## 2 Underwater Ecosystems and Biodiversity
Sustainable Development Goal 14 (SDG 14) is known as Life Below Water, which focuses on conserving and sustainably using the oceans, seas, and marine resources. It aims to protect marine ecosystems, reduce \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Impact** & **Description** & **Affected Organisms** \\ \hline \multirow{3}{*}{Noise Pollution} & Generated by machinery, vessels, and communication systems. & Marine mammals, fish, invertebrates \\ \hline \multirow{3}{*}{Habitat Disruption} & Caused by construction, installation, and operation of underwater infrastructure. & Benthic organisms, coral reefs \\ \hline \multirow{3}{*}{Chemical Pollution} & From materials used in underwater equipment and operations. & \multirow{3}{*}{Various marine species} \\ \cline{1-1} \cline{3-3}  & Disrupts marine organisms’ sensory systems. & & \\ \hline \multirow{3}{*}{Climate Change} & Indirectly impacts marine ecosystems through ocean warming and acidification. & \multirow{3}{*}{Diverse marine species} \\ \cline{1-1} \cline{3-3}  & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The impact of underwater communication on aquatic life [1; 26; 28]. pollution, and promote sustainable fishing practices [30]. SDG 14 is in alignment with the 1982 United Nations Convention on the Law of the Sea (UNCLOS). The Natural Resources Defense Council (NRDC), a US-based non-profit international environmental advocacy group, estimated that between 80% and 90% of products and commodities transportation is carried out by ships on ocean waters, significantly contributing to noise pollution [31]. Besides machine noises, technological noise emissions are equally regulated, such as acoustic signal power, modulation schemes, and acoustic frequency bands [32]. For example, spread spectrum modulation reduced signal power density per unit of bandwidth [33], and bioacoustics studies have proven animal discomfort and bio-intrusion reduction provided by this method [34]. Underwater simulations performed using the spread spectrum resulted in transmission rates of 45 bs at \(-\)18 dB Signal-to-Noise-Ratio (SNR) and 140 bs at \(-\)12 dB SNR [34]. Furthermore, the frequency ranges used for communication and active Sound Navigation and Ranging (SONAR) detection systems in some cases match those of certain marine species, causing confusion, disorientation, false alarms, and panic [1]. Ocean Care, a marine life advocacy organisation, added that underwater noise pollution is \"deafening, dangerous, and deadly to marine life\" [35]. The oceans are increasingly becoming crowded with scores of colossal, transformative, and innovative industries [34], namely long-standing offshore oil and gas, offshore wind farms, aquaculture fish farms, marine mineralogy, and underwater research and exploration. These industries utilise various types of technologies in marine environments, such as heavy machinery, powerful motors and underwater vehicles, and the installation of underwater power plants and piping systems, which are sources of vibrations, sounds, and frequencies of various sorts [1; 28; 34]. As described in [28], the main sources of noise emissions in the oceans are anthropogenic in origin. Various technologies pollute the waters with harmful noise and chemicals, altering the marine ecosystems with disturbances and other micro-climate changes that ultimately cause disorientation, hearing loss, confusion, bodily malformation, developmental dysfunction, diminished egg production and growth rates, DNA damage, and deaths to the marine life [1; 3; 28; 34]. Both fish and invertebrates use sound to meet distinct existential needs, such as navigation, mating, communication, predator avoidance, and socialising [1; 3]. Although not all fish emit active sound [3], all fish species studied to date have been found to possess the ability to hear sound [1], and invertebrates also demonstrated the ability to detect sound and vibrations and respond to acoustic cues [1; 3].