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Randall Kosaki
Papahānaumokuākea Marine National Monument, Office of National Marine Sanctuaries, National Ocean Service, National Oceanic and Atmospheric Administration, Honolulu, HI 96818, USA

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Journal article
Published: 15 November 2020 in Diversity
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The architectural complexity of coral-reef habitat plays an important role in determining the assemblage structure of reef fish. We investigated associations between the reef habitats and fish assemblages in the Northwestern Hawaiian Islands (NWHI) using in situ fish counts and data on habitat metrics and benthic community composition that were obtained from three-dimensional (3D) photogrammetric reconstructions of the surveyed sites. The structure of fish assemblage as a whole on the basis of Bray–Curtis dissimilarity, species richness and the abundances of herbivores and piscivores were associated with habitat metrics, with higher levels of architectural complexity generally supporting greater numbers of fish species and individuals. Benthic cover did not explain additional variation in these variables after the effects of habitat metrics were taken into account. Corallivorous fish was the only group that showed positive associations with both habitat metrics and benthic cover (Acropora and Pocillopora corals). The total fish abundance and the abundances of planktivores and invertivores did not show associations with either habitat metrics or benthic cover. This study suggests that an appropriate combination of habitat metrics can be used to account sufficiently for the effects of habitat architecture on fish assemblages in reef monitoring efforts in the NWHI.

ACS Style

Atsuko Fukunaga; Randall K. Kosaki; Kailey H. Pascoe; John H. R. Burns. Fish Assemblage Structure in the Northwestern Hawaiian Islands Is Associated with the Architectural Complexity of Coral-Reef Habitats. Diversity 2020, 12, 430 .

AMA Style

Atsuko Fukunaga, Randall K. Kosaki, Kailey H. Pascoe, John H. R. Burns. Fish Assemblage Structure in the Northwestern Hawaiian Islands Is Associated with the Architectural Complexity of Coral-Reef Habitats. Diversity. 2020; 12 (11):430.

Chicago/Turabian Style

Atsuko Fukunaga; Randall K. Kosaki; Kailey H. Pascoe; John H. R. Burns. 2020. "Fish Assemblage Structure in the Northwestern Hawaiian Islands Is Associated with the Architectural Complexity of Coral-Reef Habitats." Diversity 12, no. 11: 430.

Research article
Published: 07 July 2020 in PLOS ONE
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Survey cruises by the National Oceanic and Atmospheric Administration (NOAA) in 2016 and 2019 yielded specimens of an undetermined red alga that rapidly attained alarming levels of benthic coverage at Pearl and Hermes Atoll, Papahānaumokuākea Marine National Monument, Hawaiʻi. By 2019 the seaweed had covered large expanses on the northeast side of the atoll with mat-like, extensive growth of entangled thalli. Specimens were analyzed using light microscopy and molecular analysis, and were compared to morphological descriptions in the literature for closely related taxa. Light microscopy demonstrated that the specimens likely belonged to the rhodomelacean genus Chondria, yet comparisons to taxonomic literature revealed no morphological match. DNA sequence analyses of the mitochondrial COI barcode marker, the plastidial rbcL gene, and the nuclear SSU gene confirmed its genus-level placement and demonstrated that this alga was unique compared to all other available sequences. Based on these data, this cryptogenic seaweed is here proposed as a new species: Chondria tumulosa A.R.Sherwood & J.M.Huisman sp. nov. Chondria tumulosa is distinct from all other species of Chondria based on its large, robust thalli, a mat-forming tendency, large axial diameter in mature branches (which decreases in diameter with subsequent orders of branching), terete axes, and bluntly rounded apices. Although C. tumulosa does not meet the criteria for the definition of an invasive species given that it has not been confirmed as introduced to Pearl and Hermes Atoll, this seaweed is not closely related to any known Hawaiian native species and is of particular concern given its sudden appearance and rapid increase in abundance in the Papahānaumokuākea Marine National Monument; an uninhabited, remote, and pristine island chain to the northwest of the Main Hawaiian Islands.

ACS Style

Alison R. Sherwood; John M. Huisman; Monica O. Paiano; Taylor M. Williams; Randall K. Kosaki; Celia M. Smith; Louise Giuseffi; Heather L. Spalding. Taxonomic determination of the cryptogenic red alga, Chondria tumulosa sp. nov., (Rhodomelaceae, Rhodophyta) from Papahānaumokuākea Marine National Monument, Hawai‘i, USA: A new species displaying invasive characteristics. PLOS ONE 2020, 15, e0234358 .

