Effects of coral-dwelling damselfishes' abundances and diversity on host coral dynamics

Interspecific interactions, particularly positive interactions, between organisms and their physical environment are important forces in shaping ecological diversity and ecosystem structure. In coral reef ecosystems, the associations between habitat-forming corals and coral reef fishes have critical implications for the structure and function of coral reef ecosystems. Coral-dwelling damselfishes rely on branching corals for shelter and confer benefits to their host corals that promote enhanced performance, growth, and colony health. However, there is variability (in strength and symmetry) in both fish-derived and coral responses to abiotic factors and partner ecology. Global environmental change is likely to considerably disrupt fish-coral interactions on reefs through reef degradation, coastal sedimentation, and severe widespread bleaching events. Prior to collapse, however, fish-coral interactions have the potential to act as stabilizing forces on reefs, promoting coexistence, and enhancing the coral holobiont during accelerated environmental change. Thus, the overall focus of this thesis was to understand the relationship between coral-dwelling damselfishes and their small branching coral colony hosts. Specifically, I investigated the prevalence of these fish-coral associations across space, the variations in the intensity of damselfish-coral interactions over time and evaluated the influence of these coral-dwelling damselfishes on the health of their host corals under two types of environmental stress. In Chapter 2, I addressed one of the critical first steps to understanding the magnitude by which coral-dwelling damselfishes impact coral health by establishing the abundance and prevalence of select, fish-coral interaction pairs across different coral colonies, habitats, and seascapes. Through a series of underwater surveys at locations spanning > 1700 km of the Great Barrier Reef, I aimed to: (a) determine if suitable coral habitat governs patterns in damselfishes' distributions and abundances, and (b) quantify variations in damselfish species-specific biomass among coral colonies species. The abundance of fish-coral associations varied with respect to exposure level and habitat with an overall average prevalence of ~30% occupancy, with biomass hotspots confined to sheltered lagoon sand patch and reef slope habitats. Further analysis of colony microstructure traits revealed that isolation from adjacent colonies, branch spacing patterns, and colony orientation governed fine-scale usage. The research presented in Chapter 2 illustrates that coral occupancy (coral-dwelling or sole habitat use) varies significantly by damselfish species, and subsequent fish-derived services are confined to specific reef habitats. While coral-dwelling damselfishes are intimately associated with branching corals, interspecific behavioural variation can alter the nature and strength of these interactions with corals, thereby altering the dynamics of small-scale coral association networks and benefits conferred to host corals. Chapter 3 used in-situ observations to explore interspecific differences in diurnal and nocturnal behaviour among five coral-dwelling damselfish species. Resident damselfishes displayed marked differences in colony interaction and usage, with Dasycllus species exhibiting frequent and sustained interactions with host corals. Pomacentrus species displayed weaker associations and behaviours consistent with commensalistic interactions. Host coral bleaching status altered damselfishes' interactions with colonies, forecasting shifting interchanges between fishes and corals under future stress conditions. Quantifying these focal fishes' behaviours through small-scale observations is relevant to interspecific interactions and coral holobiont persistence, as environmental stressors alter the prevalence of coral-damselfish interactions and the intensity of associated mutualistic services. Global environmental change, particularly in the forms of amplified sedimentation and elevated sea-surface temperatures, could pose to significantly alter how these fish-coral interactions function in isolation and as components of the entire coral holobiont. Many species interactions, mutualistic ones in particular, arise from the ability of species to modify local conditions and diminish stress for their own benefit as well as for their partners, thereby conferring resilience. In Chapters 4 and 5, I evaluated the influence of coral-dwelling fishes (Dascyllus aruanus and Pomacentrus moluccensis, selected due to their abundance and behaviours exhibited in Chapters 2 and 3) on the health of their host corals (Pocillopora damicornis) under two types of environmental stress. When exposing the fish-coral system to daily manipulated severe sedimentation stress in Chapter 4, damselfishes were able to significantly reduce sediment accumulation and sediment-induced partial mortality on coral hosts, 2-10-fold more, compared with fish-vacant colonies. Colonies with Dascyllus aruanus exhibited up to two-fold higher chlorophyll and protein concentrations under sediment conditions compared with other treatments, reinforcing the positive nature and benefits connected with a frequent and sustained (strong) interaction with host colonies. Further linking these results to the behaviour of the damselfish species (Chapter 3), diurnal and nocturnal position of D. aruanus and P. moluccensis in aquaria, helped explain the species-specific services rendered. In Chapter 4, I demonstrated that fish mutualisms may be critical for maintaining coral health and resilience under chronic and severe sediment stress and indicated that some mutualistic or facilitative interactions may become more important for species persistence as stress levels increase. Many studies have independently investigated the effects of increased sea-surface temperatures on fishes and coral bleaching, but little is known about the impacts of coral-dwelling damselfishes on the health of their coral hosts, during and after a thermal-bleaching event. With many services that damselfishes provide to their host colonies, especially those that mimic natural mechanisms mitigating external stress, in Chapter 5, I hypothesized that colonies with symbiont damselfishes would bleach less and recover more quickly during thermal bleaching events, compared to vacant corals, due to key services of enhanced water flow and nutrients. During a natural thermal anomaly, it is evident that P. damicornis with damselfish that are subjected to temperature stress have higher Symbiodinium (+25%), chlorophyll (+30%), and tissue proteins (+57%). These results were reflected in a manipulated thermal bleaching experiment in aquaria, where corals with damselfish subjected to temperature stress again had significantly more Symbiodinium (five-fold), chlorophyll (nine-fold), and tissue biomass (three-fold) compared with vacant colonies during the recovery period. Tissue component differences translated into considerably higher photosynthetic rates in P. damicornis colonies with fish, compared with non-damselfish colonies. However, from the in-situ results from the 2016 bleaching event, it is evident that this fish influence on colony susceptibility/resilience and recovery operates only under moderate level stressors, as severe bleaching events overwhelm the coral holobiont, rendering fish-services insufficient to maintain coral health. This thesis reveals the importance of resident fishes as a fundamental aspect of the dynamic interface between corals and the abiotic environment. Although limited spatially across reef seascapes, and heavily dependent upon the species-specific behaviour of fish partners, these findings suggest that certain coral-dwelling damselfishes have the ability to mediate the impacts of environmental change with regards to coral colony stress susceptibility and survival

