scholarly journals A cross-ocean comparison of responses to settlement cues in reef-building corals

2014 ◽  
Author(s):  
Sarah W Davies ◽  
Eli Meyer ◽  
Sarah M Guermond ◽  
Mikhail V Matz
Keyword(s):  
Climate Change ◽  
Coral Species ◽  
Coral Cover ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Coral Recruitment ◽  
Coral Larvae ◽  
Settlement Cues ◽  
The Pacific ◽  
Caribbean Coral

Caribbean coral reefs have deteriorated substantially over the past 30 years, which is broadly attributable to the effects of global climate change. In the same time, Indo-Pacific reefs maintain higher coral cover and typically recover rapidly after disturbances. This difference in reef resilience is largely due to much higher coral recruitment rates in the Pacific. We hypothesized that the lack of Caribbean coral recruitment might be explained by diminishing quality of settlement cues and/or impaired sensitivity of Caribbean coral larvae to those cues, relative to the Pacific. To evaluate this hypothesis, we assembled a collection of bulk samples of reef encrusting communities, mostly consisting of crustose coralline algae (CCA), from various reefs around the world and tested them as settlement cues for several coral species originating from different ocean provinces. Cue samples were meta-barcoded to evaluate their taxonomic diversity. We observed no systematic differences either in cue potency or in strength of larval responses depending on the ocean province, and no preference of coral larvae towards cues from the same ocean. Instead, we detected significant differences in cue preferences among coral species, even for corals originating from the same reef. We conclude that the region-wide disruption of the settlement process is unlikely to be the major cause of Caribbean reef loss. However, due to their high sensitivity to the effects of climate change, shifts in the composition of CCA-associated communities, combined with pronounced differences in cue preferences among coral species, could substantially influence future coral community structure.

scholarly journals A cross-ocean comparison of responses to settlement cues in reef-building corals

2014 ◽  
Author(s):  
Sarah W Davies ◽  
Eli Meyer ◽  
Sarah M Guermond ◽  
Mikhail V Matz
Keyword(s):  
Climate Change ◽  
Coral Species ◽  
Coral Cover ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Coral Recruitment ◽  
Coral Larvae ◽  
Settlement Cues ◽  
The Pacific ◽  
Caribbean Coral

Caribbean coral reefs have deteriorated substantially over the past 30 years, which is broadly attributable to the effects of global climate change. In the same time, Indo-Pacific reefs maintain higher coral cover and typically recover rapidly after disturbances. This difference in reef resilience is largely due to much higher coral recruitment rates in the Pacific. We hypothesized that the lack of Caribbean coral recruitment might be explained by diminishing quality of settlement cues and/or impaired sensitivity of Caribbean coral larvae to those cues, relative to the Pacific. To evaluate this hypothesis, we assembled a collection of bulk samples of reef encrusting communities, mostly consisting of crustose coralline algae (CCA), from various reefs around the world and tested them as settlement cues for several coral species originating from different ocean provinces. Cue samples were meta-barcoded to evaluate their taxonomic diversity. We observed no systematic differences either in cue potency or in strength of larval responses depending on the ocean province, and no preference of coral larvae towards cues from the same ocean. Instead, we detected significant differences in cue preferences among coral species, even for corals originating from the same reef. We conclude that the region-wide disruption of the settlement process is unlikely to be the major cause of Caribbean reef loss. However, due to their high sensitivity to the effects of climate change, shifts in the composition of CCA-associated communities, combined with pronounced differences in cue preferences among coral species, could substantially influence future coral community structure.

scholarly journals Community assessment of crustose calcifying red algae as coral recruitment substrates

2021 ◽  
Author(s):  
Mari E. Deinhart ◽  
Matthew S. Mills ◽  
Tom Schils
Keyword(s):  
Dna Sequences ◽  
Red Algae ◽  
Taxonomic Diversity ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Coral Recruitment ◽  
Successful Recruitment ◽  
Ecological Roles ◽  
Coral Reef Ecosystems ◽  
Species Specific