AMA Style

Alison R. Sherwood, John M. Huisman, Monica O. Paiano, Taylor M. Williams, Randall K. Kosaki, Celia M. Smith, Louise Giuseffi, Heather L. Spalding. Taxonomic determination of the cryptogenic red alga, Chondria tumulosa sp. nov., (Rhodomelaceae, Rhodophyta) from Papahānaumokuākea Marine National Monument, Hawai‘i, USA: A new species displaying invasive characteristics. PLOS ONE. 2020; 15 (7):e0234358.

Chicago/Turabian Style

Alison R. Sherwood; John M. Huisman; Monica O. Paiano; Taylor M. Williams; Randall K. Kosaki; Celia M. Smith; Louise Giuseffi; Heather L. Spalding. 2020. "Taxonomic determination of the cryptogenic red alga, Chondria tumulosa sp. nov., (Rhodomelaceae, Rhodophyta) from Papahānaumokuākea Marine National Monument, Hawai‘i, USA: A new species displaying invasive characteristics." PLOS ONE 15, no. 7: e0234358.

Letter
Published: 21 March 2020 in Remote Sensing
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Quantifying the three-dimensional (3D) habitat structure of coral reefs is an important aspect of coral reef monitoring, as habitat architecture affects the abundance and diversity of reef organisms. Here, we used photogrammetric techniques to generate 3D reconstructions of coral reefs and examined relationships between benthic cover and various habitat metrics obtained at six different resolutions of raster cells, ranging from 1 to 32 cm. For metrics of 3D structural complexity, fractal dimension, which utilizes information on 3D surface areas obtained at different resolutions, and vector ruggedness measure (VRM) obtained at 1-, 2- or 4-cm resolution correlated well with benthic cover, with a relatively large amount of variability in these metrics being explained by the proportions of corals and crustose coralline algae. Curvature measures were, on the other hand, correlated with branching and mounding coral cover when obtained at 1-cm resolution, but the amount of variability explained by benthic cover was generally very low when obtained at all other resolutions. These results show that either fractal dimension or VRM obtained at 1-, 2- or 4-cm resolution, along with curvature obtained at 1-cm resolution, can effectively capture the 3D habitat structure provided by specific benthic organisms.

ACS Style

Atsuko Fukunaga; John H. R. Burns; Kailey H. Pascoe; Randall K. Kosaki. Associations between Benthic Cover and Habitat Complexity Metrics Obtained from 3D Reconstruction of Coral Reefs at Different Resolutions. Remote Sensing 2020, 12, 1011 .

AMA Style

Atsuko Fukunaga, John H. R. Burns, Kailey H. Pascoe, Randall K. Kosaki. Associations between Benthic Cover and Habitat Complexity Metrics Obtained from 3D Reconstruction of Coral Reefs at Different Resolutions. Remote Sensing. 2020; 12 (6):1011.

Chicago/Turabian Style

Atsuko Fukunaga; John H. R. Burns; Kailey H. Pascoe; Randall K. Kosaki. 2020. "Associations between Benthic Cover and Habitat Complexity Metrics Obtained from 3D Reconstruction of Coral Reefs at Different Resolutions." Remote Sensing 12, no. 6: 1011.

Research article
Published: 18 December 2019 in PLOS ONE
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This study examined the effects of SCUBA bubbles on fish counts in underwater visual surveys conducted in the Papahānaumokuākea Marine National Monument (PMNM). Specifically, paired fish surveys were conducted at each survey site, utilizing two different gear types: open-circuit SCUBA (OC) and closed-circuit rebreather (CCR). Bubble exhaust released from the OC equipment is a potential source of bias for in-situ fish observations, as the associated audio and visual disturbances could either attract or repel fishes depending on whether their behavior is more driven by curiosity or caution. The study area, is a large (~1.5 million km2) and extremely remote marine protected area in which the response of coral reef fishes to divers represent natural behavior of naive fishes with little or no previous contact with humans. Historically, surveys conducted on OC in this area have shown an abundance of large roving piscivores and this study set out to determine the extant, if any, the audible and visual disturbances of OC bubbles have. The species typically seen in these prior surveys were Caranx ignobilis, Caranx melampygus, Aprion virescens, and a couple of species of sharks. We found differences in counts for some roving piscivores, including significantly more jacks observed on OC than CCR (Caranx ignobilis 57% more, and Caranx melampygus 113% more). Instance of first encounter, i.e. the time when a fish was first observed during a survey, also varied for some species. Higher numbers of Aprion virescens (p = 0.04), and C. melampygus (p = <0.001) were observed in the first 5-minutes of counts by divers on OC (i.e. when they were using breathing apparatus that produced noises that could be heard over long distances). Although not the focus of the study, we also assessed differences between OC and CCR counts for other groups of fishes. Estimated abundance of benthic damselfish was higher on OC than CCR, and counts of butterflyfish were lower on OC; but there were no significant differences for the other groups considered. This is an important control study that documents the natural responses of coral reef fishes to SCUBA bubbles generated by in-situ surveys.

