Marine Life Threatened as Ocean Oxygen Levels Fall

Category: Science/Environment

Listening

Unlocking Word Meanings

Read the following words/expressions found in today’s article.

  1. stark / stɑrk / (adj) – very noticeable or easily seen
    Example:

    There is a stark contrast between the twins’ personalities. One is shy; the other is outgoing.


  2. devoid / dɪˈvɔɪd / (adj) – not having something; completely lacking something
    Example:

    During winter, most trees are devoid of leaves.


  3. respiration / ˌrɛs pəˈreɪ ʃən / (n) – the act or process of breathing
    Example:

    The doctor usually checks a patient’s heartbeat, respiration rate, body temperature, and blood pressure.


  4. accumulate / əˈkyu myəˌleɪt / (v) – to gather gradually
    Example:

    Dust will accumulate if no one cleans the house.


  5. prone / proʊn / (adj) – likely to do, experience, or suffer from something
    Example:

    Jackie is prone to headaches, so she always brings painkillers with her.


Article

Read the text below.

The world’s oceans are currently losing oxygen, a nature conservation organization reported.


According to the International Union for Conservation of Nature (IUCN), around 700 areas in oceans around the world have low oxygen levels. This is a stark increase from only 45 sites back in the 1960s. The organization also found that the volume of anoxic waters, or areas completely devoid of oxygen, has quadrupled and that the oceans’ oxygen levels have declined by 2% since the 1950s. Furthermore, the organization predicts that oceans are expected to lose 3%-4% of their oxygen levels by the year 2100.


The scientists found two major causes of deoxygenation or oxygen loss: climate change and eutrophication [yoo-tra-fuhKEI-shuhn], or excessive algae [AL-jee] growth.


Climate change has caused a global increase in temperature. Because of this, oceans have become warmer, lowering their oxygen levels. This affects marine life since metabolic and respiration rates increase as the temperature does. Additionally, warmer waters make it difficult for oxygen to travel to colder, deeper waters.


Meanwhile, eutrophication occurs when agricultural wastes, like artificial fertilizers, sewage, and animal waste, accumulate into large bodies of water and feed algae. The algae grow then decompose, causing deoxygenation.


According to the scientists, deoxygenation is threatening fish species, especially the large ones with high energy demand. These include marlin, tuna, and sharks. These marine animals are swimming closer to the surface, where there is more oxygen available, to survive. This leaves them prone to overfishing and puts them at risk from mass extinction.


To solve this, the scientists advised people to slow down deoxygenation by reducing greenhouse gas emissions and limiting agricultural waste through legislation.


Viewpoint Discussion

Enjoy a discussion with your tutor.

Discussion A

• In your opinion, how can the agriculture sector be encouraged to combat eutrophication? Discuss.
• Do you think the solutions that the scientists mentioned are enough to combat deoxygenation? Why or why not?

Discussion B

• How will the depletion of marine life affect people? Explain.
• Do you think people can survive if marine life gets further depleted? Why or why not?