The featured image you see just above is that of Airlie Beach, Queensland. Voted 34th in a lineup of the 100 Best Towns in Australia by Australian Traveller in 2009, the exclusive town, home to just over one thousand permanent residents, lives and breathes tourism, much like the rest of the Great Barrier Reef.

Tourism on natural sites such as the Great Barrier Reef is excellent in a variety of ways. First and foremost, it brings the curious tourist into direct and intimate contact with nature. Such close contact, whether it is with a gigantic humpback whale on the Great Barrier Reef, or a smaller-scale encounter with some fish swimming near shore, elicits a sense of awe and closeness with nature in humans that cannot be felt any other way.

Beyond the emotional benefits for the individual tourist and the educational value of such close experiences with nature, tourism in the Great Barrier Reef is an excellent source of revenue for the Australian Government. Take, for example, the Environmental Maintenance Charge (EMC) that is levied on tourists visiting the Great Barrier Reef. Racking up to a modest $3.50 for tourists spending more than three hours on the Reef (Great Barrier Reef Marine Park Authority, n.d.), it is only when the total number of tourists visiting the Reef is factored in that the financial contributions of tourism on the Great Barrier Reef becomes obvious. According to the GBRMPA, more than a million people visited the Reef in 2013 alone (GBRMPA, n.d.).

However, the sheer volume of people visiting the Great Barrier Reef cannot be without consequence.

With all that diving, snorkeling, boating and yachting come the challenges of keeping wildlife safe from dangers such as the slicing blades of outboard motors and collisions with boats and ships. Tourists more often than not also spend full days on the Reef, if not more, and this inevitably results in litter and human waste. One example is greywater, which is used water that has not come into contact with toilet waste, according to the Singapore’s Public Utilities Board (2014) definition. Another is bilgewater, defined by the Merriam-Webster online dictionary (n.d.) as water that collects in the bilge of the ship, its bottommost part. Such anthropogenic substances are of concern to the GBRMPA, which maintains several pages on “Responsible Reef Practices”, with one section specifically set aside to address the proper handling and disposal of these substances.

Greywater, bilgewater and other unwanted waste products will not only cause harm in the form of pollution when introduced into marine environments like the Great Barrier Reef, they also upset delicate biological processes.

For example, certain substances can provide nutrients that rapidly accelerate eutrophication, a process that occurs in both freshwater and marine ecosystems when unusually large amounts of nutrients (such as phosphates or nitrates) are added introduced into water bodies (United States Geological Survey, 2014). According to Smith, Joye and Howarth (2006), eutrophication can lead to “dramatic changes in the composition and structure of aquatic food webs” through the explosion of populations of algae (see graphic above). Such nutrient enrichment is also partly to blame for population increases in the crown of thorns starfish (Acanthaster planci) that is widespread along the Great Barrier Reef and devours coral voraciously (GBRMPA, n.d.). This particular threat will be discussed in greater detail in a later post.

Another human activity that is detrimental to the Great Barrier Reef is coal mining. Just this year, the Australian government approved the creation of the largest coal mine in the country: the Carmichael Project. Valued at a whopping $5 billion and expected to create more than 5,000 jobs once underway, this approval will allow the Indian mining company Adani to dig up roughly 60 million tons of coal every year from Galilee Basin, Queensland, transport it to Abott Point port and ship it to India for use in coal-fired powerplants.

This multifaceted project also has a wide range of potential effects on the reef. Dredging of up to five million tons of seabed to prepare for coal carrying ships as well as the possibility of coal carriers running aground (as in the case of the Chinese-registered Shen Neng 1) are some of the more obvious effects. However, some of the longer term effects of the Carmichael project include exacerbating the existing problem of coral bleaching, a harmful process that is accelerated by climate change, fueled in part by coal-fired powerplants. As such, the Carmichael Project does not only result in far-reaching ramifications for the Great Barrier Reef, but all marine life in general as well. It does not make it any better that the Carmichael project, though facing fierce opposition from environmental advocacy groups like Greenpeace, is expected to churn out coal for sixty whole years.