Archive for the 'Environmental impacts' Category

WWF Living Blue Planet Report: alarming 49% decline in marine animals since 1970

An incredibly big and serious decline of 49% has taken place in the numbers of marine animals between 1970 and 2012. This is one of the main results of an updated study of marine mammals, birds, reptiles and fish published in September 2015. WWF Living Blue Planet report is based on research results summarised by the Zoological Society of London. Overall, 5,829 populations of 1,234 species were studied.

Mangroves and sea grasses of Utila, Honduras. Photo and copyright (c) 2015 Erkki Siirila.

Mangroves and sea grasses of Utila, Honduras. Photo and copyright (c) 2015 Erkki Siirila.

Not only numbers of marine vertebrate species have plummeted, also the increasing decline of marine habitats is alarming. The deforestation rate of mangroves, which offer many on-site and off-site ecological and economic benefits, has been 70% between 1970 and 2010. Equally important wetland areas, the world’s seagrass habitats have lost about 30% of their total area the since 1879. Seagrasses store double the amount of carbon stored by on-land forests.

As regards coral reefs, where 25% of all marine species can be encountered, their live coral cover has decreased by more than 50% during the past 30 years. In addition, there has been a 34% decline in reef fish populations between 1979 and 2010. The report says that due to climate change (ocean warming and acidification), the live cover of coral reefs could practically be lost across the globe by 2050 – at least as regards the main reef component the stony corals, which are the main reef builders.

Healthy coral reef off Roatan, Honduras. Photo and copyright (c) 2015 Erkki Siirila.

Healthy coral reef off Roatan, Honduras. Photo and copyright (c) 2015 Erkki Siirila.

Regarding fish stocks (930 species and 1463 populations studied) there has been a 50% reduction in population numbers around the globe between 1970 and 2010. 29% of commercial fish stock are considered as overexploited. 61% of the stocks are classed as fully exploited.

As to such important food fish as mackerels, tuna, bonitos and their Scombridae relatives, there has been a 74% decline between 1970 and 2010. Also sharks, rays and skates are facing survival threats: global catches have increased dramatically and 25% of the populations are threatened by local extinction.

Bottom trawling is in difficulties as well: There has been a 72% decrease in catches during the last 40 years. As to deep sea trawling specifically, this practice can be considered mostly unsustainable.

Fishing vessel in Mar del Plata, Argentina. Photo and copyright (c) 2015 Erkki Siirila.

Fishing vessel in Mar del Plata, Argentina. Photo and copyright (c) 2015 Erkki Siirila.

Of the four marine turtle species facing survival threats, the leatherback is having the biggest problems with 4 of the 7 sub-populations critically endangered.

Living Blue Planet Report indicates that also seabird and shorebird populations commonly face threats. The same is true for pinnipeds (seals, sea lions, sea elephants and walruses). Other marine mammal populations (whales & dolphins) and sirenians (manatees & dugongs) were not assessed in detail in this study – the information of their population development is considered data deficient. Also most marine invertebrates belong to the same “data deficient” category and detailed information regarding their conservation status is not available.

One of the press releases presenting the report summarises the findings of Living Blue Planet in the following words:

“As well as being disastrous for ecosystems, these findings spell trouble for all nations, especially people in the developing world who depend heavily on the ocean resources.”

“While over-exploitation is identified as the major threat to ocean biodiversity, the study finds that climate change is causing the ocean to change more rapidly than at any other point in millions of years. Rising temperatures and increasing acidity levels caused by carbon dioxide are further weakening a system that is already severely degraded through overfishing, habitat degradation and pollution.”

“By over-exploiting fisheries, degrading coastal habitats and not addressing global warming, we are sowing the seeds of ecological and economic catastrophe.”

“But there are clear steps that all governments can take to restore our oceans.  Creating networks of well-managed marine protected areas is a proven way to enable wildlife and habitats to recover. Pushing for a strong global deal on climate change would help the seas sustain life far into the future.”

Living Blue Planet Report 2015 can be downloaded from these two web sites:

Seas, coasts and climate change negotiations

In 2015 the countries of the world will hopefully agree on a binding climate treaty in Paris. The outcome should stop climate change, which is currently threatening the wellbeing of the inhabitants of this planet.

