Robert John Toonen

Robert John Toonen
University of Hawaiʻi at Mānoa | UH Manoa · Institute of Marine Biology

MS Marine Sciences, PhD Population Biology

About

661
Publications
132,166
Reads
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15,121
Citations
Citations since 2017
192 Research Items
7810 Citations
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201720182019202020212022202302004006008001,0001,200
201720182019202020212022202302004006008001,0001,200
Introduction
Robert John Toonen currently works at the Hawai'i Institute of Marine Biology, at the University of Hawaiʻi at Mānoa. Rob does research in Coral Reefs, Marine Biology, Molecular Ecology, Evolutionary Biology and Conservation Genetics. His lab has a wide range of current projects in each of these areas.
Additional affiliations
August 2018 - May 2022
University of Hawaiʻi at Mānoa
Position
  • He'eia National Estuarine Research Reserve Advisory Board Chair
June 2014 - July 2018
University of Hawaiʻi at Mānoa
Position
  • He'eia National Estuarine Research Reserve Interim Manager
Education
September 1993 - December 2001
University of California, Davis
Field of study
  • Population Biology
September 1991 - August 1993
University of North Carolina at Wilmington
Field of study
  • Marine Sciences
September 1987 - June 1991
University of Alberta
Field of study
  • Honors Zology

Publications

Publications (661)
Chapter
Full-text available
Hypotheses to explain chaotic genetic structure (i.e., a surprising degree of non-geographic temporal or spatial population differentiation) include: 1) variation in source of larval recruits, 2) self-recruitment and local subdivision, 3) variance in reproductive success (sweepstakes reproduction), and 4) pre- or post-settlement natural selection....
Article
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Marine biodiversity reaches its pinnacle in the tropical Indo-Pacific region, with high levels of both species richness and endemism, especially in coral reef habitats. While this pattern of biodiversity has been known to biogeographers for centuries, causal mechanisms remain enigmatic. Over the past 20 yrs, genetic markers have been employed by ma...
Article
Full-text available
Coral reefs have great biological and socioeconomic value, but are threatened by ocean acidification, climate change and local human impacts. The capacity for corals to adapt or acclimatize to novel environmental conditions is unknown but fundamental to projected reef futures. The coral reefs of Kāne'ohe Bay, Hawai'i were devastated by anthropogeni...
Article
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Significance Although climate change is expected to decimate coral reefs, the combined impacts of ocean-warming and acidification on coral reef biodiversity remains largely unmeasured. Here, we present a two-year mesocosm experiment to simulate future ocean acidification and ocean-warming to quantify the impacts on species richness, community compo...
Article
Major gaps remain in our understanding of the ecology, evolution, biodiversity, biogeography, extinction risk, and adaptive potential of reef building corals. One of the central challenges remains that there are few informative genetic markers for studying boundaries between species, and variation within species. Reduced representation sequencing a...
Article
Full-text available
Genetic diversity within species represents a fundamental yet underappreciated level of biodiversity. Because genetic diversity can indicate species resilience to changing climate, its measurement is relevant to many national and global conservation policy targets. Many studies produce large amounts of genome‐scale genetic diversity data for wild p...
Article
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The gap between spawning and settlement location of marine fishes, wherein the larvae occupy an oceanic phase, is a great mystery in both natural history and conservation. Recent genomic approaches offer some resolution, especially in linking parent to offspring with assays of nucleotide polymorphisms. Here, we apply this methodology to the endemic...
Article
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Giant clams are ecologically important, benefitting species of all trophic levels. But numerous populations have declined drastically in numbers due to past intensive exploitation that led to their listing in both CITES Appendix II and IUCN Red List of Threatened Species. However, giant clams are notoriously difficult to identify, and recent molecu...
Preprint
Giant clams are ecologically important, benefitting species of all trophic levels. But numerous populations have declined drastically in numbers due to past intensive exploitation that led to their listing in both CITES Appendix II and IUCN Red List of Threatened Species.. However, giant clams are notoriously difficult to identify, and recent molec...
