Mangroves provide enormously important and economically valuable ecosystem services to coastal communities throughout the tropics. They provide at least US $1.6 billion each year in ecosystem services worldwide, but a startling statistic from a recent study is that eleven of the worlds 70 mangrove species (16%) are at elevated threat of extinction. The IUCN Mangrove Red List Assessment Team have recently published a peer reviewed assessment of the vulnerability to extinction risk to the worlds mangrove species. The teams assessment provides evidence that there are particular areas of geographical concern, such as the Atlantic and Pacific coasts of Central America, where as many as 40% of mangroves species present are threatened with extinction. In the Indo-Pacific region up to 14% of species are at risk. The article led by Beth Polidoro of the IUCN and published in the open access PLoS One finds that mangroves in the upper inter-tidal and estuarine environment are those species most at risk. This is principally because they are the first to be cleared from activities such as aquaculture and agriculture.

Not all areas show extinction risks, and noticeably only a small area of the Northern Territory in Australia shows any level of mangrove species extinction risk. These risks of extinction although important don’t however show the full problem, as the world is losing mangrove at an unprecedented rate. And this loss is not isolated to developing nations; mangroves are being routinely cleared for developments throughout Australia. This global loss should ring alarm bells. A well cited research article published in Nature in 2003 found that reefs in the Caribbean where mangrove had been removed contained 50% less fish biomass, and many studies have argued the value of mangrove in providing critical coastal protection.

A glimmer of hope comes from the passions of communities willing to get involved and support their own natural habitats. In the Burnett-Mary region of Queensland, communities are developing a ‘Mangrove-watch’ scheme to monitor their own mangroves and help protect the important ecosystem values of these habitats.

Here is the abstract from the journal Biodiversity Conservation:

Pollutants, originating from both land and sea, are responsible for significant lethal and sub-lethal effects on marine life. Pollution impacts all trophic levels, from primary producers to apex predators, and thus interferes with the structure of marine communities and consequently ecosystem functioning. Here we review the effects of sediments, eutrophication, toxics and marine litter. All are presently major concerns in Southeast Asia (SE Asia) and there is little indication that the situation is improving. Approximately 70% of SE Asias human population lives in coastal areas and intensive farming and aquaculture, rapid urbanization and industrialisation, greater shipping traffic and fishing effort, as well as widespread deforestation and nearshore development, are contributing towards the pollution problem. As SE Asia encompasses approximately 34% of the worlds reefs and between a quarter and a third of the worlds mangroves, as well as the global biodiversity triangle formed by the Malay Peninsular, the Philippines, and New Guinea, the need to reduce the impacts of marine pollution in this region is all the more critical.

The discussion on the problem of marine litter takes me back to an incident in Sulawesi Indonesia where school kids doing a beach clean thought that the litter was normal and started clearing up all the organic debris instead of the rubbish. Where do you start? It also reminded me about hermit crabs in the Wakatobi happily using coke bottles as a home:

I wanted to add a little to Ove’s continued defence against ‘The Australian’ on going war against science. Whilst most people see the Great Barrier Reef as being one large coral reef, it also contains an array of other habitats including seagrass meadows that are critical to the overall ecosystem. Seagrasses, amongst there many roles in the GBR, are critical in supporting biodiversity and fisheries productivity. These seagrass meadows, like coral reefs, are also under threat from increasing seawater temperatures.

The potential 4°C increase in global temperature by the end of the century, that the leader of the opposition recently described as “not a big moral challenge”, would have an enormous detrimental impact upon seagrass meadows, particularly the abundant intertidal meadows present throughout the GBR. Research published back in 2006 found how seagrasses of the GBR suffer irreparable effects from short-term or episodic changes in seawater temperatures as high as 40–45 °C. Although these temperatures sound high, intertidal pools can commonly approach and exceed these temperatures for short periods throughout the GBR, and seagrasses are observed to ‘burn’. If temperatures were to increase by 4°C, such ranges would be exceeded too regularly to allow for recovery, and seagrass meadows are likely to deteriorate with huge detrimental impacts upon fisheries and coastal productivity.

The Great Barrier Reef described to be “blue again” by ‘The Australian’ is under continued stress. Seagrasses although important in their own right make excellent ‘coastal canaries’ and their tissues are good time integrated indicators of the coastal nutrient environment. Monitoring throughout the GBR continues to find coastal seagrasses containing highly elevated C:N:P ratios, indicating rich and potentially eutrophic environments that are continuing to be enriched. Increasing nutrients onto the reef and into seagrass will continue to promote algae and reduce the resilience of coral and seagrass to future climate change and increasing temperatures.  The combination of elevated nutrients and increased temperatures are of concern as greater temperatures increase metabolic rate, resulting in increased light requirements for seagrass. Such light requirements are not possible when increasing nutrients reduce light availability due to increased epiphytes and phytoplankton, resulting in eventual loss of the seagrass.