BioTIME: A database of biodiversity time series for the Anthropocene.

MotivationThe BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables includedThe database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grainBioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2).Time period and grainBioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurementBioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.Software format.csv and .SQL

Diurnal foraging of a wild coral-reef fish Parapercis australis in relation to late-summer temperatures

In situ observations of diurnal foraging behaviour of a common site-attached shallow reef mesopredator Parapercis australis during late summer, revealed that although diet composition was unaffected by seawater temperature (range 28.3-32.4 degrees C), feeding strikes and distance moved increased with temperature up to 30.5 degrees C, beyond which they sharply declined, indicative of currently living beyond their thermal optimum. Diel feeding strikes and distance moved were however, tightly linked to ambient temperature as it related to the population's apparent thermal optimum, peaking at times when it was approached (1230 and 1700 h) and declining up to four fold at times deviating from this. These findings suggest that although this population may be currently living beyond its thermal optimum, it copes by down regulating energetically costly foraging movement and consumption and under future oceanic temperatures, these behavioural modifications are probably insufficient to avoid deleterious effects on population viability without the aid of long-term acclimation or adaptation

Diurnal foraging of a wild coral-reef fish Parapercis australis in relation to late-summer temperatures

In situ observations of diurnal foraging behaviour of a common site-attached shallow reef mesopredator Parapercis australis during late summer, revealed that although diet composition was unaffected by seawater temperature (range 28.3-32.4 degrees C), feeding strikes and distance moved increased with temperature up to 30.5 degrees C, beyond which they sharply declined, indicative of currently living beyond their thermal optimum. Diel feeding strikes and distance moved were however, tightly linked to ambient temperature as it related to the population's apparent thermal optimum, peaking at times when it was approached (1230 and 1700 h) and declining up to four fold at times deviating from this. These findings suggest that although this population may be currently living beyond its thermal optimum, it copes by down regulating energetically costly foraging movement and consumption and under future oceanic temperatures, these behavioural modifications are probably insufficient to avoid deleterious effects on population viability without the aid of long-term acclimation or adaptation

