Here's PREDICTS-ing you have a happy new year!

Greetings,

With new years hangovers out of the way and the left over mince pies well and truly gone I welcome you back to Standing Room Only.  I thought that I'd I write a post, belatedly inspired by a tweet about the PREDICTS database from UCL's very own Prof. Anson Mackay, regarding bio-diversity.

The global eco-system is suffering from a declining trend in biodiversity. Furthermore this trend is potentially accelerating. Butchart et al (2010) compile a summary of 5 biodiversity pressures and demonstrate that all possess increasing trends:

• Anthropogenic consumption of ecological resources
• Introduction of Alien species in ecologies
• Nitrogen Pollution (predominantly agricultural)
• Fisheries exploitation
• Climate change impacts

Unsurprisingly, these pressures are directly derived from Anthropogenic impacts (BTW: if you're a climate change denier then check out a fellow UCL Masters students blog that has all the facts:  Fighting-climate-change blog. C. Ferrere, 2014).

One of the biggest obstacles in evaluating species loss and biodiversity trends is the lack of empirical evidence. Numerous biodiversity projects are underway (Hong Kong's AFCD has implemented its own bio-diversity database) but many exist as separate entities that collect their own data solely for their own research. Huamán et al's (2000) seminal Inter-genebank Potato Database (complete with a summary of dimensions of wild potato germplasm) remains, unfortunately, in the realm of the Solarnum advocates. But I digress...

The PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) database represents an effort to form a global community of  contributors of terrestrial biodiversity data. To date the effort has data for more than 38,000 species across the world.

Representation of PREDICTS current geographical range of data, courtesy of www.predicts.org.uk.

The database is the result of combining numerous small scale biodiversity studies (no potatoes yet) that cover the majority of biomes (portions of the earth that demonstrate similar, if not the same, climatic and environmental conditions, typically reflecting a latitudinal relationship).

Biome classification parameters, courtesy of Marietta College.

It is estimated that up to 50% of 9 out of 14 biomes have been impacted by agricultural activity alone. This pressure is resulting in extensive damage to biodiversity in those regions (Hassan et al, 2005).

The homogenisation of biodiversity is a real problem, its potential severity reflected by its inclusion at number 7 in the United Nations Millenium Development Goals (MDG) (2008). Butchart et al's (2010)  biodiversity pressures represent activity that we have, in the course of this blog, identified as extensive in Hong Kong:

The immutable Morton (1995) points out that the boom in population and industry after the Second World War sparked an increase in the consumption of resources (both terrestrial and aquatic).

Whilst his editorial (2005) indicates that the exploitation of fishery resources over the same period has resulted in the loss of higher trophic level species.

Nitrogen pollution both from Hong Kong itself and flowing from the Pearl River Delta wreaks havoc with marine diversity causing HAB events which create toxic marine conditions and potential deplete oxygen levels, suffocating the aquaculture (Anderson et al, 2002).

Thanks for joining me again, I'll leave you with some Solarnum biodiversity that didn't make it into Huamán et al's (2000) database, more's the pity.

Courtesy of it.wikipedia.org

Teach a man to fish

Unsurprisingly, a major reason for Hong Kong's original settlement and early expansion is due to it's exceptional marine resources. The East China Sea, South China Sea and freshwater outflow from the Pearl River provide large expanses of varied aquaculture.

The increasing population of Hong Kong and its demand for these fishery resources has resulted in their severe over-exploitation with little to no evidence of improvement. A study, commissioned by the Agriculture, Fisheries and Conservation Department of the HK government, identified that over the last 25 years catches have decreased by almost 50%. In addition 12 of 17 commercial species in HK waters have been identified as being "heavily over-exploited" whilst the remaining 5 species are "fully exploited". The study is referred to in  the Fisheries Protection (Specification of Apparatus) (Amendment) Notice (2011) by LegCo (Hong Kongs Legislative Council), although the original document seems to be elusive, if you come across it please let me know.

