Kennedy Warne, author of “Let Them Eat Shrimp: The Tragic Disappearance of the Rainforests of the Sea”, answered a few questions, posed by The Ecologist, about the importance of mangroves, the devastation caused by shrimp farming and his experiences researching his book.

You call mangroves the “rainforests of the sea”. While most people know about rainforests, most don’t know about mangroves. Why is that and why are they important?

Kennedy Warne: Mangroves tend to be associated with mud, and most people don’t like mud. (With the possible exception of potters). They also tend to harbour mosquitoes, and very few people (apart from entomologists) like mosquitoes. So there are a couple of reasons straight off the bat why mangroves have been maligned and disrespected – or simply ignored. While terrestrial tropical rainforests aren’t exactly fun places to be, with their torpid heat, abundance of bugs, high rainfall and other challenging attributes, people still recognise their importance and endorse efforts to prevent their destruction. Why aren’t mangroves higher on the environmental priority list? I don’t know. Their contribution to the planet and to humankind is immense. As I write in the book, they serve as coastal barricades and land stabilizers; they supply nutrients to the sea and nursery grounds for marine life; and they provide homes and livelihoods for millions of people across the tropical world.

In the book you detail the devastation caused by shrimp aquaculture. How has the western taste for massive amounts of this “luxury” food at a cheap price played a role?

The problem with shrimp aquaculture is that in the industry’s pioneering years, during the 1970s and 1980s, the ideal site for a shrimp pond happened to be at about the same position on the shore that mangroves flourish: low enough to get occasional tidal flow, but high enough not to be affected by tides all the time. Because mangrove forests tended to be public lands occupied by subsistence communities, they were readily appropriated by a combination of commercial aggression and governmental compliance.

Governments in developing countries became keen backers of shrimp farming because shrimp fetched a high price in the West, and was therefore a reliable source of foreign exchange. It was relatively easy for aquaculture corporations to clear mangroves and build shrimp ponds, the land was cheap to rent and there was plenty of it, so the cost of farming shrimp was low. Probably the most odious part of the early years of shrimp farming was that when one pond was nutritionally exhausted, the company would abandon it and bulldoze some more mangroves to build a new one. So the forests gave way to ever-expanding swathes of ponds. And all the while, consumers in the West couldn’t believe their luck, that such a tasty seafood was flooding into supermarket freezers and on to restaurant menus for such a cheap price. They never made the connection between cheap shrimp and disappearing mangrove forests.

As you travelled, you say first-hand the devastation caused by shrimp aquaculture and massive coastal development. How has this impacted both the environment and the local communities?

When you read statistic of how much mangrove forest individual countires have lost – 50 per cent, 60 per cent, 70 per cent – it can be very hard to get a picture of what those coastlines would have looked like if they had been left alone. But then you go to a place like the Sundarbans, the largest tract of mangrove in the world, and it starts to dawn on you the magnitude of what has been lost. And because mangroves are among the most biologically diverse forests on earth, you also realise that many species that rely on mangroves have disappeared too. Australian writer Tim Flannery wrote a book called A Gap in Nature, and that is what mangrove clearance caused: a very large, unfillable gap in nature.

Initially, my interest was focused on the natural history of mangroves. But then I started to meet people whose lives had been disrupted – more than most, catastrophically damaged – by mangrove deforestation, and I started to turn my attention to the impact mangrove loss was having on coastal communities. They were losing a physical resource, of course – source of timber, thatch, medicine, food – but they were also losing a defining part of their identity as forest dwellers. It would be like living next to a river and waking up one morning and finding the river was gone. They plight affected me deeply.

The full article appeared in The Ecologist, February 17th.

Figures due to be released by the Marine Stewardship Council show that the number of fish and seafood products in the UK certified as ’sustainable’ has increased by 41% since 2010.

What fisheries minister Richard Benyon has described as a ’seismic shift’ in people’s attitudes towards the fish they eat has led to a significant increase in consumer demand for seafood products bearing the MSC logo. This certification ensures that products have come from sustainable fish stocks where fishing rates are controlled below the rate of replenishment so the population is not depleted. This move towards more sustainable fish consumption is welcome as currently, 85% of fish stocks globally are exploited to their maximum capacity or overfished.

Upcoming reforms of the EU common fisheries policy are also hoped to contribute to the protection of dwindling fish populations by changing EU fishing practices.

Aquaculture is the fastest growing food production sector but there is still a great deal of uncertainty surrounding it’s environmental impact and how this is likely to change into the future as the sector expands to meet global food demands. A new report published by Conservation International and the WorldFish Centre investigating the aquaculture sector has identified some of the challenges in ensuring that the sector minimises adverse impacts on biodiversity and ecosystem services whilst maintaining high growth to respond to global food shortages as population size increases.