ACS Style

Keolohilani H. Lopes Jr; Ivor D. Williams; Randall K. Kosaki; Andrew E. Gray; Jason C. Leonard. Effects of SCUBA bubbles on counts of roving piscivores in a large remote marine protected area. PLOS ONE 2019, 14, e0226370 .

AMA Style

Keolohilani H. Lopes Jr, Ivor D. Williams, Randall K. Kosaki, Andrew E. Gray, Jason C. Leonard. Effects of SCUBA bubbles on counts of roving piscivores in a large remote marine protected area. PLOS ONE. 2019; 14 (12):e0226370.

Chicago/Turabian Style

Keolohilani H. Lopes Jr; Ivor D. Williams; Randall K. Kosaki; Andrew E. Gray; Jason C. Leonard. 2019. "Effects of SCUBA bubbles on counts of roving piscivores in a large remote marine protected area." PLOS ONE 14, no. 12: e0226370.

Journal article
Published: 28 January 2019 in Journal of Marine Science and Engineering
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Long-term ecological monitoring of reef fish populations often requires the simultaneous collection of data on benthic habitats in order to account for the effects of these variables on fish assemblage structure. Here, we described an approach to benthic surveys that uses photogrammetric techniques to facilitate the extraction of quantitative metrics for characterization of benthic habitats from the resulting three-dimensional (3D) reconstruction of coral reefs. Out of 92 sites surveyed in the Northwestern Hawaiian Islands, photographs from 85 sites achieved complete alignment and successfully produced 3D reconstructions and digital elevation models (DEMs). Habitat metrics extracted from the DEMs were generally correlated with one another, with the exception of curvature measures, indicating that complexity and curvature measures should be treated separately when quantifying the habitat structure. Fractal dimension D64, calculated by changing resolutions of the DEMs from 1 cm to 64 cm, had the best correlations with other habitat metrics. Fractal dimension was also less affected by changes in orientations of the models compared to surface complexity or slope. These results showed that fractal dimension can be used as a single measure of complexity for the characterization of coral reef habitats. Further investigations into metrics for 3D characterization of habitats should consider relevant spatial scales and focus on obtaining variables that can complement fractal dimension in the characterization of reef habitats.

ACS Style

Atsuko Fukunaga; John H. R. Burns; Brianna K. Craig; Randall K. Kosaki. Integrating Three-Dimensional Benthic Habitat Characterization Techniques into Ecological Monitoring of Coral Reefs. Journal of Marine Science and Engineering 2019, 7, 27 .

AMA Style

Atsuko Fukunaga, John H. R. Burns, Brianna K. Craig, Randall K. Kosaki. Integrating Three-Dimensional Benthic Habitat Characterization Techniques into Ecological Monitoring of Coral Reefs. Journal of Marine Science and Engineering. 2019; 7 (2):27.

Chicago/Turabian Style

Atsuko Fukunaga; John H. R. Burns; Brianna K. Craig; Randall K. Kosaki. 2019. "Integrating Three-Dimensional Benthic Habitat Characterization Techniques into Ecological Monitoring of Coral Reefs." Journal of Marine Science and Engineering 7, no. 2: 27.

Correction
Published: 11 June 2018 in Marine Biodiversity Records
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ACS Style

Randall K. Kosaki; Julia M. Hartl. Correction to: First record of the Phoenix Islands damselfish Plectroglyphidodon phoenixensis (Schultz, 1943) from the Northwestern Hawaiian Islands. Marine Biodiversity Records 2018, 11, 10 .

AMA Style

Randall K. Kosaki, Julia M. Hartl. Correction to: First record of the Phoenix Islands damselfish Plectroglyphidodon phoenixensis (Schultz, 1943) from the Northwestern Hawaiian Islands. Marine Biodiversity Records. 2018; 11 (1):10.

Chicago/Turabian Style

Randall K. Kosaki; Julia M. Hartl. 2018. "Correction to: First record of the Phoenix Islands damselfish Plectroglyphidodon phoenixensis (Schultz, 1943) from the Northwestern Hawaiian Islands." Marine Biodiversity Records 11, no. 1: 10.

Marine record
Published: 17 April 2018 in Marine Biodiversity Records
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ACS Style

Randall K. Kosaki; Julia M. Hartl. First record of the Phoenix Islands damselfish Plectroglyphidodon phoenixensis (Schultz, 1943) from the Northwestern Hawaiian Islands. Marine Biodiversity Records 2018, 11, 7 .

AMA Style

Randall K. Kosaki, Julia M. Hartl. First record of the Phoenix Islands damselfish Plectroglyphidodon phoenixensis (Schultz, 1943) from the Northwestern Hawaiian Islands. Marine Biodiversity Records. 2018; 11 (1):7.

