ENVIRONMENTAL IMPACT REPORT

Mangrove ecosystems play an integral role within the stabilisation of coastal intertidal soil by preventing coastal erosion through their complex network of roots (“Teaching about Mangroves, 2013”). Scientifically they are defined as an assemblage of unique tropical plants which are able to survive within variable flooding conditions and withstand high salinity concentration. They do so by a selective combination of structural adaptations such as salt excretion upon leaves, and filtering of absorbed nutrients (“Encyclopaedia of Earth, 2013”). The most healthy and abundant mangrove communities occur in tropical and subtropical areas, between 30o N and 30O S latitude (“Encyclopaedia of Earth, 2013”).

An example of a mangrove community presents itself within the Moreton Bay Mangrove community located within South-East Queensland, Australia. The community possesses 8 mangroves species but is predominantly dominated by Avicennia marina (Grey Mangroves) and Aegiceras corniculatum (Black Mangrove) (“Moreton Bay Mangrove, 2013”). The Moreton Bay community provides vital protection and food source for various marine and terrestrial species including wading birds, shrimps and crabs. Structurally it is comprised of coastal environments consisting of numerous river estuaries that extend seaward (“Moreton Bay Mangrove Species, 2013”).

1. BIOTIC INTERACTIONS IN THIS MANGROVE COMMUNITY

The biotic interactions within a mangrove ecosystem are defined as the interaction between living biological factors (“Encyclopaedia of Earth, 2013”). The interactions between biotic factors create various relationships including; parasitic, mutualistic, predation and competitive relationships (“Abiotic and Biotic Influences On An Ecosystem, 2013”). One of the most fundamental biotic factors within a mangrove ecosystem is the mangrove trees. It is with the presences of mangroves that the ecosystem’s stability, distribution and abundance of both flora and fauna are determined.

The interrelationships between the biotic factors come together to form a food web, a model diagram which is formed from a connection of food chains and displays all the feeding relationships between organisms within an ecosystem (“Mangrove Ecology, A manual for a Field Course, 2013”). It is generally believed that a mangrove ecosystem possesses a detrital food web but a grazing food web also exists. This detrital food web is as described and illustrated below.

(“Fundamentals of Ecology, 2013”)

Microbial organism, such as bacteria, plays a vital role in supporting the mangrove ecosystem. It is through the interaction between bacteria, like cyanobacteria, and mangrove vegetation that nutrients are regenerated and mineralization occurs (Access Science, 2013”). It is also through such interaction that nitrogen fixation occurs with nitrifying bacteria, like cyanobacteria, converting nitrogen within the atmosphere to compounds such as ammonium. This is then in turn through the process of nitrification creating nitrates, a rich source of nitrogen for mangrove vegetation (“Tree Physiology, 2010”). Other such benefits brought upon micro-organism include phosphate solubilzation soluble phosphates, usually inaccessible to plants due to high cation levels within mangrove sediment, available to plants.

The interaction between these biotic factors, consisting of the mangroves and micro-organism, is an example of a mutualistic relationship. The micro-organisms benefits from being provided organic material as a food source and in turn release nutrients enhancing the nutrient and mineral conditions of soil in which the mangroves inhabit.

Through this mutualistic relationship, as described above, detritus (decomposed organic matter) a major food source within the ecosystem is produced. Other organisms which also aid this decomposition include fungi and micro-algae which are also considered producers. These producers represent the first trophic level within the trophic structure (complex interrelation amongst organisms within an ecosystem through the transfer of food) with the mangrove ecosystem (“Encyclopaedia of Earth”).

These nutritive food sources begin the transfer of energy from the products creates by the mangrove (a producer) and first level consumers (primary consumers). Some examples of first level consumers or herbivores within the mangrove community are shrimp, small fish such as toad fish, finch, insects and even fungi. These first consumers are referred to as the second trophic level.

These first level consumers may then provide energy to secondary consumers through a predation relationship (“The Encyclopaedia of Earth, 2013”). First order consumers such as toad fishes will in turn be preyed upon by larger organism such as ibises. It is through this interaction that a predation relationship is formed. These secondary consumers represent the third trophic level. It is through the interactions that a healthy eco-system is attained.

2. ABIOTIC FACTORS IMPACTING ON THE MANGROVE COMMUNITY

Abiotic factors are defined as the non-living components within an ecosystem (“Abiotic Factors, 2013”). It is through an organism’s interaction with abiotic features that its distribution, diversity and survival are affected (“Biotic and Abiotic Influences on an Ecosystem, 2013”).

The most influential abiotic factors which define a mangrove ecosystem include salinity, the lack of dissolved oxygen within soil (anoxic soil) and tidal fluctuation. Topography the arrangement of the natural and physical features of a landscape, in this case the hollows and mounds within the rivers will affect tidal inundation (“A Local Ecosystem-Mangroves, 2013). Tidal inundation in turn affects organisms and mangrove vegetation exposure to both salinity and oxygen availability (“A Local Ecosystem- Mangroves, 2013”). To tolerate such changes within salinity levels aquatic organism such as fish develop kidney, gills and present water from equalizing the salt dispersal across membranes (Marinebio, 2013”). Other organisms such as the fiddler crab have adapted through a behaviour adaption. The fiddler crab to deal with tidal inundation will feed at low tide but burrow into the mud at high.

