Berumen Michael L.

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Michael L.

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  • Preprint
    After continents divide : comparative phylogeography of reef fishes from the Red Sea and Indian Ocean
    ( 2011-10) DiBattista, Joseph D. ; Berumen, Michael L. ; Gaither, Michelle R. ; Rocha, Luiz A. ; Eble, Jeff A. ; Choat, J. Howard ; Craig, Matthew T. ; Skillings, Derek J. ; Bowen, Brian W.
    The Red Sea is a biodiversity hotspot characterized by unique marine fauna and high endemism. This sea began forming approximately 24 million years ago with the separation of the African and Arabian plates, and has been characterized by periods of desiccation, hypersalinity and intermittent connection to the Indian Ocean. We aim to evaluate the impact of these events on the genetic architecture of the Red Sea reef fish fauna. We surveyed seven reef fish species from the Red Sea and adjacent Indian Ocean using mitochondrial DNA cytochrome-c oxidase subunit I and cytochrome b sequences. To assess genetic variation and evolutionary connectivity within and between these regions, we estimated haplotype diversity and nucleotide diversity, reconstructed phylogenetic relationships among haplotypes and estimated gene flow and time of population separation using Bayesian coalescent-based methodology. Our analyses revealed a range of scenarios from shallow population structure to diagnostic differences that indicate evolutionary partitions and possible cryptic species. Conventional molecular clocks and coalescence analyses indicated time frames for divergence between these bodies of water ranging from 830,000 years to contemporary exchange or range expansion. Colonization routes were bidirectional, with some species moving from the Indian Ocean to the Red Sea compared with expansion out of the Red Sea for other species. We conclude that: (1) at least some Red Sea reef fauna survived multiple salinity crises; (2) endemism is higher in the Red Sea than previously reported; and (3) the Red Sea is an evolutionary incubator, occasionally contributing species to the adjacent Indian Ocean. The latter two conclusions – elevated endemism and species export – indicate a need for enhanced conservation priorities for the Red Sea.
  • Preprint
    Marine dispersal scales are congruent over evolutionary and ecological time
    ( 2016-10) Pinsky, Malin L. ; Saenz-Agudelo, Pablo ; Salles, Océane C. ; Almany, Glenn R. ; Bode, Michael ; Berumen, Michael L. ; Andrefouet, Serge ; Thorrold, Simon R. ; Jones, Geoffrey P. ; Planes, Serge
    The degree to which offspring remain near their parents or disperse widely is critical for understanding population dynamics, evolution, and biogeography, and for designing conservation actions. In the ocean, most estimates suggesting short-distance dispersal are based on direct ecological observations of dispersing individuals, while indirect evolutionary estimates often suggest substantially greater homogeneity among populations. Reconciling these two approaches and their seemingly competing perspectives on dispersal has been a major challenge. However, here we show for the first time that evolutionary and ecological measures of larval dispersal can closely agree by using both to estimate the distribution of dispersal distances. In orange clownfish (Amphiprion percula) populations in Kimbe Bay, Papua New Guinea, we found that evolutionary dispersal kernels were 17 [95% CI: 12–24] km wide, while an exhaustive set of direct larval dispersal observations suggested kernel widths of 27 [19–36] km or 19 [15–27] km across two years. The similarity between these two approaches suggests that ecological and evolutionary dispersal kernels can be equivalent, and that the apparent disagreement between direct and indirect measurements can be overcome. Our results suggest that carefully applied evolutionary methods, which are often less expensive, can be broadly relevant for understanding ecological dispersal across the tree of life.
  • Article
    Diving behavior of the reef manta ray links coral reefs with adjacent deep pelagic habitats
    (Public Library of Science, 2014-02-06) Braun, Camrin D. ; Skomal, Gregory B. ; Thorrold, Simon R. ; Berumen, Michael L.