Chicago/Turabian Style

Randall K. Kosaki; Julia M. Hartl. 2018. "First record of the Phoenix Islands damselfish Plectroglyphidodon phoenixensis (Schultz, 1943) from the Northwestern Hawaiian Islands." Marine Biodiversity Records 11, no. 1: 7.

Oceanarium
Published: 26 May 2016 in Marine Biodiversity
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ACS Style

Randall K. Kosaki; Richard L. Pyle; Jason C. Leonard; Brian B. Hauk; Robert K. Whitton; Daniel Wagner. 100% endemism in mesophotic reef fish assemblages at Kure Atoll, Hawaiian Islands. Marine Biodiversity 2016, 47, 783 -784.

AMA Style

Randall K. Kosaki, Richard L. Pyle, Jason C. Leonard, Brian B. Hauk, Robert K. Whitton, Daniel Wagner. 100% endemism in mesophotic reef fish assemblages at Kure Atoll, Hawaiian Islands. Marine Biodiversity. 2016; 47 (3):783-784.

Chicago/Turabian Style

Randall K. Kosaki; Richard L. Pyle; Jason C. Leonard; Brian B. Hauk; Robert K. Whitton; Daniel Wagner. 2016. "100% endemism in mesophotic reef fish assemblages at Kure Atoll, Hawaiian Islands." Marine Biodiversity 47, no. 3: 783-784.

Journal article
Published: 01 April 2014 in Bulletin of Marine Science
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ACS Style

Corinne Kane; Randall K Kosaki; Daniel Wagner. High levels of mesophotic reef fish endemism in the Northwestern Hawaiian Islands. Bulletin of Marine Science 2014, 90, 693 -703.

AMA Style

Corinne Kane, Randall K Kosaki, Daniel Wagner. High levels of mesophotic reef fish endemism in the Northwestern Hawaiian Islands. Bulletin of Marine Science. 2014; 90 (2):693-703.

Chicago/Turabian Style

Corinne Kane; Randall K Kosaki; Daniel Wagner. 2014. "High levels of mesophotic reef fish endemism in the Northwestern Hawaiian Islands." Bulletin of Marine Science 90, no. 2: 693-703.

Journal article
Published: 01 July 2013 in Bulletin of Marine Science
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ACS Style

Randall K Kosaki; Daniel Wagner; Jason C Leonard; Brian B Hauk; Kelly A Gleason. First Report of the Table Coral Acropora Cytherea (Scleractinia: Acroporidae) from Oahu (Main Hawaiian Islands). Bulletin of Marine Science 2013, 89, 745 -746.

AMA Style

Randall K Kosaki, Daniel Wagner, Jason C Leonard, Brian B Hauk, Kelly A Gleason. First Report of the Table Coral Acropora Cytherea (Scleractinia: Acroporidae) from Oahu (Main Hawaiian Islands). Bulletin of Marine Science. 2013; 89 (3):745-746.

Chicago/Turabian Style

Randall K Kosaki; Daniel Wagner; Jason C Leonard; Brian B Hauk; Kelly A Gleason. 2013. "First Report of the Table Coral Acropora Cytherea (Scleractinia: Acroporidae) from Oahu (Main Hawaiian Islands)." Bulletin of Marine Science 89, no. 3: 745-746.

Journal article
Published: 01 April 2011 in Pacific Science
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ACS Style

Daniel Wagner; Yannis P. Papastamatiou; Randall K. Kosaki; Kelly A. Gleason; Greg B. McFall; Raymond C. Boland; Richard L. Pyle; Robert J. Toonen. New Records of Commercially Valuable Black Corals (Cnidaria: Antipatharia) from the Northwestern Hawaiian Islands at Mesophotic Depths 1. Pacific Science 2011, 65, 249 -255.

AMA Style

Daniel Wagner, Yannis P. Papastamatiou, Randall K. Kosaki, Kelly A. Gleason, Greg B. McFall, Raymond C. Boland, Richard L. Pyle, Robert J. Toonen. New Records of Commercially Valuable Black Corals (Cnidaria: Antipatharia) from the Northwestern Hawaiian Islands at Mesophotic Depths 1. Pacific Science. 2011; 65 (2):249-255.

Chicago/Turabian Style

Daniel Wagner; Yannis P. Papastamatiou; Randall K. Kosaki; Kelly A. Gleason; Greg B. McFall; Raymond C. Boland; Richard L. Pyle; Robert J. Toonen. 2011. "New Records of Commercially Valuable Black Corals (Cnidaria: Antipatharia) from the Northwestern Hawaiian Islands at Mesophotic Depths 1." Pacific Science 65, no. 2: 249-255.