The Global Problem of Marine Noise Pollution

We live in a noisy world. Over the last 100 years as humans have increasingly used the worlds waterways for shipping, defence and natural resources the level and amount of man-made noises have increased. Marine mammals fish and invertebrates rely on sound to communicate under the water to find food, mate and stay safe. Noise can cause behavioral changes and can be fatal. Until recently in the last decade, underwater poise was not considered a worldwide concern. Last 10 ears have been concerned about the effect of sound underwater. Noise is another pressure on an already vulnerable ecosystem.

Underwater poise pollution is a serious threat. The underwater environment is filled with biotic and abiotic sounds, many of which can be important for the survival and reproduction of fish. Over the last century, human activities in and near the water have increasingly added artificial sounds to this environment. Very loud sounds of relatively short exposure, such as those produced during pile driving, can harm nearby fish. However, more moderate underwater noises of longer duration, such as those produced by vessels, could potentially impact much larger areas, and involve much larger numbers of fish. Here we call attention to the urgent need to study the role of sound in the lives of fish and to develop a better understanding of the ecological impact of anthropogenic noise.

Noise pollution raises our blood pressure, disturbs our sleep and leads to cognitive impairment in children. But it’s not just us humans that are affected by noise. Mass strandings all time high suggest lnk to NP. These observations have been seen on terrestrial species. Many studies have been done on birds that have significant results showing increases in song frequencies, area avoidance. Our hearing not as good like whales, can communate kms underwater. But how badly? Ongoing research suggest all this noise is masking their ability with each other. Seismic activity causes interruption in migragtion. Ceteans are common in new studies but new research also say invertebrates, crabs etcShippopellas produce intense loud noiseSonar sounds 10s to 100s of miles used to detect other subs.

Introduction/How sound travels

One of the earliest documentaries on underwater life was called the silent world. We have since discovered its far than that. Hard to tell which direction and how far away. Life underwater can be very loud. The world that these long lived creates have experienced is changed on a geological scale. We are seeing a different planet. Some wales live to be 150 to 200 years old. When those whales were teenagers the world was quiet. Disrupts ability to hunt or the ability of female to make a choice between the best singers because she can only hear the ones that are closest to her.

What is the impact of that? Humans have been changing the sounds of the oceans since we first started exploring the seas. But our ocean presence has exploaded over the last five decades. Over the last 60 years the number of ships moving pver the global surace of the world has increased dramatically Sound travels differently in air than water. Sound travels very well long distances underwater. Sounds of the sea Noise can be defined as any sound not of primary interest. Sound is important underwater, even in the clearest day you can only see 200ms ahead of you. Many marine mammals use sound to map their environment. Natural sources or biotic sources can come from fish like the midshipman (toadfish) (Porichthys notatus), oscillate their swim bladder to make sounds that are loud enough to keep people living on houseboats up at night (Voice of the turtle?> no toadfish loveson). Barred gruntfish (Haemulidae conodon nobilis) make a grinding sound with their pharyngeal jaws and their gullet. Snapping shrimp make similar sounds to that of a cracking knuckle. Smooth-claw snapping shrimp (Alpheidae paracrinitus) thye produce a sound by creating tiny popping bubbles with their claws and been measured at 200db louder than a gun shot. Pile driving one of the most distressing. Bubble curtains large rings around the pile reduces sound, reduced 30%.

Arguably one of the worst contirubtors to anthroprogenic noise pollution in marine environments is that made by seismic surveying. It’s a process that allows companies to locatespots on the ocean floor where they can drill for fossil fuels. Boats with about 40-50 airguns that all go off at once will move back and forth over large parts of the ocean. Bubbles from the horns expand and contract typically every 10 seconds creating a hgue amount of acoustic energy that maps geological structes feep in the ocean floor. It’s about as loud as a jet at take off. These can go on for weeks at a time. A study of seismic survey noise between 1999 and 2009 found that airgun sounds were recorded almost 2500 miles away from the survey ship itself. On some locations they were recorded on 80% of days over a year. And that changes the way marine animals behave. A study by the insititute of Marine Sciecne at the University of North Carolina found that reef fish abundance decreased by 78% during seiemic surveying (AB Paxton et al) Oil + gas exploration seismic guns weeks or months 100s of meters penetrate.

Boats

One of the most common anthroprogenic sounds heard almost anywhere in the oceans is generated from boats. Noise from ship traffic has doubled every decade since the 1960s. The oceans ambient noise is dominated by anthroprogenic noise. This is a problem for marine animals that use sound as their primary sense. The sound of nearby shipping traffic can complete mask the calls made from dolphins. Some of the sound may come from the engines that’s transmitted through the hull. The majority of it comes from what is happening right at the propeller. It’s called cavitation. Thas when the bubbles created by the blades of the propeller collapse and burst under water. It’s not so much the collapse of an individual bubble itst all of them at once creating a ery loud hiss.

Ship engines generate nosie aswell. Shipengines are historically buit is you bolt them to the frame which vibrates the frame andmakes that sound transmit though all the steel or the hull and out into the water. The effects of natural and anthroprogent sounds on mammals, fish, inverts. Sound is important for fish at their larval stage as they find their reefs after their palagic. Cues they use is the sounds reefs produce. All the activity makes sound scape. Holles et al 2013 experiments. Found if they put a fish in a little chamber one end is a speak sound, fish can decide if it wants to move towards or away. Reef sound they moved towards sound. Attracted to it. Reef and boat to gether, fish unsure spilit between towards or away. Clearly has reprocusions to find way t suitable habitat. Juvenile (Anthropogenic noise playback impairs embryonic development and increases mortality in a marine invertebrate)Sound is typically characterised by frequency, wavelength, and intensity.