The UN Food and Agriculture Organisation estimate that around 84% of the world’s fish stocks are already over exploited indicating that fisheries will not be able to meet the protein demands of a rapidly growing population. Fish farming is becoming increasingly common (the sector has grown by 8.4% per annum since 1970) particularly in Asia and Africa, and now accounts for around half of all the fish we consume reducing pressure on natural fish stocks.

To identify the main sources of environmental damage in the industry and establish opportunities for increasing sustainability into the future the researchers investigated several different methods of aquaculture, measuring their inputs (fertilizers, energy, land and water) and outputs (carbon dioxide, nitrogen, and phosphorus) and then estimated the impact of the enterprise on ecosystems and biodiversity (acidification, eutrophication, and climate change).

Perhaps unsurprisingly the enterprises producing the largest quantity of fish had the highest environmental impact. The type of fish reared also has implications for the sustainability of the fishery, for example rearing carnivorous fish such as salmon and rearing shrimps and prawns which are highly dependent on temperature control decreases the efficiency of the enterprise and increases emission of nitrogen and green house gases. Seaweeds, oysters and mussels were found to have the lowest environmental impact.

A comparison between sectors was also included in the report, showing that aquaculture has a much smaller demand on fresh water and energy than poultry, pig and cattle farming, and has lower outputs of carbon, nitrogen and phosphorus.

By 2030 the sector is expected to double in size, producing 110 million tonnes of fish and seafood and the associated environmental impact is also expected to double. The report makes a series of research and policy recommendations to ensure that the sector is sustainable in the future, whilst simultaneously meeting the global demand for meat.

These include research into innovative methods to increase sustainability and improve efficiency, establishing regional networks to help improve efficiency in developing countries and promote best practice, and a variety of legislative measures to monitor the sector and promote compliance with environmental standards. The report also emphasises the importance of preventing new enterprises from establishing in important carbon sinks such as mangrove swamps

The report suggests that aquaculture may be the best solution to the global demand for meat as requirements for energy water and land are only a fraction of that for pig, cattle and poultry farming. Aquaculture will most likely be able to produce the most meat for the least demand on ecosystems, and the report indicates that fish farming should be promoted in policy to slow expansion of the other meat production sectors.

Sustainable eel fishing may start to increase in the European Union following the development of a new labelling scheme by the Sustainable Eel Group. The group, whose members include scientists, NGOs and policymakers, have developed a new standard (the Sustainable Eel Standard) to identify and promote best practice in the eel fishing industry. The development of the new standard is part of a move in the EU to put pressure on caterers and retailers to purchase eel only when they can be certain that it has been sustainably caught.

Eel populations have declined dramatically since monitoring began. A variety of factors have contributed to this decline including habitat destruction, pollution of waterways, disease, blocking of migratory pathways, and the complexity of the European eel lifecycle. These problems led to the eel being listed as endangered in 2008, after numbers had declined by as much as 90%. The new standard will start to tackle these problems by creating wetland habitats, monitoring water quality, and making alterations to the blocks in migratory pathways to allow eels to pass.

The new standard outlines key actions that the fishery must undertake in order to obtain a green score. These include:
• To achieve 40% escapement of eels, and minimise mortality during fishing
• To be licensed and provide accurate logbook data
• To use only legal gear
• To cause only negligible impacts on bycatch species or rare and protected species
• To cause on negligible impacts on habitats
• To active contribute in research and monitoring
• To develop and implement an eel management plan for restocking, and monitor the success of restocking
The report also contains recommendations for reducing the environmental and ecological impact of cultured eel and recommendations for animal welfare. Although these recommendations will ensure progression towards sustainability in the eel fishing industry the report also recognises that the fishery can not yet be called sustainable, as recovery of the stocks has not been sufficient.

The Sustainable Eel group is working with the Environment Agency to ensure that these recommendations are implemented in line with an EU Eel Management Plan

Spanish officials today seized over £4 million worth of illegally caught fish landed in the Canary Islands. It is thought the move is the start of a new EU scheme to prevent to deter and eliminate illegal, unreported and unregulated fishing after new regulations were introduced last year. The fish seized, weighing over 1100 tonnes, were destined for sale in Europe.