What are the threats facing the coastal area and the marine systems? The answer to this question was presented in the Summary for policymakers of the Intergovernmental Panel on Climate Change (IPCC) in 2014.

Coastal systems and low-lying areas

Due to sea level rise projected throughout the 21st century and beyond, coastal systems and low-lying areas will increasingly experience adverse impacts such as submergence, coastal flooding, and coastal erosion (very high confidence).

The population and assets projected to be exposed to coastal risks as well as human pressures on coastal ecosystems will increase significantly in the coming decades due to population growth, economic development, and urbanization (high confidence).

The relative costs of coastal adaptation vary strongly among and within regions and countries for the 21st century. Some low-lying developing countries and small island states are expected to face very high impacts that, in some cases, could have associated damage and adaptation costs of several percentage points of GDP.

Healthy mangroves and sea grass beds will be needed for coastal protection in Utila, Honduras also in the future. Photo copyright (c) 2015 Erkki Siirila.

Healthy mangroves and sea grass beds will be needed for well-functioning coastal ecology and storm protection in Utila, Honduras, also in the future. Photo copyright (c) 2015 Erkki Siirila.

Marine systems

Due to projected climate change by the mid 21st century and beyond, global marine-species redistribution and marine-biodiversity reduction in sensitive regions will challenge the sustained provision of fisheries productivity and other ecosystem services (high confidence).

Spatial shifts of marine species due to projected warming will cause high-latitude invasions and high local-extinction rates in the tropics and semi-enclosed seas (medium confidence).

Species richness and fisheries catch potential are projected to increase, on average, at mid and high latitudes (high confidence) and decrease at tropical latitudes (medium confidence).

The progressive expansion of oxygen minimum zones and anoxic “dead zones” is projected to further constrain fish habitat.

Open-ocean net primary production is projected to redistribute and, by 2100, fall globally under all scenarios.

Climate change adds to the threats of over-fishing and other nonclimatic stressors, thus complicating marine management regimes (high confidence).

For medium- to high-emission scenarios, ocean acidification poses substantial risks to marine ecosystems, especially polar ecosystems and coral reefs, associated with impacts on the physiology, behavior, and population dynamics of individual species from phytoplankton to animals (medium to high confidence).

Ocean acidification poses substantial risks to the health of reef-building corals. Photo from Utila, Honduras. Copyright (c) 2015 Erkki Siirila.

Ocean acidification poses substantial risks to the health of reef-building corals. Photo from Utila, Honduras. Copyright (c) 2015 Erkki Siirila.

Highly calcified mollusks, echinoderms, and reef-building corals are more sensitive than crustaceans (high confidence) and fishes (low confidence), with potentially detrimental consequences for fisheries and livelihoods.

Ocean acidification acts together with other global changes (e.g., warming, decreasing oxygen levels) and with local changes (e.g., pollution, eutrophication) (high confidence). Simultaneous drivers, such as warming and ocean acidification, can lead to interactive, complex, and amplified impacts for species and ecosystems.

Source: IPCC, 2014: Summary for policymakers. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1-32.

Microplastic pollution – a serious threat to marine ecosystems

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

Pioneering research has shown that plastic waste entering the ocean may have more serious negative effects on marine life than what was previously thought. Two studies published in Current Biology focus on the ecosystem effects of microplastic fragments less than 1 mm in diameter. The very small pieces of plastic have been polluting the ocean for about half a century.

Previous research has concentrated on the effects of bigger plastic objects in the marine ecosystem. This time the focus is on the fragments, which are produced for example as a result of gradual breakdown of plastic bottles in nature.

The tiny plastic particles are so small that wastewater treatment plants cannot stop them from entering the sea. A serious challenge for waste management is that this pollution does not originate only in what we normally consider plastic. The sources include synthetic textiles e.g. polyester – many of our clothes release a high number of microscopic pieces of plastic fibre when they are washed. Microbeads from cosmetic facial scrubs are one more source of harmful plastic particles. On the shores and in the sea, the microscopic plastic waste sinks into the sediments in high concentrations.