Perhaps its the years I spent in my previous discipline of archaeology speaking but I feel that to appreciate the current state of affairs we really need to step back a little and take a quick look at how HK reached this situation. An article by Morton (2005) describes HK fisheries evolution from larger, slow growing species that are worth more to smaller, faster growing species that are worth less. The article, whilst not referenced, touches upon some of the land marks in this evolution, with a little fleshing out we can develop clearer idea of how the HK's fleet has evolved:

• The 'Fisheries Research Unit' (FRU) was conceptualised in the late 1930's (Morton 2005), although the its official establishment appears to have occured some 20 years later (Mellor 1981, pg 198). The FRU's aim was to determine how HK's technologically inferior fishing fleet could compete with Japans relatively mechanised, larger fleet which shared portions of the same waters and targeted the same species, effectively directly competing with China and HK for marine resources.

Late 19th Century Chinese fishing 'Junk', Courtesy of hongwrong.com

• The 2nd Sino-Japanese war saw the occupation of China. During this time the Japanese possessed a monopoly on fishery resource exploitation in the East China Sea. As a result supplies of fresh fish to HK were reduced to near zero (and as we have already seen Hong Kong is heavily dependent on imports from China). HK fishery was forced to deal with an overnight increase in demand, fairly at odds with its current, at the time, methods.
• However, Japanese occupation of HK towards the end of the war sparked a technological renovation of the local fishing fleet allowing  larger catches from larger areas to be acquired (Morton 2005).
• In 1960 a refreshed governmental focus on the state of HK's fleet began. The government assumed control of, and invested in,  the FRU (Chan et al, pg 4: 1996). Representing an official governmental recognition of the potentially troubling situation. This governmental interest and investment continued steadily for around twenty years.
• After governmental intervention the catch totals of the HK fleet were noted to rise annually from 53,000 to 224,000 in 1990. However, whilst fishery totals increased year on year it is reported that the catch per capita began to steadily decline from the late 1980's onwards. These declines are noted not only in Hong Kong but worldwide. Anderson et al's (2011) studies of trends in the expansion of invertebrate fisheries reflects Mortons conclusions of a declining trend in marine catches, albeit on a global scale, noting that total catches of marine invertebrates rose from 2 million in 1950 to 12 million present day (2011). Whilst the factors governing each decline are not identical (as we may venture into next time) they both involve a core theme of increased activity and exploitation reaching a tipping point, beyond which the environment cannot cope with the strain.

Join me next time when we will take a look at the methods that Hong Kong utilised during the enhancement of its fisheries.

After reading Anderson et al's (2011) on invertebrate fishery trends I started to read up on Sea Cucumbers.... I urge you to do the same: LOOK HOW CRAZY THEY ARE!

Courtesy of NationalGeographic.com

Land Reclamation

Welcome back, I'm assuming you're here for more porpoise and dolphin pics? Ok, but not until we've explored some of our impacts on their marine environment!

The  population, commercial and industrial expansion of Hong Kong, particularly over the last 60 years, has resulted in a degradation of its coastline and marine environment. Perhaps the most notable activity that has caused this degradation is Land Reclamation.

As we identified early on in this blog, Hong Kong possesses a huge, expanding population that is requiring more and more land in order to live, work and survive. To fulfil this demand Hong Kong has frequently utilised land reclamation techniques.

What?

Simply put, it is the building up of the sea bed to create an above sea-level surface that is stable enough for further construction or other development. There are various methods used for achieving this build up but broadly speaking they involve the replacement of the soft silt sediments on the seabed with large deposits of rocks (Yan et al, 2013).

When?

The earliest reports of land reclamation in China originated from the Western Han Dynasty where coastal areas were reclaimed in order to create terraces for the recovery of salt from sea water.
Modern reclamation, as we would consider it (i.e. the creation of land for industry etc), began in Hong Kong during the mid 19th Century (Jiao, 2000) shortly after the beginning of the British occupation. Large areas of marshland close to the harbour were bought and reclaimed by traders wishing to create easy access to the harbour.

