Robert John Toonen

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

MS Marine Sciences, PhD Population Biology

About

636
Publications
121,186
Reads
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Citations
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 (636)
Chapter
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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....
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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
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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...
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Ocean-warming and acidification are predicted to reduce coral reef biodiversity, but the combined effects of these stressors on overall biodiversity are largely unmeasured. Here, we examined the individual and combined effects of elevated temperature (+2 °C) and reduced pH (−0.2 units) on the biodiversity of coral reef communities that developed on...
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
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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...
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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...
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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...
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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...
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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
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,...
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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...
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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...
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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...
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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...
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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
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...
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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‘...
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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...
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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...
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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...
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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
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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
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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...
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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...
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
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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
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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
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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...
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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
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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
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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...
Article
Hawaiian fishponds, or loko iʻa, are ancient aquaculture systems and models of sustainable aquatic resource management from traditional Native Hawaiian harvest practices. Of the 488 fishponds documented in ancient Hawaiʻi, only 38 are currently actively managed fishponds across the State. Building on Indigenous and local knowledge, fishponds are be...
Article
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Background: As global change and anthropogenic pressures continue to increase, conservation and management increasingly needs to consider species' potential to adapt to novel environmental conditions. Therefore, it is imperative to characterise the main selective forces acting on ecosystems, and how these may influence the evolutionary potential o...
Preprint
Full-text available
Environmental gradients between marine biogeographical provinces separate distinct faunal communities; in the absence of absolute dispersal barriers numerous species nonetheless occur on either side of such boundaries. While the regional populations of such widespread species tend to be morphologically indistinguishable from each other, genetic evi...
Article
Kāne‘ohe Bay has been invaded by at least 10 non-indigenous sponge species, some of which have become dominant over native sponges and even competitors against reef-building corals. We discovered the Hawaiian tiger cowrie Cypraea tigris schilderiana to be a voracious sponge predator, particularly on some of these non-indigenous sponges. This study...
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The extent to which populations persist under environmental stress depends on the reproductive output of individuals that survive the stress. In coral systems, corals bleach in response to stress from elevated water temperature. However, little is known of the extent to which thermal stress impairs the reproductive capacity of the survivors over th...
Article
Stony corals (Scleractinia) form the basis for some of the most diverse ecosytems on Earth, but we have much to learn about their evolutionary history and systematic relationships. In order to improve our understanding of species in corals we here investigated phylogenetic relationships between morphologically defined species and genetic lineages i...
Preprint
Full-text available
Background: As global change and anthropogenic pressures continue to increase, conservation and management increasingly needs to consider species’ potential to adapt to novel environmental conditions. Therefore, it is imperative to characterise the main selective forces acting on ecosystems, and how these may influence the evolutionary potential of...
Preprint
Full-text available
Background: As global change and anthropogenic pressures continue to increase, conservation and management increasingly needs to consider species’ potential to adapt to novel environmental conditions. Therefore, it is imperative to characterise the main selective forces acting on ecosystems, and how these may influence the evolutionary potential of...
Preprint
Full-text available
Background: As global change and anthropogenic pressures continue to increase, conservation and management increasingly needs to consider species’ potential to adapt to novel environmental conditions. Therefore, it is imperative to characterise the main selective forces acting on ecosystems, and how these may influence the evolutionary potential of...
Article
Full-text available
Palau suffered massive mortality of reef corals during the 1998 mass bleaching, and understanding recovery from that catastrophic loss is critical to management for future impacts. Many reef species have shown significant genetic structure at small scales while apparently absent at large scales, a pattern often referred to as chaotic genetic patchi...
Article
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Atlantia is described as a new genus pertaining to the family Dendrophylliidae (Anthozoa, Scleractinia) based on specimens from Cape Verde, eastern Atlantic. This taxon was first recognized as Enallopsammia micranthus and later described as a new species, Tubastraea caboverdiana, which then changed the status of the genus Tubastraea as native to th...
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We examined genetic structure in the lobe coral Porites lobata among pairs of highly variable and high-stress nearshore sites and adjacent less variable and less impacted offshore sites on the islands of Oahu and Maui, Hawaii. Using an analysis of molecular variance framework, we tested whether populations were more structured by geographic distanc...
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Seabirds in the order of Procellariiformes have one of the highest proportions of threatened species of any avian order. Species undergoing recovery may be predicted to have a genetic signature of a bottleneck, low genetic diversity, or higher rates of inbreeding. The Hawaiian Band-rumped Storm Petrel (‘Akē‘akē; Hydrobates castro ), a long-lived ph...
Article
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Ocean warming and acidification are among the greatest threats to coral reefs. Massive coral bleaching events are becoming increasingly common and are predicted to be more severe and frequent in the near future, putting corals reefs in danger of ecological collapse. This study quantified the abundance, size, and survival of the coral Pocillopora ac...
Article
Zostera capensis is a keystone species providing essential ecosystem services to southern African coastal systems. Like most seagrasses globally, Z. capensis is declining and under threat from anthropogenic pressures, and indicators of seagrass health and resilience may be of interest in preventing further declines. As intraspecific diversity is an...
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Species flocks are proliferations of closely-related species, usually after colonization of depauperate habitat. These radiations are abundant on oceanic islands and in ancient freshwater lakes, but rare in marine habitats. This contrast is well documented in the Hawaiian Archipelago, where terrestrial examples include the speciose silverswords (su...
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Here, we expand on the term “ecomimicry” to be an umbrella concept for an approach to adaptive ecosystem-based management of social-ecological systems that simultaneously optimizes multiple ecosystem services for the benefit of people and place. In this context, we define ecomimicry as a strategy for developing and managing cultural landscapes, bui...
Article
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Estimates of heritability inform evolutionary potential and the likely outcome of many management actions, but such estimates remain scarce for marine organisms. Here, we report high heritability of calcification rate among the eight most dominant Hawaiian coral species under reduced pH simulating future ocean conditions. Coral colonies were sample...
Article
Full-text available
Background: Evolutionary patterns of scleractinian (stony) corals are difficult to infer given the existence of few diagnostic characters and pervasive phenotypic plasticity. A previous study of Hawaiian Montipora (Scleractinia: Acroporidae) based on five partial mitochondrial and two nuclear genes revealed the existence of a species complex, grou...