Article
Full-text available
Coral reefs are declining worldwide primarily because of bleaching and subsequent mortality resulting from thermal stress. Currently, extensive efforts to engage in more holistic research and restoration endeavors have considerably expanded the techniques applied to examine coral samples. Despite such advances, coral bleaching and restoration studi...
Article
Full-text available
Novel methodologies now make it possible to track the complete geographical movements of seafood species from reproduction to human consumption. Doing so will better inform consumers and assist resource managers in matching fisheries and conservation policies with natural borders and pathways, including stock boundaries, networks of marine protecte...
Preprint
Full-text available
Genetic diversity within species represents a fundamental yet underappreciated level of biodiversity. Because genetic diversity can indicate species and population resilience to changing climate, its measurement is relevant to many national and global conservation policy targets. Many studies of evolutionary biology, molecular ecology and conservat...
Article
Full-text available
Fish have one of the highest occurrences of individual specialization in trophic strategies among Eukaryotes. Yet, few studies characterize this variation during trophic niche analysis, limiting our understanding of aquatic food web dynamics. Stable isotope analysis (SIA) with advanced Bayesian statistics is one way to incorporate this individual t...
Article
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The survival of most reef-building corals is dependent upon a symbiosis between the coral and the community of Symbiodiniaceae. Montipora capitata , one of the main reef-building coral species in Hawai'i, is known to host a diversity of symbionts, but it remains unclear how they change spatially and whether environmental factors drive those changes...
Article
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Traditional Hawaiian fishponds, called loko iʻa, are a low‐impact and culturally important aquaculture system that historically produced significant fish yields. To better understand the structure of the contemporary food web of the restored Heʻeia fishpond, a mark‐recapture experiment was conducted to estimate the population abundance of the three...
Article
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Successional theory proposes that fast growing and well dispersed opportunistic species are the first to occupy available space. However, these pioneering species have relatively short life cycles and are eventually outcompeted by species that tend to be longer-lived and have lower dispersal capabilities. Using Autonomous Reef Monitoring Structures...
Article
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Mesophotic coral ecosystems (MCEs: ~30 to 100+ m depth) may be older and more stable than shallow coral ecosystems that are more prone to disturbances in both the long term (glacial sea level cycles) and short term (heavy weather and anthropogenic activities). Here, we assess the phylogeography of two MCE fishes, the soldierfish Myripristis chryser...
Article
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The global decline of coral reefs has driven considerable interest in active coral restoration. Despite their importance and dominance on mature reefs, relatively few coral restoration projects use slower growth forms like massive and encrusting coral species. Micro-fragmentation can increase coral cover by orders of magnitude faster than natural g...
Article
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Our changing climate poses growing challenges for effective management of marine life, ocean ecosystems, and human communities. Which species are most vulnerable to climate change, and where should management focus efforts to reduce these risks? To address these questions, the National Oceanic and Atmospheric Administration (NOAA) Fisheries Climate...
Poster
Full-text available
Overview: Here we apply a a restriction-associated DNA sequencing approach (RAD-seq) to investigate the taxonomic classification of Tridacninae giant clams (genera: Hippopus and Tridacna) and address the phylogenetic discordance within the current literature, particularly in the subgenus Chametrachea. We compared mitochondrial and nuclear genomes t...
Article
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Our perception of reef diversity is dominated by corals, fish, and a few other groups that visibly dominate the reef surface. However, the bulk of reef biodiversity resides within the reef framework, and this cryptobiota is fundamentally important for the surface community. Sponges are abundant and conspicuous on the reef surface in productive, con...
Article
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Zoantharians (Cnidaria: Hexacorallia: Zoantharia) of the genus Palythoa are ubiquitous species that occupy reef habitats in every tropical ocean. Disagreements among classifications based on morphology, reproductive traits, and molecular techniques have generated taxonomic challenges within this group. Molecular studies provide limited phylogenetic...
Article
Full-text available
The reefs at Palmyra Atoll, a small outlying atoll in the equatorial Pacific, have been undergoing a phase shift from scleractinian corals to a corallimorph-dominated benthos. It has been unclear whether there has been cryptic speciation or morphological plasticity leading to different ecotypes of Rhodactis howesii. Here, we use mitochondrial genom...