An additional problem with microplastics is that, in addition to the direct effects, they transfer harmful chemicals to marine organisms eating them. This was shown to take place in the case of lugworms by Mark Browne and his colleagues (link to Abstract). Lugworms (Wikipedia Lugworm) are an example of a common North Atlantic species using the sediments as food source. Starfish and sea cucumbers have similar feeding strategies. Mark Browne’s work was completed at Plymouth University, UK.

Plastic waste entering the Atlantic via Rio de la Plata (River Plate), Buenos Aires, Argentina.

Plastic waste entering the Atlantic via Rio de la Plata (River Plate), Buenos Aires, Argentina.

The harmful substances within the microplastics include antimicrobials, hydrocarbons and flame retardants, which are often persistent and may reduce health and biodiversity. Furthermore, minute plastic particles concentrate substances from the surrounding water on their surface: to name two examples, detergents and pesticides can be detected. The chemicals may be carried over to the next predators in the food chain – lugworms are eaten by flounders and wading birds. The harmful substances could also accumulate in the top predators, perhaps even in us humans. If lugworms are seriously affected, as they are, the whole food chain could be subject to significant adverse effects.

In the study by Stephanie Wright, University of Exeter, UK, and her colleagues, it was found that those lugworms which (in laboratory tanks) were subject to varying levels of plastic contamination, gained less weight than the worms in a clean environment. Consequently, the worms suffering from the consequences of plastic pollution had less energy for growth and reproduction. The worms were also likely to be less efficient in their important ecosystem service, i.e. in eating and keeping the sediments healthy and oxygenated for other animals. The article by Wright et al. is here: .

When interviewed by the BBC, Dr Browne summarised his earlier findings relating to 18 sediment samples from the beaches in several countries: “We found that there was no sample from around the world that did not contain pieces of microplastic.”

Based on these two ground-breaking articles in Current Biology, there seems to be an urgent need to develop the use practices and waste management techniques of plastic products in our societies. This is an important coastal and marine conservation issue.

In addition to the material published in Current Biology, summaries published by the British BBC and The Guardian, were helpful in the preparation of this Coastal Challenges’ article.


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

Coastal zone of Chile: ten management recommendations

Chile is a country with thousands of kilometres of coastline (the exact length of the coast depends on the definition applied). Naturally, moving towards integrated coastal zone management benefits a country like that.

The Coastal Challenges editor did a consultancy in the Fourth Region (Coquimbo Region) of Chile a few years ago. One of the results was a set of general guidelines for integrated coastal management in that region. In the ten conclusions/recommendations the local experiences were combined with the lessons learned in coastal management internationally.

A powerful tsunami in 2010 made Chileans aware of the need for sound coastal management. This Chilean government fax indicating there was a tsunami risk was not enough to result in massive coastal evacuations. As a result, lots of human lives were lost.

The conclusions and recommendations for integrated management of the Coquimbo coastal area are listed below:

  1. Integrated management of the coastal zone is a learning process with incremental implementation, feedback and adjustment mechanisms.
  2. At all levels of action, it is important to build the integrated management on a sustainable  financial and economic base, for example through self-funding.
  3. It is important to incorporate in the process the opinions of all the involved and interested parties, for example by applying conflict resolution mechanisms.
  4. It is essential that the actions keep focus on just a few issues which are understood by all the participants in the process. The focus on the issues means that an exact definition of the coastal zone is not a precondition for the action to begin.
  5. In general, construction on the local institutional roots is the safest option. E.g. the existing management systems, which are politically supported, can be modified instead of building totally new management institutions. Also in this case, the application of innovative ideas for real integration is important.
  6. A long-term vision is essential, and as part of this, opportunities should be left open for the future generations.
  7. The management should be based on good knowledge of the laws of nature. Implementation would need to be proactive instead of retroactive.
  8. It is important that the decision-making system is just and efficient.
  9. It is essential to understand that combining sustainable management with the poverty of resource users is difficult. Because of this, development of economic alternatives for the least favoured groups is needed.
  10. In sustainable coastal zone management, integration mechanisms are only one element. Specific action is needed also in the management of key species and habitats, pollution control, land use planning and environmental impact assessment. In addition to integration, sectoral activities in these and other action fields need to continue. (Naturally, sector-specific work needs to go on, but the sectoral actions should no more be implemented in isolation from other coastal zone activities.)

