Month: June 2015

It’s World Oceans Day – why should you care?

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On April 22nd, I celebrated Earth Day by spending an hour in darkness pondering some of the things I’ve learned over the course of the past 4 years as a PhD student. A month later, I celebrated World Turtle Day by proudly wearing a shirt featuring my favourite “heroes-in-half-shells” (though one could argue that they’re really heroes in full shells…). As a benthic ecologist working on the mudflats of the Bay of Fundy, I will assuredly spend June 29th celebrating International Mud Day. And, of course, who can forget Darwin Day? It seems that, today, there is a special day dedicated to almost anything! Although such events have often been criticized for being arbitrary and not enforcing any substantial action for the betterment of their intended cause, I would argue that such days are important for amplifying public knowledge and awareness regarding topics of utmost importance. And so today, on 08 June 2015, should you care about World Oceans Day? I think you should, and here are three reasons why:

The ocean is the source of life

The ocean is huge and is the source of almost all water on Earth (Table 1). Covering 71% of our planet, the ocean paints 140 million square miles of the earth’s surface a shade of magnificent blue (1) and makes available a 1.3 billion km3 tub of seawater (2). Furthermore, although we are terrestrial beings, we depend on the ocean for everyday life. Approximately 44% of all humans live within 150 km of the ocean (3). Furthermore, the interaction between the atmosphere and the surface of the ocean is the primary driver of the earth’s climate and weather and plays a critical role in maintaining air quality, as marine plants provide more than 80% of the earth’s oxygen (take that, trees!) (4).

Table 1. The contributions of various water sources to the relative volume and percentage of the total water on Earth.
Table 1. The contributions of various water sources to the relative volume and percentage of the total water on Earth. Data reflect that reported in Gleick (1996).

Economically, we depend on the ocean to an extraordinary degree. Commercial fisheries (capture and aquaculture) provide some 55 million jobs and provide about 400,000 tonnes of fish every day (5)! Alongside all of this, the ocean is also the source of life on Earth. It is well established, scientifically, that life itself originated in the marine realm. Ultimately, without the ocean, life as we know it would not exist. As Dr. Sylvia Earle puts it, “No water, no life. No blue, no green.”

We know less about Earth’s ocean than you might think

Although the ocean covers 71% of the planet and is the source of life on Earth, we know very little about it. To date, less than 5% of the ocean has truly been explored (6), while the surfaces of Venus, Mars, and the moon have been mapped more extensively and at a higher resolution than the sea floor (7; Table 2). Furthermore, while 12 people have visited the moon since 1969, only 3 people have visited the Mariana Trench (8) – one of them being Hollywood director James Cameron, who recently co-authored a scientific paper about biological communities of the Mariana and Britain Trenches. In fact, when we do visit the deep ocean, we make multiple new discoveries, including brand new species, almost every time. Although it’s important to understand the future of human life (i.e., space), it is just as critical, if not more critical, to understand our origin. Ultimately, despite the over-impressive efforts of marine scientists, from Captain James Cook to now, we still have much to learn about the ocean.

Table 2. Comparison between the relative percentages of three given locations (Earth's ocean, Mars, and Venus) mapped at a given resolution.
Table 2. Comparison between the relative percentages of three given locations (Earth’s ocean, Mars, and Venus) mapped at a given resolution. Data reflect percentages at a given resolution reported in Copley (2014).

Humans are impacting the ocean in a catastrophic manner

Despite depending on it for life, humans induce substantial impacts on the ocean, most notably along the coast, where more than 40% of all humans live (3; Figure 1). Nutrient loading, pollution, coastal development and habitat destruction, fishing, oil exploration and extraction, species introductions, shipping, and climate change are all human-sourced drivers that are currently imposing drastic changes to the ocean. Although you may think that the oceans are too large for humans to influence, more than 40% of the ocean experiences heavy anthropogenic impact, with very few (if any) areas remaining unaffected by human activity (9).

Figure 1. Global distribution and severity of human impacts on the world's ocean. Warmer colors indicate more severe impacts. Source: Halpern et al. (2008).
Figure 1. Global distribution and severity of human impacts on the world’s ocean. Warmer colors indicate more severe impacts. Source: Halpern et al. (2008).

