Publications
Expedition Report: EX2501, Papahānaumokuākea Mapping 3
A groundbreaking mapping expedition, EX2501, conducted by NOAA Ocean Exploration from October 19 to November 12, 2024, significantly advanced the understanding of the Papahānaumokuākea Marine National Monument. The expedition mapped an extensive area of 44,264 square kilometers of seafloor within the U.S. Exclusive Economic Zone, all at depths greater than 200 meters. This comprehensive mapping effort provides critical data for scientific research and conservation efforts in one of the most remote and ecologically significant marine regions on Earth. The expedition utilized advanced oceanographic technologies to capture detailed seafloor topography, contributing valuable insights into the geological and biological characteristics of this unique World Heritage Site.
Expedition Report: Papahānaumokuākea ROV and Mapping (EX2503)
A groundbreaking expedition in Papahānaumokuākea National Marine Monument mapped 48,219 sq. km of seafloor and conducted 16 ROV dives, significantly expanding our understanding of this UNESCO World Heritage Site. The NOAA-led mission (April 8–May 5, 2025) utilized advanced mapping and remotely operated vehicles to explore previously uncharted deep-sea terrain within the U.S. Exclusive Economic Zone. This unprecedented survey provides critical baseline data for marine conservation efforts, revealing complex seafloor topography and supporting biodiversity research in one of Earth's most remote and ecologically significant regions.
Observations of Oceanic Whitetip Sharks, Carcharhinus longimanus, a globally threatened species, in the Papahānaumokuākea Marine National Monument (central Pacific)
A rare glimpse into the distribution of oceanic whitetip sharks (Carcharhinus longimanus), a globally threatened species, was captured within the Papahānaumokuākea Marine National Monument (PMNM) in the central Pacific. Observations from 2015 to 2026 revealed that these sharks are non-randomly distributed, predominantly found at or shallower than 50 meters in the monument's northwest region. The study utilized remotely operated vehicle dives and forward-looking camera footage to document brief but significant encounters with single sharks, often accompanied by small forage fishes and other piscivores. These findings lay groundwork for understanding shark behavior and distribution patterns in one of the largest U.S. marine protected areas, offering critical insights for future conservation efforts.
A new mesophotic species Platoma piiahiluum sp. nov . (Schizymeniaceae) from the Papahānaumokuākea Marine National Monument, Hawaiʻi, USA
Researchers have discovered a new species of red algae, Platoma piiahiluum, endemic to the mesophotic coral ecosystems of Papahānaumokuākea Marine National Monument. This species, distinguished by its transparent, non-branching thalli and unique mitochondrial genome structure—featuring a stem-loop and inversion—was identified through phylogenetic, genomic, and morphological analyses. The study, utilizing plastid (rbcL) and mitochondrial (COI) markers, along with full-genome sequencing, confirms P. piiahiluum as the second known species of Platoma in Hawaiʻi, with the first, P. ardreanum, inhabiting shallow waters. This finding underscores the high endemic diversity in Hawaiian mesophotic zones and highlights the ecological significance of uninhabited islands within Papahānaumokuākea.
A predictive framework for identifying source populations of non-native marine macroalgae: Chondria tumulosa in the Pacific Ocean
A newly described marine red alga, Chondria tumulosa, has been identified as a non-native species in the Papahānaumokuākea Marine National Monument (PMNM), Hawai‘i. First observed in 2016, this cryptogenic alga has since spread across three atolls and poses significant ecological and cultural threats to the region's reefs. The study employs a predictive framework combining oceanographic modeling and environmental DNA (eDNA) assays to trace its potential origin, focusing on regions like Japan, Johnston Atoll, Palmyra Atoll, Clipperton Atoll, and the Galápagos Islands. Despite extensive sampling efforts—including eDNA screening and herbaria specimen analysis—no positive detections were found outside PMNM. The research underscores the need to clarify C. tumulosa's native range to understand its invasion dynamics and develop mitigation strategies for PMNM.
Assessment of the spatial distribution of Chondria tumulosa, a nuisance macroalga at Manawai in Papahānaumokuākea Marine National Monument using high‐resolution satellite imagery
A red macroalgal species, Chondria tumulosa, has been identified as a nuisance in Papahānaumokuākea Marine National Monument (PMNM), particularly at Manawai (Pearl and Hermes Atoll), where it overgrows native coral and algal communities. This study employed high-resolution satellite imagery from WorldView-2 and -3 to map its spatial distribution across the forereef and backreef over a 12-year period (2010–2021). By analyzing dark patches in time-series animations—first observed in 2015—and validating them against field survey data, researchers achieved an average accuracy of 78% in classifying C. tumulosa using machine learning. The findings highlight the potential of remote sensing for monitoring invasive species in remote marine environments, offering a tool for long-term management and conservation efforts.
