameFull: Fatoyinbo, Temilola
      – PersonEntity:
          Name:
            NameFull: Jensen, Daniel
      – PersonEntity:
          Name:
            NameFull: Naidoo, Laven
      – PersonEntity:
          Name:
            NameFull: Riddin, Taryn
      – PersonEntity:
          Name:
            NameFull: Simard, Marc
      – PersonEntity:
          Name:
            NameFull: Smith, Kyle
      – PersonEntity:
          Name:
            NameFull: Thakali, Pati
      – PersonEntity:
          Name:
            NameFull: van Deventer, Heidi
      – PersonEntity:
          Name:
            NameFull: van Niekerk, Lara
      – PersonEntity:
          Name:
            NameFull: Stovall, Atticus
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 10
              Text: Oct2025
              Type: published
              Y: 2025
          Identifiers:
            – Type: issn-print
              Value: 21698953
          Numbering:
            – Type: volume
              Value: 130
            – Type: issue
              Value: 10
          Titles:
            – TitleFull: Journal of Geophysical Research. Biogeosciences
              Type: main
ResultId 1