The Evolutionary Diversity and Ecological Complexity of Coral Reefs

Coral reefs are the most biodiverse marine ecosystems on the planet, with at least one quarter of all marine species associated with reefs today. This diversity, which remains very poorly understood, is nevertheless extraordinary when one considers the small proportion of ocean area that is occupied by coral reefs. Networks of competitive and trophic linkages are also exceptionally complex and dense. Reefs have a long fossil record, although extensive reef building comes and goes. In the present, coral reefs sometimes respond dramatically to disturbances, and collapses are not always followed by recoveries. Today, much of this failure to recover appears to stem from the fact that most reefs are chronically stressed by human activities, judging by observations of recovery at exceptional locations where local human activity is minimal. How long reefs can continue to bounce back in the face of warming and acidification remains an open question. Another big uncertainty is how much loss of biodiversity will occur with the inevitable degradation of coral reefs that will continue in most places for the foreseeable future.

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Mars: was There an Ancient Eden?

International Astronomical Union Colloquium ◽

10.1017/s025292110001472x ◽

1997 ◽

Vol 161 ◽

pp. 203-218 ◽

Cited By ~ 3

Author(s):

Tobias C. Owen

Keyword(s):

Positive Answer ◽

Biogenic Elements ◽

Habitable Zones ◽

The Face ◽

The Origin Of Life ◽

Early Mars ◽

Favorable Conditions ◽

Open Question ◽

Rocky Planets ◽

Impact Erosion

AbstractThe clear evidence of water erosion on the surface of Mars suggests an early climate much more clement than the present one. Using a model for the origin of inner planet atmospheres by icy planetesimal impact, it is possible to reconstruct the original volatile inventory on Mars, starting from the thin atmosphere we observe today. Evidence for cometary impact can be found in the present abundances and isotope ratios of gases in the atmosphere and in SNC meteorites. If we invoke impact erosion to account for the present excess of129Xe, we predict an early inventory equivalent to at least 7.5 bars of CO2. This reservoir of volatiles is adequate to produce a substantial greenhouse effect, provided there is some small addition of SO2(volcanoes) or reduced gases (cometary impact). Thus it seems likely that conditions on early Mars were suitable for the origin of life – biogenic elements and liquid water were present at favorable conditions of pressure and temperature. Whether life began on Mars remains an open question, receiving hints of a positive answer from recent work on one of the Martian meteorites. The implications for habitable zones around other stars include the need to have rocky planets with sufficient mass to preserve atmospheres in the face of intensive early bombardment.

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Impacts of stratospheric aerosol geoengineering strategy on Caribbean coral reefs

International Journal of Climate Change Strategies and Management ◽

10.1108/ijccsm-05-2017-0104 ◽

2018 ◽

Vol 10 (4) ◽

pp. 523-532 ◽

Cited By ~ 3

Author(s):

Zhihua Zhang ◽

Andy Jones ◽

M. James C. Crabbe

Keyword(s):

Coral Reefs ◽

Climate Model ◽

Marine Species ◽

Stratospheric Aerosol ◽

Solar Irradiation ◽

Content Type ◽

Hurricane Damage ◽

Carbon Emissions Reduction ◽

Caribbean Coral Reefs ◽

First Time

Purpose Currently, negotiation on global carbon emissions reduction is very difficult owing to lack of international willingness. In response, geoengineering (climate engineering) strategies are proposed to artificially cool the planet. Meanwhile, as the harbor around one-third of all described marine species, coral reefs are the most sensitive ecosystem on the planet to climate change. However, until now, there is no quantitative assessment on the impacts of geoengineering on coral reefs. This study aims to model the impacts of stratospheric aerosol geoengineering on coral reefs. Design/methodology/approach The HadGEM2-ES climate model is used to model and evaluate the impacts of stratospheric aerosol geoengineering on coral reefs. Findings This study shows that (1) stratospheric aerosol geoengineering could significantly mitigate future coral bleaching throughout the Caribbean Sea; (2) Changes in downward solar irradiation, sea level rise and sea surface temperature caused by geoengineering implementation should have very little impacts on coral reefs; (3) Although geoengineering would prolong the return period of future hurricanes, this may still be too short to ensure coral recruitment and survival after hurricane damage. Originality/value This is the first time internationally to quantitatively assess the impacts of geoengineering on coral reefs.