As Ove said previously, there exists no evidence to suggest that the GBR is “blue again”, and to the contrary, seagrass biomonitoring suggests nutrient conditions are continuing to deteriorate, with many coastal locations becoming increasingly eutrophic (see Figure 1 taken from the latest Seagrass-Watch magazine). The available evidence suggests that seagrasses and the coastal environment of the GBR are under increasing nutrient stress, reducing future resilience to climate change.

Darwin as a monkey – The view of the church of England and the conservative British press in 1860.

This week I travelled to Europe for an extended break (and offset my travel). From a climate change perspective what met me was such a breath of fresh-air. I’ve temporarily left Australia, a nation whose politics are torn apart by an inward looking, big business dominated, unrepresentative, and non-scientific political system whose rejection of the Emissions Trading Scheme only serves to remind me of the rejection of Darwin’s ‘then’ theory of evolution by Church of England back in 1860.

Although Europe is haemorrhaging in a barrage of disgusting neo-facism fronted by the alarming views and representations of characters such as Nick Griffin their exists so much development of opinion, media comment and personal action that can only be commended. Europe is far from perfect, but a feeling that even the most conservative right wing media outlets are mostly pushing an agenda of climate change as fact is refreshing.

I’ve witnessed competitions by employers keen to be have the greenest corporate car fleet, every conceivable renewable energy source being explored as a genuine potential power plant, and the average Joe in the street keen to do their bit by buying green electricity, and increasing recycling to 90% in some locations, and seeing low carbon economies as business opportunities. Europe is full of problems, its economies are in tatters, unemployment is high, and neo-facism is on the march. O2 emissions are enormous and car dependency is huge. But looking beyond this are the small but clear green roots of development towards a low carbon economy. If Europe can take such a path at a time of severe economic downturn then why must Australia be hesitant?

As my mother expressed yesterday: “these are not issues of economics or lifestyle, they’re about the future prosperity and happiness of our very own children and grand children. Inaction by politicians and governments about such an issue that will define our generation bring me to tears”.

The politicians of Australia need to remember that they are elected to undertake a mandate. Australia may be presented as a nation of climate sceptics by its politicians, its media, and its big business, but in 2007 the people democratically elected the Labor government with a mandate to join the Kyoto treaty and develop an ETS. The time is right for some politicians to respect the democratic will of the people and help introduce legislation intended to progress Australia towards that low carbon economy that is being developed in other regions of the World.

This week saw an impassioned plea from one of the Indian Oceans foremost marine biologists to create the Worlds biggest no-take marine reserve. The proposal presented by Prof Charles Sheppard at the Reef Conservation UK conference in London is to turn the entire Chagos Archipelago located in the centre of the Indian Ocean into one enormous marine sanctuary.

The bold plan supported by a network of institutions and scientists (the Chagos Trust) involved with conservation and research in the Chagos Archipelago and recently submitted to the UK government would double the entire global area of no-take areas and increase the total coverage of marine reserves by 13%.

But why is this important? The Archipelago contains ½ of the Indian oceans remaining healthy coral reefs, and harbours the world’s largest coral atoll in a quarter of a million square miles of the world’s cleanest seas. Creating the Worlds biggest MPA would prevent one of the last bastions of untouched coral reefs succumbing to the increasing intensity of fishing that is beginning to change these pristine reefs forever.

Creating such an enormous marine reserve would not only protect the internal biodiversity of the Chagos but would serve to add greater resilience to the marine environment of the entire Indian Ocean. Supported by global NGO’s such as the Pew Foundation the Chagos Archipelago would act as a legacy site, ensuring that nations such as the Maldives and the Seychelles, who are only just developing sufficient capacity to manage their reef systems will have the capacity to recover into the future. The Chagos would act as one large source of productivity to support diversity throughout the Indian Ocean.

For those such as myself who were not around the remember the complex politics of the Chagos, they have belonged to Britain since 1814 (the Treaty of Paris) and are constituted as the British Indian Ocean Territory (BIOT). In the 1960s and 70s, Britain secretly removed the Chagos Islanders off their islands, to make way for a US and British military base. Only Diego Garcia, where there is a base, now remains inhabited (by military personnel and employees). The other 54 tiny islands add up to only 16 square kms (8 square miles) in total. It is now by far Britain’s greatest area of marine biodiversity.

At a time of increasing appreciation of the marine environment in the UK through the development of the Marine Bill it is time that its other areas of Britains biodiversity such as the Chagos receive similar protection.

Developing the Chagos as a full No-take area was described by Prof. Sheppard as creating an insurance policy for the Worlds oceans. This is critically important at a time of increasing climate change that threatens the Worlds biodiversity.