Description of a novel Ligia species from Nihoa, a remote island in the Papahānaumokuākea Marine National Monument
A novel species of Ligia, named Ligia barack sp. nov., has been discovered on Nihoa, a remote island within the Papahānaumokuākea Marine National Monument (PMNM). This finding significantly expands the known biodiversity of the PMNM and underscores the region's unique ecological significance. The discovery was made using molecular taxonomic approaches, which revealed that Ligia from Nihoa form a highly divergent and reciprocally monophyletic lineage distinct from other Hawaiian Ligia species. This study highlights the importance of continued exploration and conservation efforts in remote and biodiverse regions like the PMNM, where additional cryptic species may yet remain undiscovered.
First report of Acanthophora spicifera (Rhodophyta, Ceramiales) from the Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands)
Acanthophora spicifera, a highly invasive red alga known for its dominance in intertidal and subtidal habitats across the Main Hawaiian Islands, has been documented for the first time within the Papahānaumokuākea Marine National Monument. This discovery at Kuaihelani (Midway Atoll) marks a significant expansion of the species' recorded range, despite extensive surveys since 1989 in the Northwestern Hawaiian Islands. The report details this rare observation, highlighting its ecological implications for one of the world's most remote and ecologically significant marine regions.
Navigating uncertainty in environmental DNA detection of a nuisance marine macroalga
A novel environmental DNA (eDNA) assay demonstrates high sensitivity and reliability for detecting the nuisance marine macroalga Chondria tumulosa at low abundances, with detection probabilities of at least 92% at occupied sites in Papahānaumokuākea Marine National Monument. The study validated the assay using site-occupancy modeling from quantitative PCR (qPCR) data and high-throughput sequencing, achieving false-positive rates of 3% or less and false-negative errors of 11% or less. This cost-effective tool enhances early detection capabilities for invasive species, supporting timely conservation interventions in shallow marine environments (< 10 m). The research addresses uncertainties in eDNA analyses, providing a robust framework for balancing molecular and visual detection methods in ecological monitoring.
No pump, no problem: evaluating passive eDNA sampling for marine biomonitoring of a nuisance macroalga
Passive environmental DNA (eDNA) sampling proves equally effective as active filtration for detecting the nuisance macroalga Chondria tumulosa in remote marine environments, offering a cost-effective and scalable alternative. The study found that 15-minute deployments of passive eDNA samplers (PEDS), when paired with increased qPCR replicates, matched the detection sensitivity of traditional active filtration methods, successfully identifying C. tumulosa at low abundances (<1%) in all known cases within the Papahānaumokuākea Marine National Monument. While PEDS showed higher probabilities of false-positives and false-negatives compared to active sampling, they performed comparably across stationary buoys and roving SCUBA divers, with absorbent cotton rounds outperforming research-grade filters in DNA yield reliability. The findings highlight the potential of passive eDNA sampling for biomonitoring cryptic taxa in resource-limited settings, though further optimization is needed to minimize erroneous detections.
Papahānaumokuākea National Marine Sanctuary Final Environmental Impact Statement: Volume I
Papahānaumokuākea, recognized as a UNESCO World Heritage Site and a critical marine ecosystem, is set to be designated as a National Marine Sanctuary by the NOAA. This decision aims to protect its significant biological, cultural, and historical resources while integrating it into the National Marine Sanctuary System. The Final Environmental Impact Statement (EIS) outlines potential management strategies for the sanctuary, addressing environmental considerations under the Hawaiʻi Environmental Policy Act (HEPA), National Environmental Policy Act (NEPA), and the National Marine Sanctuaries Act (NMSA). Accompanied by a sanctuary management plan, this EIS evaluates various alternatives to ensure sustainable conservation of the region's unique marine environment.
Papahānaumokuākea National Marine Sanctuary Final Environmental Impact Statement: Volume II
Papahānaumokuākea, a UNESCO World Heritage Site and one of the largest marine protected areas in the world, is set to be designated as a National Marine Sanctuary by NOAA. This decision aims to recognize its significant biological, cultural, and historical value while ensuring continued protection under the National Marine Sanctuary System. The final environmental impact statement (EIS) evaluates multiple management alternatives for the sanctuary, including the expansion of the Papahānaumokuākea Marine National Monument. Prepared in collaboration with the State of Hawaiʻi and adhering to federal and state environmental laws, this EIS provides a comprehensive framework for safeguarding the region's unique ecosystems. Accompanied by a detailed management plan, it outlines goals, strategies, and actions to preserve this ecologically critical area for future generations.
