The Effects of Climate Change and Disruption on Coral Mortality and Associated Implications

by Fatima Ammar (2018)

Introduction

Coral reefs are amongst the most biodiverse ecosystems in the world. They are depended upon by several hundred million people in the world for food, jobs, and protection against storms and erosion (NOAA Gov, 2017). 

Coral bleaching, a large scale event that causes significant damage to the reefs, has a global impact on economy, tourism, fishery, and ecology. Corals produce over 70% of the world’s oxygen supply meaning that serious endangerment of the coral reefs could be hazardous to life. The rapid decline of coral reefs has shown to cause the decline of multiple other marine species thus disturbing the natural balance within the marine ecosystem (NOOA, 2017).  

Observing the biggest threats to coral reefs will help better understand the importance of preserving the reefs and how to prevent this decline. It will also show how these factors cause corals to bleach and why this happens (Vaughan, 2017).  

The leading research on coral growth and bleaching utilises the latest technologies to measure photosynthesis, photoinhibition, growth, and adaptability.  Pulse-Amplitude Modulated Fluorescence spectroscopy (PAM), a non-invasive method, has been used in recent years to note how zooxanthellae react to different lighting spectrums and even observe photoinhibition at a more intimate level by measuring chlorophyll fluorescence and the stress levels (non-chemical quenching) of the algae under high lighting or heating (Muller et al, 2001). These methods produce the most accurate and precise results possible. 

Bleaching occurs when corals become stressed. Bleaching is when a stressed coral dispels its microalgae from its polyps. This is thought to be a response to photosynthetic damage within the symbionts. It is named bleaching as colourful specimens become ghostly white when they lose the photosynthetic pigmentation provided by the zooxanthellae. Usually this will result in the death of the coral host as it relies heavily on the endosymbiotic relationship with the dinoflagellates (Guldberg, 2011; Welle, 2017). 

Bleaching inhibits coral growth and can disrupt reproduction which reduces the abundance of many species. If conditions are altered, these effects may be temporary as some zooxanthellae may return to host polyps. However, recovery requires a long period under optimal conditions which is why such efforts are almost uniquely successful in controlled lab settings alone (Guldberg, 2011; Vaughan, 2015).  

Frequent and mass bleaching events are thought to cause disease outbreaks such as what is occurring within the Great Barrier Reef. Some genetic types of microalgae are thought to be more resistant to increase in temperature or lighting than others but this is yet to be studied further (GBRMPA, 2017).  

Environmental Changes  

Climate Change: 

Research conducted by Ove Hoegh-Guldberg (1999) shows that elevated sea temperatures explain many incidents of mass bleaching and that there are other causes which cause a gradation in bleaching intensity within a colony. Limits to coral growth are much shallower in areas where sedimentation reduces the transmission of light through the water column or smothers corals. He also confirmed that photosynthetic activity of heat-stressed coral is drastically reduced.   

The ideal water temperatures for coral survival are between 72-78° F, or approximately 24-28˚C. Over the past century, water temperature in the tropics has increased by 1°C.   

Chemical Changes : 

NOAA PMEL Carbon Program (2017) has alleged that when carbon dioxide (CO2) is absorbed by seawater. Chemical reactions occur that reduce the pH and carbonate ion concentration. This is called ocean acidification or “OA”.  Around 30% of all CO2 is absorbed by seawater and the atmospheric increase in CO2 due to climate change means an increase of that amount yearly.  

Calcium carbonate minerals are the building blocks for the skeletons of corals. Continued ocean acidification is causing many parts of the ocean to lose vast quantities of these minerals, which is likely to affect the ability of corals to produce and maintain their shells.  

Sedimentation 

While sedimentation is not usually a climate factor (hurricanes and cyclones do cause much sedimentation and also the accumulation of debris such as plastic in oceans see below), it is often caused by human activity such as urbanisation and farming which are activities known to contribute to greenhouse gas emissions and thus climate change (Martin, 2011).  

Terrigenous sediment deposition on coral reefs greatly impacts survival chances as it can lead to stunted growth due to light blocking which inhibits photosynthesis. It can also cause suffocation (McClenachan et al; 2017).  

Sedimentation is the major stressor to reefs in Hawaii, Guam, and the Northern Mariana Islands as well as being one of the major destructive components of various other reefs around the Americas (U.S. Commission on Ocean Policy, 2004).  

