Most of us are aware of the environmental threats facing polar bears, tigers, pandas, and other large land animals, but we tend to forget about the species we cannot see as easily. The International Programme on the State of the Ocean held a conference this past April and came to the conclusion that ocean species are becoming extinct at a very concerning rate. This is not the result of any particular recent human action, but rather due to multiple, slow-acting (largely human-related) factors that have been in action for decades.
Not to state the obvious, but an ecosystem’s diversity is essential for it to adapt to a changing environment. Biodiversity ensures that if one variant of a species is wiped out, then similar organisms will rise to serve the same function in the ecosystem, resulting in minimal disruption of the many interconnected living cycles. Basically, if ocean species are quickly dying out, the consequences to us may not be immediately apparent, but they would be severe.
The first of three main culprits of oceanic extinction is warming. What’s especially difficult about this is that, as polar ice continues to melt, the rate of water warming also increases and is very difficult to reverse (remember that water has a high specific heat capacity). Water warming is devastating to cold-water species such as many corals, which can no longer be hosts to a microclimate of tiny organisms. Previously colourful coral reefs are turning white, a sign that its pigment-rich resident microorganisms have left or died. This means a lack of food source for larger organisms, and the effects travel up the food chain.
The second culprit, ocean acidification, is largely because of rising CO2 levels in the air, which then dissolve in the water to form carbonic acid — also contributing to coral bleaching. Suggestions to mitigate ocean acidification include better control over greenhouse gas emissions and improved natural carbon sinks like living plants around ocean areas. Unfortunately, like the rate of ocean warming, the rate of acidification is increasing as well.
The final major factor of ocean species extinction is chemical water pollutants that deplete the oxygen concentration in the water. This causes marine dead zones where aquatic organisms no longer have enough oxygen needed to survive. Coastal regulation of chemical and other waste dumping varies nation to nation, but they are generally poorly-enforced. Waters that are busy shipping routes especially suffer from chemical contamination. The oceans are massive bodies of water, but dilution can only go so far; the oceans are complex with thermal layering and concentration gradients, so chemical contamination has more localized and severe long-term effects than one might expect.
The point of all of this is not to perpetrate more doomsday preaching, but to remind people that an “out of sight, out of mind” mentality to environmental protection will come back to bite us. As our ocean (and land) ecosystems become less resilient to change, the gravity of this issue should concern anyone who relies on natural resources being abundant and available. Yes, that includes you.
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