    Recent successful efforts to increase protection for manta rays has highlighted the lack of basic ecological information, including vertical and horizontal movement patterns, available for these species. We deployed pop-up satellite archival transmitting tags on nine reef manta rays, Manta alfredi, to determine diving behaviors and vertical habitat use. Transmitted and archived data were obtained from seven tagged mantas over deployment periods of 102–188 days, including three recovered tags containing 2.6 million depth, temperature, and light level data points collected every 10 or 15 seconds. Mantas frequented the upper 10 m during daylight hours and tended to occupy deeper water throughout the night. Six of the seven individuals performed a cumulative 76 deep dives (>150 m) with one individual reaching 432 m, extending the known depth range of this coastal, reef-oriented species and confirming its role as an ecological link between epipelagic and mesopelagic habitats. Mean vertical velocities calculated from high-resolution dive data (62 dives >150 m) from three individuals suggested that mantas may use gliding behavior during travel and that this behavior may prove more efficient than continuous horizontal swimming. The behaviors in this study indicate manta rays provide a previously unknown link between the epi- and mesopelagic layers of an extremely oligotrophic marine environment and provide evidence of a third marine species that utilizes gliding to maximize movement efficiency.
  • Preprint
    External tagging does not affect the feeding behavior of a coral reef fish, Chaetodon vagabundus (Pisces: Chaetodontidae)
    ( 2009-07-05) Berumen, Michael L. ; Almany, Glenn R.
    Increasingly, the ability to recognize individual fishes is important for studies of population dynamics, ecology, and behavior. Although a variety of methods exist, external tags remain one of the most widely applied because they are both effective and cost efficient. However, a key assumption is that neither the tagging procedure nor the presence of a tag negatively affects the individual. While this has been demonstrated for relatively coarse metrics such as growth and survival, few studies have examined the impact of tags and tagging on more subtle aspects of behavior. We tagged adult vagabond butterflyfish (Chaetodon vagabundus) occupying a 30-ha insular reef in Kimbe Bay, Papua New Guinea, using a commonly-utilized t-bar anchor tag. We quantified and compared feeding behavior (bite rate), which is sensitive to stress, of tagged and untagged individuals over four separate sampling periods spanning four months post-tagging. Bite rates did not differ between tagged and untagged individuals at each sampling period and, combined with additional anecdotal observations of normal pairing behavior and successful reproduction, suggest that tagging did not adversely affect individuals.
  • Preprint
    Tracing carbon flow through coral reef food webs using a compound-specific stable isotope approach
    ( 2015-11) McMahon, Kelton W. ; Thorrold, Simon R. ; Houghton, Leah A. ; Berumen, Michael L.
    Coral reefs support spectacularly productive and diverse communities in tropical and sub26 tropical waters throughout the world’s oceans. Debate continues, however, on the degree to which reef biomass is supported by new water column production, benthic primary production, and recycled detrital carbon. We coupled compound-specific δ13C analyses with Bayesian mixing models to quantify carbon flow from primary producers to coral reef fishes across multiple feeding guilds and trophic positions in the Red Sea. Analyses of reef fishes with putative diets composed primarily of zooplankton (Amblyglyphidodon indicus), benthic macroalgae (Stegastes nigricans), reef-associated detritus (Ctenochaetus striatus), and coral tissue (Chaetodon trifascialis) confirmed that δ13C values of essential amino acids from all baseline carbon sources were both isotopically diagnostic and accurately recorded in consumer tissues. While all four source end-members contributed to the production of coral reef fishes in our study, a single source end-member often dominated dietary carbon assimilation of a given species, even for highly mobile, generalist top predators. Microbially-reworked detritus was an important secondary carbon source for most species. Seascape configuration played an important role in structuring resource utilization patterns. For instance, L. ehrenbergii, showed a significant shift from a benthic macroalgal food web on shelf reefs (71 ± 13% of dietary carbon) to a phytoplankton-based food web (72 ± 11%) on oceanic reefs. Our work provides insights into the roles that diverse carbon sources play in the structure and function of coral reef ecosystems and illustrates a powerful fingerprinting method to develop and test nutritional frameworks for understanding resource utilization.
