American Samoan Reefs Hold on for Now, but Worst is Yet to Come

Posted on March 17, 2016 by jwh11

In 2015, reefs in American Samoa saw the worst of that year’s bleaching in February [1]. In 2016, they seem to be holding on. Last time we looked at how the natural resilience of American Samoa’s corals are helping stave off bleaching events, and it seems to be paying off.

Unfortunately, it seems like coral bleaching threats in the Samoan region are just now starting to heat up. According to monitoring and predictions from NOAA’s Coral Reef Watch, the Samoan region is under a “Bleaching Watch”, but if patterns from last year follow, the situation will become dire in a matter of weeks [2].

Screen Shot 2016-03-17 at 3.52.28 PM

Bleaching warning levels in the Samoas since July 2015  From http://coralreefwatch.noaa.gov/vs/timeseries/polynesia.php

Within the next month, things will get worse but quickly spring back to normal. One to four weeks from now, the Samoan region will experience the highest bleaching warning level, “Alert Level 2”, but after that, things will begin to improve. While bleaching stress will still be strong in the general region, the waters in and around American Samoa should be experiencing no bleaching stress at all [3].

Screen Shot 2016-03-17 at 4.05.27 PM

Prediction of bleaching warnings in the Samoas region from March 2016 From http://coralreefwatch.noaa.gov/vs/gauges/samoas.php

So why had bleaching not hit American Samoa so hard yet? It could be that aren’t as bad this year since the El Niño has passed its maximum [1]. One thing is for certain though, coral bleaching in 2016 is not over.

Screen Shot 2016-03-17 at 4.19.16 PM

Bleached coral in American Samoa  From https://www.fws.gov/coralreef/proceedings/Day%202%20PDF/6-Peter%20Craig.pdf

1.) Kahn, Brian. “Longest Global Coral Bleaching On Record Isn’t Over Yet.”ClimateCentral. Climate Central, 23 Feb. 2016. Web. <http://www.climatecentral.org/news/longest-global-coral-bleaching-20062>.

2.) “Polynesia 5-km Coral Bleaching Data Products.” NOAA Coral Reef Watch. US Department of Commerce, Mar. 2016. Web.<http://coralreefwatch.noaa.gov/vs/timeseries/polynesia.php>.

3.) “Samoas 5-km Bleaching Thermal Stress Gauges.” NOAA Coral Reef Watch. US Department of Commerce, 15 Mar. 2016. <http://coralreefwatch.noaa.gov/vs/gauges/samoas.php>.

Posted in Uncategorized | Tagged , , , , , , , , , , | Comments Off on American Samoan Reefs Hold on for Now, but Worst is Yet to Come

Extreme sea temperatures worry scientists – Hawaiian corals untouched so far

Posted on March 17, 2016 by Sasha

In a previous post I discussed one of the largest threats facing Hawaiian reefs: coral bleaching (Figure 1). I failed, however, to go into detail about what bleaching has occurred in the past year, and what is expected to occur in the upcoming year. As a reminder, coral bleaching is when corals lose their symbiotic algae (zooxanthellae). The zooxanthellae provide the coral’s coloring, so without them the coral appear a ghostly white – hence the term “bleaching.” Coral can only live for short periods of time without zooxanthellae, and they must get back the zooxanthellae relatively quickly if they are going to survive [1].

ebio 372 bleached coral

Figure 1. A sea turtle swims over bleached cauliflower coral (Pocillopora meandrina) at Honokohau in Hawaii. Image by Lindsey Kramer

Hawaii began to see its most recent bleaching trend in the fall of 2014 [2]. At that point, scientists were worried, but most of the bleaching wasn’t fatal. During the winter, water temperatures cool, and sometimes corals are able to recover. The next widespread instance of bleaching began the next fall, in 2015. In an interview with Hawaii Tribune-Herald, Dr. Misaki Takabayashi called the bleaching “unprecedented” [3]. In October, Eyes of the Reef Hawaii, and organization for community reporting of coral health, organized “Bleachapalooza,” an event to gather data on the extent of coral bleaching all around Hawaii. Volunteers estimated bleaching and were able to report their results online [4]. As of now a final report for 2015 has not been released, but estimations for the extent of bleaching ranged from 30-80% of total coral cover [3].

 

So far this year, Hawaii has not had significant bleaching. Sea surface temperatures have largely stayed under 30°C, which is at the high end of tolerable for corals [1] (Figure 2).

ebio 372 sst march 2016

Figure 2. Maximum sea surface temperatures (°C) in Hawaii from January 1 – March 15, 2016. Image from NOAA’s Coral Reef Watch.

Unfortunately, other reefs around the world are not getting the same relief that Hawaiian reefs are. El Niño is continuing to track warm water throughout the Pacific Ocean, which is wreaking havoc on many reefs [5]. Even more worrying is the current global temperature trend. Due to the combined effects of El Niño and climate change, February saw record-high temperatures. The average temperature for February was 1.35°C above the 1951-1980 global average for the month. It was also 0.21°C above the previous record – which was set in January. While 0.21°C may not sound like a lot, it is an incredibly large amount when speaking of global averages throughout history [6]. If this trend continues, corals will not be able to adapt fast enough to survive the warming water.

 

The National Oceanic and Atmospheric Administration (NOAA) monitors a website called Coral Reef Watch (http://coralreefwatch.noaa.gov/satellite/index.php), which tracks ocean conditions to predict where coral bleaching is most likely to occur [7]. Current predictions are available for March 2016 – June 2016 (Figure 3). According to these predictions, Hawaiian reefs should be able to continue to recover for a few more months. However, bleaching is expected between July and October, which is when water temperatures are highest in Hawaii. Last year in September, most of Hawaii was under Alert Level 1, which means that bleaching was likely. The parts of Hawaii that were not under Alert Level 1 were instead under Alert Level 2, which means that mortality was likely (Figure 4). Based on current trends, it seems likely that this fall will be as bad or worse for Hawaiian corals than last fall was.

ebio 372 bleaching jan mar

Figure 3. Coral reef bleaching risk predictions for March – June 2016. Image from NOAA’s Coral Reef Watch.

ebio 372 bleaching sept 2015

Figure 4. Coral reef bleaching risk for September 2015. This fall will likely see similar trends. Image from NOAA’s Coral Reef Watch.

References:

[1] Sheppard, Charles R. C., Simon Davy, Graham Pilling. The Biology of Coral Reefs. (2009)

[2] Stallard, Brian. “Coral bleaching event: worst in decades.” Nature World News. 07 Oct. 2014.

[3] Callis, Tom. “East Hawaii Coral Bleaching ‘unprecedented’.” Hawaii Tribune-Herald. 15 Oct. 2015.

[4] “Volunteers statewide learn to spot coral bleaching.” Hawaii Department of Land and Natural Resources. 3 Oct. 2015.

[5] Ferraro, Kathleen. “Global coral ‘bleaching’ threatens reef survival.” Medill Reports Chicago. 9 Mar 2016.