Hurricanes, Tsunamis and Cyclones

Climate change is suggested to increase the frequency of hurricanes and tsunamis (USGS 2017). Coral reefs protect shores from flooding. However rising sea levels due to an increase in storm activity reduces this protective attribute significantly and fierce storms cause the mechanical destruction (breakage) of coral skeletons which leads to the spreading of disease throughout the reef (McClenachan et al, 2017; Herron et al, 2014).   

In May of 2009, a 7.3-magnitude earthquake in the west Caribbean destroyed half of the Belizean Barrier Reef (second largest reef ecosystem in the world) lagoon’s corals reefs by an upheaval that displaced them into deeper waters (Martin, 2011). 

Cyclones can cause a lowering of water salinity due to an increase in alkalinity, sudden changes in temperature, an increase in turbidity and sedimentation leading to erosion which all cause stress and decline of reefs (Vivien-Harmelin, 1994). 

Marine debris, which is usually caused by ‘dumping’ and pollution from shipping barges and factories, can be caused by hurricanes too. Large objects can block out light which results in photo-inhibition, thus starvation and bleaching of corals. Heavy objects crush coral skeletons (NOAA Marine Debris Program, 2018). 

Central Role of Symbioses in Coral Reefs

Corals have a symbiotic relationship with microscopic algae that live in their tissue. These single-celled algae are called zooxanthellae. Zooxanthellae photosynthesise to provide the coral with its pigment and translocate up to 95% of their photosynthetic production to it such as amino acids, complex carbohydrates, and sugars. Coral supplies the dinoflagellates with crucial plant nutrients such as ammonia and phosphates. Both are dependent on the other for survival.  

When the symbiotic relationship becomes stressed due to ocean acidification caused by high CO2 emissions and debris or increased temperature; the algae leave the coral tissue. Without its algae, the coral loses its major food source and its colour. It is more susceptible to disease and will become bleached and vulnerable unless temperature is reduced (NOAA, 2017). 

Acclimatisation and Adaptation

Reef-building corals have effectively evolved necessary adaptation and acclimatisation mechanisms over time yet this has not prepared them for the sudden and massive destruction due to the acceleration of climate change and non-natural causes which is why they are at their limits under these modern conditions. 

Samoan lagoons are the unlikely home to acropora corals which are notorious for being the most sensitive to extreme temperatures. Temperatures can average at 35°C for a few hours a day. This means that they must have adapted to not only survive the heat but to thrive in it too (Mascarelli, 2014).   

In the Arabian Gulf, corals can survive 36°C. Corals may adapt to tolerate these temperatures by altering their biochemical pathways. Locally, this is probably due to acclimatisation. Where the corals grow scattered across widely separated geographic areas in the Red Sea, there may be a larger component of genetic selection, especially where local tolerance to extreme conditions is involved (Veron, 2013). 

Researchers are studying ways to achieve ‘human-assisted evolution’ by creating hardy, resistant corals in controlled settings to be introduced to the wild and rebuild destroyed reefs (Vollmer 2006; van Oppen, 2006). 

 Discussion

There is much controversy as to various anomalies discovered in data concerning coral stress and bleaching. Some argue that cyclones and hurricanes caused much reef damage during some data collation meaning climate and pollution are not wholly to blame for results. De’ath et al (2012) suggested the damage was mostly due to cyclones and unusually large swarms of crown-of-thorns starfish (Acanthaster planci), which eat reef-building corals.  

Although no one is yet attempting to create genetically modified corals, some researchers are concerned that human-assisted evolution is disruptive of the natural order. “If you’re basically farming a reef, you’ve taken a natural habitat and you’ve converted it.” (Steve Vollmer, 2014). 

It is evident, however, that the recent frequency and intensity of mass coral bleaching are of major concern and are directly attributable to rising atmospheric greenhouse gases. This has been shown in various researches and is a continuous trend with climate change (Hoegh-Guldberg et al, (2007). 