Communication

Light doesn’t penetrate very deep in water, so a lot of marine life have evolved to use sound as their primary sense. Because water particles are more densely packed together than air sound travels about 4 times farther and faster in water. That makes it an efficient medium of communication at any depth or time of day. For animals like whales - who reply on complex sound communication systems to socialise, find food and mate – that poses a huge problem. William A Watkins whales sounds lower frequnies in past, now increasing frequencies. Can be seen in many terrestical species such as extensively observed birds. Whales are singing at higher and higher frequencies to hear each other over the hum of ship noise.

Stress

Chronic noise causes stress and may decrease their breeding success. Apart from habitat displacement and communication changes there is also evididence that boat noises simply stresses these animals out. After the September 11th attacks researchers in Canadas bay of fundy compared underwater noise levels during a period of reduced ship traffic to the stress related hormone levels in the right whale population.

The discovered a 6bd noise decrease in the bay after 9/11 which correlated to lower baseline levels of stress related hormoones. Effects like this go all the way down the food chain. McCauley RD et al 2017 study found that there were two to three times more dead zooplankton after a day of blasts from a single airgun. The large of krill which whales rely on for food were totally destroyed. Orcas increase their calls around container ships japan. Food at depths Locate breathing holes See them avoiding ice breakers at great distances eg buluga excess 50 km. they want a lot of space between. Whales diver gets bends some beach and die but many unnoticed. Low frequency sonar not so much used these days. Mid-frequency sonar much loder but doesn’t propagate as far. Different frequencies can travel different distances. This information could be further studied to create propllats and siesim pile driving that are created at such high frequencies that MMO’s can mitigate the immediet danger. Effects on ecosystemsGreen house gases melt artic ice that would buffer wind noise. Also allows access and Invasion of subartic species into northn waters. What are the repercussions of this. Might they introduce disease or parasites. What are the new sounds doing to soundsape.

Often migrating animals, cant control every country. In 2017 trump signed for more offshore drilling which could potentially increase the noise loads. 2014 IMO international maritime organisation adopted guidelines for reducing commercial ship noise levels with things like noise muffling propellas and insulated enginees though they are not mandatory yet. 2015 US navy agreed to limit sonar testing which has been linked to whales stranding themselves on beaches in ahbitats near southern California and Hawaii following a lawsuit against environmental groups. 2016 national oceanic atosphetiic administration laid out an ocean noise stratgegy road map. It’s the start of a 10 year plan to assess the human impact on underwate soud and the measures required to reduce it. Seismic surveys can work better too. Norway has started multiple client surveys so that seismic data from a particulat are is only collected once. US authorities are considering a similar process.

Restic access in regions or seasons. Get smarter by quieting ships/Mega absorber reduces engine noise using sound proofing. Slower ship is a quieter ship. A major challenge towards understanding the effect of anthropogenic noise on free-ranging marine species lies in the difficulty of conducting controlled experiments. But there is speculation (Slabbekoorn H. 2016 Aiming for progress in understanding underwater noise impact on fish: complementary need for indoor and outdoor studies. Adv. Exp. Med. Biol. 875,1057–1065. (doi:10. 1007/978-1-4939-2981-8_131) as to how accurate of a representation tank experiments are of open marine ecosystems. Tanks however can replicate good noise exposure experiments where individuals cannot avoid noise expose and can tell us the extreme responses to continuous loud noise. It is recommended these experiments still hold value and can teach us which species can habituate to nose exposure over long periods of time.

Conclusion

Like plastic, chemicals, and waste, noise pollutes our oceans. Understanding that is key to doing our part to protect it. There is comprehensive evidence that anthroprogoenic noise exposure affects several taxa groups development, physiology and behaviour. These damaging effects have been studied across the terrestrial ecosystem, and considering sound travels farther in water it can be assumed the damage would likely be much greater. The benefit of this pollution is that it is relitely easy to control. Noise can be turned off, and with the right regulations and push toward engeneeirng reduced shipping equipment it is a problem that can be solved. IvertsSeveralstudies show that marine noise is also affecting invertebrate species. Similarly to who they would respond to predators, crustaceans have eben shown to exibit defensive behaviour in response to incoming sounds. Study by x on cuttlefish found 37 protiens were damaged in one the statocyst (sensory receptor). Blue muscles are harvest to eat, x billion a year. A study by x found that blue muscles exposed to greater noise levels broke their dna. A chemical produced probably due to stress levels. Marine invertebrates, fish and mammals all use sound to communicate, navigate, detect predators.

All the anthroprogenic noise is dereasing the acoustic soundspace over which marine species communicate. Many have evolve to deal ith higher levels of marine noise such as breaking sea ice and other marine animals. But they have evolved with these noises and some are vital to their survival. Intro – natural marine noise, unnatural noise, things that cause it and briefly what it effects. The ocean is a symphony of sounds. Marine species use these sounds to communicate, navigate, find prey and find mates. Some scientists estimate the oceans are 100 times noiser today than they were 100 years ago. Mainly due to shipping traffic.

Unlike many pollutants we have direct control over the noise and we can choose when and where we make it. Marine noise as a concern is relitely new. Most study have elooked at marine mammals that use echolocation to communicate and navigate. More recemtly researchers have shown more focus on smaller species including fish, invertebrates and their larvae. Fpr sp,ething that has pn;y been exposed over the last 60 years it is a growning issues across taxa. These new sounds are lloud and alien.