Illegal fishing of the coast of West Africa is a serious problem for local people, who rely on fishing for employment and as a source of protein. EU officials estimate that Sierra Leone loses around $29 million per year as a result of illegal fishing. Declines in fish stocks can increase pressure on other natural resources such as bush meat. Environmental Justice Foundation, the organisation to which the illegal fishing was first reported, said that the EU needs to take more responsibility for policing it’s waters. Among the species illegally caught were octopus, squid, sole, shrimp, and grouper some of which are known to be endangered or have depleted stocks.

Three boats involved in the illegal fishing, owned by South Korea, Panama, and China, were apprehended in the port of Las Palmas. Fish were taken from waters off the coast of Sierra Leone which are reserved for use by local fishermen under international fishing agreements. Other allegations were also made against the vessels, including use of child labour, damage to the local fishermen’s equipment, and even assault. EU officials noted that illegal fishing often goes hand in hand with other criminal activities.

This move is the most drastic action the European Union has ever taken on illegal fishing and a second strike is planned for later this year. Europe is currently investigating the activities of over 70 vessels from both member states and other countries. If vessels are found to be involved in illegal fishing they can be banned from landing fish in any European port, excluding them from the world’s biggest market for fish. Europe is also demanding answers from the Panamanian authorities who provided certificates to show that the fish landed were caught within international fishing agreements which protect certain areas for use by local fishermen.

See Fish worth £4m seized in EU crackdown on illegal fishing by Robert Booth for more information.

2,700 scientists in over 80 nations have collaborated to create the first ever Census of Marine Life (CoML). In a 64 page report, the highlights of over 10 years of marine biological research are presented, with some groundbreaking findings, including the discovery of over 200 new species. The census will contribute substantially to knowledge of global marine biodiversity and marine ecosystem function. It also includes reference to changes in species distribution across European Seas –the Baltic, Atlantic and Mediterranean- which indicate considerably high levels of threat to biodiversity in these waters.

An original paper, which describes the full inventory of life recorded was published as part of a special edition of PLoS ONE in August 2010. The CoML is widely welcomed, ahead of the final TEEB (Economics of Ecosystems and Biodiversity) report, to be published shortly with support from the European Commission, as part of it’s vision for Sustainable Devlopment

Source: Costello, M.J., Coll, M., Danovaro, R., Halpin, P., et al. (2010). A census of marine biodiversity knowledge, resources and future challenges. PLoS ONE. 5(8): e12110.

According to a report published on 4th February by the Centre for Hydrology and Ecology and Pond Conservation, 80% of ponds in England and Wales are in a ‘poor’ or ‘very poor’ condition, thus failing to provide vital habitat for aquatic plants and animals. These findings are particularly worrying given that reports by the Environment Agency last autumn showed that 75% of UK rivers will fail to meet new European biological standards. Although large numbers of new ponds are created each year in the UK, many of these ponds are located in agricultural areas and suffer from pollution by nutrient run-off. This eventually results in overgrowth of vegetation and stagnant water. In contrast, the report found that ponds close to rivers, streams and other wetlands are in much better condition. These results highlight the importance of developing future ponds in areas that are protected from pollution, in order to protect Britain’s future freshwater biodiversity.

Pond Conservation Press Release: First national survey shows Britain’s wildlife ponds are in a ‘terrible state’

Scientists at the Institute for Applied Ecology at the University of Canberra, Australia, have found a turtle that does better in a suburban habitat than it does in nature reserves. Eastern long-necked turtles (Chelodina longicollis) living in the suburbs of Canberra occupy home ranges nearly three times larger than turtles in the nature reserves. They are better able to cope with periods of drought, have higher population abundances and growth rates, and at last equivalent recruitment levels.

Eastern long-necked turtles, common across much of south eastern Australia, can be found in many freshwater habitats in the wild and in towns and cities. The researchers compared turtles that lived in the suburbs of Canberra to those in adjacent nature reserves, attaching miniature radio transmitters to the turtles in each habitat and following their weekly movements over the course of a year. Both turtle populations made long journeys of up to two and a half kilometres between bodies of water. It was expected that given their extensive movements, the suburban turtles would have a high rate of encounters with vehicles on roads, and thus fewer would survive. In fact, suburban turtles did not suffer appreciably higher mortality than their counterparts on reserve lands, only one of the 36 radio tracked turtles being hit by a vehicle. Vegetated drainage lines and drainage culverts running under roads protected the turtles.

Given the severe droughts that have been affecting much of Australia, the different populations’ response to drought was also notable. Turtles in the nature reserves responded to the drying up of the wetlands by lying dormant buried under leaf litter. However, suburban turtles were able to maintain aquatic activities throughout periods of drought as suburban water bodies remained flooded. Suburban landscapes, despite their unique challenges, may therefore be higher quality habitats than nature reserves for turtles during drought. The researchers hope to further evaluate whether well-designed urban areas hold any promise as long term drought refuges for some turtle populations.