 

Bibliography 

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Sometimes Too Hot the Eye of Heaven Shines

the soul’s dream lingers in moments of eternity

a shadow emerged from my death –

it escaped me seeking you

everything starts and withers at the roots

charred by the worldly sun

you came to me from a fragment of light –

a mirage of an isle in the sea’s foam

*

this I do not say, I sing

I smash the light and it multiplies for you

I paint my eyelids in the colours of the earth

my eyes which lock onto a notion of beauty

a notion you view as intimate modesty

I gather the white pebbles of my death

I fly, clinging briefly to life –

to the gentle curve of time

you left me a fragment of light –

a mirage of an isle in the sea’s foam

*

in this world, I am a fruit –

sad and happy within the lips that kiss me

dawn’s voice melds with yours

this I do not say, I sing

that which escaped me longs to find you

since the day my shadows scattered –

-twilight shines from the face of a berber god –

the day a swarm of innocent birds flew past –

the mirage of an isle in the sea’s foam

a pure dream embedded in the flesh of time

so I, a free captive, am complete –

reborn of night’s miracle light

*

you materialised and vanished with the impetuosity of spring

stark like a stripped body in the dim light

like a star in the enchanted night

you charm me with a phantom smile

and I celebrate my inner tumult –

the madness of a slowly destroyed woman

reconstructed with the slightest of smiles

extending through the stillness of my verse

a woman of few words

writes like one who knows how

*

writes a history of melancholy –

blooming in her body

and the airy innocence of her shadows

***

(Translation of Amina Said’s poem: l’elan le souffle le silence (the momentum the breath the silence). Not a precise translation. Day 5 prompt was to translate a poem). Art by: Mourad Chaaba. Original poem in French, follow external link: https://www.lyrikline.org/en/poems/lelan-le-souffle-le-silence-1333#.WsY2CPnwbIW.

In Egypt or Troy? (#GloPoWriMo)

Which way is South? Around me is an echo of rodents scuttling across stone floors. Orange blossoms invade my senses. The sun is dying, spilling red all over the sky. There is no West, there is no East. There’s only a never-ending dusk. Dewy palms (Phoenix dactylifera?) stroke my bare arms as I walk onward towards the gaping chaos.  My feet sink into sand on occasion, glinting furiously in the glare.

(i) I stand on mosaic floors stretching to the beach. The beach strewn with wreckage from battles against men and gales. Sea-gods stare from their crashing coves, clashing among their own. Their disputes fatal and unfair. The lawyers stand between them, gold slipping between their fingers (piles and piles of it). A smoky haze wears me out, a torched Laurus nobilis once stood tall now a phantom crisp. I see a bird fall from fatigue or torched wings. It spirals and vanishes in the snarl.

(ii) Olive branches teeter in the howling god’s grasp. I cannot see through the whipping strands of hair, stinging my raw skin. My eyes water, saltier than sea breeze. I hear my name screamed on the wind. From this land or across the sea, there is no way to know. The air is permeated with cries of despair and curses to my name. I’ve reached a shore devoid of hope. Tonight there is but one flaw, and it is that of the entitled, claiming what was never theirs. They are the villains. But I am to blame.

(iii) The red woman rises in the storm. I glance at her and we exchange a nod. A mutual understanding passes in that ember glance. We watch as drowning men fight against their fate. We close our eyes to burning men as they wail to a louder god.

(iv) Thunder and lightning kiss jasmine flowers. Juniperus communis vanishes from sight. Vegetation spits out into nymphaea caerulea. I see my way clearly now. Away from the sea. I transpire as the air thickens and moisture is sucked out. The blazes simmer as the smokes darken. Darker than night, darker than sin, darker than Egypt.

(v) Flames burn ships on the Mediterranean tonight. Fire gods exhaust their powers on mere mortals. I turn and follow the ancient paths, in search of fresher waters. This winding snake spilling into the sea must lead to calmer roars.

(vi) Helen has escaped them all. Warmongering men, warmongering gods, flaming ships, drowning chaos, and dashed hope… The desert beckons her now.

(A/N: It seems I can only guilt myself into writing every April now xD. Didn’t even know it was April til yesterday night. So here’s my first entry. Title and inspiration from Day 1 featured poet: Lauren Russell. Read her work on the external link: https://tarpaulinsky.com/wp-content/uploads/2015/06/Russell-TS-selections.pdf. As I seem to do every NaPoWriMo, I’m trying out different writing styles and techniques.)

