Archive for the 'Coral reefs' Category

Ocean state alarming – policy changes are needed

Text and photos (c) 2013 Erkki “Eric” Siirila, copyright & all rights reserved. 

Urgent measures are needed to stop ocean degradation related to climate change. The speed and negative effects are greater and more clearly felt that previously thought. These are the most important conclusions of recent work by an international marine scientist panel.

The results of the latest wide-ranging international review were made public by the World Conservation Union (IUCN) at the beginning of October 2013. Behind the work were the experts of IUCN and International Programme of the State of the Ocean (IPSO). The outcomes have also been published in the scientific journal Marine Pollution Bulletin.

Evening in the South Atlantic.

Evening in the South Atlantic.

An IUCN press release highlights the contents by telling us the following preoccupying facts: The ocean is absorbing much of the global warming. Unforeseen levels of carbon dioxide are bound by the ocean. The cumulative impact of this, together with other ocean stressors, is much more threatening than past estimates.

The other contributing stressors include decreasing oxygen levels in the sea and runoff of nitrogen from land. Also chemical pollution and serious overfishing are hampering the ocean’s capacity to act as a balancing factor in what is called “carbon preturbations”.

A comment by Professor Alex Rogers of Somerville College, Oxford (also Scientific Director of IPSO) is cited in the IUCN summary paper: “The health of the ocean is spiraling downwards far more rapidly than we had thought. We are seeing greater change, happening faster, and the effects are more imminent than previously anticipated. The situation should be of the gravest concern to everyone since everyone will be affected by changes in the ability of the ocean to support life on Earth.”

Professor Dan Laffoley, from IUCN, commented the new interdisciplinary findings by saying: “What these latest reports make absolutely clear is that deferring action will increase costs in the future and lead to even greater, perhaps irreversible, losses. The UN climate report confirmed that the ocean is bearing the brunt of human-induced changes to our planet. These findings give us more cause for alarm – but also a roadmap for action. We must use it.“

Dead fish on the beach of Bombinhas, Brazil.

Dead fish on the beach of Bombinhas, Brazil.

More in depth, the foreseen challenges and problems include the following:

Oxygen levels in the ocean are expected to decline between 1% and 7% by 2100.  Tropical  oceans and and the North Pacific have had a trend of decreasing oxygen levels during the past 50 years and this will continue because of global warming. In addition, lack of oxygen will be a serious problem in coastal seas commonly affected by eutrophication (sewage and agricultural runoff being the main reasons).

In case CO2 release by us planet Earth inhabitants continues at the current level, acidification of sea water will be a major factor affecting ocean life, marine food production and coastal protection. Acidification would be felt for example on coral reefs, where erosion in the near future could exceed reef formation (calcification). This in turn would degrade the reef habitat and result in the destruction of the natural breakwaters formed by corals – a serious consideration in coastal regions commonly hit by heavy storms.

As to the direct physical and geochemical consequences of global warming in the ocean by 2050, they include: reduced seasonal ice zones, increasing stratification (separation) of ocean layers leading to oxygen depletion, increased venting of methane from the bottom of the Arctic Sea, and more common low oxygen -events in the oceans.

Around the globe, fisheries management is still unable to stop overfishing. The decline of key species and damage to the ecosystems where the fish stock live continue. All this undermines the resilience of the oceans.

Unauthorised fishing in the national economic zone: Argentine coast guard proudly presents the foreign fishing vessels detained by its patrol vessel. Photo from Puerto Madryn, Argentina.

Unauthorised fishing in the national economic zone: Argentine coast guard proudly presents the foreign fishing vessels detained by its patrol vessel. Photo from Puerto Madryn, Argentina.

Urgent measures proposed by IPSO and IUCN include:

Reduction of global CO2 emissions to keep temperature rise in less than 2 degrees C.

Implementation of community- and ecosystem-based management and favouring small-scale fisheries. Harmful fisheries’ subsidies resulting in overcapacity would need to be eliminated. In addition, vulnerable ecosystems would need an increased level of protection. Finally, illegal, unreported and unregulated fishing would need to to be combated.

