John F. Kennedy said, “We’re tied to the ocean. And when we go back to the sea, whether it is to sail or to watch — we’re going back from whence we came.” This quote is more poignant than you might think. We are inevitably linked to the ocean: All life on Earth originates from its depths — and it is crucial for our future, too.
Covering about 71 percent of Earth’s surface, the ocean is instrumental in the processes that keep us alive. Whilst the rainforests may be referred to as “the lungs of the planet,” it is actually the ocean that provides 50 to 80 percent of the oxygen we breathe. Through a “conveyor belt” action, it helps regulate Earth’s climate by transporting heat away from the equator (赤道), towards the poles to cool. The ocean also proves itself essential in the fight against climate change. It absorbs 50 times more carbon dioxide (CO2) than our atmosphere — or rather, it is not the ocean itself…but what lives within it.
Many forms of aquatic life naturally absorb and hold carbon. From microscopic phytoplankton (浮游生物) to gigantic whales, life of all shapes and sizes play a part in feeding these carbon sinks (areas that absorb more CO2 than they release). Perhaps one of the most incredible forms is the humble seagrass.
Across the globe, there are more than 70 different species of seagrass. It grows in the vast underwater meadows of 159 countries on six continents, covering 300,000 square kilometers — barely occupying 0.2 percent of the seafloor. This is where the super seagrass comes into its own: It absorbs ten percent of the ocean’s carbon each year and captures carbon up to 35 times faster than tropical rainforests.
Seagrass constructs its leaves and roots through the use of carbon, which it gains from water through the process of photosynthesis (光合作用) — and it holds on to this carbon even after its death. Dead plant material slowly decomposes on the ocean floor, which means that the carbon stored within it ends up getting buried under the seabed.
It is ironic that such an effective natural solution to climate change is itself under threat from climate change, as temperatures rise and more violent storms destroy seagrass beds. Pollution, the long-term development of coastlines, and unregulated fishing have all played additional roles in its decline.
Experts say that reversing the decline of seagrass will take an international effort. Fortunately, restoration missions are already underway. The Ocean Conservation Trust, for example, has opened a seagrass cultivation lab. Here, seagrass is grown in batches, using seed-bearing shoots that have been hand-picked by divers. In April 2021, 2,200 bags of these seedlings were planted on the seabed of Plymouth Sound, England. They are expected to flourish into a meadow the size of six football pitches.
Could seagrass be one of the Earth’s great survivors that will end up saving us all? As with most things, only time will tell.
【小题1】What does the underlined word “instrumental” in the second paragraph mean?| A．important | B．alarming | C．consequential | D．mechanical |
| A．The carbon is taken in through photosynthesis by seagrass’s roots and leaves. |
| B．The carbon gets buried together with the decomposed plant material. |
| C．The carbon is eaten by various forms of aquatic life that feed on the dead plants. |
| D．The remaining carbon is cultivated in an artificial lab to convert to seagrass. |
| A．Paradise for Aquatic Life | B．Ocean is Under Threat |
| C．the Irreversible Climate Change | D．Kelp (海藻) Can Help |