It also through the tolerance of such for such fluctuation that a process referred to as zonation occurs. It is through the process of zonation that fauna is distributed within a mangrove community (“Mangrove Watch Australia, 2013”). For example species such as salt marsh majorly exists at areas where only whilst highest tides occurs that the area is inundated while mangroves which there higher tolerance of both salinity levels are able to withstand constant daily fluctuation with salinity and oxygen levels are found within areas which experience higher frequencies of tidal inundations. This process of zonation is as illustrated below.

(“A Local Ecosystem, 2013”)

To cope the stress of salinity levels Grey Mangroves, like those found within Moreton Bay, several structural adaptations have taken place including the development of roots in which are able to reduce to intake of salt by filtering it before it enters the plant. Other adaptations also include salt secretion through their leaves. The Grey Mangrove can also store salt through its leaves and discard them when the concentration of salt gets to high (“Redland City Council, 2013”).

Other adaptations to mangrove vegetation to cope with the lack of oxygen dissolved with the soils the inhabit due tidal inundation include the structural development of pneumatophores (aerial roots) (“OzCoasts, 2013”). Through these aerial roots mangroves are able to obtain oxygen from the atmosphere when at low tide. The roots themselves also provided stability for the mangroves within such unstable soil conditions.

Air temperature plays is another abiotic factor that plays major role within the distribution of mangrove species with some species such as the Grey Mangrove and River Mangrove with mangrove seed being (“A Local Ecosystem, 2013”). Temperature will also affect the distribution of fauna and flora such as fish, crabs and other aquatic organisms. This is as it is temperature plays a major influence upon the total amount of dissolves oxygen within water. The amount of dissolved oxygen within the water will dictate whether the ecosystem will be able to support a larger and more diverse of group of aquatic organisms which need this fundamental abiotic factor to live(“A Local Ecosystem-Mangroves, 2013”).

3. HUMAN IMPACT ON THE MANGROVE COMMUNITY AND RESULTANT EFFECTS ON THE MORETON BAY MARINE PARK

Within the recent decades human activities have played a major role within affecting the stability of the mangrove community. It is estimated that 17% of Australia’s mangroves have been removed due to urbanisation (“Mangrove Watch Australia, 2013”) for activities such as residential and industrial development (“Department of National Parks, Recreation, sport and Racing, 2013”). These human activities have resulted in the degradation of such ecosystems, causing dieback of mangrove and other vegetation. The ecosystems ability to function effectively will be significantly affected as the reduction of mangroves, a fundamental producer within the ecosystem. This reduction of mangroves will in turn affect various other organisms within the community which depend upon the mangroves as a food source, protection and habitat and nursery for their young (“OzCoast,2013”)

The removal of mangrove as a result of human activities has also increased the rate of natural sediment run off. As mentioned previously mangroves play a fundamental role within the stabilisation of soils banks. By removing these natural stabilisers the likelihood of soil erosion and sedimentation is increased. This in turn may directly in turn affect the Moreton Bay Marine park by increasing levels of turbidity and water quality which can harm aquatic organisms within the ecosystem (“Biodiversity Management Issues, 2013”). For example high concentrations of sediment may damage fish gills causing illness, reduced growth and an increase within their mortality rate (“Biodiversity Management Issues, 2013”).

Another significant impact arises from chemical runoff. Chemical runoff attributed through industrial processes such as the chemical management of sewage are of a major concern. An example presents itself in the runoff of chemical fertilisers due to agricultural activities which have in turned caused massive algae blooms. This is caused by the fact that the fertiliser run off will cause an increase within the growth rate of existing algae. This unnatural increase within the algae population puts a strain upon the demand of oxygen, reducing the total amount of oxygen for other organisms within the water. Once the alga begins to decompose, the amount of bacteria will increase further reducing the amount of available oxygen. If allowed to continue the water will become anaerobic (without oxygen) and not be able to support marine life form. This whole process is referred to as eutrophication (“Human Impacts on Mangroves, 2013”). Physical pollution from such as plastic debris has also affected Marina with birds such as ibises being entangled or ingesting such waste and dying.

Though a large range of negative impacts exist some positive human impacts have also arisen to combat these issues. The re-establishment and re-growth of mangrove have through some communities begun to occur. Various mangrove communities have also been given a protected such status and left to naturally regenerate and aided by physical restoration through human aid. These protected mangrove communities have also been under constant monitoring. For example organisation such as Urban Utilities closely monitor the condition of the Moreton Bay Ecosystem by testing if the water levels are at the appropriate pH, its conductivity to find the amount of salt and salinity concentrations of the soil and water. Constant monitoring ensures that chemical run offs such as oil spills will not be unnoticed a quick action be done to promote the survival of mangroves and existing organism and vegetation within the ecosystem.