Development of a more relevant global infrastructure for high-seas ocean governance is necessary. Especially a new implementing agreement for the conservation and sustainable use of biodiversity in areas beyond national jurisdiction is needed (within the United Nations Law of the Sea – UNCLOS – framework).

Progress in Tela reef conservation in Honduras

Text and photos (c) 2013 Erkki “Eric” Siirila, copyright & all rights reserved. 

Some years ago the city of Tela in Honduras was only known for its beaches. No one was aware that underwater additional national heritage could be found. The coral reefs of the Tela Bay are this other treasure.

The Tela Bay in Honduras has coral reefs, the conservation of which needs attention. Photographer and copyright (c) 2013 Erkki Siirila.

The Tela Bay in Honduras has coral reefs, the conservation of which needs attention. Photographer and copyright (c) 2013 Erkki Siirila.

Francois Ligeard, The Chamber of Tourism of Tela, says: “The good news is that we can offer a new site for both the national and international tourist. We have to highlight the fact that this place is very beautiful. It has high cover of live coral. We notice that always when we dive on this reef. One easily gets emotional because every time we go the local reef we find something new and more beautiful.”

Dennis Sierra, The Prolansate Conservation Foundation, Tela, sees the “newly discovered” coral reefs in the following way: “The best news is that in Tela we have many people both in the civil society, local government and the business sector who are very interested in the conservation of the coral banks of the Tela Bay. The preservation needs have an acceptance at the community level. Also at the level of the central government there is a lot of interest in declaring a marine park in the Bay of Tela.”

Only fishing was done on the local Capiro Reef in the past. Nowadays, divers come here to see the angelfish and the many species of coral. For example, black coral is found here.

The coral bank of Capiro is the best known reef area in the Tela waters. Photo and copyright (c) 2013 Erkki Siirila.

The coral bank of Capiro is the best known reef area in the Tela waters. Photo and copyright (c) 2013 Erkki Siirila.

Dennis Sierra: “Logically we look toward the future generations. We need to implement conservation actions in the Bay area, if we want to leave this ecosystem as a heritage to our children. Tela has been favored by God. We have to remember that the natural richness we have in Tela contributes in a positive way to tourism opportunities here. Tela has its future in the resources of that Bay.”

Francois Ligeard: “The biggest challenge we face is to take care of the reef both for our generation and the future generations. We need to get the fishermen and other local people involved to be able to preserve this reef. We have been working already by installing permanent mooring buoys. In this way, we need not anchor the boats and we can stop the damage that has been caused to the reef by anchors in the past.”

The mangroves of the Bay may not be forgotten as reef conservation is promoted. The mangroves produce nutrition for marine life. In addition, among the roots, many species of coral reef fish live during their juvenile stage. The mangroves also protect the coast from the waves of the sea.

The seagrass beds in the Tela waters have functions similar to those of the mangroves. In addition, many reef fish migrate to the seagrass areas in order to eat.

When forests are preserved, there is only little erosion on land and less mud enters the sea via the rivers. This is crucial in reef conservation as the corals need clean and clear water. Related to the above, it is also necessary to develop the treatment of sewage and waste waters.

In the Tela Bay there are very healthy coral colonies. It is important to take care of the reefs, because climate change threatens them, through the elevated sea-water temperatures and through the acidification of the sea.

Coral reefs will be more resistant to global environmental changes, when at the local level there is no overfishing and when the other pressures are kept at the minimum level. In this way, the coral reefs of Tela will produce economic and environmental benefits to us also in the future.

The following Youtube video was shot and produced by the Coastal Challenges’ Editor. It tells the above story of the Tela coral reefs in Spanish. The original is in high definition; this lower-resolution Youtube version can be best seen be adjusting the image resolution under the Youtube window to 480 p.