AbstractSuccessful recruitment of invertebrate larvae to reef substrates is essential to the health of tropical coral reef ecosystems and their capacity to recover from disturbances. Crustose calcifying red algae (CCRA) have been identified as important recruitment substrates for scleractinian corals. As such, CCRA as a whole or subgroups (e.g., crustose coralline algae, CCA) are often used at the functional group level in experimental, ecological, and monitoring studies. Species of CCRA, however, differ in their ecological roles and their value as coral recruitment substrates. Here, we (1) investigate the species richness and community composition of CCRA on experimental coral recruitment tiles, and (2) assess if there is a recruitment preference of the coral Acropora surculosa for any of these CCRA species. 27 species of two orders of CCRA (Corallinales and Peyssonneliales) were identified from the recruit tiles. None of the DNA sequences of these species matched released sequences in GenBank or sequences of CCRA collected from natural reef systems in Guam. The similarity in CCRA communities between the recruitment tiles was high. Two species of CCRA were significantly preferred as recruitment substrates over the other CCRA species. Both of these species belonged to the subfamily of the Lithophylloideae. These two species are closely related to Pacific species that have been referred to as Titanoderma -but probably have to be assigned to another genus- and many of the latter have been attributed to be preferred coral recruitment substrates. Of all CCRA, Lithophylloideae sp. 1 had the highest benthic cover on the recruitment tiles and was the most preferred recruitment substrate. These findings highlight the high taxonomic diversity of CCRA communities and provide insight into species-specific ecological roles of CCRA that are often overlooked.

scholarly journals Associations between Benthic Cover and Habitat Complexity Metrics Obtained from 3D Reconstruction of Coral Reefs at Different Resolutions

2020 ◽  
Vol 12 (6) ◽  
pp. 1011 ◽  
Author(s):  
Atsuko Fukunaga ◽  
John H. R. Burns ◽  
Kailey H. Pascoe ◽  
Randall K. Kosaki
Keyword(s):  
Fractal Dimension ◽  
Coral Reefs ◽  
Habitat Structure ◽  
Coral Cover ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Surface Areas ◽  
Abundance And Diversity

Quantifying the three-dimensional (3D) habitat structure of coral reefs is an important aspect of coral reef monitoring, as habitat architecture affects the abundance and diversity of reef organisms. Here, we used photogrammetric techniques to generate 3D reconstructions of coral reefs and examined relationships between benthic cover and various habitat metrics obtained at six different resolutions of raster cells, ranging from 1 to 32 cm. For metrics of 3D structural complexity, fractal dimension, which utilizes information on 3D surface areas obtained at different resolutions, and vector ruggedness measure (VRM) obtained at 1-, 2- or 4-cm resolution correlated well with benthic cover, with a relatively large amount of variability in these metrics being explained by the proportions of corals and crustose coralline algae. Curvature measures were, on the other hand, correlated with branching and mounding coral cover when obtained at 1-cm resolution, but the amount of variability explained by benthic cover was generally very low when obtained at all other resolutions. These results show that either fractal dimension or VRM obtained at 1-, 2- or 4-cm resolution, along with curvature obtained at 1-cm resolution, can effectively capture the 3D habitat structure provided by specific benthic organisms.