[6] Masters, Jeff, Bob Henson. “February Smashes Earth’s All-Time Global Heat Record By A Jaw-Dropping Margin.” Countercurrents. 14 Mar 2016.

[7] Coral Reef Watch Satellite Monitoring. National Oceanic and Atmospheric Administration.

Posted in Uncategorized | Tagged , , , , , , | Comments Off on Extreme sea temperatures worry scientists – Hawaiian corals untouched so far

Bouncing Back After Bleaching?

Posted on March 17, 2016 by amk12

Widespread bleaching has not yet affected the Seychelles in what is now a devastatingly long world bleaching event. The Seychelles is currently under a bleaching warning, but factors have not become extreme enough to issue an alert level 1 or 2 such as in eastern parts of the Indian Ocean (Figure 1).3 Mark Eakin, an oceanographer working for NOAA announced in February of 2016 that the likelihood of the bleaching event lasting into 2017 is high, so the Seychelles could still be impacted.1 The next question to ponder is how reefs will respond to this ecological devastation after the event is over. A look at recovery of reefs in the Seychelles after the 1998 bleaching event is possible thanks to a study conducted by Australian scientists.

2015_2016_ts_seychelles

Figure 1. “NOAA Satellite and Information Service” Sea surface temperature is graphed in purple at the top of the graph. The blue line represents the sea surface temperature at which reefs are in danger of bleaching. Degree heating weeks is expressed on the bottom part of the graph, which shows how much heat stress has accumulated. The Seychelles are experiencing a bleaching warning.

Nicholas Graham is a coral researcher at the renowned James Cook University in Australia and is the lead author in the study Predicting climate-driven regime shifts versus rebound potential in coral reefs published by Nature in February 2015. His research team assessed the shifts in ecosystem function on 21 reefs in the Seychelles using data from a 17-year long period.2 These reefs were surveyed in 1994, before the bleaching event of 1998 that wiped out over 90% of hard coral cover in the Seychelles, and again in 2005, 2008, and 2011, all using identical methods. Before the bleaching event of 1998, average hard coral cover across all reefs surveyed was marked at 28% and macroalgal cover was at 1%.2

Of the 21 reefs surveyed, 12 have recovered post-bleaching with an average hard coral cover of 23% across these sites and macroalgal cover less than 1% in 2011. In the other nine reefs, a shift regime occurred where macroalgal cover increased to 42% and coral cover remained below 3%.2 Since all of these reefs were similar in composition before the bleaching event, this new data is evidence that bleaching events can cause a shift in ecosystem dynamics that favor microalgae cover years after the event.2 Furthermore, the study also observed changes in the abundance of fish at the reefs and found that populations more or less recovered on the reefs that bounced back but that the abundance of fish was altered on the reefs dominated by fleshy algae.2

thingy

Figure 2. “Graham 2015” The black line represents the mean model fit. The blue dot indicates the point where a regime shift and recovery are equally likely. The grey dots indicate reefs that have recovered (0) and reefs that underwent a regime shift (1). The blue region represents the interval where a regime shift is decreasingly unlikely to occur.

This study also attempted to identify factors that would likely indicate whether a reef would recover or undergo a regime shift after a bleaching event. Reefs were more likely to recover if they had architectural complexity, were located in deeper waters that had low nutrient loads, and had an abundant population of fish and juvenile corals (Figure 2).2 This is crucial information to know for management and restoration efforts as these bleaching events are likely to become an increasing occurrence as ocean temperatures continue to warm. Check in next time to learn more about the fate of the Seychelles coral reefs.

  1. Gaworecki, Mike. “The longest coral bleaching event in history isn’t over yet.” Mongabay. 25 Feb 2016. Web. 16 Mar. 2016
  2. Graham et al Predicting climate-driven regime shifts versus rebound potential in coral reefs. Nature, (2015)
  3. “Western Indian Ocean 5-km Coral Bleaching Data Products.” Coral Reef Watch. NOAA Satellite and Information Service. Web. 16 Mar. 2016.

 

 

Posted in Uncategorized | Tagged , , | Comments Off on Bouncing Back After Bleaching?

Corals in the Keys: Safe… For Now

Posted on March 17, 2016 by meh9

The National Oceanic and Atmospheric Administration (NOAA) recently announced that the longest global coral bleaching event on record is going to get even longer [1]. For the past 21 months, tropical waters throughout the globe have experienced above average temperatures that cause coral disease, stress, and bleaching [1]. The current global coral bleaching event – the third in recorded history – is being fueled by global warming and an unusually intense El Niño [1]. This longer than expected event is predicted to keep going into 2017.

Extending the current, stressful oceanic conditions could prove disastrous for corals in the Caribbean and, more specifically, the Florida Keys.

As I mentioned last post, the entire Caribbean area was expected to be hit by the global bleaching event. In accordance with this prediction, the Florida Keys hit critically high temperatures in August – September of 2015 and experienced bleaching [2]. Bleaching in the Keys area has not only reduced overall coral coverage, but changed the species composition.

Changing species compositions come from the fact that some species are more strongly affected than others by extreme abiotic conditions such as temperature, aragonite composition, nutrients, and salinity. For example, Montastraea cavernosa (Figure 1a) and Porites astreoides (Figure 1b), two common coral species in the Florida Keys, are more stress and heat tolerant than other genera like Acropora and Orbicella [3]. Additionally, M. cavernosa is more resistant to extreme high temperatures whereas P. astreoides is more resistant to extreme low temperatures. These thermally resistant species have mitigated the overall loss of coral caused by large temperature changes.

Two species of coral that are common in the Florida Keys. (a) Montastraea cavernosa, and (b) Porites astreoides

Figure 1. Two species of coral that are common in the Florida Keys, (a) Montastraea cavernosa, and (b) Porites astreoides.

Interestingly, inshore patch reefs also showed more resistance to high temperatures than offshore reefs. Despite experiencing the same heat stress, inshore reefs were less inhibited in terms of growth. The researchers who found these results suggest that sustained growth is either a result of inshore corals’ capacity for acclimatization/adaptation or stimulated growth from elevated nutrients and/or high aragonite composition [4]. In either case, inshore corals have also been able to mitigate the harmful effects of high temperatures.

Figure 2.

Figure 2. Current stress levels of the Florida Keys area [5].

Despite these factors that have contributed to lessened damage, corals in the Florida Keys still experienced widespread bleaching through 2014 and 2015 [2]. In order for the coral reefs to survive, recovery from bleaching is critical. As of now, temperatures in the Florida Keys have returned to average (Figure 2) [5]. However, if El Niño is prolonged as predicted, the Florida Keys could soon undergo another bleaching event (Figure 3) [6]. This time, it could be largely fatal.

Figure 3.

Figure 3. Predicted thermal stress levels for June to August, 2016 [6].