Shipwrecks support coral conservation in Egypt

Text and photos (c) 2013 Erkki “Eric” Siirila, copyright & all rights reserved. (The article below is a short version of a more complete magazine article published elsewhere.)

In popular diving areas like the Red Sea, sunken ships can take diving pressure away from the heavily used coral reefs. This is the story of five recently located wrecks in Egypt. They do not only relieve the pressure caused by divers on the reefs, they are even in the process of becoming reefs by themselves. Fish and coral have started to colonise the remaining ship structures already.

Four of the new dive sites are 100-250 kilometres north of Hurghada in the Gulf of Suez, one is just a day trip from the city shores. Recently innovative dive guides and underwater photographers like Kimmo Hagman, a Finn based in Hurghada, have initiated week-long live-aboard expeditions to these little-known sunken ships.

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The northernmost of the “new” wrecks is SS Turkia (part of the propeller pictured above). The construction of this British ship was completed in Hull, U.K., in 1910. The 91-meter long vessel sank on its keel after a fire and explosions onboard. Everything was not destroyed, and there is a lot to explore, as the image (below) demonstrates.

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The disaster took place off Zafarana in 1941. The reasons for the events (air attack or an “ordinary” explosion of hazardous cargo of military material) are not clear. On this wreck the dive depths vary between 15 and 24 metres.

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Another little-known wreck, which is extremely interesting to explore, is SS Scalaria (image above), a Shell oil tanker from Britain. The vessel was launched in Newcastle, U.K., in 1921. While being anchored in the Ras Gharib oil production area, close to the western shores of the Gulf of Suez, the ship was attacked by German war planes and destroyed by powerful explosions in 1942. 11 men lost their lives.

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Of the main hull structures of this 125-metre long vessel, only the bow (photo above)  and stern can be identified by divers. The ship sits on its keel and most of the dive will be spent at only 10 to 12 metres.

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The third big and rarely visited wreck in the Gulf of Suez is the Egyptian cargo vessel MV Aboudy (image above). The 76-metre long ship was constructed in Ville de Tenes in the Netherlands and  launched in 1959 or 1960. Aboudy met its destiny during a storm in 1988. The disaster occurred in the shallow waters of Ras Gharib.  The hull of the vessel, which lies on its port side, is in a good condition. Aboudy is an enjoyable dive: the maximum depth is 12 metres and visibility about 25 metres.

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MS Bakr is an easily dived small wreck (foredeck visible above) close to surface in the Ras Gharib area. The vessel was built in Kiev, Ukraine, in 1964, when Ukraine was still part of the Soviet Union. Before sinking in an attack by Israeli fighter planes in the Yom Kippur war in 1973, Bakr functioned as a survey vessel in the Egyptian oil exploration. The hull is still quite intact in spite of the missile attack.  The maximum depth is 10 metres. You can explore the whole ship during one visit, as it is only 49 metres long. Visibility  is 10 to 15 metres.

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The fifth virgin dive site, which takes dive pressure away from the heavily visited “old reefs”, is MS Hebat Allah (photo above), built in Ingrandes, France in 1985. This 44.5-metre wreck is a small cargo ship which was damaged during a storm and intentionally sunk in order to make it Egypt´s first artificial reef for scuba divers in 2004. Accidentally the ship went down into deeper water than planned and never became everyman´s dive site. Now Hebat Allah can be found sitting upright on sand in the marine area between Small Giftun Island, Gota Abu Ramada and Hurghada City. The bottom depth is 46 metres, and 40-metre visiblity is common (see the second image below).