Effect of climate change on crustose coralline algae at a temperate vent site, White Island, New Zealand

2015 ◽  
Vol 66 (4) ◽  
pp. 360 ◽  
Author(s):  
T. J. Brinkman ◽  
A. M. Smith
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Dissolved Inorganic Carbon ◽  
Preliminary Investigation ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Climate Change Research ◽  
Seasonal Basis ◽  
Additional Monitoring ◽  
White Island

Natural CO2 vents allow study of the effects of climate change on marine organisms on a different scale from laboratory-based studies. This study outlines a preliminary investigation into the suitability of natural CO2 vents near White Island, Bay of Plenty, New Zealand (37°31.19′S, 117°10.85′E) for climate change research by characterising water chemistry from two vent and three control locations on a seasonal basis, as well as examining their effects on skeletons of the local calcifying crustose coralline algae. pH measurements at vent sites, calculated from dissolved inorganic carbon and alkalinity, showed reduced mean pH levels (7.49 and 7.85) relative to background levels of 8.06, whereas mean temperatures were between 0.0 and 0.4°C above control. Increases in sulfur and mercury at sites near White Island were probably a result of volcanic unrest. Crustose coralline algae did not show significant variability in skeletal Mg-calcite geochemistry, but qualitative comparisons of calcite skeletons under scanning electron microscopy saw greater deformation and dissolution in coralline algae calcite crystals from vent sites compared to controls. Although additional monitoring of pH fluctuations and hydrogen sulphides is still needed, the low pH and increased temperatures indicate potential for studying multistressor effects of projected climate changes in a natural environment.

Coral larvae change their settlement preference for crustose coralline algae dependent on availability of bare space

Coral Reefs ◽  
2018 ◽  
Vol 37 (2) ◽  
pp. 397-407 ◽  
Author(s):  
Franziska Elmer ◽  
James J. Bell ◽  
Jonathan P. A. Gardner
Keyword(s):  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Coral Larvae

Factors Affecting Coral Recruitment and Calcium Carbonate Accretion Rates on a Central Pacific Coral Reef

2021 ◽  
Author(s):  
◽  
Franziska Elmer
Keyword(s):  
Coral Reef ◽  
Calcium Carbonate ◽  
Coral Reefs ◽  
Benthic Community ◽  
Coral Cover ◽  
Coralline Algae ◽  
Benthic Organisms ◽  
Coral Recruitment ◽  
Central Pacific ◽  
Accretion Rates

<p>Coral recruitment and calcium carbonate (CaCO₃) accretion are fundamental processes that help maintain coral reefs. Many reefs worldwide have experienced degradation, including a decrease in coral cover and biodiversity. Successful coral recruitment helps degraded reefs to recover, while CaCO₃ accretion by early successional benthic organisms maintains the topographic complexity of a coral reef system. It is therefore important to understand the processes that affect coral recruitment and CaCO₃ accretion rates in order to understand how coral reefs recover from disturbances.  The aim of this thesis was to determine how biophysical forcing factors affect coral recruitment, calcification and bioerosion on a pristine coral reef. I used artificial settlement tiles to measure coral recruitment and CaCO₃ accretion at ten sites (four on the fore reef, four on the Western Reef Terrace and two at the Entrance Channel) at Palmyra Atoll. Fungia skeletons and pieces of dead coral rock were used to measure bioerosion rates, which were combined with the CaCO₃ accretion rates to obtain a net CaCO₃ budget of the reef substratum. Interactions between coral recruits and other benthic organisms on the settlement tiles were recorded to determine the settlement preferences and competitive strength of coral recruits. The settlement preference of Pocillopora damicornis for divots shaped like steephead and bumphead parrotfish bites marks was determined by adding P. damicornis larvae to a container with a settlement tile with the aforementioned divots.  I found that coral recruitment and CaCO₃ accretion are influenced by biophysical forcing factors. Most pocilloporids likely recruit close to their parents while the origin of poritid larvae is much more distant. Pocilloporid recruitment rates were also significantly correlated with the successional stage of the benthic community on the settlement tiles, especially the cover of biofilm and bryozoa. Biofilm and crustose coralline algae (CCA) were preferred as settlement substrata by coral larvae, however both pocilloporids and poritids settled on a large number of different benthic substrata. P. damicornis larvae showed a significant settlement preference for divots shaped like parrotfish bite marks over a flat settlement surface. Coral recruits were good competitors against encrusting algae but were often outcompeted by filamentous and upright algae. Settlement tiles were almost entirely colonised by benthic organisms within three to twelve months of deployment. The mass of CaCO₃ deposited onto the settlement tiles negatively correlated with herbivore grazing pressure on the benthic community. Bioerosion rates within pieces of coral (internal bioerosion) increased over time but overall bioerosion rates (internal and external) rarely exceeded CaCO₃ deposition by CCA.  My results show how variability in biophysical forcing factors leads to natural variation in coral recruitment and CaCO₃ accretion. This thesis highlights the importance of measuring herbivore grazing, CCA and turf algae cover to gain a better understanding of reef resilience. I conclude that models constructed for Caribbean reefs may not be suited to predict resilience in Pacific reefs and that within the Pacific, two different kinds of resilience models need to be constructed, one for human-inhabited coral reefs and one for uninhabited coral reefs.</p>