SOURCES:

[1] “El Niño Prolongs Longest Global Coral Bleaching Event.” AGU. American Geophysical Union, 23 Feb. 2016. Web. 17 March 2016.

[2] “El Niño and the 2014-2016 Global Coral Bleaching Event.” NOAA Satellite and Information Service. National Oceanic and Atmospheric Administration, 2015. Web. 17 March 2016.

[3] Aronson, Richard, and William Precht. “White-band Disease and the Changing Face of Caribbean Coral Reefs.” Hydrobiologia 460.1 (2001): 25-38. Web. 17 March 2016.

[4] Manzello, Derek et al. “Coral Growth Patterns of Montastraea cavernosa and Porites astreoides in the Florida Keys: The importance of thermal stress and inimical waters.” Journal of Experimental Marine Biology and Ecology 471 (2015): 198-207. Web. 17 March 2016.

[5] “Florida Keys: 5-km Bleaching Thermal Stress Gauge.” NOAA Satellite and Information Service. National Oceanic and Atmospheric Administration, 2016. Web. 17 March 2016.

[6] Eakin, Mark C. “2016 Outlook on Coral Bleaching: El Niño, the guest overstaying his welcome.” NOAA Coral Reef Watch, National Oceanic and Atmospheric Administration, 2016. Web. 17 March 2016.

Posted in Uncategorized | Tagged , , , , , | Comments Off on Corals in the Keys: Safe… For Now

What doesn’t kill you makes you stronger: Galapagos reef recovery.

Posted on March 17, 2016 by aay1

Hello again! I really hope corals have started to “grow” on you guys too. Corals have had it rough over the years but in the words of Gloria Gaynor, “[they] will survive.”

currents

Location of the Galapagos Islands

The Galapagos sits at the intersection of five major ocean currents, resulting in a rapidly changing climate island to island and season to season. [2] As I stated in my previous post, the 1982-1983 El Nino decimated the coral population near the Galapagos Islands. It caused over 95% of the corals to bleach, and recovery has been a long uphill battle since. [1] Despite the threat from another strong El Nino in 1997-1998, Galapagos reefs managed to continue to survive. [2]

Global trends in the extent and severity of mass coral bleaching (1998-2006) [1]

The rapid warming of the ocean waters is not allowing enough time for corals to naturally evolve tolerance as they possess a poor genetic ability to adapt to such stresses in their long lifetimes. [1] A Satellite Bleaching Alert Level 2 (signifying widespread coral bleaching and mortality) was issued by NOAA for areas including the Galapagos Islands. However, recent observations by scientists suggest that the influence of large-scale thermal stress may have been overestimated. [4] In the summer of 2012 a team of researchers surveyed the corals of 8 islands and recorded coral recovery as well as factors that were significant in making corals resilient to environmental disturbances. [2] They found promising signs of recovery for the Galapagos reefs, a glimmer of hope in wake of our current situation, the third ever global coral bleaching event.

Screen Shot 2016-03-17 at 9.54.11 AM

Porites lobata colonies that survived the 1982–3 El Niño event. Most colonies are encrusted with patches of the acorn barnacle Megabalanus peninsularis (arrow). Scale resting on coral colony in background is 20 cm in length. Darwin reef, 12 m depth, 6 Mar 2007 [3]

Three northern islands, Marchena, Wolf and Darwin, showed the most signs of recovery. [2] A research paper done in 2009 attributes the intact coral frameworks at Darwin Island to relatively low levels of bio erosion. This has permitted the surviving coral patches to regenerate as well as allowed the settlement of coral recruits. [3] The abundance of colonies with dead patches decreased to 93.8% in 2000 to 5.7% in 2007, a dramatic change by anyone’s standards. [3] It is predicted that a full recovery would take centuries, but it is in progress. [3]

Screen Shot 2016-03-17 at 9.56.58 AM

Several live Porites lobata colonies on eroded colonies killed during the 1982–3 El Niño event. Scale is 20 cm in length. Darwin reef, 12 m depth, 6 Mar 2007. [3]

The amount of coral bleaching that takes place also may depend on the distribution of coral species in the area. Patches of P. stellate have been found within the Devil’s Crown in the Galapagos Islands. Their recovery can be attributed to the settlement of larvae from upstream source populations. [5] Studies have shown that Psammocora spp. especially have exhibited adaptive characteristics that facilitate recovery: “(1) relative resistance to bleaching/mortality, especially below 10–12 m depth, (2) persistence of surviving deep source populations that can potentially promote recruitment into decimated shallow reef habitats, (3) prolonged seasonal reproductive periods and high fecundities, (4) asexual reproduction.” [5] These adaptations have allowed these colonies to experience less bleaching, minimal mortality, and faster recovery rates. [5]

Psammocora stellata. Galapagos Islands. Usual appearance of small colonies. Photograph: Paul Humann.

Psammocora stellata. Galapagos Islands. Usual appearance of small colonies. Photograph: Paul Humann.

These studies show that there is hope for the Galapagos coral reefs, despite the tremendous stresses they’ve been put through. Hopefully we can continue to watch as they defy odds and (very) slowly return to their former glory.

Sources:

[1] “How Global Warming Is Driving Mass Coral Bleaching.” Skeptical Science. N.p., 23 Sept. 2015. Web. <https://www.skepticalscience.com/coral-bleaching.htm>.

[2] Smith, Julian. “Threatened Galapagos Coral May Predict the Future of Reefs Worldwide.” Mongabay Environmental News. N.p., 07 Nov. 2012. Web. <http://news.mongabay.com/2012/11/threatened-galapagos-coral-may-predict-the-future-of-reefs-worldwide/>.

[3] Glynn, Peter W., et al. “Coral reef recovery in the Galápagos Islands: the northernmost islands (Darwin and Wenman).” Coral Reefs 34.2 (2015): 421-436.

[4] “2014-16 Bleaching Event Continues: June 2015 Update.” Coral Reef Watch. NOAA Satellite and Information Service, 2 June 2015. Web. <http://coralreefwatch.noaa.gov/satellite/analyses_guidance/global_bleaching_update_20150602.php>.

[5] Glynn, Peter W., et al. “Reef coral reproduction in the equatorial eastern Pacific: Costa Rica, Panamá, and the Galápagos Islands (Ecuador). VII. Siderastreidae, Psammocora stellata and Psammocora profundacella.” Marine biology 159.9 (2012): 1917-1932.

Posted in Uncategorized | Tagged , , , , , , , , , , | Comments Off on What doesn’t kill you makes you stronger: Galapagos reef recovery.

Have the reefs off Kenya dodged a bullet?

Posted on March 16, 2016 by mcj2

Where are these reefs again?

Kenya is located on the eastern coast of Africa, and its reefs continue south to Tanzania. source: NG MAPS. “Map of Kenya.” Image. National Geographic Kids. Web. 16 Feb. 2016.

Kenya is located on the eastern coast of Africa, and its reefs continue south to Tanzania. source: NG MAPS. “Map of Kenya.” Image. National Geographic Kids. Web. 16 Feb. 2016.

