Archive for the 'Caribbean Sea' Category

Progress in Tela reef conservation in Honduras

Published April 23, 2013 Caribbean Sea , Climate change , Coral reefs , Fisheries , Mangroves , Marine parks , Seagrass meadows , Sediment control , Tourism Closed

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.

Coral conservation in Honduras: building on local roots is important

Published May 17, 2012 Caribbean Sea , Coastal management , Coral reefs , Pollution , Sediment control , Tourism Closed

“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.

Image

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

Published September 20, 2011 Atlantic Ocean , Caribbean Sea , Climate change , Coral reefs , Endangered species Closed

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

Published September 20, 2011 Caribbean Sea , Coastal management , Coral reefs , Environmental impacts , Pollution Closed

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