demonstrates a stress response in invertebrates was conducted on the squid species doryteuthis pealeii. the squid was exposed to sounds of construction known as pile driving, which impacts the sea bed directly and produces intense substrate-borne and water-borne vibrations. the squid reacted by jetting, inking, pattern change and other startle responses. since the responses recorded are similar to those identified when faced with a predator, it is implied that the squid initially viewed the sounds as a threat. however, it was also noted that the alarm responses decreased over a period of time, signifying that the squid had likely acclimated to the noise. regardless, it is apparent that stress occurred in the squid, and although further investigation has not been pursued, researchers suspect that other implications exist that may alter the squid's survival habits. an additional study examined the impact noise exposure had on the indo-pacific humpbacked dolphin (sousa chinensis). the dolphins were exposed to elevated noise levels due to construction in the pearl river estuary in china, specifically caused by the world's largest vibration hammer—the octa-kong. the study suggested that while the dolphin's clicks were not affected, their whistles were because of susceptibility to auditory masking. the noise from the octa-kong was found to have been detectable by the dolphins up to 3.5 km away from the original source, and while the noise was not found to be life-threatening it was indicated that prolonged exposure to this noise could be responsible for auditory damage. marine life noise pollution is common in marine ecosystems, affecting at least 55 marine species. for many marine populations, sound is their primary sense used for their survival; able to detect sound hundreds to thousands kilometers away from a source, while vision is limited to tens of meters underwater. as anthropogenic noises continue to increase, doubling every decade, this compromises the survivability of marine species. one study discovered that as seismic noises and naval sonar increases in marine ecosystems, cetacean, such as whales and dolphins, diversity decreases. noise pollution has also impaired fish hearing, killed and isolated whale populations, intensified stress response in marine species, and changed species' physiology. because marine species are sensitive to noise, most marine wildlife are located in undisturbed habitats or areas not exposed to significant anthropogenic noise, limiting suitable habitats to forage and mate. whales have changed their migration route to avoid anthropogenic noise, as well as altering their calls. for many marine organisms, sound is the primary means of learning about their environments. for example, many species of marine mammals and fish use sound as their primary means of navigating, communicating, and foraging. anthropogenic noise can have a detrimental effect on animals, increasing the risk of death by changing the delicate balance in predator or prey detection and avoidance, and interfering with the use of the sounds in communication, especially in relation to reproduction, and in navigation and echolocation. these effects then may alter more interactions within a community through indirect ("domino") effects. acoustic overexposure can lead to temporary or permanent loss of hearing. noise pollution may have caused the death of certain species of whales that beached themselves after being exposed to the loud sound of military sonar. (see also marine mammals and sonar) even marine invertebrates, such as crabs (carcinus maenas), have been shown to be negatively affected by ship noise. larger crabs were noted to be negatively affected more by the sounds than smaller crabs. repeated exposure to the sounds did lead to acclimatization. underwater noise pollution due to human activities is also prevalent in the sea, and given that sound travels faster through water than through air, is a major source of disruption of marine ecosystems and does significant harm to sea life, including marine mammals, fish and invertebrates. the once-calm sea environment is now noisy and chaotic due to ships, oil drilling, sonar equipment, and seismic testing. the principal anthropogenic noise sources come from merchant ships, naval sonar operations, underwater explosions (nuclear), and seismic exploration by oil and gas industries. cargo ships generate high levels of noise due to propellers and diesel engines. this noise pollution significantly raises the low-frequency ambient noise levels above those caused by wind. animals such as whales that depend on sound for communication can be affected by this noise in various ways. higher ambient noise levels also cause animals to vocalize more loudly, which is called the lombard effect. researchers have found that humpback whales' song lengths were longer when low-frequency sonar was active nearby. underwater noise pollution is not only limited to oceans, and can occur in freshwater environments as well. noise pollution has been detected in the yangzte river, and has resulted in the endangerment of yangtze finless porpoises. a study conducted on noise pollution in the yangzte river suggested that the elevated levels of noise pollution altered the temporal hearing threshold of the finless porpoises and posed a significant threat to their survival. impacts on communication terrestrial anthropogenic noise affects the acoustic communications in grasshoppers while producing sound to attract a mate. the fitness and reproductive success of a grasshopper is dependent on its ability to attract a mating partner. male corthippus biguttulus grasshoppers attract females by using stridulation to produce courtship songs. the females produce acoustic signals that are shorter and primarily low frequency and amplitude, in response to the male's song. research has found that this species of grasshopper changes its mating call in response to loud traffic noise. lampe and schmoll (2012) found that male grasshoppers from quiet habitats have a local frequency maximum of about 7319 hz. in contrast, male grasshoppers exposed to loud traffic noise can create signals with a higher local frequency maximum of 7622 hz. the higher frequencies are produced by the grasshoppers to prevent background noise from drowning out their signals. this information reveals that anthropogenic noise disturbs the acoustic signals produced by insects for communication. similar processes of behavior perturbation, behavioral plasticity, and population level shifts in response to noise likely occur in sound-producing marine invertebrates, but more experimental research is needed. impacts on development boat-noise has been shown to affect the embryonic development and fitness of the sea hare stylocheilus striatus. anthropogenic noise can alter