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Phenotypic states become increasingly sensitive to perturbations near a bifurcation in a synthetic gene network

eLife ◽

10.7554/elife.07935 ◽

2015 ◽

Vol 4 ◽

Cited By ~ 15

Author(s):

Kevin Axelrod ◽

Alvaro Sanchez ◽

Jeff Gore

Keyword(s):

Gene Network ◽

Environmental Variability ◽

Synthetic Gene ◽

Phenotypic Switching ◽

Proper Function ◽

Critical Transition ◽

Environmental Perturbations ◽

The Face ◽

Synthetic Gene Network ◽

Open Question

Microorganisms often exhibit a history-dependent phenotypic response after exposure to a stimulus which can be imperative for proper function. However, cells frequently experience unexpected environmental perturbations that might induce phenotypic switching. How cells maintain phenotypic states in the face of environmental fluctuations remains an open question. Here, we use environmental perturbations to characterize the resilience of phenotypic states in a synthetic gene network near a critical transition. We find that far from the critical transition an environmental perturbation may induce little to no phenotypic switching, whereas close to the critical transition the same perturbation can cause many cells to switch phenotypic states. This loss of resilience was observed for perturbations that interact directly with the gene circuit as well as for a variety of generic perturbations-such as salt, ethanol, or temperature shocks-that alter the state of the cell more broadly. We obtain qualitatively similar findings in natural gene circuits, such as the yeast GAL network. Our findings illustrate how phenotypic memory can become destabilized by environmental variability near a critical transition.

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Adding fossil occupancy trajectories to the assessment of modern extinction risk

Biology Letters ◽

10.1098/rsbl.2015.0813 ◽

2016 ◽

Vol 12 (10) ◽

pp. 20150813 ◽

Cited By ~ 7

Author(s):

Wolfgang Kiessling ◽

Ádám T. Kocsis

Keyword(s):

Fossil Record ◽

Extinction Risk ◽

Strong Predictor ◽

Marine Species ◽

Species Traits ◽

Latent Extinction ◽

Extant Species ◽

Temporal Trajectory

Besides helping to identify species traits that are commonly linked to extinction risk, the fossil record may also be directly relevant for assessing the extinction risk of extant species. Standing geographical distribution or occupancy is a strong predictor of both recent and past extinction risk, but the role of changes in occupancy is less widely assessed. Here we demonstrate, based on the Cenozoic fossil record of marine species, that both occupancy and its temporal trajectory are significant determinants of risk. Based on extinct species we develop a model on the additive and interacting effects of occupancy and its temporal changes on extinction risk. We use this model to predict extinction risk of extant species. The predictions suggest a moderate risk for marine species on average. However, some species seem to be on a long-term decline and potentially at a latent extinction risk, which is not considered in current risk assessments.

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Coral microatolls and a probable Middle Ordovician example

Journal of Paleontology ◽

10.1017/s0022336000042220 ◽

1990 ◽

Vol 64 (1) ◽

pp. 39-43 ◽

Cited By ~ 7

Author(s):

David R. Kobluk ◽

Iqbal Noor

Keyword(s):

Coral Reefs ◽

Fossil Record ◽

Scleractinian Coral ◽

Regional Scale ◽

Southern Ontario ◽

Middle Ordovician ◽

Reef Environments ◽

Maximum Water ◽

Water Depths ◽

Tabulate Corals

A disk-shaped massive colony of Tetradium, from the Middle Ordovician Bobcaygeon Formation in southern Ontario, displays features of a coral microatoll. This is the first pre-Holocene coral microatoll yet described, indicating that some tabulate corals in level-bottom communities were growing as microatolls as do many modern colonial skeleton-secreting organisms.The microatoll therefore is not strictly a Quaternary or even Cenozoic phenomenon, but has a fossil record that may span most of the Phanerozoic. This indicates that the special conditions necessary for microatoll growth have existed outside of reef environments, and were present before the advent of scleractinian coral reefs. It may be possible to use ancient microatolls to estimate absolute water depths at low tide, thereby providing a means for estimating maximum water depths on a local and regional scale.

