Sea Mammal Monitoring
The effects of noise on aquatic life are one of the big unknowns of current marine science. The current state of uncertainty combined with the potential for future consequences has led some to take a precautionary view within the legislation. The human contribution to ocean noise has increased during the past few decades with human noise becoming the dominant component of marine noise in some regions. This noise is directly correlated with the increasing industrialization of the ocean. Sound is an important factor in the lives of many marine organisms and the human additions to ocean sound overlap the full range of animal uses for sound in the ocean.
Theories and increasing observations suggest that man-made noise could be approaching levels at which negative effects on marine life may be occurring. Researchers need to identify the thresholds of such effects for each marine species and predict how increasing anthropogenic sound will enhance the effects. Researchers need to examine the functional relationship between sound and the viability of key marine organisms. Researchers and scientists are using passive acoustic monitoring in the form of hydrophones to study marine mammals.
Ocean Observatories are being developed and deployed by researchers, scientists and institutions around the world’s oceans. Some observatories are cabled, some are moored, and some are made up of surface buoys. The Ocean Networks Canada Observatory, comprising VENUS and NEPTUNE Canada cabled networks, supports transformative coastal to deep ocean research and technology. It enables real-time interactive experiments, focused on ocean health, ecosystems, resources, natural hazards, and marine conservation. Currently, there are two icListen High-Frequency Smart Hydrophones and one icListen Low-Frequency Smart Hydrophone on NEPTUNE, and one icListen Low-Frequency Smart Hydrophone on VENUS. The cabled network is a 24/7 connection to the seafloor which enables researchers to constantly observe the ocean in real-time. The data is considered real-time because within seconds of it being collected it is streamed online which allows scientists, researchers, and the public the opportunity to access and analyze the data so they can see for themselves the changes in ocean properties.
The successful detection and tracking of sources of underwater noise are of particular interest for both the monitoring of marine life, as well as for reducing potential threats to port and harbour security. The use of passive acoustics is a cost-effective solution to the monitoring of unidentified underwater targets, whether hostile, friendly or purely environmental.
Underwater acoustics is used in the interest of having an undetectable surveillance system. A common method used for passive acoustics in the detection and tracking of targets is the utilization of hydrophones, hydrophone arrays, and radio buoys. If real-time data is needed the Ocean Sonics GSM Radio Buoy can supply instrument power and a link if cables are not possible. This link sends hydrophone data over the Internet to the user’s desktop.
“Ocean Networks Canada performed a wide range of tests on the hydrophones prior to deployment to verify the manufacturer’s specifications. The hydrophone instruments met all the manufacturer’s specifications and were easy to use. Both models satisfy our requirements for dynamic range, sensitivity and, most importantly, reliability. When coupled with the fast and friendly customer support we have received, these LF and HF hydrophones are a good choice for our ocean observatory.”Tom Dakin Sensor and Technology Business Development Officer and Resident Ocean Acoustician Ocean Networks Canada
“We have been working with Ocean Sonics in our technology demonstration program since the first prototypes. Our science users have been very impressed with the very high quality data sets. Ocean Networks Canada is expanding our hydrophone network with Ocean Sonic icListen HF smart hydrophones across our observatory including new sites across coastal BC, as part of the Smart Oceans™ program. The compact size, Ethernet interface, high reliability and exceptional performance make these systems ideal for ocean observing applications such as mammal classification, vessel and ambient noise studies.”Scott McLean Director(Former) Ocean Networks Canada
“I have used many different hydrophones on different systems, but these icListen hydrophones are the best I’ve seen in many years. They’re calibrated to very low frequencies where I’ve never been able to get reliable data.”
Ross Chapman Professor Emeritus University of Victoria
The Ocean Observatories Initiative (OOI) Regional Scaled Nodes (RSN) had requirements for very broadband hydrophones with good noise floor characteristics and a wide dynamic range. The icListen HF hydrophones satisfied these requirements at a reasonable cost. The hydrophones were quite easy to use out of the box, and easily passed our intensive First Article tests centered on assuring any instrument will not interfere with or corrode any other instrument. Customer support has been quite good, with very detailed questions answered quickly and accurately.
Skip Denny Principal Ocean Engineer, RSN Applied Physics Lab, University of Washington.