Of those areas impacted, coastlines bare the brunt of the effects, particularly in Europe, North America, the Caribbean, China and Southeast Asia. Large areas of the Bering Sea, the China Seas, and the North Sea are also heavily impacted. Not all is yet lost, however. The poles stand out among the least impacted areas, while the North coast of Australia and areas in the tropical Pacific also appear less impacted than the rest of the globe. As a result, species are dying (10), the ocean is warming (11; Figure 2a), its chemistry is changing (12; Figure 2b), and sea level is rising (13; Figure 2c). Consequently, humans are not only invoking irreparable harm to the ocean and marine life, but we are risking our own livelihood as well.

Figure 2. Annual trends in sea surface temperature (a), sea surface pH (b), and sea level rise (c) over time.
Figure 2. Annual trends in global sea surface temperature in degrees Celsius (a), sea surface pH (b), and sea level rise in cm (c).

So why should you care about World Oceans Day? The oceans are the source of life on earth and allow us to live in the way that we do, by providing us with oxygen, food, and a means to navigate our planet (among other things). However, we don’t really know much about our planet’s life support system and we are rapidly impacting it in such a way that we might not get to learn much about it. Fortunately, not all is lost and there is still time to salvage what we do have. So today, you should reflect on what the ocean has given and continues to give you, take a stance for a healthy ocean, and inform those around you of the threats that face our oceans. A wise man once said, “Unless someone like you cares a whole awful lot, nothing is going to get better; it’s not.” (Dr. Seuss, The Lorax). That is why you should care about World Ocean Day – we all need you to.

References

1. UN Division for Ocean Affairs and the Law of the Sea. 2011. The oceans are the very foundation of human life [online]. Retrieved 08 June 2015 from http://www.un.org/depts/los/oceans_foundation.htm.

2. Gleick PH. 1996. Water resources. In: Encyclopedia of climate and weather, Vol. 2 (ed. SH Schneider). Oxford University Press, New York, pp.817-823.

3. UN Atlas of the Oceans. 2010. Human settlements on the coast [online]. Retrieved 08 June 2015 from http://www.oceansatlas.org/servlet/CDSServlet?status=ND0xODc3JjY9ZW4mMzM9KiYzNz1rr3M~.

4. Hall, J. 2011. The most important organism? [online]. Retrieved 08 June 2015 from http://www.ecology.com/2011/09/12/important-organism/.

5. FAO. 2015. The post-2015 development agenda and the millennium development goals [online]. Retrieved 08 June 2015 from http://www.fao.org/post-2015-mdg/14-themes/fisheries-aquaculture-oceans-seas/en/.

6. NOAA. 2015. Ocean [online]. Retrieved 08 June 2015 from http://www.noaa.gov/ocean.html.

7. Copley, J. 2014. Just how little do we know about the ocean floor? Scientific American [online]. Retrieved 08 June 2015 from http://www.scientificamerican.com/article/just-how-little-do-we-know-about-the-ocean-floor/.

8. Thar, J. 2011. World Oceans Day: why should we know more about the moon that our oceans? [online]. Retrieved 08 June 2015 from http://blogs.vancouversun.com/2011/06/07/world-oceans-day-why-should-we-know-more-about-the-moon-than-our-oceans/.

9. Halpern, BS et al. 2008. A global map of human impact on marine ecosystems. Science, 319:948-952.

10. Braje, TJ & Erlandson, JM. 2013. Human acceleration of animal and plant extinctions: a Late Pleistocene, Holocene, and Anthropocene continuum. Anthropocene, 4:14-23.

11. Levitus, S et al. 2000. Warming of the world ocean. Science, 287:2225-2229.

12. Doney, SC et al. 2009. Ocean acidification: the other CO2 problem. Annual Review of Marine Science, 1: 169-192.

13. Church, JA & White NJ. 2006. A 20th century acceleration in global sea-level rise. Geophysical Research Letters, 33: L01602.

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