Well folks, where we left off last time the reefs off the coast of Kenya were at a huge risk of the highest severity level of bleaching predicted between the months of February and March 2016 [1]. As of 2008, most sites off Kenya were at an intermediate level of recovery from the 1997-1998 bleaching even that devastated all but 10% of coral cover in many places off Kenya’s coast [2][3]. An organization known as CORDIO, or Coastal Oceans Research and Development – Indian Ocean East Africa has been closely tracking bleaching events from January 1st of this year, and on March 2nd there was a report of a bleaching even (pictured below) off the coast of Mombasa [4].

Bleaching observations as of Jan 1st, 2016. Yellow indicates low bleaching, orange indicates medium, and green indicates none. One low severity bleaching observation was reported off Mombasa on March 2nd 2016 by Jennifer O'Leary [2]

Bleaching observations as of Jan 1st, 2016. Yellow indicates low bleaching, orange indicates medium, and green indicates none. One low severity bleaching observation was reported off Mombasa on March 2nd 2016 by Jennifer O’Leary. source: cordioea.net/bleaching_resilience/wio-coral-bleaching-alert/

The observation was made by Jennifer O’Leary, a marine ecologist at California Polytechnic State University, who has been working in the area since 2010. O’Leary reported a low level of bleaching (1-10%) which was ‘spotty’, and observed a mortality rate of 1-10% [5]. That doesn’t seem too bad, but if we consider that there is only a 11-33% coral cover at this site to begin with, results of the bleaching could still spell disaster [5]. Below the threshold of 10% coral cover, CaCO3 accretion flips from net positive to negative [6]. This means that instead of building new reef, the reef itself is undergoing decomposition.

Bleaching forecast for 2016. So far, minimal to no bleaching has occurred off Kenya's coast, but it's not out of danger quite yet. source: cordioea.net/wp-content/uploads/2016/03/Summary-160315.jpg

Bleaching forecast for 2016. So far, minimal to no bleaching has occurred off Kenya’s coast, but it’s not out of danger quite yet. source: cordioea.net/wp-content/uploads/2016/03/Summary-160315.jpg

From the image above, we can gather that bleaching has been milder than predicted, with nearly no bleaching being observed off the Kenyan coast [5]. Though extensive bleaching has not yet been reported, the warming waters, low rainfall, and calming monsoon winds that characterize the northeast monsoon season could change that [3]. This shift in abiotic (nonliving) factors leaves reefs more prone to bleaching events [7]. Bleaching, and potentially severe bleaching is predicted to occur off Kenya before March [5].

Despite the relatively mild bleaching occurrences this year, we cannot be certain about the reefs’ future. Even though pressures from human civilization tend to be lower on average than other parts of the world, including Asia, Kenya and other eastern African countries have weaker governance structure and a lower overall capacity to respond to bleaching events [2]. To add to flimsy governmental management of the environment, eastern African countries tend to place a low priority on marine and coastal habitat maintenance [2]. Historically, problems do not get addressed until they become extremely pressing, and only then are attempts to resolve the issue made [2].

While pressures in the region tend to be lower than in Asia as population densities are lower and historical pressure has been much less, eastern African countries tend to have weaker governance structures and lower technical capability to manage impacts to the environment [7]. And apart from the small island states, marine and coastal issues tend to have a low priority for central governments and for society as a whole, so problems tend to persist and worsen before attempts at resolution are made [2].

References:

  1. NOAA Coral Reef Watch Methodology, Product Description, and Data Availability of NOAA Coral Reef Watch (CRW) Operational and Experimental Satellite Coral Bleaching Monitoring Products (2011) NOAA Satellite and Information Service.
  2. Obura, D.O., Tamelander, J., & Linden, O. (Eds) (2008). Ten years after bleaching – facing the consequences of climate change in the Indian Ocean. CORDIO Status Report 2008. Coastal Oceans Research and Development in the Indian Ocean/Sida-SAREC. Mombasa. http//:www.cordioea.org.
  3. McClanahan, T.R. (1988) Seasonality in East Africa’s coastal waters. Mar. Ecol. Prog. Ser. 44: 191-199.
  4. Wilkinson, C. (2008). Status of coral reefs of the world: 2008. Global Coral Reef Monitoring Network and Reef and Rainforest Research Centre, Townsville, Australia, 296 p.
  5. CORDIO: East Africa (2016) WIO Coral Bleaching Alert– what to expect?
  6. Perry, C. T. et al. (2013) Caribbean-wide decline in carbonate production threatens coral reef growth. Nat. Commun. 4:1402 doi: 10.1038/ncomms2409 .
  7. ICRI: Status of Coral Reefs of the World, 2008 (2008) 91- 96.
Posted in Uncategorized | Comments Off on Have the reefs off Kenya dodged a bullet?

Marshall Islands Coral Bleaching Update

Posted on March 16, 2016 by Hanna

In an earlier post, I mentioned that the Marshall Islands are currently undergoing their worst bleaching event in recorded history.  Thanks to the recent observations and data of a group of scientists working in the Marshall Islands, I can now tell you about the past and current bleaching events in more detail.

This post will review the bleaching progress in the islands, other important contributing factors, and management efforts of these issues.

Bleaching Progress in the Marshall Islands

From June 2014 – January 2015, scientists observed a significant coral bleaching event [1].

Screen Shot 2016-03-16 at 11.25.46 AM Screen Shot 2016-03-16 at 11.25.56 AM

Sea temperature levels for October 2010 and 2014, showing a marked increase for 2014 sea temperature [1].

Most of the bleaching took place in late 2014, despite there being no official El Niño event.  Significant bleaching was seen from August to December with little coral recovery. Below is a comparison of 2014 and 2015 sea level temperatures.  They are seen to be mostly lower during the first part of the year during the 2015 moderate El Niño event.  In 2015, patches of bleaching were observed through mid November [1].

Screen Shot 2016-03-16 at 11.26.10 AM

Left: 2014 sea temperatures during an unofficial and weak El Niño season versus Right: 2015 sea temperatures during a confirmed El Niño event. 

A rise in sea level temperature in June-October 2015 was observed due to the combination of Westerly winds and strong Easterly tradewinds [1].

Only time and future observations will tell us how global temperature patterns will affect 2016 bleaching events.  Below is a map of bleaching risk published for January 2016 with relation to the Marshall Islands.

.Screen Shot 2016-03-16 at 2.41.36 PM

The hard-to-read title says, “NOAA Coral Reef Watch Daily 5-km Geo-Polar Blended Night-Only Bleaching Alert Area 7d Max 16 Jan 2016”. The encircled islands in the middle of the image are the Marshall Islands. 

Until further observations are made, it is important to track the progress of coral bleaching events and how the reefs have been affected so far. Following the 2014 bleaching event, it was estimated that three quarters of shallow branching corals, two thirds of table corals, and around one quarter of massive corals had been killed.

