So you may be wondering what coral polyps and zooxanthellae are? Well they are just the constituents that make up a coral reef. In fact, thousands of coral polyps make up a coral colony. Coral polyps have a symbiotic relationship with the microscopic algae, zooxanthellae, with the latter residing in the polyps providing a greater ability to fix food, nutrients and oxygen for the coral colony as a whole. Further, they give the polyps their amazing colours. So the title was just me trying to be clever...
Anyway, there are many reasons why reefs matter! First and foremost, coral reefs are one of THE most productive and biologically rich ecosystems on earth. Whilst they spread over 250,000 sq km of the ocean, which roughly equates to less than 1/10th of 1% of the marine environment (for you budding mathematicians out there…that’s 0.001%), reefs are home to 25% of all know marine species (McAllister, 1995). Importantly, reefs support more species per unit area than any other marine environment. This includes 4,000 coral reef fish species and 800 species of hard corals amongst hundreds of other species that form complex food webs (Paulay, 1997). Whilst coral reefs are dynamic environments that are an important habitat for many species, they also provide numerous ecosystem services that millions of people globally depend on (Burke et al., 2011). These can be broken down into three categories…
1a. Coral reefs provide substantial
socioeconomic benefits. According to Burke et al. (2011), 850 million people
live within 100 km of a coral reef (fig. 1) and as a consequence, a high
proportion of these people are likely to derive some benefits from the reefs.
Coral reefs are even more important for those 250 million people that live
within 30 km of reefs (fig. 1), many of which who reside in developing
countries or island nations. For these populations, reef associated species
provide an important source of protein that equates to, on average, one quarter
of total fish catch in developing countries. Lastly, coral reefs have great
potential. A healthy, well-managed reef could yield between 5 and 15 tons of
fish per sq km per year (Jennings and Polunin, 1995; Newton et al., 2007). This
is significant in terms of a subsistence livelihood as well as economically,
through export. For example, whilst coral reefs play an important cultural role
in American Samoa, they supply over 50% of fish caught for food (NOAA, 2001).
1b. Coral reefs form the backbone of
local economies through tourism. They are crucial for sustained and stable
tourism interests in many tropical regions. After experiencing the beautiful
reefs along the coast of the Red Sea, one can truly appreciate the integral
role reefs play in a country’s tourism strategy. The coral reefs provide not
only excellent sites in terms of diving and snorkeling but they also benefit
other businesses such as restaurants and the like. Burke et al. (2011) identifies
clearly the importance of coral reefs; approximately 200 countries benefit from
tourism related to reefs and moreover, tourism contributes more than 30% of
export revenue in 20 of these countries (The World Bank, 2010; UN World Tourism
Organization, 2010). Consequently, there is no doubting the importance that reefs
play in terms of food and livelihoods.
Fear not, I haven't forgotten about the other two categories, they will come later this week. If I put it all in one then it will be a bit of a brain overload and you will probably get bored.
Until next time,
Seb
Seb
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