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More information on the new Egyptian wreck attractions can be found on the web sites mentioned below. In addition to several dives on the sunken ships, these internet addresses were used as information sources for this article:

http://www.aquatours.com/

http://www.shipwrecksofegypt.com/

http://www.deeplens.com/

http://www.facebook.com/KimmoHagman.Photographer

UN Conference on Sustainable Development: highlights of the Rio+20 final document

At the UN Conference on Sustainable Development in Rio (June 2012), binding new international agreements were not agreed upon, which was disappointing. Nevertheless, the final document is worth summarising in order to highlight the most important common views of the world´s governments as regards sustainable development and the marine environment. Luckily, in the management of seas and oceans important progress was achieved. The following is a summary – with special reference to coasts, seas and oceansof  the final document “The Future We Want”:

The document states that for sound development in general, holistic, integrated and sustainable management of natural resources needs to be promoted. At the same time, economic, social and human development should be supported.  Also, the international community is asked to move the sustainable development agenda forward, through the achievement of internationally agreed goals including the existing Millennium Development Goals. Green economy in the context of sustainable development and poverty eradication is mentioned as one of the important tools available for achieving sustainable development.

The United Nations Conference on Sustainable Development was held in Rio de Janeiro in June 2012. The achievements of the meeting were minor. Only in the “seas and oceans” action area important progress was achieved. Aerial photo of Rio (c) 2012 copyright Erkki Siirila.

The Rio participants recognise the key role that improving energy efficiency plays. This includes the increasing share of renewable energy and cleaner, more energy-efficient technologies. Climate change as a persistent crisis is acknowledged: the global nature of climate change calls for the widest possible cooperation by all countries and their participation in an effective international response. Naturally, reduction of greenhouse gas emissions is needed. Also the related urgent needs of Small Island Developing States (SIDS) are mentioned in the final document.

The need for effective, transparent, accountable and democratic natural resources´ management institutions is mentioned in the document. So is the need for contributions towards sustainable development by both the public/private sectors and the scientific/technological communities. We are also reminded of the important role of citizens at the grass-root level, e.g. fishers, in the development of production activities which are environmentally more sound. The valuable contributions by  NGOs in promoting sustainable development are acknowledged.

The establishment of UNEP as a permanent UN organisation (instead of being a non-permanent programme) was not achieved, but it was decided that UNEP would be strengthened. In addition, the participants decided to establish an intergovernmental high-level political forum replacing the current UN Commission on Sustainable Development.

In the final document, the participating states recognise the severity of global biodiversity loss and degradation of ecosystems: this underlines the importance of biodiversity conservation, enhancing habitat connectivity and building ecosystem resilience.

In the Oceans and Seas chapter of The Future We Want, important progress can be observed. To begin with, the participating states commit to protect and restore the health, productivity and resilience of oceans and marine ecosystems, and to maintain their biodiversity for the conservation / sustainable use by the present and future generations. Furthermore, the participants agree to apply an ecosystem approach and the precautionary principle in marine management.

The Rio conference delegations recognise the importance of UNCLOS (Law of the Sea) in advancing sustainable development and they emphasise the need for cooperation in marine scientific research. The states also support the Regular Process for Global Reporting and Assessment of the State of the Marine Environment (established under the UN General Assembly) and look forward to the completion of its first global integrated assessment by 2014.

In Rio de Janeiro, the participating states supported the Regular Process for Global Reporting and Assessment of the State of the Marine Environment. The states look forward to the completion of the first global integrated assessment by 2014. The marine image was taken off Callao, Peru, photo copyright (c) 2012 Erkki Siirila.

In the seas and oceans chapter, the importance of the conservation / sustainable use of marine biodiversity beyond areas of national jurisdiction is recognised. Building on the work of an international working group (and before the end of the 69th Session of the United Nations General Assembly) the Rio participants commit to address this issue on an urgent basis.

The states also note with concern that the health of the oceans and marine biodiversity are negatively affected by marine pollution. The final document mentions marine debris, plastic, persistent organic pollutants, heavy metals, and nitrogen-based compounds. The sources mentioned include marine and land-based sources, including shipping and land runoff. The participants commit to take action to reduce the incidence and impacts of such pollution on marine ecosystems. The relevant measures would include implementation of IMO conventions and the follow-up of relevant initiatives such as the Global Programme of Action for the Protection of the Marine Environment from Land-based Activities. With the help of scientific assessments, the states further commit to take action to significantly reduce marine debris by 2025.