scholarly journals “Coral Dominance”: A Dangerous Ecosystem Misnomer?

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Peter S. Vroom
Keyword(s):  
Climate Change ◽  
Calcium Carbonate ◽  
Global Climate Change ◽  
Scientific Community ◽  
Global Climate ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Reef Management ◽  
Reef Accretion ◽  
Tropical Reef

Over 100 years ago, before threats such as global climate change and ocean acidification were issues engrossing marine scientists, numerous tropical reef biologists began expressing concern that too much emphasis was being placed on coral dominance in reef systems. These researchers believed that the scientific community was beginning to lose sight of the overall mix of calcifying organisms necessary for the healthy function of reef ecosystems and demonstrated that some reefs were naturally coral dominated with corals being the main organisms responsible for reef accretion, yet other healthy reef ecosystems were found to rely almost entirely on calcified algae and foraminifera for calcium carbonate accumulation. Despite these historical cautionary messages, many agencies today have inherited a coral-centric approach to reef management, likely to the detriment of reef ecosystems worldwide. For example, recent research has shown that crustose coralline algae, a group of plants essential for building and cementing reef systems, are in greater danger of exhibiting decreased calcification rates and increased solubility than corals in warmer and more acidic ocean environments. A shift from coral-centric views to broader ecosystem views is imperative in order to protect endangered reef systems worldwide.

scholarly journals Low recruitment due to altered settlement substrata as primary constraint for coral communities under ocean acidification

2017 ◽  
Vol 284 (1862) ◽  
pp. 20171536 ◽  
Author(s):  
Katharina E. Fabricius ◽  
Sam H. C. Noonan ◽  
David Abrego ◽  
Lindsay Harrington ◽  
Glenn De'ath
Keyword(s):  
Coral Reefs ◽  
Ocean Acidification ◽  
Field Experiments ◽  
Later Life ◽  
Coralline Algae ◽  
Life Stages ◽  
Crustose Coralline Algae ◽  
Coral Recruitment ◽  
Recovery Potential ◽  
Coral Communities

The future of coral reefs under increasing CO 2 depends on their capacity to recover from disturbances. To predict the recovery potential of coral communities that are fully acclimatized to elevated CO 2 , we compared the relative success of coral recruitment and later life stages at two volcanic CO 2 seeps and adjacent control sites in Papua New Guinea. Our field experiments showed that the effects of ocean acidification (OA) on coral recruitment rates were up to an order of magnitude greater than the effects on the survival and growth of established corals. Settlement rates, recruit and juvenile densities were best predicted by the presence of crustose coralline algae, as opposed to the direct effects of seawater CO 2 . Offspring from high CO 2 acclimatized parents had similarly impaired settlement rates as offspring from control parents. For most coral taxa, field data showed no evidence of cumulative and compounding detrimental effects of high CO 2 on successive life stages, and three taxa showed improved adult performance at high CO 2 that compensated for their low recruitment rates. Our data suggest that severely declining capacity for reefs to recover, due to altered settlement substrata and reduced coral recruitment, is likely to become a dominant mechanism of how OA will alter coral reefs.