BioTIME: A database of biodiversity time series for the Anthropocene

Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km(2) (158 cm(2)) to 100 km(2) (1,000,000,000,000 cm(2)). Time period and grainBio: TIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.European Research Council; EU [AdG-250189, PoC-727440, ERC-SyG-2013-610028]; Natural Environmental Research Council [NE/L002531/1]; National Science Foundation [DEB-1237733, DEB-1456729, 9714103, 0632263, 0856516, 1432277, DEB 9705814, BSR-8811902, DEB 9411973, DEB 0080538, DEB 0218039, DEB 0620910, DEB 0963447, DEB-1546686, DEB-129764]; National Science Foundation (LTER) [DEB-1235828, DEB-1440297, DBI-0620409, DEB-9910514, DEB-1237517, OCE-0417412, OCE-1026851, OCE-1236905, OCE-1637396, DEB 1440409, DEB-0832652, DEB-0936498, DEB-0620652, DEB-1234162, DEB-0823293, OCE-9982105, OCE-0620276, OCE-1232779]; Fundacao para a Ciencia e Tecnologia [POPH/FSE SFRH/BD/90469/2012, SFRH/BD/84030/2012, PTDC/BIA-BIC/111184/2009]; Ciencia sem Fronteiras/CAPES [1091/13-1]; Instituto Milenio de Oceanografia [IC120019]; ARC Centre of Excellence [CE0561432]; NSERC Canada; CONICYT/FONDECYT [1160026, ICM PO5-002, 11110351, 1151094, 1070808, 1130511]; RSF [14-50-00029]; Gordon and Betty Moore Foundation [GBMF4563]; Catalan Government; Marie Curie Individual Fellowship [QLK5-CT2002-51518, MERG-CT-2004-022065]; CNPq [306170/2015-9, 475434/2010-2, 403809/2012-6, 561897/2010, 306595-2014-1]; FAPESP (Sao Paulo Research Foundation) [2015/10714-6, 2015/06743-0, 2008/10049-9, 2013/50714-0, 1999/09635-0 e 2013/50718-5]; EU CLIMOOR [ENV4-CT97-0694]; VULCAN [EVK2-CT2000-00094]; DFG [120/10-2]; Polar Continental Shelf Program; CENPES - PETROBRAS; FAPERJ [E-26/110.114/ 2013]; German Academic Exchange Service; New Zealand Department of Conservation; Wellcome Trust [105621/Z/14/Z]; Smithsonian Atherton Seidell Fund; Botanic Gardens and Parks Authority; Research Council of Norway; Conselleria de Innovacio, Hisenda i Economia; Yukon Government Herschel Island-Qikiqtaruk Territorial Park; UK Natural Environment Research Council ShrubTundra Grant [NE/M016323/1]; IPY; Memorial University; ArcticNet; Netherlands Organization for Scientific Research in the Tropics NWO [W84-194]; Ciencias sem Fronteiras and Coordenacao de Pessoal de Nivel Superior (CAPES, Brazil) [1091/13-1]; U.S. Fish and Wildlife Service/State Wildlife federal grant [T-15]; Australian Research Council Centre of Excellence for Coral Reef Studies [CE140100020]; Australian Research Council Future Fellowship [FT110100609]; University of Lodz; NSF DEB [1353139]; Catalan Government fellowships (DURSI) [1998FI-00596, 2001BEAI200208]; MECD Post-doctoral fellowship [EX2002-0022]; FONDECYT [1141037]; FONDAP [15150003]; [SFRH/BD/80488/2011]; [PD/BD/52597/2014]; [REN2000-0278/CCI]; [REN2001-003/GLO]; [CGL2016-79835-P]; [AGAUR SGR-2014453]; [SGR-2017-1005]; [FCT - SFRH / BPD / 82259 / 2011]; [OCE 95-21184]; [OCE-0099226]; [OCE 03-5234]; [OCE-0623874]; [OCE-1031061]; [OCE-1336206]; [DEB-1354563]; [OPP-1440435]12 month embargo; published online: 24 July 2018This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

BioTIME:a database of biodiversity time series for the Anthropocene

Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of two, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology andcontextual information about each record.Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1 000 000 000 000 cm2).Time period and grain: BioTIME records span from 1874 to 2016. The minimum temporal grain across all datasets in BioTIME is year.Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton, and terrestrial invertebrates to small and large vertebrates.Software format: .csv and .SQ

Are rare species useful species? Obstacles to the conservation of tree diversity in the dry forest zone agro-ecosystems of Mesoamerica

Aim To test the potential to conserve rare dry forest tree and shrub species circa situm.Location Oaxaca, Mexico and Southern Honduras.Methods Local uses (timber, posts and firewood) of species were determined principally through semistructured interviews with 20 rural householders in each of four communities in Honduras and four in Oaxaca. Tree and shrub diversity inventories were carried out in a total of 227 forest patches and parcels of farmland in those eight communities. Species’ conservation priorities were determined using the star system of Hawthorne (1996) and IUCN listings.Results Despite a large number of useful species, remarkably few were also conservation priorities. Useful species were found to be substitutable as is illustrated by Bombacopsis quinata, Cordia alliodora, Guaiacum sanctum and G. coulteri.Conclusions In these areas, circa situm conservation is inhibited by the lack of species that are both rare and useful. Usefulness must be interpreted as a function of substitutability. Natural regeneration provides an abundance of diversity, farmers are unlikely to invest in the management of a species when suitable substitutes are freely available. The key to conserving rare species may be in maintaining or enhancing the value of the landscape elements in which they are found

BioTIME:a database of biodiversity time series for the Anthropocene

Abstract Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community‐led open‐source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km² (158 cm²) to 100 km² (1,000,000,000,000 cm²). Time period and grain: BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates. Software format: .csv and .SQL