conditions in the environment that have a negative effect on invertebrate survival. although embryos can adapt to normal changes in their environment, evidence suggests they are not well adapted to endure the negative effects of noise pollution. studies have been conducted on the sea hare to determine the effects of boat noise on the early stages of life and the development of embryos. researchers have studied sea hares from the lagoon of moorea island, french polynesia. in the study, recordings of boat noise were made by using a hydrophone. in addition, recordings of ambient noise were made that did not contain boat noise. in contrast to ambient noise playbacks, mollusks exposed to boat noise playbacks had a 21% reduction in embryonic development. additionally, newly hatched larvae experienced an increased mortality rate of 22% when exposed to boat noise playbacks. impacts on ecosystem anthropogenic noise can have negative effects on invertebrates that aid in controlling environmental processes that are crucial to the ecosystem. there are a variety of natural underwater sounds produced by waves in coastal and shelf habitats, and biotic communication signals that do not negatively impact the ecosystem. the changes in behavior of invertebrates vary depending on the type of anthropogenic noise and is similar to natural noisescapes. experiments have examined the behavior and physiology of the clam (ruditapes philippinarum), the decapod (nephrops norvegicus), and the brittlestar (amphiura filiformis) that are affected by sounds resembling shipping and building noises. the three invertebrates in the experiment were exposed to continuous broadband noise and impulsive broadband noise. the anthropogenic noise impeded the bioirrigation and burying behavior of nephrops norvegicus. in addition, the decapod exhibited a reduction in movement. ruditapes philippinarum experienced stress which caused a reduction in surface relocation. the anthropogenic noise caused the clams to close their valves and relocate to an area above the interface of the sediment-water. this response inhibits the clam from mixing the top layer of the sediment profile and hinders suspension feeding. sound causes amphiura filiformis to experience changes in physiological processes which results in irregularity of bioturbation behavior. these invertebrates play an important role in transporting substances for benthic nutrient cycling. as a result, ecosystems are negatively impacted when species cannot perform natural behaviors in their environment. locations with shipping lanes, dredging, or commercial harbors are known as continuous broadband sound. pile-driving, and construction are sources that exhibit impulsive broadband noise. the different types of broadband noise have different effects on the varying species of invertebrates and how they behave in their environment. another study found that the valve closures in the pacific oyster magallana gigas was a behavioral response to varying degrees of acoustic amplitude levels and noise frequencies. oysters perceive near-field sound vibrations by utilizing statocysts. in addition, they have superficial receptors that detect variations in water pressure. sound pressure waves from shipping can be produced below 200hz. pile driving generates noise between 20 and 1000 hz. in addition, large explosions can create frequencies ranging from 10 to 200hz. m. gigas can detect these noise sources because their sensory system can detect sound in the 10 to < 1000hz range. the anthropogenic noise produced by human activity has been shown to negatively impact oysters. studies have revealed that wide and relaxed valves are indicative of healthy oysters. the oysters are stressed when they do not open their valves as frequently in response to environmental noise. this provides support that the oysters detect noise at low acoustic energy levels. while we generally understand that marine noise pollution influences charismatic megafauna like whales and dolphins, understanding how invertebrates like oysters perceive and respond to human generated sound can provide further insight about the effects of anthropogenic noise on the larger ecosystem. the aquatic ecosystems are known to use sound to navigate, find food, and protect themselves. in 2020, one of the worst mass stranding of whales occurred in australia. experts suggest that noise pollution plays a major role in the mass stranding of whales. noise pollution has also altered avian communities and diversity. anthropogenic noises have a similar effect on bird population as seen in marine ecosystems, where noises reduce reproductive success; cannot detect predators due to interferences of anthropogenic noises, minimize nesting areas, increase stress response, and species abundances and richness declining. certain avian species are more sensitive to noises compared to others, resulting in highly-sensitive birds migrating to less disturbed habitats. there has also been evidence of indirect positive effects of anthropogenic noises on avian populations. it was found that nesting bird predators, such as the western scrub-jay (aphelocoma californica), were uncommon in noisy environments (western scrub-jay are sensitive to noise). therefore, reproductive success for nesting prey communities was higher due to the lack of predators. noise pollution can alter the distribution and abundance of prey species, which can then impact predator populations. noise assessment metrics of noise researchers measure noise in terms of pressure, intensity, and frequency. sound pressure level (spl) represents the amount of pressure relative to atmospheric pressure during sound wave propagation that can vary with time; this is also known as the sum of the amplitudes of a wave. sound intensity, measured in watts per meters-squared, represents the flow of sound over a particular area. although sound pressure and intensity differ, both can describe the level of loudness by comparing the current state to the threshold of hearing; this results in decibel units on the logarithmic scale. the logarithmic scale accommodates the vast range of sound heard by the human ear. depiction of frequency weighting frequency, or pitch, is measured in hertz (hz) and reflects the number of sound waves propagated through the air per second. the range of frequencies heard by the human ear range from 20 hz to 20,000 hz; however, sensitivity to hearing higher frequencies decreases with age. some organisms, such as elephants, can register frequencies between 0 and 20 hz (infrasound), and others, such as bats, can recognize frequencies above 20,000 hz (ultrasound) to echolocate. researchers use different weights to account for noise frequency with intensity, as humans do not perceive sound at the same loudness level. the most commonly used weighted levels