Screen Shot 2016-03-16 at 11.45.53 AM

A photo of a partially bleached coral at 40 ft at southeast Catalin Pass, Majuro atoll.  Half of all table corals at this location have bleached [2].

Some corals were more resistant to coral bleaching than others, however.  Porites rus, a common coral around the large Majuro atoll, Porites cylindrica, and deeper growing Porites were all observed to be fairly resistant [2].

Throughout 2014 and 2015, observations of coral bleaching locations around the Marshall Islands show which corals and locations were most affected. The following pictures represent a brief timeline of the findings, focusing on the reefs surrounding two major atolls, Majuro and Arno. Both of these locations suffer from fishing pressures, however Arno is significantly more rural. Majuro in particular was chosen because it houses much of the population of the Marshall Islands, meaning the sustainability of the reef and its wildlife is essential [3]  

The locations chosen for study may be referred to as “lagoon side” or “oceanside“, indicating which side of the island they are located on.  Locations may also be described directionally, referring to their position relative to the entire atoll.  Results were gathered using the spot check and manta tow monitoring methods as well as quadrat measuring techniques.

Screen Shot 2016-03-16 at 2.20.48 PM

Two notable atolls for these studies, Majuro and Arno atolls.  The observations listed below are all centered around these two atolls [1].

Screen Shot 2016-03-16 at 2.30.47 PMOctober 2014: reports from locals indicate coral bleaching around the Arno atoll and the Majuro atoll. Species, depth, and percentage was not recorded, however anemones were notably bleached [2].

Screen Shot 2016-03-16 at 2.29.13 PM

Late October 2014: Observations of the eastern end of Long Island on the South Majuro atoll reported total bleaching of all Acropora colonies. The stressed reef flat was otherwise covered in invasive Hypnea algae [2].

Screen Shot 2016-03-16 at 2.28.19 PM

October-November 2014: Western end of Long Island on the South Majora atoll. Bleached corals were observed between 10-25 ft, mostly covered in green and black algae, indicating that bleaching occurred at least one month prior [2].

Screen Shot 2016-03-16 at 2.25.40 PM

December 2014: Lagoon side patch reef off of north Majuro atoll, around 25% coral cover.  Shallow depths had lower bleaching levels due to widespread resistant corals.  Below 75 ft, three quarters of the coral cover is bleached. Pictured above at a depth of 100 ft is Acropora nasuta and an Astreopora species [2].

Screen Shot 2016-03-16 at 2.24.39 PM

December 2014: East side of Calalin Pass, north Majuro atoll, 40% coral cover. The most severe bleaching occurred from 50-70 ft, where about three quarters of coral cover was bleached. Pictured above at a depth of 30 ft is a bleached Acropora species [2].

Screen Shot 2016-03-16 at 2.22.00 PM

Mid-December 2014: Arno atoll is found to have cleaner water and less algal cover, but more grazers. No coral cover or bleaching data was recorded, but it is estimated that percentages would be lower than at Majuro. This suggests that reefs farther from population centers have a higher chance of recovery from coral bleaching. Pictured above is a partially bleached coral at Arno atoll.

Screen Shot 2016-03-16 at 2.43.41 PM

July 2015: Oceanside Uliga East Majuro, 10% coral cover. Pocillopora species colonies display 50% bleaching on the reef flat.

Screen Shot 2016-03-16 at 2.49.04 PM

August 2015: Lagoon side Airport South Majuro. Only resistant corals exist here, but bleached anemones can be seen.

Screen Shot 2016-03-16 at 2.52.20 PM

August 2015: Lagoon side Landfill southeast Majuro, 15% coral cover at 9-23 ft. 30% of Pocillopora and Acropora species colonies are bleached. An example colony is pictured above. 

Screen Shot 2016-03-16 at 2.58.19 PMScreen Shot 2016-03-16 at 2.56.45 PMScreen Shot 2016-03-16 at 2.57.38 PM

November 2015: Oceanside Batkan southeast Majuro, 10% coral cover at 16-115 ft. 30% of non-Porites colonies are bleached. Three examples are pictured above.

Screen Shot 2016-03-16 at 3.06.50 PMScreen Shot 2016-03-16 at 3.07.24 PM

November 2015: Lagoon side Ajeltake south Majuro, 10% coral cover at 16-82 ft. 15% of non-Porites colonies are bleached. Above are two pictures of various species. 

Screen Shot 2016-03-16 at 3.33.06 PMScreen Shot 2016-03-16 at 3.33.16 PMScreen Shot 2016-03-16 at 3.32.58 PM

November 2015: Lagoon side Woja southwest Majuro, 15% coral cover at 20-33 ft. 10% of non-Porites colonies are bleached. Three pictures of various species are above. 

Screen Shot 2016-03-16 at 3.39.48 PMScreen Shot 2016-03-16 at 3.38.01 PM

November 2015: Oceanside Rongrong northwest Majuro, 70% coral cover at 13-115 ft. This area had 5% bleaching recorded.  It was also the only site not observed in previous years, but seemed to have no evidence of previous bleachings.

Contributing Factors

There are several important factors contributing to coral bleaching and the health of reefs and the surrounding island communities. These include not only coral bleaching, but also climate change, severe weather, inundation events, and over fishing.

Since the 1990s, attempts have been made to limit the rise in global surface temperature to 2°C per year.  Recent studies have shown that the non-linear nature of temperature patterns will cause even a 1°C rise to be as detrimental as a 2°C rise in temperature any other year. A 2°C rise will

“far worse than double the sea level rise, coral bleaching, storms, and drought that the [Marshall Islands] experiences today” [4].  

Coral reef scientists say that 1.5°C more is the upper limit for coral growth [4], and the countries that make up the Pacific Island Forum are pushing for this limit.

Severe weather is also an important stressor.  Cyclones are common, and can cause damage to reefs through physical damage and by changing normal salinity and pH levels, but also damage island communities. Below is a map of cyclone probability in the Marshall Islands

 Screen Shot 2016-03-16 at 4.14.15 PM

Above: A map of the Marshall islands with underlying colors indicating the chance of cyclones.  Over half the islands are at a 25% chance or above. Data from IBTrACS and Spennemann (2004).

Storms and swell waves cause another phenomenon in the Marshall Islands known as inundation events.  These events can range from moderate to severe flooding on the islands. Below is a 6-day inundation forecast during a period of high risk.

Screen Shot 2016-03-16 at 4.19.53 PM

An inundation level forecast from Feb 26- Mar 6 of 2014.  Some predictions indicate inundations of over 8 ft or as low as 2 ft [1].  

Inundation events are associated with high wave energy, which can be damaging to reefs and contribute to erosion. Coral reefs are not the only ones affected by inundation events, however. As sea levels rise every year, inundation events are more and more common for the local communities living in the Marshall Islands.  These floods create large amounts of property damage and decrease the amount of freshwater available on the islands.