Whereas many of the Worlds proposed marine reserves involve complex political difficulties the potential of protecting the Chagos Archipelago is politically possible. There are little in the way of commercial fishing interests associated to the Islands, and many of these are Illegal. If any Islanders do ever return to the Archipelago, numbers are likely to be so low as to easily fit into a future management plan, and many of the stakeholders with interests in the islands are currently in support of the proposals.

As the newly established ProtectChagos.org website states “Now, before it is too late, there is an opportunity to save this precious natural environment, creating a conservation area comparable with the Galápagos or the Great Barrier Reef”.

Whilst those countries largely responsible for initially causing global climate change (e.g. parts of Europe, the US and Australia) may have improved fisheries production in 2050, the tropical regions that contain the majority of the worlds developing nations could have fisheries declines of up to 40%. Nations at the forefront of debate in Europe about the need for climate change adaptation assistance (e.g. Brazil and Indonesia) may suffer huge socio-economic consequences of reduced fisheries production. Such impacts have the potential to particularly hit those vulnerable members of society most dependent upon seafood for daily subsistence protein requirements.

Change in maximum catch potential (10-year average) from 2005 to 2055 in each 300 _300 cell under climate change scenarios: (a) Special Report on Emission Scenarios A1B and (b) stabilization at 2000 level (Chueng et al. 2009)

Whilst these proposed scenarios are only models, and may contain many inaccuracies, they do provide some of the most detailed levels of information available about what the direct consequences of global warming could be to the world’s fisheries. When you consider that factors such as ocean acidification, overfishing, pollution and coastal development are not included within these models, fisheries production in 2050 could be a lot worse with much greater socio-economic consequences.

These findings are of great importance at a time of continued debate about who should take what level of responsibility for emissions reductions and climate adaptation.

A new study has determined that the global coverage of seagrass meadows is now declining at an unprecedented rate of 7% per year. The findings of this the study conducted by researchers in the US, Australia and Europe show that seagrasses are now disappearing at rates similar to coral reefs and tropical rainforests. The research estimates that seagrasses have been disappearing at the rate of 110 square-kilometers (42.4 square-miles) per year since 1980 (see Seagrass Watch for more details).

Although seagrasses, and particularly their fauna, are under increasing pressure from changing climate, declining water quality and coastal development are the major reasons that seagrass is being lost. For example the large scale loss’ of seagrass in Chesapeake Bay (U.S) in the 1970’s and Florida Bay in the 1990s were the result of poor water quality.

But why should anyone really care about these ecosystems that are considered to be ‘not as sexy as coral reefs‘. Are seagrasses really as important as rainforests?

Another high profile recent research paper published in Frontiers in Ecology and Environment by the same group of scientists highlights that seagrass meadows provide a vital role in supporting numerous faunal species. Many of these are either threatened with extinction or subjected to overexploitation.

Seagrasses have a vital role in supporting fisheries, particularly as nursery grounds, they are also important in global cycling of CO2. As seagrass grows, develops, and then dies, much of the carbon that is incorporated in to leaf tissue can be locked away in sediments, and sometimes become sequested for thousands of years. Seagrasses in some locations have also been found to be as productive as many of the most productive forest communities.

These recent research articles highlight the continuing need for governments, community groups, conservation organisations, fishermen, and all stakeholders that have a vested interest in conserving seagrass meadows to be more aware of the importance of seagrass meadows. Despite not being as sexy as coral reefs, their economic and ecological value demands that they are not left to their current plight.

Recent research by the Universities of Dar es Salaam, Tel Aviv and Stockholm published in the Marine Ecology Progress Series (volume 382) and conducted in tropical seagrass meadows of East Africa have investigated the impact of such pH changes.  Semasi et al. revealed that this change in pH can cause localised increases in the rates of calcification and growth of calcareous algae such as Hydrolithon sp., Mesophyllum sp., and Halimeda sp., hence seagrass buffers high acidity (low pH).

As has been debated by ClimateShifts previously, there is increasing evidence that oceans have become more acidic since the start of the industrial era. Recent predictions suggest that oceans could become much more acidic over the next 100 years as a result of increasing CO₂ emissions. Current predictions suggest that this will result in (amongst other things) declining reef calcification rates.

Although this study by Semesi et al. shows the effects of seagrass upon algae, the questions on the lips of many reef conservationists will be whether such findings are cross transferable to the calcification of corals. These studies in Zanzibar were small scale, carried out in seagrass mesocosms, and currently only reflect small scale patterns. Whether seagrass productivity can result in larger spatial scale changes that could buffer pH changes on nearby reefs remains to be seen. Maybe the World should be looking at seagrass meadows with greater attention?