For further information, please see here.

Water quality in England and Wales has improved for the nineteenth year in a row the Environment Agency announced today. Seven out of 10 English rivers and nine out of 10 Welsh rivers achieved what is termed “very good” or “good” status in terms of chemical and biological water quality in 2008. Wildlife has been returning to some of these rivers. 50 years ago, no salmon were seen on the River Tyne, but already this year more than 10,000 have been recorded migrating up river. Meanwhile otters have this year been recorded in both Greater Manchester and the lower Thames for the first time in 40 years. After moving into Sussex this year, otters can now once again be found in every English county.

However, only five of the 6,114 rivers in England and Wales are in pristine condition, and more than three-quarters are expected to fail new European quality standards. The European Water Framework Directive, which became law in the UK in 2003, sets even higher quality standards, using a wider and more sophisticated range of more than 30 different measures. Only 26% of rivers in England and Wales are classified as “good” under the new requirements, and only five satisfy the highest standards. These are in remote areas of Northumberland and Wales.

Under the new standards, 117 rivers are classified as being in bad condition, ranked on a par with the dirtiest rivers in eastern Europe, a further 742 are considered to be in “poor condition” and 3,654, or 60%, are in “moderate” condition. This presents a headache for the government because it is legally required by Europe to ensure that 95% of all British rivers are in “good” ecological condition by 2015. At the present rate of improvement, only a further 5% will meet the conditions by 2015. This could eventually leave Britain open to unlimited fines and court cases on a European level.

Lakes are faring no better, with only one out of 762 English and Welsh lakes considered to be of high status, and seven considered “bad”. None were named by the agency but it admits nearly 70% of lakes are in line to miss the targets.
It is estimated that it could cost £9bn to get 95% of UK rivers to “good” status by 2015. If, as expected, this proves impossible, the EU allows interim targets to be set for 2015 and 2021.

The government is currently preparing its River Basin Management Plans, which will be published on 22 December 2009. These will outline the targets and methods used to improve water quality in 11 catchment areas. A six-month consultation took place on the proposed plans earlier in the year. A coalition of major NGOs declared that the proposals showed ‘an unacceptably weak level of ambition’. Perhaps the EU will help the UK become more ambitious.

For further details, visit the ‘Our Rivers’ website.

With their large surface-to-volume ratios, shallow lakes are prone to environmental change, and clear, biodiverse waters can become turbid and less biodiverse relatively easily. It has long been known that shallow lakes might therefore be vulnerable to global warming trends, but few studies have been conducted until now.

As part of the EU Euro-limpacs project (Evaluating the Impacts of Global Change on European Freshwater Ecosystems), a team of British researchers used 48 tanks to simulate shallow lake communities. They studied the effects of warming by 4°C (the high emission scenario for the temperature increase during a hundred years period) and the effects of two levels of nutrient loading relevant to current degrees of eutrophication. Levels of nutrients, oxygen and pH, as well as phytoplankton, fish and plants, were also studied. During the experiment the highest temperatures reached 21°C in unheated shallow lakes and 25°C in heated lakes, whilst neither type of lake ever dropped below 3°C.

The study demonstrated that warming increased the concentration of soluble phosphate in the water. It also increased total plant biomass, but surprisingly reduced the amount of phytoplankton. The fall in phytoplankton is thought to be caused by shading from increased floating plants, which may be linked to a warming-induced release of soluble phosphate from the sediment. Warming also reduced fish biomass, which was probably the result of oxygen stress. Perhaps more importantly, high nitrogen loading as well as warming reduced the number of plant species.

Although temperature rises alone are unlikely to cause a switch in water conditions, they could intensify signs of eutrophication in shallow lakes. For example, increased temperature together with increased nutrient loading may cause nuisance growths of floating plants which may affect biodiversity.

The Water Framework Directive suggests that nitrogen concentrations should be considered when assessing the ecological quality of water. The limited evidence of the effects of nitrogen concentrations (compared to the evidence of the effects of phosphorus in fresh-waters) has made many government agencies reluctant to apply standards for nitrogen. This research indicates that nitrogen concentrations should be assessed however and that managing nitrogen loadings is an important part of maintaining good water quality, especially under a changing climate.

For more information, see:
Feuchtmayr, H., Moran, R., Hatton, K. et al. (2009). Global warming and eutrophication: effects on water chemistry and autotrophic communities in experimental hypertrophic shallow lake mesocosms. Journal of Applied Ecology. 46: 713-723.