Other activities being done include efforts in raising the awareness of how vital these ecosystems are through eco-tourism (“Encyclopaedia of Earth, 2013”). Boardwalks built allow tourist and visitors to view the mangrove ecosystem and highlight the abundance in flora and fauna they support. Along these board walks notice boards are usually placed to educate visitors upon the existing wildlife within the community and their dependence upon the mangrove, further highlighting the importance of preservation of such ecosystem.

4. BENEFITS FROM THE ELANORA PARK MARINA DEVELOPMENT

Commercially the development of the Elnora Park Marina will bring various economic benefits to both the community and developers. By creating such park with facilities such as restaurants, club houses and amenities blocks it will give the opportunity for expansion and development of small businesses. This will in turn provide revenue. With development of such marina direct employment during both the construction process and maintenance of the marina will provide jobs opportunities (Fraser Straits Marina, 2013”).

With the influx of more tourist and guest this may even bring upon further development creating further opportunities for economic gain. Another main benefit also rests in the fact that the Marina may also play a role in fostering eco-tourism by allow further access into the natural water front and resources. These parks surrounded by the abundance of exotic vegetation, fauna and flora highlight the beauty of the mangrove ecosystems and raise awareness of their existence. This in turn may cause society to become more conscious in the protection these vital environments. It is through the Marina’s development that locals and tourist will also have better access to water front and be able to access the waters using motor boats and other such aquatic vehicles.

5. RISKS FROM THE ELANORA PARK MARINA DEVELOPMENT

Though there may be many financial incentives there are also definite risks involved with the development of the Elanora Marina Park. The destruction of vegetation and mangroves would be necessary in order for the development. This in turn will cause the degradation within the ecosystem and may result in dieback of species present, causing an unbalance within biomass and disruptions within the ecosystem.

The appearance of human activity will also play of significant disturbance to existing wild life. With the influx of human and human activity brought upon the development of the marina increased risks of physical pollution and waste such as plastic bags, water bottles and food waste also arise. The management of waste not only from tourist but also from the proposed Elanora Park Marina itself also raises much concern.

If as proposed above that this Marina is to bring an influx of tourist and local residents to the area further urbanisation and development would be required and with this would be the further exploitation of the environment with further development and expansion of area needed in order to facilitate a larger amount of people, increase within tourist also increases the risk of pollutant being exposed to the environment. This combination of physical and chemical waste caused by the presence of human will also result to the further degradation of the ecosystem and die back of vegetation limiting the available food source for present fauna. If the long term if this degradation is to continue significant loses of present species may occur and even result in further extremities such as extinction. In stream disturbance from the motor vehicles may also lead to increase sedimentation and erosion of shoreline (“Notes on shoreline erosion due to boat wakes and wind waves, 2013”).

6. RECOMMENDATION

As presented above whilst there are proposed benefits from the development of the Elanora Marina Park including financial benefits and eco-tourism gain, the negative ecological and long term financial statistics heavily weigh those benefits.

In order for the Elanora Marina Park to be developed I believe that that some clearing of the mangroves would necessary in order to expand shorelines for the development of the proposed facilities. This will in turn cause several negative implications upon the stability and health of the ecosystem. The removal of vegetation in order for the industrial development to take place as proposed above in addition to the pollutants created by tourists and the proposed Marina facility will cause problems such as degradation. If this short term consequence is left to continue it may lead to more extreme future problems including the extinction of various species of both vegetation and marine and terrestrial organisms within the ecosystem. This is as the degraded soil and water conditions will not be able to support fundamental producers such as mangroves which are depended upon by higher trophic level organisms. This will in turn decrease the stability of the ecosystem.

The financial cost to develop rehabilitation programs to assist the flora and fauna survival due to the effects of degradation and habitat disturbance for could heavily out-weigh those of short term profit produced through tourism and the small business being proposed. Financial aid would also have to be invested by the government to research the best way to rehabilitate the species and fauna and flora affected.

It is also with the continuation of development that erosion of the shoreline is likely to occur with the influx of tourist and visitors. With such increase within people there would also be an increase within the motor boats and vehicles, increasing the amount of in stream disturbance from motor boats this may then lead to increase sedimentation and erosion of shoreline. Further financial aid would then be provided by the government or developers to fix such issue if the environment was to rehabilitated. It is due to these numerous negative implications that heavily out weight those of proposed benefits and thus it is highly recommended that the development of the marina does not take place.

However if the development is to still commence one of the long term alternatives that could be taken to reduce the amount of negative impacts include, relocating the area of where the proposed Marina is to be situated, so that it is out of the Moreton Bay Reserve. Other controls include close monitoring of waste products by both the Marina and tourist so that waste in minimalized should also be implemented with large penalties if breached. If implemented successfully may allow for long term success with little amount of pollutants affecting the mangrove ecosystem. As mentioned earlier disturbances within the waters caused by the wake of boats may caused issues with the turbidity of the waters and may in result cause erosion of shorelines. To minimalize such aspects caused by human disturbances it is proposed that speed limits be placed upon the motor boats and restrictions be applied upon the maximum number of crafts allowed within the water.