Article
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Elevated seawater temperatures associated with climate change lead to coral bleaching. While the ultimate causes of bleaching are well understood, the proximate physiological mechanisms underlying the bleaching response are not as well defined. Here we measured nitric oxide synthase activity, oxidative stress, and cell death in algal symbionts (Sym...
Preprint
Full-text available
Coral reefs are iconic examples of climate change impacts because climate-induced heat stress causes the breakdown of the coral-algal symbiosis leading to a spectacular loss of color, termed coral bleaching. To examine the fine-scale dynamics of this process, we re-sampled 600 individually marked Montipora capitata colonies from across Kāneohe Bay,...
Preprint
Giant clams are keystone species on coral reefs, but global demand for their harvest has decimated populations and resulted in all Tridacnids being listed on both CITES and IUCN lists. However, giant clams are notoriously difficult to identify, and recent molecular work has revealed that morphological misidentification of giant clams have confounde...
Article
Full-text available
The drastic decline in coral coverage has stimulated an interest in reef restoration, and various iterations of coral nurseries have been used to augment restoration strategies. Here we examine the growth of two species of Hawaiian Montipora that were maintained in mesocosms under either ambient or warmed annual bleaching conditions for two consecu...
Article
Full-text available
Climate change poses a major threat to coral reefs. We conducted an outdoor 22-month experiment to investigate if coral could not just survive, but also physiologically cope, with chronic ocean warming and acidification conditions expected later this century under the Paris Climate Agreement. We recorded survivorship and measured eleven phenotypic...
Article
Full-text available
Many marine animals have a biphasic life cycle in which demersal adults spawn pelagic larvae with high dispersal potential. An understanding of the spatial and temporal patterns of larval dispersal is critical for describing connectivity and local retention. Existing tools in oceanography, genetics, and ecology can each reveal only part of the over...
Article
Full-text available
The deep reef refuge hypothesis (DRRH) postulates that mesophotic coral ecosystems (MCEs) may provide a refuge for shallow coral reefs (SCRs). Understanding this process is an important conservation tool given increasing threats to coral reefs. To establish a better framework to analyze the DRRH, we analyzed stony coral communities in American Sāmo...
Preprint
Full-text available
The survival of reef-building corals is dependent upon a symbiosis between the coral and the community of Symbiodiniaceae. Montipora capitata , one of the main reef building coral species in Hawaiʻi, is known to host a diversity of symbionts, but it remains unclear how they change spatially and whether environmental factors drive those changes. Her...
Article
Full-text available
To evaluate potential coral adaptive mechanisms, we investigated physiological traits (biomass, lipid, protein, chlorophyll, and isotopic proxies for trophic strategy) in eight Hawaiian corals species along an environmental gradient of significant wave height, sea surface temperature, and seawater chlorophyll a concentration around the island of O‘...
Article
Full-text available
The resistance of corals to a changing climate has been linked to physiological parameters including heterotrophic capacity and energy reserves. Recently, the potential flexibility and diversity of coral-associated microbial communities have also been related to coral health and resistance to environmental stress. This study uses the island of O‘ah...
Article
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Background Understanding region-wide patterns of larval connectivity and gene flow is crucial for managing and conserving marine biodiversity. Dongsha Atoll National Park (DANP), located in the northern South China Sea (SCS), was established in 2007 to study and conserve this diverse and remote coral atoll. However, the role of Dongsha Atoll in con...
Article
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Genomic data are being produced and archived at a prodigious rate, and current studies could become historical baselines for future global genetic diversity analyses and monitoring programs. However, when we evaluated the potential utility of genomic data from wild and domesticated eukaryote species in the world’s largest genomic data repository, w...
Article
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Herbivorous reef fishes are an important component of coral reef ecosystems and a focal point in reef management. Herbivore diets have been examined using a myriad of methods, making it difficult to compare between analyses and to examine consistency or variability in diet across large spatial scales or heterogeneous environments. Here, we present...