  • Article
    Novel polymorphic microsatellite markers developed for a common reef sponge, Stylissa carteri
    (Springer, 2013-04-04) Giles, Emily C. ; Saenz-Agudelo, Pablo ; Berumen, Michael L. ; Ravasi, Timothy
    Despite the ubiquitous role sponges play in reef ecosystem dynamics, little is known about population-level connectivity in these organisms. The general field of population genetics in sponges remains in its infancy. To date, microsatellite markers have only been developed for few sponge species and no sponge population genetics studies using microsatellites have been conducted in the Red Sea. Here, with the use of next-generation sequencing, we characterize 12 novel polymorphic loci for the common reef sponge, Stylissa carteri. The number of alleles per loci ranged between three and eight. Observed heterozygosity frequencies (Ho) ranged from 0.125 to 0.870, whereas expected (He) heterozygosity frequencies ranged from 0.119 to 0.812. Only one locus showed consistent deviations from Hardy-Weinberg equilibrium (HWE) in both populations and two loci consistently showed the possible presence of null alleles. No significant linkage disequilibrium was detected for any pairs of loci. These microsatellites will be of use for numerous ecological studies focused on this common and abundant sponge.
  • Article
    Seascape and life-history traits do not predict self-recruitment in a coral reef fish
    (The Royal Society, 2016-08-09) Herrera, Marcela ; Nanninga, Gerrit ; Planes, Serge ; Jones, Geoffrey P. ; Thorrold, Simon R. ; Saenz-Agudelo, Pablo ; Almany, Glenn R. ; Berumen, Michael L.
    The persistence and resilience of many coral reef species are dependent on rates of connectivity among sub-populations. However, despite increasing research efforts, the spatial scale of larval dispersal remains unpredictable for most marine metapopulations. Here, we assess patterns of larval dispersal in the angelfish Centropyge bicolor in Kimbe Bay, Papua New Guinea, using parentage and sibling reconstruction analyses based on 23 microsatellite DNA loci. We found that, contrary to previous findings in this system, self-recruitment (SR) was virtually absent at both the reef (0.4–0.5% at 0.15 km2) and the lagoon scale (0.6–0.8% at approx. 700 km2). While approximately 25% of the collected juveniles were identified as potential siblings, the majority of sibling pairs were sampled from separate reefs. Integrating our findings with earlier research from the same system suggests that geographical setting and life-history traits alone are not suitable predictors of SR and that high levels of localized recruitment are not universal in coral reef fishes.
  • Article
    Phytoplankton phenology indices in coral reef ecosystems : application to ocean-color observations in the Red Sea
    (Elsevier, 2015-02-18) Racault, Marie-Fanny ; Raitsos, Dionysios E. ; Berumen, Michael L. ; Brewin, Robert J. W. ; Platt, Trevor ; Sathyendranath, Shubha ; Hoteit, Ibrahim
    Phytoplankton, at the base of the marine food web, represent a fundamental food source in coral reef ecosystems. The timing (phenology) and magnitude of the phytoplankton biomass are major determinants of trophic interactions. The Red Sea is one of the warmest and most saline basins in the world, characterized by an arid tropical climate regulated by the monsoon. These extreme conditions are particularly challenging for marine life. Phytoplankton phenological indices provide objective and quantitative metrics to characterize phytoplankton seasonality. The indices i.e. timings of initiation, peak, termination and duration are estimated here using 15 years (1997–2012) of remote sensing ocean-color data from the European Space Agency (ESA) Climate Change Initiative project (OC-CCI) in the entire Red Sea basin. The OC-CCI product, comprising merged and bias-corrected observations from three independent ocean-color sensors (SeaWiFS, MODIS and MERIS), and processed using the POLYMER algorithm (MERIS period), shows a significant increase in chlorophyll data coverage, especially in the southern Red Sea during the months of summer NW monsoon. In open and reef-bound coastal waters, the performance of OC-CCI chlorophyll data is shown to be comparable with the performance of other standard chlorophyll products for the global oceans. These features have permitted us to investigate phytoplankton phenology in the entire Red Sea basin, and during both winter SE monsoon and summer NW monsoon periods. The phenological indices are estimated in the four open water provinces of the basin, and further examined at six coral reef complexes of particular socio-economic importance in the Red Sea, including Siyal Islands, Sharm El Sheikh, Al Wajh bank, Thuwal reefs, Al Lith reefs and Farasan Islands. Most of the open and deeper waters of the basin show an apparent higher chlorophyll concentration and longer duration of phytoplankton growth during the winter period (relative to the summer phytoplankton growth period). In contrast, most of the reef-bound coastal waters display equal or higher peak chlorophyll concentrations and equal or longer duration of phytoplankton growth during the summer period (relative to the winter phytoplankton growth period). The ecological and biological significance of the phytoplankton seasonal characteristics are discussed in context of ecosystem state assessment, and particularly to support further understanding of the structure and functioning of coral reef ecosystems in the Red Sea.