Simple Passive Environmental DNA Samplers for Marine Biomonitoring in Resource‐Limited Programs
Passive environmental DNA samplers (PEDS) offer a cost-effective, scalable solution for marine biomonitoring, enabling rapid biodiversity assessment without specialized equipment. Unlike traditional eDNA methods requiring pumps or filtration systems, PEDS capture ambient DNA using cotton membranes during short field exposures (~15 minutes), simplifying deployment and retrieval. Validated at Papahānaumokuākea Marine National Monument, this approach successfully detected Chondria tumulosa, a cryptogenic nuisance alga, supporting conservation efforts. The protocol minimizes contamination risks and optimizes DNA recovery, making it ideal for resource-limited programs. Its adaptability—suitable for both stationary buoys and roving surveys—expands its utility across aquatic ecosystems.
Elucidating Temporal Patterns in Coral Health and Assemblage Structure in Papahānaumokuākea
A significant shift in coral colony composition was detected in Papahānaumokuākea, the largest contiguous fully protected marine conservation area in the United States, following a mass coral bleaching event in 2014 and Hurricane Walaka in 2018. The study, which analyzed long-term monitoring data from 20 permanent sites at three islands/atolls (Lalo, Kapou, and Manawai) between 2014 and 2021, found that coral assemblages transitioned from the Montipora dilatata/flabellata/turgescens complex to M. capitata dominance in multiple sites, particularly at Kapou and one site at Manawai. Despite being dominant before the bleaching event, the M. dilatata/flabellata/turgescens complex has not been recorded in recent years. The research also revealed that coral genera exhibited different sensitivities to conditions such as bleaching, predation, subacute tissue loss, Porites pigmentation response, and trematodiasis. These findings underscore the importance of continued species-level monitoring across diverse coral assemblage compositions and habitat types in Papahānaumokuākea.
Modeling the dispersal of the cryptogenic alga Chondria tumulosa (Rhodophyta, Ceramiales) in the Papahānaumokuākea Marine National Monument
A study modeling the dispersal of the invasive alga Chondria tumulosa in Papahānaumokuākea reveals that its spread is likely driven by fragments rafting on marine debris rather than tetraspores. Analysis using oceanographic data and connectivity modeling showed that while tetraspores had a negligible settlement rate (0.02%) at Kuaihelani, drifting fragments settled 195 times more effectively (3.85%), extending their potential range ~600 km further southeast toward the Main Hawaiian Islands. The findings highlight the role of marine flotsam in accelerating invasion dynamics and suggest targeted management strategies to mitigate its impact on benthic habitats.
Blue-Washing the Colonization and Militarization of "Our Ocean"
A critical analysis reveals that the expansion of marine national monuments, such as Papahānaumokuākea, under the Antiquities Act of 1906, serves to further colonize, militarize, and privatize Pacific waters without public or Indigenous consultation. Unlike official sanctuaries, which require extensive community engagement, these monuments are unilaterally designated by presidents, restricting public access and violating Indigenous rights by separating communities from sacred spaces. Additionally, the designation process facilitates future military use of these areas, reflecting a 'logic of military conservation' that prioritizes federal control over public or Indigenous trust.
Distribution and structure of deep-sea demersal fish assemblages across the central and western Pacific Ocean using data from undersea imagery
Deep-sea demersal fish assemblages in the central and western Pacific Ocean exhibit significant regional and depth-related variations, with diversity decreasing as depth increases. The study, leveraging data from 227 underwater vehicle dives, identified 89 families and 175 genera of fishes across four Marine National Monuments, revealing that these regions are not replicates but complementary components of the regional fauna. Depth and region were the primary drivers of assemblage structure, followed by environmental factors such as seafloor particulate organic carbon flux, dissolved oxygen concentrations, and salinity. The Line Islands and Tokelau Ridge showed the highest fish abundance at shallower depths (250-1000 m) due to higher food supply proxies. Taxon accumulation curves suggested that genus-level diversity had not been fully captured in most regions except at the deepest zones. This research highlights the importance of considering both regional and depth-related factors when assessing deep-sea fish biodiversity, with implications for conservation efforts in these remote marine areas.