scholarly journals Coral Resilience at Malauka`a Fringing Reef, Kāneʻohe Bay, Oʻahu after 18 years

2019 ◽  
Vol 7 (9) ◽  
pp. 311 ◽  
Author(s):  
Barnhill ◽  
Bahr
Keyword(s):  
Climate Change ◽  
Species Composition ◽  
Coral Species ◽  
Coral Cover ◽  
Kappaphycus Alvarezii ◽  
Percent Cover ◽  
Fringing Reef ◽  
Porites Compressa ◽  
Original Survey ◽  
Composition Changes

Globally, coral reefs are under threat from climate change and increasingly frequent bleaching events. However, corals in Kāneʻohe Bay, Hawaiʻi have demonstrated the ability to acclimatize and resist increasing temperatures. Benthic cover (i.e., coral, algae, other) was compared over an 18 year period (2000 vs. 2018) to estimate species composition changes. Despite a climate change induced 0.96°C temperature increase and two major bleaching events within the 18-year period, the fringing reef saw no significant change in total coral cover (%) or relative coral species composition in the two dominant reef-building corals, Porites compressa and Montipora capitata. However, the loss of two coral species (Pocillopora meandrina and Porites lobata) and the addition of one new coral species (Leptastrea purpurea) between surveys indicates that while the fringing reef remains intact, a shift in species composition has occurred. While total non-coral substrate cover (%) increased from 2000 to 2018, two species of algae (Gracilaria salicornia and Kappaphycus alvarezii) present in the original survey were absent in 2018. The previously dominant algae Dictyosphaeria spp. significantly decreased in percent cover between surveys. The survival of the studied fringing reef indicates resilience and suggests these Hawaiian corals are capable of acclimatization to climate change and bleaching events.

Indicators of coral reef ecosystem recovery following reduction in logging and implementation of community-based management schemes in the Solomon Islands.

2014 ◽  
Vol 20 (1) ◽  
pp. 75 ◽  
Author(s):  
S Albert ◽  
A Grinham ◽  
B Gibbes ◽  
I Tibbetts ◽  
J udy
Keyword(s):  
Water Quality ◽  
Management Practices ◽  
Pacific Islands ◽  
Coral Cover ◽  
Solomon Islands ◽  
Coralline Algae ◽  
Herbivorous Fish ◽  
Crustose Coralline Algae ◽  
Ecosystem Recovery ◽  
Community Based

The livelihood of many coastal communities in the Pacific Islands is directly dependent on the health of adjacent coral reefs. Reduction in water quality and over-harvesting of herbivorous fish are known to drive reef ecosystems towards a more degraded state. Community-based resource management practices have the potential to improve damaged reefs but quantitative data on their effectiveness remains largely unreported. This study investigated how land use changes and implementation of marine management influenced water quality, herbivorous fish biomass and reef condition of Marovo Lagoon in the Solomon Islands. Four study sites were located along a gradient of water quality, with two of the sites located inside marine protected areas (MPAs) designated in 2006. The results suggest that water quality in coastal areas adjacent to catchments modified by logging was negatively impacted. However, following natural revegetation of bare soil in the catchment between 2000 and 2010, water quality improved at all sites. The biomass of herbivorous fish was significantly greater in the MPAs compared to other sites and, importantly, we detected an increase in herbivore biomass between 2005 and 2008. Inshore reefs adjacent to logging operations had significantly lower coral cover and higher macroalgal cover than those offshore. Between 2005 and 2008 all sites showed an increase in crustose coralline algae cover and a decrease in turf algae colonising rocks, with the changes indicative of improving reef health. Collectively, these results indicate that reduction in logging and implementation of community-based management can have a positive influence on reefs in Marovo Lagoon.

Sign in / Sign up

Export Citation Format

Share Document