  • Preprint
    Remote marine protected area reveals unusual social behaviour in Chaetodon trifascialis
    ( 2016-06) Coker, Darren J. ; Braun, Camrin D. ; Cavin, Julie M. ; Payet, S. ; Berumen, Michael L.
  • Preprint
    Otolith geochemistry does not reflect dispersal history of clownfish larvae
    ( 2010-06) Berumen, Michael L. ; Walsh, Harvey J. ; Raventos, N. ; Planes, Serge ; Jones, Geoffrey P. ; Starczak, Victoria R. ; Thorrold, Simon R.
    Natural geochemical signatures in calcified structures are commonly employed to retrospectively estimate dispersal pathways of larval fish and invertebrates. However, the accuracy of the approach is generally untested due to the absence of individuals with known dispersal histories. We used genetic parentage analysis (genotyping) to divide 110 new recruits of the orange clownfish, Amphiprion percula, from Kimbe Island, Papua New Guinea, into two groups: “self-recruiters” spawned by parents on Kimbe Island and “immigrants” that had dispersed from distant reefs (>10km away). Analysis of daily increments in sagittal otoliths found no significant difference in PLDs or otolith growth rates between self-recruiting and immigrant larvae. We also quantified otolith Sr/Ca and Ba/Ca ratios during the larval phase using laser ablation inductively coupled plasma mass spectrometry. Again, we found no significant differences in larval profiles of either element between self-recruits and immigrants. Our results highlight the need for caution when interpreting otolith dispersal histories based on natural geochemical tags in the absence of water chemistry data or known-origin larvae with which to test the discriminatory ability of natural tags.
  • Preprint
    The use of specialisation indices to predict vulnerability of coral-feeding butterflyfishes to environmental change
    ( 2011-07) Lawton, Rebecca J. ; Pratchett, Morgan S. ; Berumen, Michael L.
    In the absence of detailed assessments of extinction risk, ecological specialisation is often used as a proxy of vulnerability to environmental disturbances and extinction risk. Numerous indices can be used to estimate specialisation; however, the utility of these different indices to predict vulnerability to future environmental change is unknown. Here we compare the performance of specialisation indices using coral-feeding butterflyfishes as a model group. Our aims were to (i) quantify the dietary preferences of 3 butterflyfish species across habitats with differing levels of resource availability; (ii) investigate how estimates of dietary specialisation vary with the use of different specialisation indices; (iii) determine which specialisation indices best inform predictions of vulnerability to environmental change; and (iv) assess the utility of resource selection functions to inform predictions of vulnerability to environmental change. The relative level of dietary specialisation estimated for all three species varied when different specialisation indices were used, indicating that the choice of index can have a considerable impact upon estimates of specialisation. Specialisation indices that do not consider resource abundance may fail to distinguish species that primarily use common resources from species that actively target resources disproportionately more than they are available. Resource selection functions provided the greatest insights into the potential response of species to changes in resource availability. Examination of resource selection functions, in addition to specialisation indices, indicated that Chaetodon trifascialis was the most specialised feeder, with highly conserved dietary preferences across all sites, suggesting that this species is highly vulnerable to the impacts of climate-induced coral loss on reefs. Our results indicate that vulnerability assessments based on some specialisation indices may be misleading and the best estimates of dietary specialisation will be provided by indices which incorporate resource availability measures, as well as assessing responses of species to changes in resource availability.