Mai Ka Pō Mai: applying Indigenous cosmology and worldview to empower and transform a management plan for Papahānaumokuākea Marine National Monument
A groundbreaking management plan for Papahānaumokuākea Marine National Monument integrates Indigenous Hawaiian cosmology and worldview, demonstrating how such approaches can empower Native Hawaiians and transform conservation practices. The study highlights that collaborative processes, long-term capacity-building, and an enabling policy environment fostered the creation of a guidance document rooted in place-based knowledge and human-nature reciprocity. This work underscores the potential for Indigenous-led management to enhance adaptive governance and co-management arrangements, offering a model for other protected areas considered sacred by Indigenous peoples.
Rapid expansion of the invasive‐like red macroalga, Chondria tumulosa (Rhodophyta), on the coral reefs of the Papahānaumokuākea Marine National Monument
A rapid and exponential expansion of the invasive-like red macroalga, Chondria tumulosa, has been observed on the coral reefs of Manawai Atoll within Papahānaumokuākea Marine National Monument. Initially detected in 2016 forming dense mats on the forereef, this alga exhibited a dramatic increase in abundance over five years. By 2021, unattached C. tumulosa formed extensive dark accumulations spanning 41.32 km in length and covering 101.34 km² in area, marking a 56-fold and 115-fold increase from its first detection, respectively. High-resolution satellite imagery revealed an exponential expansion rate of approximately 16.02 km per year in length and 44.75 km² per year in area. This study provides a comprehensive temporal and spatial analysis of the alga's spread since its discovery, offering critical data for ecologists and resource managers to monitor its invasive-like behavior.
The occurrence of humpback whales across the Hawaiian archipelago revealed by fixed and mobile acoustic monitoring
Nearly the entire Hawaiian archipelago, including remote atolls and seamounts within Papahānaumokuākea Marine National Monument (PMNM), is utilized by humpback whales during winter and early spring breeding seasons. This discovery challenges previous assumptions about whale distribution in the region. Researchers employed a combination of moored acoustic recorders and an autonomous Wave Glider to monitor whale song across 1500 km, revealing varying levels of song prevalence. Highest chorusing was detected off Maui and French Frigate Shoals, with notable patterns suggesting potential subpopulation structures or habitat preferences in PMNM. The study highlights the effectiveness of acoustic monitoring in remote, challenging environments to elucidate whale behavior and distribution.
The reproductive system of the cryptogenic alga Chondria tumulosa (Florideophyceae) at Manawai, Papahānaumokuākea Marine National Monument
Research on the cryptogenic red alga Chondria tumulosa at Manawai, Papahānaumokuākea Marine National Monument reveals a predominantly asexual reproductive system, with 20% of thalli bearing tetrasporophytic structures and no evidence of gametophytes. Genetic analysis using five microsatellite loci identified repeated genotypes in 41 thalli, indicating high rates of fragmentation and clonal reproduction. This suggests that C. tumulosa, which forms thick mats and reduces coral reef biodiversity, may spread rapidly to nearby atolls through asexual means. The study highlights the importance of understanding reproductive systems for managing invasive macroalgae, aligning with observed patterns in other red algal invasions.
A new species of Gibsmithia (Dumontiaceae, Rhodophyta) from mesophotic depths of the Papahānaumokuākea Marine National Monument, Hawai‘i, USA
Researchers have identified a new species of red algae, Gibsmithia punonomaewa, from the mesophotic depths (79–104 m) of the Papahānaumokuākea Marine National Monument in Hawaiʻi. This discovery increases the number of Gibsmithia species recorded from Hawaiʻi to three and highlights the unique characteristics of this species, including moderate thallus size, smooth and terete gelatinous lobes, presence of a stipe (often branched), globose carposporangia, and non-isodiametric shaped cells subtending tetrasporangia. Phylogenetic analyses revealed that G. punonomaewa is most closely related to species found in tropical and subtropical surface waters, contrasting with its dark mesophotic habitat. The study used molecular phylogenetic techniques to clarify the diversity of Dumontiaceae, including a tentative record of Dudresnaya babbittiana, pending type material sequencing.
A remote coral reef shows macroalgal succession following a mass bleaching event
A remote coral reef at Kapou (Lisianski) Island in Papahānaumokuākea experienced unprecedented heat stress in 2014, leading to nearly total loss of live coral cover. Following the bleaching event, macroalgae such as Halimeda and Boodlea rapidly colonized the newly available substrata. While Halimeda remained dominant, other algae began to establish themselves between 2017 and 2021, increasing benthic diversity. Erosion of reef substrata continued post-bleaching, with signs of coral recovery observed through new Montipora colonies. The study used underwater photogrammetric techniques to track these changes from 2014 to 2021, highlighting the complex successional dynamics following mass coral mortality.