Article
Full-text available
Zoantharians (Cnidaria: Hexacorallia: Zoan-tharia) of the genus Palythoa are ubiquitous species that occupy reef habitats in every tropical ocean. Disagreements among classifications based on morphology, reproductive traits, and molecular techniques have generated taxonomic challenges within this group. Molecular studies provide limited phylogeneti...
Preprint
Full-text available
Coral reefs are among the most sensitive ecosystems affected by ocean acidification and warming, and are predicted to shift from net accreting calcifier-dominated systems to net eroding algal-dominated systems over the coming decades. Here we present a long-term experimental study examining the responses of entire mesocosm coral reef communities to...
Article
Full-text available
Surgeonfishes (Acanthuridae) are an important group of herbivores that are abundant on reefs globally. Acanthurids consume macroalgae that can compete with corals for space, turf algae that can proliferate on degraded reefs, and detritus that may smother adult corals or inhibit settlement. For these reasons, they are of particular interest at prese...
Article
Full-text available
Corals obtain nutrition from the photosynthetic products of their algal endosymbionts and the ingestion of organic material and zooplankton from the water column. Here, we use stable carbon (δ13C) and nitrogen (δ15N) isotopes to assess the proportionate contribution of photoautotrophic and heterotrophic sources to seven Hawaiian coral species colle...
Article
Full-text available
Phylogenomic studies can provide insights into speciation, adaptation, and extinction, while providing a roadmap for conservation. Hawaiian tree snails are a model system for an adaptive radiation facing an extinction crisis. In the last 5 years, nearly all populations of Hawaiian tree snails across the 30 remaining species in the subfamily Achatin...
Article
Environmental gradients between marine biogeographical provinces separate distinct faunal communities. However, the absence of absolute dispersal barriers allows numerous species to occur on both sides of such boundaries. While the regional populations of such widespread species are often morphologically indistinguishable from each other, genetic e...
Article
Full-text available
Many marine animals have a biphasic life cycle in which demersal adults spawn pelagic larvae with high dispersal potential. An understanding of the spatial and temporal patterns of larval dispersal is critical for describing connectivity and local retention. Existing tools in oceanography, genetics, and ecology can each reveal only part of the over...
Data
Supplementary information about the specimens used in this research, including location of voucher specimens and link to field photographs on Dryad: https://datadryad.org/stash/share/5atVNHU8tBYO3dsNkqqIOlQvlpg-xbd4XsyEV-5G9Sw
Article
Full-text available
Despite their ecological importance, sponges are often avoided in biodiversity studies and monitoring programs because they are notoriously difficult to identify using morphological or molecular methods. Here, we investigate the metabarcoding performance of universal degenerate cytochrome c oxidase subunit I (COI) primers in detecting species from...
Article
Full-text available
Coral bleaching is the single largest global threat to coral reefs worldwide. Integrating the diverse body of work on coral bleaching is critical to understanding and combating this global problem. Yet investigating the drivers, patterns, and processes of coral bleaching poses a major challenge. A recent review of published experiments revealed a w...
Article
Full-text available
Globally, an increasing recognition of the importance of ecosystem-based management (EBM), Indigenous resource management (IRM), and Indigenous-led research and management is emerging; yet, case studies within scholarly literature illustrating comprehensive application of these theories and philosophies are scarce. We present the collaborative mana...
Article
Full-text available
Genetic data represent a relatively new frontier for our understanding of global biodiversity. Ideally, such data should include both organismal DNA-based genotypes and the ecological context where the organisms were sampled. Yet most tools and standards for data deposition focus exclusively either on genetic or ecological attributes. The Genomic O...
Article
Full-text available
Conservation genetic approaches for elasmobranchs have focused on regions of the mitochondrial genome or a handful of nuclear microsatellites. High-throughput sequencing offers a powerful alternative for examining population structure using many loci distributed across the nuclear and mitochondrial genomes. These single nucleotide polymorphisms are...
Article
Full-text available
The ‘species’ is a key concept for conservation and evolutionary biology, yet the lines between population and species-level variation are often blurred, especially for corals. The ‘Porites lobata species complex’ consists of branching and mounding corals that form reefs across the Pacific. We used reduced representation meta-genomic sequencing to...