  • Article
    Rank change and growth within social hierarchies of the orange clownfish, Amphiprion percula
    (Springer, 2022-10-05) Fitzgerald, Lucy M. ; Harrison, Hugo B. ; Coker, Darren J. ; Sáenz-Agudelo, Pablo ; Srinivasan, Maya ; Majoris, John E. ; Boström Einarsson, Lisa ; Pujol, Benoit ; Bennett-Smith, Morgan ; Thorrold, Simon R. ; Planes, Serge ; Jones, Geoffrey P. ; Berumen, Michale L.
    Social hierarchies within groups define the distribution of resources and provide benefits that support the collective group or favor dominant members. The progression of individuals through social hierarchies is a valuable characteristic for quantifying population dynamics. On coral reefs, some clownfish maintain size-based hierarchical communities where individuals queue through social ranks. The cost of waiting in a lower-ranked position is outweighed by the reduced risk of eviction and mortality. The orange clownfish,Amphiprion percula, maintains stable social groups with subordinate individuals queuing to be part of the dominant breeding pair. Strong association with their host anemone, complex social interactions, and relatively low predation rates make them ideal model organisms to assess changes in group dynamics through time in their natural environment. Here, we investigate the rank changes and isometric growth rates ofA. percula from 247 naturally occurring social groups in Kimbe Island, Papua New Guinea (5° 12′ 13.54″ S, 150° 22′ 32.69″ E). We used DNA profiling to assign and track individuals over eight years between 2011 and 2019. Over half of the individuals survived alongside two or three members of their original social group, with twelve breeding pairs persisting over the study period. Half of the surviving individuals increased in rank and experienced double the growth rate of those that maintained their rank. Examining rank change in a wild fish population provides new insights into the complex social hierarchies of reef fishes and their role in social evolution.
  • Article
    Characterization of new microsatellite loci for population genetic studies in the Smooth Cauliflower Coral (Stylophora sp.)
    (Springer, 2013-01-09) Banguera-Hinestroza, Eulalia ; Saenz-Agudelo, Pablo ; Bayer, Till ; Berumen, Michael L. ; Voolstra, Christian R.
    A total of one hundred microsatellites loci were selected from the draft genome of Stylophora pistillata and evaluated in previously characterized samples of Stylophora cf pistillata from the Red Sea. 17 loci were amplified successfully and tested in 24 individuals from samples belonging to a single population from the central region of the Red Sea. The number of alleles ranged from 3 to 15 alleles per locus, while observed heterozygosity ranged from 0.292 to 0.95. Six of these loci showed significant deviations from Hardy–Weinberg equilibrium (HWE) expectations, and 4/136 paired loci comparisons suggested linkage disequilibrium after Bonferroni corrections. After excluding loci with significant HWE deviation and evidence of null alleles, average genetic diversity over loci in the population studied (N = 24, Nloci = 11) was 0.701 ± 0.380. This indicates that these loci can be used effectively to evaluate genetic diversity and undertake population genetics studies in Stylophora sp. populations.
  • Article
    First records of two large pelagic fishes in the Red Sea: wahoo (Acanthocybium solandri) and striped marlin (Kajikia audax)
    (Cambridge University Press, 2022-11-02) Williams, Collin T. ; Arostegui, Martin C. ; Braun, Camrin D. ; Gaube, Peter ; Shriem, Marwan ; Berumen, Michael L.
    This report provides the first confirmed identifications of wahoo (Acanthocybium solandri) and striped marlin (Kajikia audax) in the Red Sea, expanding the known ranges of these species into the basin. Potential mechanisms responsible for the lack of regional documentation of the two species are further discussed. These findings illustrate the need for systematic biodiversity surveys of pelagic fish assemblages in the Red Sea.
  • Preprint
    Topography and biological noise determine acoustic detectability on coral reefs
    ( 2013-07) Cagua, E. Fernando ; Berumen, Michael L. ; Tyler, E. H. M.