Characterization and spatial variation of the deep-sea fish assemblages on Pioneer Bank, Northwestern Hawaiian Islands
Deep-sea fish assemblages on Pioneer Bank, a seamount within the UNESCO-listed Papahānaumokuākea Marine National Monument, exhibit significant spatial variability both across its sides and with depth. A study using autonomous underwater vehicle transects identified 81 species, dominated by Gadiformes, Perciformes, and Stomiiformes, with the highest relative abundance observed on the NW side at 450 meters. Species richness, diversity, and assemblage structure varied significantly between the S and NW sides, with depth being a more influential factor than horizontal distance. This spatial heterogeneity mirrors findings from nearby Necker Island, underscoring the complexity of seamount ecosystems. The study provides critical baseline data for managing and conserving deep-sea environments, highlighting the importance of salinity, rugosity, chlorophyll-a, and substrate characteristics in shaping fish assemblage structure.
HĀNAU KA PALIHOA, LELE! The story, genealogy, and process of the Papahānaumokuākea Marine National Monument Native Hawaiian Cultural Working Group Nomenclature Subcommittee
A groundbreaking initiative by the Papahānaumokuākea Native Hawaiian Cultural Working Group Nomenclature Subcommittee has established a systematic process for naming newly discovered marine species, drawing deeply from traditional Hawaiian knowledge and genealogy. This approach, rooted in the cosmogonic chant Kumulipo, recognizes the intrinsic cultural significance of names in preserving and guiding the relationship between Kānaka ‘Ōiwi (Native Hawaiians) and their environment. The subcommittee's work ensures that newly identified species—such as algae (limu), coral (ko‘a), fish, birds, and plants—are not only scientifically documented but also culturally anchored, reinforcing their importance in Hawaiian heritage and conservation efforts. This dual process of discovery and naming bridges traditional practices with modern scientific exploration, offering a model for integrating Indigenous knowledge into biodiversity research.
Nā Hulu Aloha — A Precious Remembering: Origin Stories of the Papahānaumokuākea Marine National Monument Native Hawaiian Cultural Working Group Kiamanu Subcommittee
A transformative approach to seabird conservation in Papahānaumokuākea challenges the dominant narrative of overharvesting by integrating Native Hawaiian cultural practices and resilience. The Kiamanu Subcommittee of the Native Hawaiian Cultural Working Group advocates for salvage-appropriate seabird gathering, blending traditional stewardship with modern conservation needs. This study highlights how Indigenous knowledge can address climate-induced biodiversity loss, militarization pressures, and cultural erosion in the Pacific region. By centering community-driven solutions, it offers a model for sustainable coexistence with ecological and spiritual challenges.
Spillover benefits from the world’s largest fully protected MPA
Research demonstrates that the world's largest fully protected marine protected area (MPA), Papahānaumokuākea Marine National Monument, provides measurable spillover benefits for migratory tuna species. Specifically, catch rates for yellowfin and bigeye tuna increased significantly near the MPA following its expansion in 2016, compared to areas farther from it. This finding challenges skepticism about MPAs' ability to support fishery spillover benefits, often attributed to their small size relative to migratory species' ranges. The study analyzed independent fishery observer data for individual vessels, comparing catch rates before and after the MPA's expansion. These results underscore the potential for large-scale, fully protected areas to enhance fisheries sustainability by supporting migratory fish populations.
Underwater Photogrammetry Captures the Initial Recovery of a Coral Reef at Lalo Atoll
Initial signs of coral reef recovery at Lalo Atoll, part of Papahānaumokuākea Marine National Monument, have been captured using underwater photogrammetry. Following complete destruction by Hurricane Walaka in 2018, the site showed colonization by corals (Pocillopora meandrina and Porites lobata), macroalgae, and sponges, alongside a decrease in sand coverage. Despite low biotic benthic cover, visual fish surveys identified 35 reef fish species, marking significant progress from none recorded in 2019. The study highlights the potential role of rubble bed cryptofauna in supporting reef recovery and emphasizes the need for continuous monitoring to determine whether the reef will revert to its original Acropora dominance or transition to a different coral assemblage.
