Questão 11 - UEA - Geral UEAM - Conhecimento gerais 2021

Leia o texto para responder à questão abaixo.

 

Underwater noise pollution could damage crucial ocean plants

 

    Under the Mediterranean Sea lie meadows of Posidonia oceanica, a native seagrass species. It might not look like it’s doing much — just swaying back and forth with the current — but seagrass absorbs carbon dioxide, emits oxygen, protects coasts from erosion and provides habitat for fish.
    But a new threat to seagrass beds has been detected:
underwater noise pollution caused by humans. A team of European scientists reported in the journal Communications Biology that when P. oceanica is exposed to noise, organs in the plant that store energy and detect gravity are destroyed, adding to concern for this already-threatened species.
    Anthropogenic underwater noise is “a big concern,” said Nicola Quick, a marine biologist at Duke University, who was not involved in the study. There certainly have been natural subaquatic sounds from earthquakes and heavy rain, as well as from marine organisms, but humans have been adding noise to the soundscape from activities such as shipping, oil and gas extractions, and renewable energy development.
    Despite P. oceanica’s seeming accessibility, it took the team six months to obtain the authorization needed to collect the protected species. After successfully acquiring the permits, the team collected 84 seagrass plants. They placed the samples in experimental tanks and played sounds with changing frequency from 50 to 400 Hz — the range that covers the noise generated by human activities. The noise level was around 157 dB underwater, equivalent to roughly 95 dB in the air, somewhere between a bass drum and a subway train.
    The team discovered that two hours of noise exposure damaged a plant organ responsible for detecting gravity, meaning noise could affect the plant’s capacity to stay rooted. Moreover, the number of starch grains inside the organ decreased, which could affect the seagrass’s ability to store energy. The starch grains continued to disappear even after the noise stopped.

(Karen Kwon. www.discovermagazine.com, 08.07.2021. Adaptado.)

No trecho do terceiro parágrafo “as well as from marine organisms”, a expressão sublinhada indica