    Acoustic telemetry is an increasingly common tool for studying the movement patterns, behaviour, and site fidelity of marine organisms, but to accurately interpret acoustic data, the variability, periodicity and range of detectability between acoustic tags and receivers must be understood. The relative and interactive effects of topography with biological and environmental noise have not been quantified on coral reefs. We conduct two long-term range tests (one and four months duration) on two different reef types in the central Red Sea, to determine the relative effect of distance, depth, topography, time of day, wind, lunar phase, sea surface temperature and thermocline on detection probability. Detectability, as expected, declines with increasing distance between tags and receivers, and we find average detection ranges of 530 and 120 m, using V16 and V13 tags respectively, but the topography of the reef can significantly modify this relationship, reducing the range by ~70%, even when tags and receivers are in line-of-sight. Analyses that assume a relationship between distance and detections must therefore be used with care. Nighttime detection range was consistently reduced in both locations and detections varied by lunar phase in the four month test, suggesting a strong influence of biological noise (reducing detection probability up to 30%), notably more influential than other environmental noises, including wind-driven noise, which is normally considered important in open-water environments. Analysis of detections should be corrected in consideration of the diel patterns we find, and range tests or sentinel tags should be used for more than one month to quantify potential changes due to lunar phase. Some studies assume that the most usual factor limiting detection range is weather-related noise; this cannot be extrapolated to coral reefs.
  • Preprint
    First genealogy for a wild marine fish population reveals multi-generational philopatry
    ( 2016-10) Salles, Océane C. ; Pujol, Benoit ; Maynard, Jeffrey A. ; Almany, Glenn R. ; Berumen, Michael L. ; Jones, Geoffrey P. ; Saenz-Agudelo, Pablo ; Srinivasan, Maya ; Thorrold, Simon R. ; Planes, Serge
    Natal philopatry — the return of individuals to their natal area for reproduction — has advantages and disadvantages for animal populations. Natal philopatry may generate local genetic adaptation but may also increase the probability of inbreeding that can compromise persistence. While natal philopatry is well documented in anadromous fishes, marine fish may also return to their birth site to spawn. How philopatry shapes wild fish populations is, however, unclear because it requires constructing multi-generational pedigrees that are currently lacking for marine fishes. Here we present the first multi-generational pedigree for a marine fish population by repeatedly genotyping all individuals in a population of the orange clownfish (Amphiprion percula) at Kimbe Island (Papua New Guinea) over a 10-year period. Based on 2927 individuals, our pedigree analysis revealed that longitudinal philopatry was recurrent over five generations. Progeny tended to settle close to their parents, with related individuals often sharing the same colony. However, successful inbreeding was rare and genetic diversity remained high, suggesting occasional inbreeding does not impair local population persistence. Local reproductive success was dependent on the habitat larvae settled into, rather than the habitat they came from. Our study suggests that longitudinal philopatry can influence both population replenishment and local adaptation of marine fishes. Resolving multi-generational pedigrees over a relatively short time period, as we present here, provides a framework for assessing the ability of marine populations to persist and adapt to accelerating climate change.
  • Article
    Pieces in a global puzzle: population genetics at two whale shark aggregations in the western Indian Ocean
    (Wiley Open Access, 2022-01-25) Hardenstine, Royale S. ; He, Song ; Cochran, Jesse E. M. ; Braun, Camrin D. ; Cagua, E. Fernando ; Pierce, Simon J. ; Prebble, Clare E. M. ; Rohner, Christoph A. ; Saenz-Agudelo, Pablo ; Sinclair-Taylor, Tane H. ; Skomal, Gregory B. ; Thorrold, Simon R. ; Watts, Alexandra M. ; Zakroff, Casey ; Berumen, Michael L.