Catch rate composition affects assessment of protected area impacts
A reanalysis of catch rate data reveals that the composition of catches significantly influences assessments of protected area impacts on Hawaii’s deep-set longline fishery. While previous studies, including those by Lynham et al. and Chan, yielded conflicting findings—one showing no negative impact from the expansion of the Papahānaumokuākea Marine National Monument (PMNM) and the other reporting a 7% decrease in catch rates and 9% drop in revenues for vessels with a history of fishing in PMNM—Sweeney’s analysis identifies catch rate composition as the critical factor. The study suggests that aggregate commercial catch rate is a more robust measure of catch per unit effort (CPUE) than previously used methods, recommending a reanalysis of Lynham et al.’s model to account for this insight.
Complete chloroplast genome of Chondria tumulosa (Ceramiales, Rhodophyta), a recently described cryptogenic species with invasive traits from Papahānaumokuākea Marine National Monument, Hawaiʻi
Researchers have sequenced and analyzed the complete chloroplast genome of Chondria tumulosa, a red alga from Manawai (Pearl and Hermes Atoll) within Papahānaumokuākea Marine National Monument. The genome spans 172,617 base pairs and encodes 231 genes, including protein-coding, transfer RNA, ribosomal RNA, and non-coding RNA genes, mirroring the structure of other Rhodomelaceae family members. Phylogenomic analysis revealed that C. tumulosa is a distinct species within the Chondrieae tribe, representing an early diverging lineage relative to other known Chondria species. This discovery sheds light on the genetic diversity and evolutionary relationships of red algae in this region, with potential implications for understanding invasive traits.
Diversity of Kallymeniaceae (Gigartinales, Rhodophyta) associated with Hawaiian mesophotic reefs
Researchers have identified two new species of small red algae, Psaromenia laulamaula and Meredithia hawaiiensis, within the family Kallymeniaceae, previously undocumented in Hawaiian waters. These discoveries were made through surveys of the Papahānaumokuākea Marine National Monument (PMNM) and Main Hawaiian Islands (MHI), combining morphological and molecular analyses. Psaromenia laulamaula is distinguished by its large, solitary blades found exclusively at mesophotic depths (83–94 m), while Meredithia hawaiiensis exhibits high morphological plasticity, occurring in both shallow (0–17 m) and mesophotic zones (55 m). The study highlights the underappreciated biodiversity of Kallymeniaceae in Hawaiian reefs, particularly at deeper, less-explored depths. This research underscores the importance of integrating molecular techniques to unravel cryptic diversity in marine macroalgal floras.
Non-commercial Fishing in Policy, Practice, and Culture: Insights from the Papahānaumokuākea Marine National Monument
A critical analysis of non-commercial fishing practices and policies in the Northwestern Hawaiian Islands offers valuable insights for managing the newly expanded Papahānaumokuākea Marine National Monument (PMNM). The study identifies key cultural, practical, and regulatory aspects of non-commercial fishing that could inform the development of future management plans for the PMNM's Monument Expansion Area (MEA), which prohibits commercial fishing but allows for potential non-commercial activities. By synthesizing existing documents, the research provides a foundation for crafting regulations that balance conservation goals with traditional and recreational fishing practices. This work is essential as the U.S. government prepares to draft regulations in coordination with the Western Pacific Regional Fishery Management Council and NOAA.
World-making through mapping
Global maps of large-scale marine protected areas (LSMPAs) reveal a shift from undifferentiated ocean spaces to visually distinct conservation zones, challenging traditional perceptions of ocean governance. The expansion of LSMPAs, exemplified by the Papahānaumokuākea Marine National Monument, disrupts uniform representations of oceans, symbolizing progress in conservation while also reflecting complex geopolitical dynamics such as sovereignty assertions or neocolonial influences. This study interrogates how mapping practices perform world-making, reshaping ocean resources and governance paradigms.
Beyond the boundaries: How regulation-centered marine protected area information improves ocean protection assessments
A comprehensive analysis reveals that 85% of U.S. waters are subject to managed areas restricting living resource extraction, with only 3% designated as highly protected no-take zones. Notably, Papahānaumokuākea and the Pacific Remote Islands Marine National Monuments host significant portions of these highly protected areas, primarily in low-populated regions. The study, leveraging the ProtectedSeas database, demonstrates that incorporating regulatory information enhances ocean protection assessments, particularly by illustrating how overlapping management and gear restrictions can amplify overall protection levels. For instance, California's state waters show that 40% are under some form of marine protected area (MPA) management, with 13.4% benefiting from high-level fishing impact protection. The research underscores the importance of granular regulatory data in informing both current and future conservation strategies, offering ocean users clearer pathways to compliance.
