BIO358 001 1st Edition Lecture 19 Outline of Last Lecture I Methods of Tracking dives II D Tag III Right Whale D Tag Study IV Beaked Whale D Tag Study Outline of Current Lecture I Answers to questions Current Lecture 1 What are some of the anthropogenic sources of sound in the ocean shipping commercial recreational fishing high resolution imaging explosives air guns 2 Is noise in the ocean increasing If so by how much and why increase in 3Db per decibel in certain parts northern hemisphere due to shipping 3 Which frequency of sounds low or high travels farther in the ocean What is a good marine mammal example of a long range acoustic signal travel through the ocean Low frequency travels much better than high frequency ships make low frequency Subwoofer sound goes through the whole room Higher frequencies need to be pointed right at you to hear it These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Low frequency sounds can travel VERY far in the ocean 3 True False Seismic airguns and sonar are high amplitude sounds True 4 What is the largest source of anthropogenic sounds in the ocean Shipping Seismic is getting there 5 A concern about increasing levels of shipping noise is acoustic masking What does this term mean It is getting too loud for communication Animals unable to use communication space when ships go by 6 Is there any evidence that exposure to chronic noise causes physiological changes in any organism Rats exposed chronically to noise throughout life adrenals higher in mass than expected other organs less heavy than expected Smaller young young that do not thrive as well Heart rate and behavior from resting to non resting with exposure to noise Stress increase in adrenals and thyroid measure steroid levels in fecal samples of whales Trained dogs to smell whale poop 7 Please be able to discuss the study that was able to infer that shipping noise might impact right whale stress levels Rolland et al 2012 Frequency in Hz Shipping after 9 11 shipping turned off for a few days reduction of noise Fecal glucocorticoid metabolites before and after 9 11 drop from before and after 9 11 substantial drop in glucocorticoid metabolites in whale fecal samples 9 What is the largest source of noise from large ships The propeller cutting through the water propeller cavitation makes hole in the water and the water caves in to that hole making noise 10 Is the IMO International Maritime Organization taking steps to reduce ship noise Please also know that the European Union has proposed that shipping noise and other anthropogenic sources be identified as a marine pollutant Engineering project to reduce ship noise Long term solution ships last 3 decades 11 True False Marine shipping is expected to decrease by 50 by 2030 False 12 In a general sense how do seismic air guns work Large boat tows an array of air guns used to use dynamite Massive air compressors that send air to gun Highly compressed air hits water and expands and then contracts and makes a controlled explosion Signal every 12 10 seconds Hydrophones to hear the return sound and how it changes Data produced shows if there is gas hydrocarbon on the seafloor 13 Do seismic air gun pulses travel far in the ocean If so what magnitude of distance can they travel Yes Kilometers Long distances 3900 km 14 Is there any evidence that any marine mammal might change any aspect of its behavior in the presence of seismic air gun activity Fin whales before survey number of calls higher than after the survey and they moved from where they wanted to be Sperm whales change in foraging rate massive reduction in buzz rate which indicates feeding reduced feeding as you move closer to the air gun array 15 Oil and gas seismic exploration in the mid Atlantic think about what some of the potential impacts are on marine mammals Is there the potential problem of cumulative effects Chronic stress smaller calf sizes Difficulty communicating for mating and feeding Disruption of migration pathways Disruption of body weight due to disruption of feeding Cumulative effects not much research done more needed