    The whale shark Rhincodon typus is found throughout the world's tropical and warm-temperate ocean basins. Despite their broad physical distribution, research on the species has been concentrated at a few aggregation sites. Comparing DNA sequences from sharks at different sites can provide a demographically neutral understanding of the whale shark's global ecology. Here, we created genetic profiles for 84 whale sharks from the Saudi Arabian Red Sea and 72 individuals from the coast of Tanzania using a combination of microsatellite and mitochondrial sequences. These two sites, separated by approximately 4500 km (shortest over-water distance), exhibit markedly different population demographics and behavioral ecologies. Eleven microsatellite DNA markers revealed that the two aggregation sites have similar levels of allelic richness and appear to be derived from the same source population. We sequenced the mitochondrial control region to produce multiple global haplotype networks (based on different alignment methodologies) that were broadly similar to each other in terms of population structure but suggested different demographic histories. Data from both microsatellite and mitochondrial markers demonstrated the stability of genetic diversity within the Saudi Arabian aggregation site throughout the sampling period. These results contrast previously measured declines in diversity at Ningaloo Reef, Western Australia. Mapping the geographic distribution of whale shark lineages provides insight into the species’ connectivity and can be used to direct management efforts at both local and global scales. Similarly, understanding historical fluctuations in whale shark abundance provides a baseline by which to assess current trends. Continued development of new sequencing methods and the incorporation of genomic data could lead to considerable advances in the scientific understanding of whale shark population ecology and corresponding improvements to conservation policy.
  • Article
    Community change within a Caribbean coral reef Marine Protected Area following two decades of local management
    (Public Library of Science, 2013-01-14) Noble, Mae M. ; van Laake, Gregoor ; Berumen, Michael L. ; Fulton, Christopher J.
    Structural change in both the habitat and reef-associated fish assemblages within spatially managed coral reefs can provide key insights into the benefits and limitations of Marine Protected Areas (MPAs). While MPA zoning effects on particular target species are well reported, we are yet to fully resolve the various affects of spatial management on the structure of coral reef communities over decadal time scales. Here, we document mixed affects of MPA zoning on fish density, biomass and species richness over the 21 years since establishment of the Saba Marine Park (SMP). Although we found significantly greater biomass and species richness of reef-associated fishes within shallow habitats (5 meters depth) closed to fishing, this did not hold for deeper (15 m) habitats, and there was a widespread decline (38% decrease) in live hard coral cover and a 68% loss of carnivorous reef fishes across all zones of the SMP from the 1990s to 2008. Given the importance of live coral for the maintenance and replenishment of reef fishes, and the likely role of chronic disturbance in driving coral decline across the region, we explore how local spatial management can help protect coral reef ecosystems within the context of large-scale environmental pressures and disturbances outside the purview of local MPA management.
  • Preprint
    Trade-offs associated with dietary specialization in corallivorous butterflyfishes (Chaetodontidae: Chaetodon )
    ( 2007-10-25) Berumen, Michael L. ; Pratchett, Morgan S.
    Increasing dietary specialisation is an inherently risky strategy because it increases a species’ vulnerability to resource depletion. However, risks associated with dietary specialisation may be offset by increased performance when feeding on preferred prey. Though rarely demonstrated, highly specialised species are expected to outperform generalists when feeding on their preferred prey, whereas generalists are predicted to have more similar performance across a range of different prey. To test this theory, we compared growth rates of two obligate coral-feeding butterflyfishes (Chaetodon trifascialis and C. plebeius) maintained on exclusive diets of preferred versus non-preferred prey. In the field, C. trifascialis was the most specialised species, feeding almost exclusively on just one coral species, Acropora hyacinthus. Chaetodon plebeius meanwhile, was much less specialised, but fed predominantly on Pocillopora damicornis. During growth experiments, C. trifascialis grew fastest when feeding on A. hyacinthus and did not grow at all when feeding on less preferred prey (P. damicornis and Porites cylindrica). Chaetodon plebeius performed equally well on both A. hyacinthus and P. damicornis (its preferred prey), but performed poorly when feeding on P. cylindrica. Both butterflyfishes select coral species that maximise juvenile growth, but contrary to expectations, the more specialised species (C. trifascialis) did not outperform the generalist (C. plebeius) when both consumed their preferred prey. Increased dietary specialisation, therefore, appears to be a questionable strategy as there was no evidence of any increased benefits to offset increases in susceptibility to disturbance.
  • Article
    Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the Coral Sea
    (Public Library of Science, 2014-01-08) Werry, Jonathan M. ; Planes, Serge ; Berumen, Michael L. ; Lee, Kate A. ; Braun, Camrin D. ; Clua, Eric
    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark–human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km3. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a priority for future research.