Biodiversity of Hawaiian Peyssonneliales (Rhodophyta): Sonderophycus copusii sp. nov., a new species from the Northwestern Hawaiian Islands
A new species of red algae, Sonderophycus copusii, has been discovered in the Northwestern Hawaiian Islands, specifically at Kure Atoll. This finding represents the first record of the genus Sonderophycus in Hawaii and highlights its distinct morphological traits, such as secondary perithallial growth and unique rhizoid emergence patterns. The discovery was made through mesophotic surveys of Papahānaumokuākea Marine National Monument using both morphological and molecular analyses, including mitochondrial cytochrome oxidase subunit 1 (COI) and chloroplast rbcL DNA sequencing. S. copusii was identified as a dominant member of the algal community at Kure Atoll, suggesting its potential ecological significance in deep-water benthic ecosystems. This study underscores the unexplored biodiversity of Peyssonneliales in Hawaii and emphasizes the need for further exploration of mesophotic depths to uncover additional species.
Economic impacts of Papahānaumokuākea Marine National Monument expansion on the Hawaii longline fishery
The expansion of the Papahānaumokuākea Marine National Monument (PMNM) in 2016 led to significant economic impacts on Hawaii's longline fishery. Specifically, catch per unit effort (CPUE) decreased by 7%, while revenue per trip dropped by 9%, amounting to a loss of $3.5 million over the first 16 months post-expansion. The study used difference-in-differences models with fixed effects to assess these impacts on vessels that previously fished extensively within the Monument Expanded Area (MEA). The findings suggest that fishers, displaced from traditional grounds, are still adapting to new fishing areas, leading to reduced efficiency and productivity.
Haraldiophyllum hawaiiense sp. nov. (Delesseriaceae, Rhodophyta): a new mesophotic genus record for the Hawaiian Islands
Researchers have identified Haraldiophyllum hawaiiense as a new species of mesophotic alga and the first record of its genus in the Hawaiian Islands, specifically within Papahānaumokuākea Marine National Monument. This discovery was supported by morphological analysis and molecular phylogenetics, including sequences from the plastidial rbcL gene and nuclear LSU rRNA gene. The species is distinct within the genus Haraldiophyllum, though its placement remains debated due to the paraphyletic nature of the genus. The study underscores the biodiversity of mesophotic coral ecosystems, advocating for further exploration to uncover hidden marine life in these understudied depths.
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
Researchers have identified and described a new species of red alga, Chondria tumulosa, found in the Papahānaumokuākea Marine National Monument, Hawai‘i. This discovery stems from NOAA survey cruises in 2016 and 2019 that uncovered an undetermined seaweed rapidly covering benthic areas at Pearl and Hermes Atoll. Through light microscopy and molecular analysis—including mitochondrial COI barcode marker, plastidial rbcL gene, and nuclear SSU gene—the study confirmed the alga's unique genus-level placement within Rhodomelaceae. Chondria tumulosa is distinguished by its large, robust thalli, mat-forming tendency, and distinct morphological traits. While not meeting the criteria for an invasive species, its sudden appearance and rapid proliferation in this pristine, uninhabited island chain raise concerns about potential ecological impacts.
Mass coral bleaching due to unprecedented marine heatwave in Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands)
A unprecedented marine heatwave in 2014 triggered the most severe and widespread coral bleaching event recorded in Papahānaumokuākea Marine National Monument (PMNM), with up to 91% bleaching at shallow habitats of Lisianski Island. This event, characterized by extreme heat stress, differed significantly from previous bleaching events due to variations in heat exposure and potential local acclimatization. Researchers analyzed in situ surveys and satellite data across four islands/atolls to assess the drivers of bleaching patterns, its impact on coral mortality and community structure, and long-term changes in heat stress. The study found that the 2014 event was unprecedented in terms of duration and intensity, with cumulative heat stress reaching around 20°C-weeks, and highlighted a significant increase in exposure to bleaching-level heat stress since 1982, underscoring the escalating threat of climate change to these fragile ecosystems.
Papahānaumokuākea: Integrating Culture in the Design and Management of one of the World's Largest Marine Protected Areas
Papahānaumokuākea Marine National Monument, the world's largest marine protected area and the first mixed conservation site in the U.S., demonstrates how integrating indigenous cultural knowledge with scientific management can enhance conservation outcomes. This biocultural approach, rooted in Native Hawaiian values and practices, has proven effective in managing both natural and cultural resources. The study highlights the importance of involving cultural practitioners in policy, education, and research, which has led to innovative strategies that respect traditional epistemologies and relationships with place. Recognized as a cultural seascape with deep spiritual significance for Native Hawaiians, Papahānaumokuākea serves as a global model for sustainable marine conservation.