Screen Shot 2016-03-16 at 4.23.15 PM

Inundation event on March 3, 2014 on Ejit Island [1].

Screen Shot 2016-03-16 at 4.24.55 PM

Inundation events are damaging to local communities as well. This image was taken following an inundation event on October 9, 2014 [1].

Over fishing is also an issue for reef life.  Reef herbivores help maintain a healthy balance of algae and coral on the reefs, and efforts have been made to protect them.  Organizations like the Marshall Islands Marina Resources Authority (MIMRA), the Coastal Management Advisory Council (CMAC), the Marshall Islands Mayors Association (MIMA), and local government strive to limit fishing of herbivores , especially in periods of environmental stress [5]. A 3 month closure of commercial herbivore fishing is tentative for March through May of 2016 [1].

Management Efforts

Researchers have made efforts to relocate corals away from sites where dredging is threatening coral colonies.  The UH Sea Grant program relocated six large table corals and over 50 smaller colonies.  The corals were moved from a site called Lojemwa on the Long Island of Majuro to a location 500 ft away that lacks coral [6]. Relocation procedure included,

“the large table corals were mostly relocated with their bases intact, and floated with locally-adapted lift bags with the assistance of a small boat. Other colonies were strategically secured on elevated reef surfaces in the new area, and smaller ones along with broken pieces inserted into wet concrete 2×2 foot forms” [6].

Screen Shot 2016-03-16 at 5.17.33 PM

Above: Divers relocating pieces of Acropora digitifera. [6]

Screen Shot 2016-03-16 at 5.17.41 PM

Above: A relocated table coral. This colony is an Acropora species. [6]

Screen Shot 2016-03-16 at 5.18.16 PM

Above: Cement block containing relocated coral fragments. Researchers expect the cement block to be overgrown in a year, and it is currently heavy enough to withstand most swell activity [1,6].

This treatment involved the help of local divers, and in addition to saving the corals, increased local knowledge of coral life and protection.

In addition to efforts by researchers, it is important to include the efforts of others on the islands. It is difficult to quantify the importance of coral reefs to those in the Marshall Islands.  Many local resources are available to both educate and assist individuals who want to protect their home, be that their physical houses on the island or the surrounding flora and fauna. Guidebooks like A Landowner’s Guide to Coastal Protection [6] prepare locals for natural hazards. Many other programs assist in conservancy on a local scale [5]. 

Additionally, a program called Reimaanlok has been implemented by the Coastal Management Advisory Council. Reimaanlok means “looking to the future”, and functions as a conservation framework, creating a space for conservation agencies, local organizations and government, and other interests to work together and address conservation issues [5,6].

Locals know that the reefs protect the islands.  To many, protecting the coral reefs is just returning the favor.

Acknowledgements

Special thanks to the direction and information provided by Karl Fellenius, Dr. Peter Houk, and Dr. Matt Kendall. 

Resources

[1] Hess, D., Fellenius, K. Impacts and Initiatives: Climate Change in the RMI. January 2016 Presentation to the Climate Change Working Group US Coral Reef Task Force. College of the Marshall Islands, UH Sea Grant. 2016.

[2] Fellenius, K. Republic of the Marshall Islands Coral Bleaching Report. University of Hawai’i Sea Grant, Coastal Management Extension. Dec 31, 2014.

[3] Houk, P. et al. Status of Coral Reefs across Majuro Atoll, RMI. University of Guam Marine Laboratory, Marshall Islands Marine Resources Authority, College of the Marshall Islands. 2015.

[4] Fellenius, K. Threshold of 1.5 or 2 degrees Celsius. University of Hawai’i Sea Grant, College of the Marshall Islands. 2015. 

[5] White, R., Stege, M., Fellenius, K. Republic of the Marshall Islands Oceans and Tides Capacity Mapping Report. COSPPac. 22 pp. 2015.

[6] Fellenius, K. Coral Divers Mainstream Shoreline Protection with Dredge Site Mitigation in the Marshalls. Ka Pili Kai: Coastal Hazards, Climate Change, and Community Resilience. Vol 36, No 3. pp 14-15. 2014.

Posted in Uncategorized | Tagged , , , , , , , , , , , , , , , , , , , | Comments Off on Marshall Islands Coral Bleaching Update

Update on Abrolhos Marine National Park: will it bleach? That is the question

Posted on March 14, 2016 by pb21

The third global Coral Bleaching event is still out there, and is already the longest event of the type in history (1). It has affected multiple reef areas causing enormous damage is many (e. g. 2), and might still cause a lot of damage (1) what is very sad for the already endangered coral reef ecosystems. In 2016, some areas are still predicted to suffer with the thermal anomalies (see figure 1, upper image), what is the main cause of coral bleaching, extending this event even more and causing greater concern for the conservation of the beautiful and diverse reefs.

Although the event is still going on, the forecast for some areas has changed, and the event can be either tougher or milder than expected. South Atlantic, where the Abrolhos Marine National Park is at, is always expected to be affected between March and May (3), months in which thermal anomalies occur in that area of the ocean, and that is what was predicted by NOAA in the last few months.

However, Southwest Atlantic did not read their forecast, and is behaving a bit differently than expected. The NOAA`s probabilistic bleaching thermal stress watch graph (figure 1, upper image) shows that the area is an “island of stability” amongst a global belt of unfavorable forecast in the tropical areas.  Other previous graphs had this area as a milder target (alert level 1), but now, for the happiness of coral reefs in the area, chances are lower.

Figure 1: NOAA`s previsions on Coral Bleaching. Upper image: NOAA Coral Reef Watch Probabilistic / Bleaching Thermal Stress Watch. Probability of Thermal Stress is very high for most areas in the Tropics. Note that Southwest Atlantic and some parts of South Pacific are stability Islands with lower probability. Green Arrow shows approximate position of the Abrolhos Marine National Park. Lower Images: Satellite Bleaching Alert and Outlook. Abrolhos area is inside black lines in upper left square (Current). Note the stability island inside the area. Dark red and red patches starting in the next weeks in the area show that thermal stress is likely to hit the area. In Lower Right image (Weeks 9-12), Note that the Park is going to be in a Hot Spot. Images adapted from and available at 5 and 6

Figure 1: NOAA`s previsions on Coral Bleaching. Upper image: NOAA Coral Reef Watch Probabilistic / Bleaching Thermal Stress Watch. Probability of Thermal Stress is very high for most areas in the Tropics. Note that Southwest Atlantic and some parts of South Pacific are stability Islands with lower probability. Green Arrow shows approximate position of the Abrolhos Marine National Park. Lower Images: Satellite Bleaching Alert and Outlook. Abrolhos area is inside black lines in upper left square (Current). Note the stability island inside the area. Dark red and red patches starting in the next weeks in the area show that thermal stress is likely to hit the area. In Lower Right image (Weeks 9-12), Note that the Park is going to be in a Hot Spot. Images adapted from and available at 5 and 6

However, everything isn`t flowers. Although reefs in Northeast Brazil are likely safe for now, Abrolhos is further south, and an “arm of instability” may affect Brazil`s lower coast, having the Abrolhos` area as its end (see lower figure 1). If the forecast is accurate, the sanctuary, which is house to all hard coral species in South Atlantic (4), should face in the next two months a somewhat intense hot spot, putting the area in Alert. Nonetheless, the Current thermal map in the area shows the park as “Watch”, relatively close to a stability island, requiring the pattern to reverse for the previsions to become reality.

Whether the reefs bleached or not in the last 1 month of “Watch”, of if it is going to bleach in the next expected month of instabilities, we don`t know yet. However, coinciding with the previsions of greater possible damage, there are planned expeditions. Researchers of Federal University of Bahia (UFBA), led by Dr. Kikuchi and Dr. Leão will visit the Marine National Park in two weeks, and reports on how the reef responded to recent events should be available from then. Amid so many disastrous effects of the bleaching in the globe, we hope that that area is not affected, and remains as a refuge for reefs in the region.

 

References

[1] Slezak, M. (2016). Available at http://www.theguardian.com/environment/2016/feb/23/global-coral-bleaching-event-threatens-great-barrier-reef, accessed in 3/13/2016

[2] Marszal, A. (2014). Available at http://www.telegraph.co.uk/news/worldnews/australiaandthepacific/marshallislands/11308173/Global-warming-blamed-for-worst-ever-Marshall-Islands-coral-bleaching.html, accessed in 3/13/2016

[3] Leão, Z., Kikuchi, R., Oliveira, M., & Vasconcellos, V. (2010). Status of Eastern Brazilian coral reefs in time of climate changes. Pan-American Journal of Aquatic Sciences, 5(2), 224–235. http://doi.org/10.1016/B978-044451388-5/50003-5

[4] Leão, Z.M.A.N., Kikuchi,R.K. and Testa,V., (2003). Corals and coral reefs of Brazil. In Latin American Coral Reefs, J. Cortés (Ed.), pp. 9–52 (Amsterdam: Elsevier). In In Krug, L. A., Gherardi, D. F. M., Stech, J. L., de Andrade, Z. M., & de Kikuchi, R. K. P. (2012). Characterization of coral bleaching environments and their variation along the Bahia state coast, Brazil. International Journal of Remote Sensing, 33(13), 4059–4074.http://doi.org/10.1080/01431161.2011.639505

[5] http://coralreefwatch.noaa.gov/vs/gauges/abrolhos_reefs.php, accessed in 3/13/2016

[6] http://coralreefwatch.noaa.gov/satellite/bleachingoutlook_cfs/current_images/cur_img_v3_ss_watch_outlookprob_cfs_45ns.gif, accessed in 3/13/2016

Posted in Uncategorized | Tagged , , , , , , | Comments Off on Update on Abrolhos Marine National Park: will it bleach? That is the question

Will Love Prevail? A Story of Caribbean Corals

Posted on February 18, 2016 by meh9

When I think of coral reefs, I think of towers of tangled coral branches, exploding with movement, color, and life. I think of Mr. Ray from Finding Nemo guiding a school of young fish through a maze of corals and algae. That’s why it just feels… wrong… to see bleached reefs. Bleached corals don’t look like anything from the movies – they look like sickly, white masses of tissue and bone.

To put it in terms of human emotions, bleached corals look sad. And that’s because they’re missing their soulmates… their life partners… their symbiotic micro-algae.

Bleached coral colonies looking sad. Photo (by Edwin A. Hernandez-Delgado) from the cover of Ecosphere.

These micro-algae, belonging to the genus Symbiodinium, are unicellular protists that live inside of healthy corals. When times are good, the corals provide shelter and other compounds to the algae. In return, the algae produce oxygen, remove waste, and create energy for their hosts [1]. They also contain pigments that give corals their signature bright colors. Like any relationship, the symbiosis between coral and alga is a delicate balance of give and take. They both need each other to survive, but under stress, the relationship can fall apart.

When reef ecosystems are exposed to stressors like increased temperatures, pollution, overexposure to sunlight, and/or low tides, corals expel their Symbiodinium and become bleached [2]. Bleaching can be widespread and disastrous for reefs. In 2005, extremely high temperatures in the Caribbean, around 1.2 ºC higher than average, caused over 80% of corals in the area to bleach. That year, over 40% of the surveyed Caribbean corals died from bleaching [3].

High temperatures that caused coral bleaching in the Caribbean during the 2005 bleaching event. Figure from Eakin et al, 2010 [4].

High temperatures that caused coral bleaching in the Caribbean during the 2005 bleaching event. Figure from Eakin et al, 2010 [4].

Unfortunately, the loss and decline of coral reefs is not contained to the Caribbean. As sea temperatures rise through climate change and events like El Niño, it looks as though the tale of corals and their symbionts throughout the world is a tale of Romeo and Juliet. These star-crossed lovers need to be with each other, but are tragically thwarted by external forces.

But the story isn’t over yet!

As we enter a year that the National Oceanic and Atmospheric Administration (NOAA) has declared to be the “third ever global coral bleaching event,” the suspense thickens [2]. After surviving the first two global bleaching events in 1998 and 2010 as well record high temperatures in 2005, Caribbean reefs are damaged, yet alive [3].

Throughout the next couple of months, I’ll be following scientific research on the warming reefs of the Caribbean. What will happen to our Caribbean friends? Are they too damaged to recover, or has the previous history of bleaching made them stronger? Is there still something we can still do, or is this the last straw?

Only time will tell!

 

References

[1] “Symbiotic Algae.” NOAA Coral Reef Conservation Program. National Oceanic and Atmospheric Administration, 13 May 2011. Web. 17 February 2016.

[2] “NOAA Declares Third Ever Global Coral Bleaching Event.” NOAA. National Oceanic and Atmospheric Administration, 8 Oct. 2015. Web. 17 February 2016.

[3] “Heat Stress to Caribbean Corals in 2005 Worst in Record.” NOAA. National Oceanic and Atmospheric Administration, 15 Nov. 2010. Web. 17 February 2016.

[4] Eakin, Mark et al. “Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005.” PLoS One 15.5 (2010):e13969. Web. 18 February 2010. 

Posted in Uncategorized | Tagged , , , , , , , , | Comments Off on Will Love Prevail? A Story of Caribbean Corals

Trouble Down Under: Coral Bleaching to Hit the Great Barrier Reef

Posted on February 18, 2016 by ams13
Comparison of coral bleaching before (left) and after (right). credit: nature.org

Comparison of coral bleaching before (left) and after (right). credit: nature.org

When the month of October rolled around in 2015, and El Niño was beginning to bring heavy rains across the western United States, many naive Californians were filled with hope that an end to the state’s four-year drought was in sight. Unfortunately, this reoccurring climate pattern known as the El Niño-Southern Oscillation (ENSO) was causing much greater problems out at sea than on the thirst-driven West Coast.

On October 8th 2015, the National Oceanic and Atmospheric Administration (NOAA) announced the third ever coral bleaching event occurring on a global scale1. One effect of ENSO is the dramatic rise in sea surface temperatures across the Pacific, which causes stress on the dynamic aquatic ecosystems, especially coral reefs. According to the National Aeronautics and Space Administration’s (NASA) Global Climate Change website, there is a direct link between the increased amount of greenhouse gases being emitted to the atmosphere and the Earth’s warming2. Evidence for this global warming includes dramatic increases in the sea level in the past decade, which was nearly double that of the past century3, as well as increases in global surface and oceanic temperatures2. These existing global warming issues coupled with the current El Niño storm perpetuate a harsh environment for coral reefs, and triggered the current mass bleaching event.

But first, how does coral bleaching happen? Coral have a symbiotic relationship with algae, meaning that the two are dependent on each other for survival. The algae, called zooxanthellae, lives inside the coral tissue and gives its host oxygen and other nutrients while the coral gives the zooxanthellae carbon dioxide4. Each organism needs these compounds to live. Under normal conditions, this relationship is very successful and the coral lives a happy and healthy life. When you think of coral reefs, you likely think of a scene out of Pixar’s Finding Nemo, with brilliantly colored corals. The algae are what give corals their beautiful color. Unfortunately, when factors such as temperature are changed, this causes stress on the coral and forces the algae to abandon its host. Without the algae, the coral is left without its partner (and primary source of food), so it turns white and is very vulnerable to disease, which can lead to its death. This phenomenon is known as coral bleaching.

How Coral Bleaching Works

How Coral Bleaching Happens. credit: NOAA

When NOAA announced the global bleaching event in October, the primary areas of concern for being affected in the first stage (October – January 2016) the most were the Hawaiian Islands, Caribbean and the South Pacific, as seen in the picture below. These are the areas in dark red.

NOAA's map of global projections for areas at high risk for coral bleaching between October and January of 2016.

NOAA’s map of global projections for areas at high risk for coral bleaching between October and January of 2016. credit: NOAA

At the time, the Great Barrier Reef (GBR), located off the Northeast coast of Australia, was predominantly labeled as a “Warning” zone, so it was at risk but not as severely as other reefs. However, in NOAA’s projections for the February – May 2016 stage of the bleaching event, the GBR is bumped up to Alert Levels 1 and 2.

NOAA's global map of projections for areas at high risk of coral bleaching between February and May of 2016.

NOAA’s global map of projections for areas at high risk for coral bleaching between February and May of 2016. credit: NOAA

Unfortunately, this means trouble for the world’s largest coral reef system. The GBR is composed of over 3,000 individual reefs and is one of the most sought destination for travelers across the globe5. There’s a reason this beautiful and unparalleled ecosystem is one of the seven wonders of the natural world. The national marine park covers over 300km (1800 miles) along the coast of Queensland and is home to more than 600 types of coral, 1500 species of tropical fish and 200 types of birds5,6. The GBR is one of Earth’s most treasured natural habitats and it is now in grave danger.

Great Barrier Reef from above.

Great Barrier Reef from above. credit: http://d3lp4xedbqa8a5.cloudfront.net/s3/digital-cougar-assets/AusGeo/2013/09/10/5446/great-barrier-reef.jpg

However, this wont be the first time the GBR has experienced coral bleaching. In 1998, during the first ever global coral bleaching event, 16% of the world’s coral reefs were affected while 50% of the reefs on the GBR experienced bleaching7,8. In 2002 there was another mass bleaching event, and this time 60% of the reefs on the GBR suffered bleaching. During each of these events, 5% of the reefs were severely damaged6.

Pie charts of affected GBR coral in past bleaching events.

Pie charts of affected GBR coral in past bleaching events. credit: GBRMPA

After the 2002 event, the Great Barrier Reef Marine Park Authority (GBRMPA), which oversees the reef, developed a risk and impact assessment plan to respond to bleaching events in the future, like right now. This plan outlines a way to strategically monitor and assess coral bleaching impacts. According to a study conducted by NOAA and the University of Queensland, the current coral bleaching even is expected to be worse than ever before for the GBR7. While the GBRMPA uses their plan on an annual basis to monitor the reefs, it will be of vital importance to document the upcoming changes.

It’s difficult to know how to respond to this kind of news as an individual. It feels like we are just standing idly by, watching the sky turn grey and waiting for the storm to roll in, helpless against the inevitability. We know that this massive coral bleaching event is happening, and that it will spread soon, but what can we do about it? Isn’t there any way to stop it? Luckily, bleaching is not necessarily a death sentence for coral. Resilient corals can bounce back after bleaching and regain their symbiotic relationship with zooxanthellae. Agencies like the Nature Conservancy are pioneering these reef resilience efforts8. But again, that is an after-the-fact method of helping coral reef.

A scientific diver uses a quadrat to monitor coral reef.

A scientific diver uses a quadrat to monitor coral reef. credit: livingoceansfoundation.org

In the mean time, the best thing we can do as individuals is to spread awareness of what’s happening and what’s at risk. Coral reefs constitute only 1% of the ocean ecosystem, yet shelter 25% of all marine species9. Coral reefs are also vital for protecting shorelines and supporting sustainable fishing industries9. Additionally, doing our best as individuals to reduce the human carbon foot print can also help prevent further coral bleaching. Reducing energy consumption means contributing less greenhouse gases, which is a crucial step for combating global and oceanic warming. So, living a “greener” lifestyle can help the corals!

This blog will follow the coral bleaching event in the Great Barrier Reef and report on the status of the coral as the information becomes available. Stay tuned, and in the meantime, tell a friend about coral bleaching!

 

References:

  1. http://www.noaanews.noaa.gov/stories2015/100815-noaa-declares-third-ever-global-coral-bleaching-event.html
  2. http://climate.nasa.gov/evidence/
  3. Church, J. A. and N.J. White (2006), A 20th century acceleration in global sea level rise, Geophysical Research Letters, 33, L01602, doi:10.1029/2005GL024826.
  4. http://oceanworld.tamu.edu/students/coral/coral3.htm
  5. http://www.greatbarrierreef.org/about-the-reef/
  6. http://www.gbrmpa.gov.au/about-the-reef/facts-about-the-great-barrier-reef
  7. http://www.gbrmpa.gov.au/managing-the-reef/threats-to-the-reef/climate-change/what-does-this-mean-for-species/corals/what-is-coral-bleaching
  8. http://www.abc.net.au/news/2015-10-08/mass-coral-bleaching-predicted-to-occur-in-2016/6838580
  9. http://www.nature.org/ourinitiatives/habitats/coralreefs/coral-reefs-coral-bleaching-what-you-need-to-know.xml
Posted in Uncategorized | Tagged , , , , , , , | Comments Off on Trouble Down Under: Coral Bleaching to Hit the Great Barrier Reef