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Secure local aquatic food systems in the face of declining coral reefs

One Earth ◽

10.1016/j.oneear.2021.08.023 ◽

2021 ◽

Vol 4 (9) ◽

pp. 1214-1216

Author(s):

Christina C. Hicks ◽

Nicholas A.J. Graham ◽

Eva Maire ◽

James P.W. Robinson

Keyword(s):

Coral Reefs ◽

Food Systems ◽

The Face ◽

Aquatic Food

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6. Reef fish and other major predators

10.1093/actrade/9780199682775.003.0006 ◽

2014 ◽

Author(s):

Charles Sheppard

Keyword(s):

Coral Reef ◽

Coral Reefs ◽

Reef Fish ◽

Feeding Ecology ◽

Natural Habitat ◽

Marine Species ◽

Reef Fishes ◽

Symbiotic Relationships ◽

The Earth ◽

Reef Communities

Healthy reefs provide a habitat for an immense number of fish that come in a variety of shapes, sizes, and colours. No other natural habitat in the ocean shows this diversity and abundance. About a quarter of all marine species may be found on coral reefs even though this habitat occupies only one or two per cent of the area of the earth. ‘Reef fish and other major predators’ describes the diverse feeding ecology of reef fishes; coral reef predators such as the colourful crown of thorns starfish, Acanthaster plancii; symbiotic relationships between different species of fish or with different invertebrates; and the dangers of overfishing in reef communities.

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The Changing Face of the Television Industry

Media Information Australia ◽

10.1177/1329878x8704400105 ◽

1987 ◽

Vol 44 (1) ◽

pp. 16-17

Author(s):

Kate Harrison

Keyword(s):

Foreseeable Future ◽

Television Industry ◽

Dominant Position ◽

Television Station ◽

The Face ◽

As If

In the last few months the face of television station ownership in Australia has changed dramatically. While a year ago it looked as if major owners such as Packer and Murdoch would remain in a dominant position in the television industry for the foreseeable future, now both Packer and Murdoch have sold off their stations, and media watchers are facing a new line-up of television owners.

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Conservation evidence from climate-related stressors in the deep-time marine fossil record

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2019.0223 ◽

2019 ◽

Vol 374 (1788) ◽

pp. 20190223 ◽

Cited By ~ 1

Author(s):

Matthew E. Clapham

Keyword(s):

Global Change ◽

Fossil Record ◽

Extinction Risk ◽

Marine Species ◽

Activity Levels ◽

Deep Time ◽

Geographical Patterns ◽

Time Record ◽

Uncertain Future ◽

Natural Settings

Conservation of marine species requires the ability to predict the effects of climate-related stressors in an uncertain future. Experiments and observations in modern settings provide crucial information, but lack temporal scale and cannot anticipate emergent effects during ongoing global change. By contrast, the deep-time fossil record contains the long-term perspective at multiple global change events that can be used, at a broad scale, to test hypothesized effects of climate-related stressors. For example, geologically rapid carbon cycle disruption has often caused crises in reef ecosystems, and selective extinctions support the hypothesis that greater activity levels promote survival. Geographical patterns of extinction and extirpation were more variable than predicted from modern physiology, with tropical and temperate extinction peaks observed at different ancient events. Like any data source, the deep-time record has limitations but also provides opportunities that complement the limitations of modern and historical data. In particular, the deep-time record is the best source of information on actual outcomes of climate-related stressors in natural settings and over evolutionary timescales. Closer integration of modern and deep-time evidence can expand the types of hypotheses testable with the fossil record, yielding better predictions of extinction risk as climate-related stressors continue to intensify in future oceans. This article is part of a discussion meeting issue ‘The past is a foreign country: how much can the fossil record actually inform conservation?’

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