In the seas and oceans chapter the participants note the significant threat which alien invasive species pose to marine ecosystems, and commit to implement measures to prevent their introduction. The management of the adverse environmental impacts will be improved including those alien species adopted in the framework of IMO.

Sea level rise and coastal erosion are noted as serious threats for many coastal regions and islands particularly in developing countries. International action to address these challenges is called for in the final document.

The participating states also call for support to initiatives that address ocean acidification and the impacts of climate change on marine and coastal ecosystems and resources. They reiterate the need to work collectively to prevent further ocean acidification, as well as to enhance the resilience of marine ecosystems and of the communities whose livelihoods depend on them. The importance of marine scientific research, monitoring and observation of ocean acidification and of particularly vulnerable ecosystems through international cooperation are mentioned.

In the Rio final document the participating states stress their concern about the potential environmental impacts of ocean fertilization. They recall the decisions related to ocean fertilization adopted by the relevant intergovernmental bodies, and decide to continue addressing ocean fertilization with utmost caution. The precautionary approach will be applied.

In Rio the participating states promised to intensify the efforts to meet the 2015 target as to maintenance or restoring fisheries stocks to levels that can produce maximum sustainable yield on an urgent basis. The photo of the fishing vessel is from the Falkland Islands (Islas Malvinas), copyright (c) 2012 Erkki Siirila.

The Rio participants commit, on an urgent basis, to intensify the efforts to meet the 2015 target as to maintenance or restoring fisheries stocks to levels that can produce the maximum sustainable yield. The foreseen time frame is “the shortest time feasible”. To achieve this, the states commit to urgently develop and implement science-based management plans. Fisheries reduction and suspension are listed as management methods. The importance of by-catch reduction and the control of destructive fishing practices are mentioned as well as the importance of impact assessments.

Relating to UNCLOS, the Rio delegations urge states to fully implement the 1995 Agreement on the Conservation and Management of Straddling and Highly Migratory Fish Stocks. Furthermore, all States are called upon to implement the Code of Conduct for Responsible Fisheries and the corresponding FAO International Plans of Action and technical guidelines.

The final document acknowledges that illegal, unreported and unregulated (IUU) fishing deprives many countries of a crucial natural resource and remains a persistent threat to their sustainable development. A recommitment to eliminate IUU fishing is presented. Reference is made to the Johannesburg Plan of Implementation which aims at preventing and combating these practices in the following ways: a) by implementing national and regional action plans in accordance with FAO’s international IUU combat plan, b) by identifying vessels engaged in IUU fishing, c) by depriving offenders of the benefits accruing from IUU fishing, and d) by cooperating with developing countries to systematically identify needs and build capacity (monitoring, control, surveillance, compliance and enforcement systems).

The Rio delegations recognise the need for transparency and accountability in fisheries management by regional fisheries management organizations (RFMOs). The efforts already made by those RFMOs that have undertaken independent performance reviews are recognised. A call is presented on all RFMOs to regularly undertake such reviews, publish the results and implement the recommendations.

Furthermore, the Rio final document reaffirms the Johannesburg Plan of Implementation as to elimination of subsidies that contribute to illegal, unreported, and unregulated fishing and overcapacity, mentioning the importance of this sector to developing countries. Reference is made to the WTO Doha Development Agenda and the Hong Kong Ministerial mandates for more vigorous control of fisheries subsidies. Prohibition of subsidies that contribute to overcapacity and over-fishing is mentioned as a control measure. States are also encouraged to eliminate subsidies that contribute to overcapacity and over-fishing, to refrain from introducing new such subsidies and to refrain from extending or enhancing existing subsidies.

A commitment to ensure access to fisheries and corresponding markets by fishers (subsistence, small-scale, artisanal) and women fish workers and indigenous peoples is also presented, highlighting the needs of these communities in developing countries and small island developing states.

The importance of coral reef conservation and marine protected areas is highlighted in the final document of the Rio conference on sustainable development. Image from a Red Sea coral reef in Egypt, photo copyright (c) 2012 Erkki Siirila.

