Dataset Information

Growth estimates of Caribbean reef sponges on a shipwreck using 3D photogrammetry.

ABSTRACT: The growth rates and ages of many benthic marine organisms are poorly understood, complicating our understanding of ecosystem change. This is particularly true for sponges, which are morphologically diverse and lack indicators of annual growth. In this study, we used emerging technologies to measure volume, surface area, and approximate age of 16 sponge species on the Tibbetts shipwreck off Cayman Brac, Caribbean Sea. Photogrammetry was used to determine the volume of individual sponges on the wreck surface, and a time series of YouTube videos was amassed in order to approximate the greatest possible age of the sponges as 8.74 y. Applying the volume measurements to an existing growth equation for the Caribbean sponge Aiolochroia crassa yielded age estimates of 5.2-10.4 y for the largest individuals of the 16 species. Specific growth rates were then calculated for 7 species from the Tibbetts and 8 species from a second shipwreck (Spiegel Grove, Key Largo, FL). Subsequent growth forecasts from these 15 species corroborate a resource trade-off between growth and the production of chemical defenses. Shipwrecks and other anthropogenic structures can be an important source of demographic information for benthic organisms, provided that certain assumptions about their provenance and history can be met.

SUBMITTER: Olinger LK

PROVIDER: S-EPMC6895235 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Growth estimates of Caribbean reef sponges on a shipwreck using 3D photogrammetry.

Olinger Lauren K LK Scott Alexander R AR McMurray Steven E SE Pawlik Joseph R JR

Scientific reports 20191205 1

The growth rates and ages of many benthic marine organisms are poorly understood, complicating our understanding of ecosystem change. This is particularly true for sponges, which are morphologically diverse and lack indicators of annual growth. In this study, we used emerging technologies to measure volume, surface area, and approximate age of 16 sponge species on the Tibbetts shipwreck off Cayman Brac, Caribbean Sea. Photogrammetry was used to determine the volume of individual sponges on the w ...[more]

PMID: 31804527

Similar Datasets

Project description:The characterisation of changes in coral communities depends heavily on systematic monitoring programs and the collection of necessary metrics to assess reef health. Coral cover is the most used metric to determine reef health. The current organizational shift in coral requires the evaluation of complementary metrics, such as colony size and frequency distributions, which help to infer the responses of the coral populations to local stress or larger scale environmental changes. In this study, underwater digital photogrammetry techniques were used to assess the live cover of all coral colonies ≥3 cm2 and determine the size-frequency distribution of the dominant species in the shallow reefs of the Cozumel Reefs National Park (CRNP). In addition, the minimum sampling area (m2) needed to obtain a representative sample of the local species pool was estimated. Areas between 550 and 825 m2 per reef were photographed to generate high-resolution digital ortho-mosaics. The live area of the colonies was digitised to generate community matrices of species and abundance. EstimateS software was used to generate accumulation curves and diversity (Shannon H') at increasing area intervals. Chi-Square tests (χ 2, p = 0.05) were used to compare the observed vs estimated species richness. Spearman's coefficients (r s ), were calculated to correlate the increase in sampling area (m2) vs H', and the Clench's function was used to validate the observed richness (R 2 = 1 and R > 90%). SIMPER analysis was performed to identify dominant species. Comparisons in terms of abundance, coral cover and size-frequencies were performed with Kruskal-Wallis (H test, p = 0.05), and paired Mann-Whitney (U test, p = 0.05). In order to obtain 90% of the species richness, a minimum sampling area of 374 m2is needed. This sampling area could be used in shallow Caribbean reefs with similar characteristics. Twelve (mainly non-massive) species: Agaricia agaricites, A humilis, A. tenuifolia, Eusmilia fastigiata, Meandrina meandrites, Montastrea cavernosa, Orbicella annularis, Porites astreoides, P. porites, Pseudodiploria strigosa, Siderastrea radians andS. siderea, were dominant in terms of abundance and coral cover. A significant increase (p < 0.05) in the number of colonies and live coral (m2) was observed from north to south of the study area. Furthermore, a wide intraspecific variation of size-frequency, even between adjacent reefs, was also observed. The size-frequency distributions presented positive skewness and negative kurtosis, which are related to stable populations, with a greater number of young colonies and a constant input of recruits. Considering the increase in disturbances in the Caribbean and the appearance of a new coral disease, digital photogrammetry techniques allow coral community characteristics to be assessed at high spatial resolutions and over large scales, which would be complementary to conventional monitoring programs.

Project description:BackgroundHerbivory is an important top-down force on coral reefs that regulates macroalgal abundance, mediates competitive interactions between macroalgae and corals, and provides resilience following disturbances such as hurricanes and coral bleaching. However, reductions in herbivore diversity and abundance via disease or over-fishing may harm corals directly and may indirectly increase coral susceptibility to other disturbances.Methodology and principal findingsIn two experiments over two years, we enclosed equivalent densities and masses of either single-species or mixed-species of herbivorous fishes in replicate, 4 m(2) cages at a depth of 17 m on a reef in the Florida Keys, USA to evaluate the effects of herbivore identity and species richness on colonization and development of macroalgal communities and the cascading effects of algae on coral growth. In Year 1, we used the redband parrotfish (Sparisoma aurofrenatum) and the ocean surgeonfish (Acanthurus bahianus); in Year 2, we used the redband parrotfish and the princess parrotfish (Scarus taeniopterus). On new substrates, rapid grazing by ocean surgeonfish and princess parrotfish kept communities in an early successional stage dominated by short, filamentous algae and crustose coralline algae that did not suppress coral growth. In contrast, feeding by redband parrotfish allowed an accumulation of tall filaments and later successional macroalgae that suppressed coral growth. These patterns contrast with patterns from established communities not undergoing primary succession; on established substrates redband parrotfish significantly reduced upright macroalgal cover while ocean surgeonfish and princess parrotfish allowed significant increases in late successional macroalgae.SignificanceThis study further highlights the importance of biodiversity in affecting ecosystem function in that different species of herbivorous fishes had very different impacts on reef communities depending on the developmental stage of the community. The species-specific effects of herbivorous fishes suggest that a species-rich herbivore fauna can be critical in providing the resilience that reefs need for recovery from common disturbances such as coral bleaching and storm damage.

Dataset Information

Growth estimates of Caribbean reef sponges on a shipwreck using 3D photogrammetry.

Publications

Growth estimates of Caribbean reef sponges on a shipwreck using 3D photogrammetry.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets