Geology for Global Development

Environmental Management

The importance of wetlands

The importance of wetlands

World Wetlands day is celebrated on 2nd February, marking the adoption of the Convention on Wetlands, also known as Ramsar Convention, in the Iranian city of Ramsar on 2nd February 1971. It “provides the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources.

Today 170 countries have adopted it and 2,341 Ramsar sites covering over 2,5 million km² are designated as Wetlands of International Importance. But what are wetlands and why should we care about them? I’ll address these questions and other important points in this article.

First, what are wetlands?

Basically, a wetland is an area of land that is covered with water, whether natural or artificial, permanent or temporary. This water can be salt, fresh or somewhere in between, and have a maximum depth of six metres. Mangroves, marshes, ponds, peatlands, swamps, deltas, estuaries, low-lying areas that frequently flood are all wetlands and they can be found on every continent. Some of the largest ones are the Sundarbans mangrove forest in the Ganges-Brahmaputra delta in Bangladesh, the Amazon River basin (figure below), and the Pantanal, both in Brazil.

Wetlands cover about 3% of world’s surface. A web-based map shows the global distribution of wetlands and peat areas. It was launched in 2016 by researchers from Sustainable Wetlands Adaptation and Mitigation Program – SWAMP and is based on satellite images acquired by the  Moderate Resolution Imaging Spectroradiometer (MODIS) instrument.

Why should we care about wetlands?

Wetlands are rich but also fragile environments. They can provide water, fish/biodiveristy, recreational areas and help to regulate the climate.

  • Biodiversity: Wetlands function as wildlife refuge, supporting high concentration of mammals, birds, fish and invertebrates, being nurseries for many of these species.
  • Resources: Further, they can be a huge resource for humans, supporting rice paddies (Figure 2), a staple food. They also help purify water by trapping pollutants and heavy metals in the soil and neutralizing harmful bacteria by breaking down suspend solids in the water.
  • Geohazards: Wetlands provide flood control and storm protection in coastal areas acting like a sponge during storm events such as hurricanes, reducing their power of destruction.
  • Climate change: Here is another important point that I would like to highlight about wetlands. They play an important role in climate change mitigation and adaptation, since they store huge amounts of carbon. If you are curious about this topic, see this post where Heather [a regular contributor to the GfGD Blog] discusses how carbon is stored in peat soils in the tropics and the main threats to these areas.

Wetlands in Amazon river basin during the dry season (Oct 2017), close to Santarém, Brazil – Photo: Bárbara Zambelli

Threatened environment

Despite their social and ecological importance, wetlands are continuously being degraded and even destroyed worldwide. According to this research the world has lost 64-71% of their wetlands since 1900 AD. Here is a list of the main threats towards wetlands:

  • Pollution: Generally located in low-lying areas, they receive fertilizers and pesticides from agricultural runoff, industrial effluents and households waste or sewage. These pollutants have detrimental effects on water quality and threaten the fauna and flora of wetlands. As I mentioned before, wetlands work as water filters, therefore there is a growing concern about how pollution will impact drinking water supplies and wetland biological diversity.
  • Agriculture and urbanization: One of the biggest threats to this environment is its drainage to make room for agriculture and human settlements. Such activities are an increasing threat and they destroy the ecosystem and all the benefits wetlands can provide.
  • Dams: The construction of a dam alters the natural flow of water through a landscape. This alteration may lead to an increase or decrease of water flow through a wetland, being potentially harmful for wetland ecosystems. Thus, it is essential to choose the location of a dam wisely, to reduce the impact on existing ecosystems.
  • Climate change: Climate change is shifting the world’s temperature and precipitation patterns. Wetlands are getting lost due both too much and too little water. Shallow coastal wetlands such as mangroves are being swamped because of sea level rise. In areas affected by droughts, estuaries, floodplains and marshes are drying up. Wetlands and climate change are the theme of World Wetlands Day in 2019.

Opportunities – taking action

Wetlands are a critical environment and their effective management can give a substantial contribution to biodiversity conservation and restoration, maintaining its bioecological characteristics and allowing the using of resources economically.

According to SWAMP, “carbon-rich mangroves and peatlands are high priorities in climate change adaptation and mitigation strategies throughout the world.”

With their partners, SWAMP have developed a collaborative agenda expected to raise the awareness about sustainable management of wetlands in changing world and livelihoods of local communities. The Ramsar Convention, an international agreement, is still important today because it supports environmental policy development and it encourages countries to commit to it. It is also valuable as an international forum for gathering and sharing knowledge about sustainable wetlands management. Also international NGOs such as Worldwide Fund for Nature (WWF) and Wetlands International play an important role.

Finally, regarding the Sustainable Development Goals (SDGs), recently Ramsar published a briefing note of how wetlands can contribute to their achievement. Access it hereto find out more details.

New mining frontiers: Digging into the unknown

New mining frontiers: Digging into the unknown

While climate change occupies the headlines as our biggest long-term concern for sustainability,  there may well be further anthropogenic challenges that arise in the next century as we disrupt the delicate interplay of natural ecological and geological cycles to satisfy the need for resources of our ever-growing population. The mining industry makes for a pertinent example: it sits on the verge of new key locations for digging – from the deep ocean to deep space – the consequences of which may not be fully explored.

The shift to a low-carbon economy is likely to entail an increase in demand for a wide variety of minerals. A 2017 report from the World Bank highlights the growth in demand for Lithium, Platinum and Lead, for new battery technology and rare earth element demand for solar and wind technology is also likely to increase.

As demand for these metals and resources rises, the cost and difficulty of extracting them rises too. Millennia of mining have exhausted the easy-to-access deposits for most metals, and the ratio of exploration sites that turn into actual mines is in the order of 1 in 1000. Combined with a decline in the overall quality of ore that is mined, it’s not hard to see why mining industry strategists are looking to previously unusable locations for their new mining ventures.

Geologists have known for a long time that the sea floor contains extensive mineral deposits of a wide variety of types; from ferro-manganese nodules to ores linked to submarine volcanism, economic minerals are spread across the global ocean floor. Until recently, the economics of dredging these sea beds for minerals have not been favourable, and technology has been too rudimentary to make an effective industry out of this approach. Now, however, prices and demand for these minerals are high enough that seafloor mining is beginning to take place in a few locations around the world.

Extraction like this could, of course, have major consequences. Biodiversity in the deep ocean is, even today, poorly understood, so strip mining these systems before we explore them fully could cause untold damage. At a small scale, this kind of mining might only have more limited, local impacts, but for the first time in the history of human society we have the capability to affect biological systems and geological cycles at a global scale, to a degree that might have significant and deleterious effects.

For example, mining waste on land can lead to contamination of local water supplies with acidic runoff. Deep sea mining could similarly lead to acidification of sea water, which could have far reaching consequences. Marine creatures living in the ocean are often very finely tuned to the chemistry of the water they’re bathed in; even small changes in acidity have been linked to increased coral bleaching and death. The risk of heavy metal pollution has also been pointed out from sand and mud kicked up by mining activity as it disturbs the sea bed; these toxic metals could cause problems both the sea life and to humans, as the fishery stocks would become increasingly exposed to heavy metals. The global extent of ocean currents mean that these effects wouldn’t be limited to the vicinity of the mining, as chemicals would be mixed into the whole ocean over time.

Unlike mining on the surface, the spread of this kind of pollution could be truly global; ocean currents could eventually spread the pollutants, and the mining itself would hardly be limited to a specific locality. Humans are poorly positioned to deal with this kind of crisis; a negative impact on the ocean – a global resource, not owned by any individual nation state – is a classic ‘tragedy of the commons’, much like carbon dioxide accumulation in the atmosphere. Given the lack of ownership of the oceans, individual states or mining companies lack strong incentives to regulate the exploitation of such sea-floor resources. Moreover, the globalised nature of the extractive industry means this could be a truly significant impact; the combined revenue of the top 40 surface mining companies is approximately half a trillion dollars, dwarfing all but the largest national economies, affording such corporations major financial clout to explore and develop mining on the sea floor.

At the dawn of the fossil fuel era in the Industrial revolution, the risks of burning coal, and later oil and gas, were poorly understood in comparison to today. Some authors suggest that since we are now much more aware of environmental issues, we are better placed to assess the future risks and rewards of deep sea mining than the earlier resources for which we mined and drilled.

It is perhaps worth pointing out, though, that with the range out impacts still poorly constrained even as dredging begins, it is incumbent upon geologists to explore and quantify the potential risks; academic research must keep pace with the growth of industry.

Even if deep sea mining does not have major, long-lasting impacts, there is one other mining frontier for which the risks are nearly totally unconstrained: asteroids.

It may sound like science fiction, but serious consideration is being given to mineral resources on near Earth asteroids. Given their potential value (some estimates – of the asteroid Psyche suggest mineral resources worth a quintillion dollars – an amount of money that’s basically inconceivable), it’s not surprising that enterprising drillers are looking up, as well as to the sea floor. Again, though, research into the potential geological hazards needs to be undertaken well before such ventures are carried out.

Our ever increasing environmental footprint has the potential to spread to new and poorly studied horizons, and we should endeavour not to make the same mistakes as we did with fossil fuels.

Robert Emberson is a science writer, currently based in Vancouver, Canada. He can be contacted via Twitter (@RobertEmberson) or via his website (www.robertemberson.com).

**This article expresses the personal opinion of the author. These opinions may not reflect official policy positions of Geology for Global Development.**

Weighing up the pros and cons of artificial coral reefs

Weighing up the pros and cons of artificial coral reefs

The world’s oceans cover 71% of the Earth’s surface and contain 97% of Earth’s water. They play a key role in the climate cycle and, though perhaps not always visibly, are suffering significantly under our changing climate. An place where we can see the alarming effects of rising temperatures and increasingly acidic waters is coral reefs, which experienced the longest, most widespread, and possibly the most damaging coral bleaching event on record between 2014 and 2017. In today’s post, Heather Britton compares natural vs. artificial coral reefs in the context of protecting life below the water (UN sustainability goal 14).

Reefs around the world are dying – approximately half of the world’s coral reefs have disappeared over the past 30 years, and many are showing signs of following in their stead – be it due to increased water temperature, sea level change or an influx of sediment in previously nutrient-poor conditions. Many of the factors contributing to the bleaching and eventual death of these ecosystems stem from the impact of people, such as global warming and the development of resorts in the vicinity of fragile reef environments.

The disappearance of coral reefs would lead to a catastrophic loss of biodiversity – coral reefs are thought to be the most biodiverse ecosystems on the planet, displaying a greater variety of life than even rainforests, and it is clear that we need to act now if these environments are to be saved – for many reefs it is already too late.

One popular response to the loss of natural coral reefs has been to construct artificial reefs, replacing those that have died and providing a habitat for organisms that may otherwise become extinct. These structures take a plethora of forms, from sunken ships to cinder block stacks, but as long as they are made of a hard substrate and are able to offer protection and a place for sheltering organisms to spawn there is potential for a reef to develop in as little as two-three years.

In many ways, this is an elegant solution. Not only do artificial reefs help to combat the loss of biodiversity associated with the decline of their natural counterparts, but they attract divers and other tourists to the sites where they are placed, bringing in tourism and strengthening the economy in the area. This benefit is particularly valuable to lower income countries, some of which boast extensive coral reef ecosystems. In addition, reefs are known to concentrate fish populations and therefore are popular with the fishing industry worldwide – the first recorded artificial reefs were developed by fishermen in Japan in the 18th century, who sunk makeshift shelters to increase their haul. Reefs form from man-made substrates relatively easily, and they are certainly preferable to a lack of reefs altogether – but can artificial reefs really ever match their natural cousins?

Diver installing ocean-chemistry monitoring equipment at Florida Keys. Credit: Ilsa B. Kuffner (U.S. Geological Survey). Distributed via U.S. Geological Survey. 

Artificial reefs are created extensively off the coast of Florida, as much for the economic benefit that the tourism brings (both through fishing and diving) as increasing ocean biodiversity. The region is encountering problems, however, one of which is local people choosing to develop their own personal reefs using suboptimal materials. For example, tyres, when strapped together, attract aquatic organisms as they provide a place to spawn and the shelter of a natural reef, but the toxicity of the rubber can negatively impact the environment in ways that a ship or concrete blocks will not. Ships that are sunk professionally for the purpose of artificial reef formation are extensively prepared before they are placed underwater, whereas amateurs rarely take the time to prepare their seeding structures properly. This has led some countries, such as Australia, to develop laws against the formation of artificial reefs without a permit.

Artificial reefs are also celebrated because they attract divers away from the surviving natural reefs, meaning that each individual reef is less damaged by people. It is also possible, however, that the number of tourists in total might increase in response to the increased number of dive-sites, having the opposite effect and causing dive sites in the region to become more popular.