Revolutionary method: gypsum controls runoff

An interesting discovery is helping in Baltic Sea conservation efforts in Finland. It involves the use a gypsum, which is a chemical substance known to most of us.

The environmental challenge we are talking about is that phosphorus, an essential plant nutrient, is transported from the farming fields through runoff into the rivers and sea. In the sea water, elevated levels of phosphorus cause eutrophication.

Yara, a chemical company, has together with a few Finnish partners developed a gypsum-based technique to stabilize soil particles in the farming fields. The method reduces soil (and nutrient) erosion caused by surface runoff.

The results achieved indicate that a high percentage of the phosphorus stays in the soil when the new technique is used. Consequently, harmful nutrient inputs into the waterways and sea are highly reduced. The new method also helps the farmer as more phosphorus is available for the agricultural plants. Furthermore, there is less need for costly, additional phosphorus fertilizers.

In spite of not being visible in this image, eutrophication caused by excessive nutrients is a problem on the Baltic coast of Finland. Photo (c) 2010 Erkki Siirila.

The method involves spreading of a gypsum-based product on the farming field after harvest or before planting. The product, which is basically gypsum (calcium sulphate), infiltrates with water into soil. According Yara, this well-known chemical compound in its slightly developed form improves “particle aggregation and dissolved phosphorus retention”. In addition, “better soil structure means that the earth resists rain and melting snow better and therefore prevents erosion and phosphorus leakage”.

Gypsum is useful to the farmer also because it improves the plants’ ability to utilise the phosphorus reserves of the soil. In addition, farmers can continue their agricultural activities as before. For the gypsum treatment to be effective, it would need to be repeated once in three to four years.

Gypsum treatment of the soil could be important news for many countries. Soil,sediment and nutrient runoff is degrading forestry and agricultural areas around the world. This runoff is also killing shallow marine ecosystems. Could gypsum help save the world’s endangered coral reefs?

A brochure on the gypsum-based method to control agricultural runoff into the sea can be found here:

Alarming coral death on South-East Asian reefs

“It is certainly the worst coral die-off we have seen since 1998. It may prove to be the worst such event known to science,” says Dr. Andrew Baird, an Australian coral reef specialist in an interview by published on 18 October, 2010.

Dr. Baird estimates that approximately 80% of Acropora coral colonies and 50% of colonies by other species have died during the past six months on the bleached coral reefs in the Indian and Pacific Oceans.

Healthy-looking and bleached coral side by side. Photo (c) 2010 Erkki Siirila.

The reefs are numerous: the mass bleaching affects an area which extends from the Seychelles to Sulawesi and the Philippines. Included are reefs in Sri Lanka, Burma, Thailand, Malaysia, Singapore, and Indonesia.  The most diverse reefs of the world are found in the so-called “Coral Triangle” which is within the affected area.

In the Underwatertimes article Dr Baird comments the seriousness of the situation by stating that the live percentage coral cover on the reefs could drop from 50% to about 10% (these are average values).  The recovery, if it ever occurs, will take years.  Fisheries and tourism in the affected coastal and island nations will suffer: the livelihoods of millions of people are likely to be hampered.

The bleaching is being caused by elevated mean seawater temperatures which result in the loss of symbiotic microalgae from the coral tissues. As the pigments are in the algae, the coral colony turns white. When the seawater temperature stays higher than normal for weeks, the bleached coral colonies often die – for nutrition the coral depends on the algae.

The warming of seawater to levels which are higher than normal is related to the planet-wide effects of the periodic El Niño and La Niña weather disturbances, which in turn seem to be getting more extreme with global climate change.

In non-scientific terms the recent events in South-East Asia could perhaps be summarised by stating that “the rainforests of the sea are dying”.  People who have seen a healthy coral reef might also use the expression “a very sad and serious ecological disaster is taking place”.

Coral builds impressive living structures in the tropical oceans. Climate change, seawater warming and coral bleaching may kill these underwater cities. Photo from Hurghada,Egypt, copyright (c) 2010 Erkki Siirila.