Since those initial projects, land reclamation has been undertaken on much larger scales culminating in an estimated 10% increase in land surface across Hong Kong by 2000. Furthermore, this increase is due to accelerate with the recent commencement of several larger scale industrial projects (Jiao et al, 2000). The graphic below gives an impression of how reclamation projects have advanced from their humble beginnings and have predominantly been focused on both sides of Victoria harbour with more recent undertakings towards the western edges of Lantau and the New territories.

Estimates of the evolution of land reclamation across Hong Kong, courtesy of www.scmp.com

Where?

Two of the most recent reclamation projects carried out (and in fact still being carried) in Hong Kong are the construction of the HK International Airport and the construction of the Macau-Zhuhai-Hong Kong Bridge:

Hong Kong International Airport

Take another quick look at our 'evolution of land reclamation' graphic; you see the huge area on the northern edge of Lantau? That's the site of Hong Kong's newest airport and home to over 12km^2 of reclaimed land, Hong Kong's largest, completed reclamation project so far (Plant et al, 1998).

If you're desperate for a little more on reclamation methods here's a link for a promo video released on Hong Kong International airports offical youtube channel, I won't embed the video because its seriously cheesy and saccharine with the positive (marketing) aspects of reclamation, but it does offer a brief synopsis of the reclamation project: HK Airport Reclamation.

Hong Kong - Zhuhai - Macau Bridge (HZMB)

A little further west from the airport is the bridge project which aims to be the first step in connecting three of the largest population centres of the Pearl River Delta (China's industrial centre) through a combination of bridge and tunnel networks. A large portion of this project is the creation of a series of new islands.

Preparatory construction work for the bridge commenced in late 2009 and has a predicted completion data of 2016  (ARUP website, 2010) .

Route of the New bridge, courtesy of www.NCE.co.uk

Impacts

It seems logical that the deposition of 1000s of tons of material into a coastal area is perhaps one of the most powerful impacts to which we could subject a marine environment.  Jefferson et al, (2009) created an informal hierarchy of  'development activities' associated with the industrialisation of Hong Kong and their respective impacts on the marine environment which placed land reclamation at the top of the list.

Those of you who tuned in last week may also notice that these two examples are placed, at least partially, within the same zone that the WWF Hong Kong identified as containing White Dolphin populations. Hung et al (2004) confirm that the ranging area of the dolphin populations identified across the Pearl River Estuary extend across western Hong Kong waters, although they go on to state that further investigation of true numbers are required. Regardless, it is clear that the reclamation being undertaken for these projects will have an impact upon these local cetacean populations.

Aside from the complete removal of swathes of environment, there are additional impacts relating to the upcast sediments and potential contaminants sealed within these deposits. Yan et al (2013) provide a case study for the future off-shore airport at Jinzhou Bay that models the impacts of two reclamation methods: Underwater Explosion and Silt dredging.

• As the name implies the 'Underwater Explosion' method of soft silt removal is through the explosion of Trinitrotoluene (TNT) packages that are placed deep within the sediments. The explosion leaves the sediment, and any previously sealed contaminants suspended in the water allowing rock deposits, that were previously dumped on top of the sediment, to enter the newly cleared area. This method can have two catastrophic effects on marine ecology: the primary explosion can disorientate, or even kill marine life, particularly those that possess carefully balanced swim-bladders (Jefferson et al, 2009), within a given radius whilst the dense spread of suspended sediment can extend across huge areas destroying the ability of phytoplankton to photosynthesise and negatively affecting zooplankton growth (Yan et al, 2013).

• The 'Silt Dredging' method involves the construction of dredgers which suck up the silt and deposit it elsewhere. This method lacks the severe impact of the former, but possesses the same risk of disturbing contaminated sediments whilst also requiring an additional area for dumping of the extracted deposits.

A quick aside: for any Environmental Modelling MSc people out there I really recommend having a look over the case study I mentioned earlier (Yan et al, 2013). It's a good example of a modern project involving comparisons, predictions and evaluations through model application and is the kind of work that any of us may be involved with in the future.

And now, as promised....porpoises!

D'AAAAAW!!!! courtesy of www.china.org.cn