Arguably, the most important question to be asked when discussing natural vs artificial reef structures is: do artificial reefs have biodiversity equivalent to that of natural reefs? The answer is unclear, but it certainly seems that the biodiversity of each kind of reef is different. Artificial reefs, at first glance, seem to attract more fish to them than natural reefs. This suggests that that artificial reefs may be encouraging fish to reproduce more than the naturally occurring reefs scattered throughout the oceans. However, many of the marine animals attracted to feed and shelter around artificial reefs do not breed there, and simply visit from other regions of the ocean. Artificial reefs therefore may only be acting to concentrate the fish in a single area, making them more susceptible to fishing and generally increasing the effect of fishing pressure on marine populations. This is commonly referred to as the ‘aggregation vs production’ debate. If the fish are more numerous at artificial reefs because they are breeding there, then the reef is likely acting to increase the population of that particular fish species and artificial reefs are helping to sustain the biodiversity of the oceans. If they are simply concentrating fish that typically spend their time swimming between reefs, however, fish numbers are likely to be negatively, not positively affected.

Dead corals turned to rubble, off the coast of the US Virgin Islands. Credit: Curt Storlazzi (U.S. Geological Survey). Distributed via U.S. Geological Survey.

A study on the Caribbean island of Bonaire provides some insight into the differences in diversity between natural and artificial reefs. Equal diversity was found at partnered artificial and natural reefs, but the composition of this diversity was starkly different. Whilst the sergeant major and bluehead wrasse fish were most commonly seen on the artificial reef, the natural was more commonly frequented by bicoloured damselfish and brown chromis. Similar trends were visible within the benthic community of organisms, suggesting that although artificial reefs may preserve the diversity that we see within the oceans today, some organisms appear to populate natural reefs to a far greater extent than their artificial counterparts, and these species may still be lost.

For this reason it is of the utmost importance that every effort is made to protect the natural coral reefs of today, thereby working to achieve UN sustainability goal 14 (Life below the Water). Artificial reefs are helping to preserve the biodiversity of the oceans and save countless organisms from extinction, but it is important to remember that what causes the corals of natural reefs to die will also impact the corals which begin to grow on artificial reefs. In order to prevent the loss of these ecosystems we need get to the root of the problem and combat the things that are harming coral reefs – global warming, human physical destruction of reef environments and the pollution of our oceans.

Speleology and local development

Križna jama cave, in Slovenia

Many of us seek adventures, new experiences and sights in far flung places, but very often there are beautiful wonders right on our doorstep. In today’s post, Barbara Zambelli Azevedo highlights how the promotion of local geological regions can be a valuable and effective way to encourage development and instil a sense of pride in local communities. 

Plato said in the Allegory of the Cave that men could only be free from ignorance when they leave the shadow world and see the real world outside. For me, caves have the opposite meaning. My first time in a cave at the end of 2011 changed me forever. To see the beauty hidden in the dark, countless endogenous species and curious formations in such a delicate and unique environment, thrilled me.

I was touched by speleology and I think that other people may feel the same. Even though karst areas are common throughout the world, still many people don’t know anything about caves, nor have they ever been in one. I believe in valorisation and promotion of speleological heritage in karstic areas as a way to promote sustainable territorial development. This could be done combining four different approaches:

Tourism: Implementation of a speleological management plan allowing and regulating public visitation, seeking at the same time the conservation of the cave, its surroundings and its attributes (physical and biological) as well as the transformations it might need to receive the general public. These transformations could be stairs, handrail, lights, bridges and walkways. It is important to consult the local community before starting any kind of business to know if the chosen cave has a special meaning, if it represents a sacred place or it is part of their culture.

Conservation: Conservation practices must be adopted to ensure the preservation of the speleological heritage. Cave guides should come preferably from the local community. They must receive appropriate training and instruction about security during exploration and conservation of the karst. In Brazil we use the motto:

“In a cave nothing is taken away except photographs, nothing is left but tracks and nothing is killed except time.”

Parks: Implementation of parks in areas where caves are concentrated in a given territory. This territory can be at local or regional level, and the park administration takes charge of the preservation and management of the speleological heritage.

Education: Promote local empowerment through science communication and environmental education. As I mentioned before, there are not a lot of people who know about speleology. In this context it is important to assess the knowledge of the local community when it comes to karst, caves and their formation, as well as their unique fauna, the delicate and complex hydrologic system. When a population is aware of its heritage, is more likely they will ensure its preservation.

Finally, it is crucial to highlight that before starting any kind of business regarding speleology, many different interdisciplinary and multidisciplinary studies must be carried on the areas, in order to select the most appropriate ones for developing tourism or any other activities.