As to coral reefs and mangroves, the Rio delegations recognise the significant economic, social and environmental contributions of coral reefs, in particular to islands and other coastal states, as well as the significant vulnerability of the reefs and mangroves to impacts including from climate change, ocean acidification, overfishing, destructive fishing practices and pollution. Support for international cooperation is expressed in order to conserve coral reef and mangrove ecosystems and to realise their social, economic and environmental benefits. Facilitation of technical collaboration and voluntary information sharing are mentioned as supporting measures. Surprisingly, sea grass beds are not separately mentioned in the Rio final document. (The importance of healthy sea grass beds as carbon sinks in fighting global climate change has recently been acknowledged by the marine science research community).

In the seas and oceans chapter of The Future We Want, the delegations reaffirm the importance of area-based conservation measures, including marine protected areas, consistent with international law and based on best available scientific information. The participants note decision X/2 of the 10th Meeting of the Conference of the Parties to the Convention on Biological Diversity, that by 2020, 10 percent of coastal and marine areas, especially areas of particular importance for biodiversity and ecosystem services, are to be conserved through effectively and equitably managed, ecologically representative and well-connected systems of protected areas and other effective area-based conservation measures.

Finally, it may be considered surprising that the importance of managing the sea-land interface as a special area was not mentioned in The Future We Want. As the coastal zone is an area of many opportunities, user conflicts, resource degradation and lost opportunities, it would have been natural to say something in the Rio final document about the need for integrated coastal zone management.

Coral conservation in Honduras: building on local roots is important

“We have got one of the best coral reefs in the Caribbean”, says Nelbin Bustamante from the Prolansate Foundation and Amatela reef conservation group of the Town of Tela, Honduras.  More in detail, Mr. Bustamante summarises the good news of a recent underwater study on the Tela reefs in the following words: “The live coral cover on our reefs is nearly 70 per cent per square metre”. This high number was registered on the Capiro Reef just seven kilometres from the city centre.

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An offshore reef near Tela, Honduras. Photographer and copyright (c) 2012 Erkki Siirila.

Nevertheless, all the evaluation results were not positive. Mr. Bustamante says: “It could also be observed that the number of herbivorous and commercial fishes had reduced. Their biomass had gone down.”

As regards the threats, two main threats were identified in the study. One was the loss of forest cover. The other one was the lack of wastewater treatment. The Tela wastewaters flow directly into the sea and coral reefs. In addition to soil, the runoff contains many chemicals including fertilizers. The nutrients in the runoff may facilitate algal growth on the reefs as, at the same time, the levels of herbivorous fishes consuming the algae are lower than normal. Overfishing is an additional threat which needs to be controlled in Tela.

In any case Tela is a good and encouraging example in a world where the coral reefs are threatened by high fishing pressure, global climate change and other side effects of the growth of human societies. Off Tela, fairly healthy coral reefs can still be found and new awareness is creating motivation to protect the reefs.

Mr. Marcello Dicunta Servellón, who operates a dive centre in Tela, is satisfied: “Healthy coral reefs represents incredible opportunities. One of the most obvious ones is recreational diving. A well-managed dive industry on healthy reefs can result in high economic growth for the community.”

A Spanish-speaking documentary (Corales para amar – Tela protege sus arrecifes) with the above-mentioned content can be watched on Youtube:

Days of Eastern Caribbean reefs are numbered

The West Indies’ coral reefs will disappear in a few decades. This is the shocking result of a new scientific study. Individual coral colonies will survive in the region even in the future, but the coral reef ecosystem as we currently know it will disappear. All this will lead to significant economic losses, particularly for island and coastal people whose livelihoods are closely linked to coral reefs and the ecosystem services they provide.

Global climate change is the main reason for the dramatic changes. The powerful adverse effects were shown in the Eastern Caribbean already in 2005, when the health of the region’s reefs weakened and live cover dropped during an extensive coral bleaching.