Anarcha-Feminism in Tunisia

Robert Graham's Anarchism Weblog

feminism attack more graffitti

Below I reproduce an unattributed translation from the French anarchist publication,Le Monde Libertaire, of an interview with the Tunisian anarchist feminist group, Feminism Attack! I follow that with an earlier report about the Tunisian feminist activist, Amina Sboui, leaving the Femen group and declaring herself an anarchist. Femen is a radical feminist group founded in Ukraine which has captured some media attention through its topless protests where Femen activists paint various political slogans across their chests. One area in which Femen has been particularly active is in protesting prostitution and the traffic in women. For an anti-authoritarian critique of prostitution and its connection with male domination see the excerpts from Carole Pateman’s The Sexual Contract in Volume Three of Anarchism: A Documentary History of Libertarian Ideas.

feminism attack better poster

Interview with Feminism Attack!

Tunisia, with a strong feminist movement for over a hundred years, is often considered the most advanced…

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Pristine Coral Reefs Destroyed by ‘Great Wall of Sand’

HK Marine Life

China is creating a ‘great wall of sand’ in the South China Sea, according to the Daily Mail.

The latest huge land mass is four square kilometres in size and was created by dumping sand on live coral reefs, damaging local ecosystems.

But this is just one of several artificial islands China has been creating in the region – and the exact purpose of them is unknown.  

 

 

The large expanses of sand and concrete – the latest being Johnson Reef – are being built among the Spratly Islands in the South China Sea.

China is creating the area by using dredging vessels to dig up sediment from the sea, and then dumping it on subermeged coral reefs to make islands.

China has supposedly been carrying out the land reclamation in order to build airstrips and other structures in the region.

  

Five islands in total have been…

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North West Cancer Research

Moonshine Noire

In April 2018, students from Southport College, including myself, will be taking on a challenge of a lifetime.  Over two gruelling days, staff and students will take on the wild and push themselves to the limit. They will abseil over 150ft, explore caves and tunnels, waterfall and cliff jump, zip wire over quarries and live in the outdoors under canvas with minimal supplies.

We are undertaking this challenge in support of North West Cancer Research.

The money raised is for a very worthy cause. North West Cancer Research is the only independent cancer research charity fighting the toughest cancers in North West England and North Wales. The charity only funds the very best cancer research into fighting those cancers that affect you locally. The carefully targeted research is independently and internationally scrutinized to make sure your donation makes the biggest difference possible. £13 million will be spent on cancer research…

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Why Smashwords ?

Notes from An Alien

I self-published my novel nearly seven years ago. At first, I was using FastPencil; with a print and ebook edition distributed to Amazon, Barnes & Noble, and a number of other retailers… Smashwords Review and Predictions

In September of last year, I switched to Smashwords.

That meant dropping the production of the print version; but, one day, I may add print back…

I feel good about the move to Smashwords—it feels “cleaner” than Amazon (none of that seemingly constant “How is Amazon mistreating authors again?” stuff…); though, I still sometimes buy a kindle e-book…

I’ve done quite a bit of posting here about Smashwords; if you take that last link, you might see this post at the top of the scrollable list…

One thing about Smashwords, even though it’s e-book-only—they distribute much more widely than Fastpencil.

I know many writers are still stuck with the idea that having a book…

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North West Cancer Research

In April 2018, students from Southport College, including myself, will be taking on a challenge of a lifetime.  Over two gruelling days, staff and students will take on the wild and push themselves to the limit. They will abseil over 150ft, explore caves and tunnels, waterfall and cliff jump, zip wire over quarries and live in the outdoors under canvas with minimal supplies.

We are undertaking this challenge in support of North West Cancer Research.

The money raised is for a very worthy cause. North West Cancer Research is the only independent cancer research charity fighting the toughest cancers in North West England and North Wales. The charity only funds the very best cancer research into fighting those cancers that affect you locally. The carefully targeted research is independently and internationally scrutinized to make sure your donation makes the biggest difference possible. £13 million will be spent on cancer research over the next five years and every penny you raise in your participation of this event will go towards this ground breaking research.

I am fundraising for North West Cancer Research. Too many families are affected by . My mum has been battling it on/off since she was my age. My target goal is £250.

https://www.justgiving.com/fundraising/fatima-ammar

Please donate and help us make a difference.

Donating through JustGiving is simple, fast and totally secure. Your details are safe with JustGiving – they’ll never sell them on or send unwanted emails. Once you donate, they’ll send your money directly to the charity. So it’s the most efficient way to donate – saving time and cutting costs for the charity.

https://www.justgiving.com/fundraising/fatima-ammar