Latitudinal Trends and Drivers in the CO2–Carbonic Acid System of Papahānaumokuākea Marine National Monument
Coral reefs in the northern atolls of Papahānaumokuākea Marine National Monument (PMNM) are particularly vulnerable to climate change and ocean acidification, according to a study analyzing latitudinal trends in marine carbon chemistry. Researchers found that surface seawater pH and CO₂ levels vary three times more near reefs than in open ocean waters, with this variability detectable up to 50 km away from the nearest coral ecosystems. The findings suggest that coral reef metabolism significantly influences local carbon chemistry, while environmental factors like temperature, wind speed, and water residence time further shape these conditions. The study also identified a net calcification process creating an alkalinity sink across PMNM waters, highlighting the complex interplay between biological and physical drivers in this remote yet ecologically critical region.
Bibliographic Catalogue of the Marine Benthic Algae in the Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands)
A comprehensive catalogue of marine benthic algae in the Papahānaumokuākea Marine National Monument (PMNM) reveals 335 species across ten Northwestern Hawaiian Islands, atolls, and shoals. The study organizes these species into four phyla—Cyanobacteria, Rhodophyta, Ochrophyta, and Chlorophyta—and provides detailed taxonomic listings with reference citations for each location. Notably, French Frigate Shoals hosts the highest diversity (173 species), while Nihoa Island has the lowest (33). The catalogue includes a chronological island-reference index and brief notes on select species, offering a foundational resource for algal research in this UNESCO-listed marine region.
Chapter 19. Protecting and Perpetuating Papahānaumokuākea: Involvement of Native Hawaiians in Governance of Papahānaumokuākea Marine National Monument
A symbiotic relationship between Native Hawaiians and the Northwestern Hawaiian Islands (NWHI) is central to the preservation of Papahānaumokuākea Marine National Monument, one of the last nearly pristine marine ecosystems in the Hawaiian Archipelago. This study highlights how integrating Native Hawaiian traditions, values, and resource management practices into monument governance not only protects the ecosystem but also perpetuates living Hawaiian culture. By involving Native Hawaiians in stewardship, the research demonstrates a pathway to maintain ancestral connections and sustain traditional skills that thrived before Western contact.
Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models
Classic atolls with islands on shallow rims are more vulnerable to the combined effects of sea-level rise and storm waves, leading to earlier and more severe inundation than predicted by passive models. This study compared dynamic inundation models—accounting for wave-induced set-up and run-up—to passive 'bathtub' models using Midway Atoll (shallow rim) and Laysan Island (deep rim). Findings revealed that sea-level rise increases wave heights and wavelengths, amplifying run-up despite reduced set-up. Dynamic modeling showed substantial inundation at lower sea-level rise thresholds than passive models, suggesting infrastructure and ecosystems on shallow-rim atolls face heightened risks sooner in the 21st century.
Sailing through Time: A Historical Examination of the Explorations and Expeditions of the Papahānaumokuākea Marine National Monument
Decades of exploration and documentation reveal the Northwestern Hawaiian Islands (NWHI) as dynamic, pristine ecosystems with significant cultural, economic, and scientific value. This study highlights how past expeditions—spanning voyaging, monitoring, and protection efforts—have laid the foundation for modern ecosystem-based management, exemplified by the successful implementation of the Papahānaumokuākea Marine National Monument (PMNM). By integrating local knowledge with scientific research, the NWHI serves as a model for large-scale, archipelagic-wide conservation strategies. The findings underscore the importance of historical exploration in shaping current research priorities and future management directions, offering insights that support global ocean systems understanding and environmental stewardship.
The Ecology of Coral Reef Top Predators in the Papahānaumokuākea Marine National Monument
Coral reef ecosystems within the Papahānaumokuākea Marine National Monument (PMNM) are uniquely dominated by top-level predators, notably giant trevally and Galapagos sharks, which significantly influence shallow-water reef fish assemblages. Unlike other remote Pacific atolls, PMNM exhibits lower diversity among predatory teleosts such as groupers and snappers. Predators in this region demonstrate strong site attachment to specific atolls while exhibiting extensive movement within those atolls, with highest abundances observed in fore-reef habitats. The study highlights the diverse foraging behavior of these top predators and their potential for exerting indirect ecological impacts on reef ecosystems. Identified knowledge gaps suggest directions for future research to better understand predator dynamics in this protected marine environment.
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