The study by Buddemeier et al. tells that it is already too late to stop the reef death. The big changes in the coral reef environment will take place even if substantial emission cuts of greenhouse gases are implemented in the coming years.

Coral reefs of the Caribbean are facing difficult times: efficient conservation measures are needed urgently. In addition to global emission cuts of greenhouse gases, innovative local conservation actions would be important. Photo copyright (c) 2011 Erkki Siirila.

The study published in the journal Climate Change in 2011 focuses on Eastern Caribbean reef health and especially the Virgin Islands’ area. The COMBO (COral Mortality and Bleaching Output) model was used for the predictions. Three realistic emission scenarios for greenhouse gases were the basis for the simulation.

The results indicate that future bleaching episodes will be followed by the reduction of live coral cover on the reefs. (Most of the damage will be caused by the warming of sea waters and related bleaching. The decline in reef condition will take place even if the adverse effect of ocean acidification is calculated as minor.)

If there is no adaptation by the corals to the elevated mean water temperatures, the live coral cover on the West Indies’ reefs will decrease to less than 5% already by the year 2035. In a scenario where corals develop an additional 1–1.5 degrees Celcius of heat tolerance (through a shift in the symbiotic algae that live in the coral tissues) coral cover above 5% could last until 2065.

The researchers did not include reefs which are located more than 30m underwater. Live coral cover between 5 and 10% was considered a limit where the reef would not be able to regenerate itself and could not be called a real coral reef any more. For several of these modeling scenarios, the researchers used starting levels of coral cover of 7%, 15%, and/or 30%. These values are realistic values in the Eastern Caribbean.

Buddemeier et al. summarise their study by saying that “coral reef communities are likely to be essentially gone from substantial parts of the Southeast Caribbean by the year 2035, given the current low cover values following the 2005 event” and that “the conversion of coral reefs to fundamentally different systems will have large implications for the provision of ecosystem services”. The authors add: “Given the modeling results presented here, urgent efforts are needed to identify and protect what appear to be the most resilient coral reefs in the Caribbean.”

The whole study (R. W. Buddemeier, Diana R. Lane and J. A. Martinich, Modeling regional coral reef responses to global warming and changes in ocean chemistry: Caribbean case study, Climatic Change, 2011, DOI: 10.1007/s10584-011-0022-z) can be found here: Study by Buddemeier et al.

Human wastewaters infect elkhorn coral

A human pathogen has been shown to contribute to the degradation of elkhorn coral (Acropora palmata) colonies in the Caribbean Sea. The pathogen Serratia marcescens is known to be present in human wastewaters, which enter the coastal marine areas untreated in many parts of the Caribbean. In the recent study by K.R. Sutherland et al., strain PDR60 of the pathogen was shown to cause disease signs in A. palmata colonies in as little as four or five days, when the surrounding waters were polluted with S. marcescens.

In the Caribbean the lack of wastewater treatment is a common problem. This colony of elkhorn coral looks healthy in spite of the fact that raw sewage enters the sea 100m from the reef. Photo taken in Utila, Honduras, copyright (c) 2011 Erkki Siirila.

In 2003 there was an outbreak of this coral disease called acroporid serratiosis (APS). During the episode, the corallivorous snail Coralliophila abbreviata and stony coral Sideastrea siderea were noticed to be play a role in the development of the disease. Now, in aquaria experiments, wastewater has been demonstrated to be a definitive, direct source of the disease, while C. abbreviata and S. siderea are known to act as vectors and reservoirs, which may also to contribute to the infection of A. palmata.

The research results by K.R.Sutherland et al. published in 2011 demonstrate for the first time that a human pathogen can be passed from us humans to marine invertebrates and infect them. The authors of the study “Human Pathogen Shown to Cause Disease in the Threatened Eklhorn Coral Acropora palmata” say that “these findings underscore the interaction between public health practices and environmental health indices such as coral reef survival”.

A direct link to the article is here:  Elkhorn and sewage