Acoustic Tagging of Large Sharks – Potential for Acoustic Interference
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CITIZEN SCIENCE – CS 05-11-17) Acoustic tagging of large sharks – Potential for acoustic interference (CS 05-11-17) – Kim Allen independent researcher Citizen science overview This paper is one of a series of unfunded, independent research initiatives that question mainstream science, Animal ethics approaches and Governments’ apparent acceptance of “Validated” science in the area of wildlife electronic tracking. Clearly, the Australian shark issue is extremely contentious as well as political and emotionally charged. Over $100 million has been expended by State and Federal governments in an attempt to find answers and make our beaches safer. Unfortunately, at no stage has a strategic approach been taken to identify the key disciplines of science that need to be considered, assessed, and applied. Significant investment has been directed into the construction and support of wide-scale acoustic receiver arrays and individual sensors as well as significant tagging of large sharks off our coastline for research and public safety. Previous satellite archival tagging programs conducted by CSIRO gave us good insight into shark movements, however since this time despite significant investment minimal progress appears to have been made and the potential risks appear to have been ignored. This CSIRO document clearly outlines the types of tags that are used for shark research, it also clearly defines the recommended protocols that should be used for shark tagging operations. From photographic details shared in the public domain it is clear that shark tagging operations undertaken by Fisheries departments don’t follow these stringent protocols. (www.cmar.csiro.au/e-print/open/2009/bradfordrw a.pdf ) It is extremely difficult for “Unqualified” Citizen scientists to challenge mainstream research particularly given the potential erosion of future funding sources if technical criticism is determined as valid. When any document is presented as a purely scientific paper, it will be challenged by scientists and regulators/politicians who will always “Listen to the science” regardless of its validity. Therefore, this series of information papers attempts to present a clear evidence and fact- based overview of the situation and poses relevant questions. Associated Citizen Science shark research papers – • Acoustic tagging of large sharks – Potential for behavioural changes (CS 06-11-17) • The effectiveness of acoustic tags for research and public safety (CS 03-11-17) • Shark repellents – The case for Australian standards certification (CS 11-09-17) • The effectiveness of above-water shark surveillance measures (CS 04-08-17) • The challenges of reliable underwater shark detection (CS 22-09-17) CITIZEN SCIENCE – CS 05-11-17) Document purpose Highlighting the fact that the “Precautionary Principle” is sometimes not considered when potentially damaging research interventions are used. Seeking the suspension and possible cessation of acoustic tagging for shark research and public safety. Highlighting the deficiencies and disparities of Animal ethics approvals across States and Territories. Ensuring that the existing Australian code for the care and use of animals for scientific purposes 8th edition is revised to accurately reflect the number of electronic devices used by researchers and the potential environmental impacts that they may have. Highlighting the need for underwater frequency management and monitoring, particularly in sensitive marine parks where scientists appear to undertake the most marine wildlife tagging. Demonstrating that there is a requirement to sometimes “Challenge” and not just “Listen to” the science! Undertaking research on wildlife is regulated in different ways across state and territory borders depending on whether the species is listed under the Animal welfare act (for that state or territory), there is also consideration applied if the species is protected under the Federal EPBC act. Finally, any research activities should seek and procure Animal ethics approval from a relevant panel informed by the Australian code for the care and use of animals for scientific purposes 8th edition1 which should cover all potential risks and consequences of any research interventions. Unfortunately, in the case of the “Tracking the movement of wildlife”, section 3.3.40 simply states “When devices are used to track the movement of wildlife, the weight, design and positioning of attached devices must minimise interference with the normal survival requirements of the animal”. Clearly given the advent and development of numerous electronic devices used extensively in the field by researchers these guidelines fall well short and provide no guidance or background to animal ethics panels to influence their judgements when approving research programs. In the case of large shark tagging programs, there are many significant potential issues arising. This document attempts to illustrate and unpack the key potential issues surrounding the use of long-term ultrasonic tracking tags on large sharks off Australian beaches. CITIZEN SCIENCE – CS 05-11-17) Introduction To understand the implications of using high-power ultrasonic pingers (tracking tags) for research purposes it’s important to consider the issues presented in the marine environment. What is an Acoustic tag A Coded acoustic tag is an electro-mechanical device that emits sequenced high frequency pulses every 60-90 seconds for up to 10 years. These pulses are pre-programmed to represent a unique ID code like a telephone number to identify the aged animal. Acoustic pinger tag External attachment – Surgical implant Construction of acoustic tag The tag is powered by a Lithium polymer battery that energises some electronics (oscillator) to power a ceramic “transducer” that acts like a loudspeaker. This transducer physically vibrates to create the ultrasonic pulses at 69,000 cycles per second (69KHz). CITIZEN SCIENCE – CS 05-11-17) The power levels of these tags ensure that receiver units can detect them up to 400-500 metres away, of course depending on the hearing sensitivity of certain marine mammals these tags could be heard much further away. In summary – The use of these coded tags with a 10-year battery life in the open ocean should deserve special attention! Sound in the ocean Unlike land-based species, marine animals place a high degree of dependence on sound for communicating, predation and navigation. Sound travels around 5 times faster underwater than it does on land. So, its clear to see that anything related to sound underwater requires careful consideration in relation to marine ecology. On land, we have strict regulations regarding radio frequencies and how they are used, in fact we have a government agency2 managing and policing allocated frequencies. Interestingly, land-based species don’t user or rely on these frequencies to survive this is mainly in force for safety and providing structure to ensure that communications remain reliable. Unfortunately, underwater there are no such rules and regulations to monitor and control emissions that can and do have significant impacts on marine species (particularly marine mammals). A range of impulsive noise emitting sources are always considered including defence sonar, seismic surveys, pile driving, dredging and vessel noise. However, the advent of acoustic tags which introduce a periodic noise emission for up to 10 years has not been considered by the regulators. Ultrasonic acoustic tracking tags have been used extensively by research scientists and fisheries agencies for over a decade. Australian researchers are one of the major users of this type of technology for shark (and other marine species) research. It’s important to consider that acoustic tags are electro-mechanical devices that are either attached to or implanted into large sharks for research purposes. Over the last few years, government agencies have attempted to re-purpose and promote this research approach as an enhanced public safety measure to make our beaches safer. CITIZEN SCIENCE – CS 05-11-17) The issues to consider Prior to the production this document, all avenues were explored including comprehensive collaboration with marine acoustics experts to debate and validate concerns raised. For many years fish tagging has served a useful purpose, mainly through the use of plastic numbered tags that were recovered from time to time allowing coarse scale movement and other research data to be collected. On-land, radio and GPS tracking have been successful providing valuable insights into animal movements. Unfortunately, radio waves don’t travel well underwater, so these types of tracking have not been successful. Therefore, the two technologies considered are acoustic and satellite tags. In the case of satellite tags, they are used in two ways to provide periodic positioning of tagged animals. Over the years acoustic tagging of small fish in freshwater environments has been extremely successful. This has been for the following reasons: • The detection ranges are typically small – Across a river for example • Freshwater sound propagation is much better than salt water • High frequency tags can be made much smaller than the lower frequency tags meaning they can be inserted in smaller fish. • The typical frequency used around 400KHz is too high to have any potential for interference with any other wildlife. When ocean-based long term acoustic tracking was considered, the frequency range selected was around 70KHz which although propagating well through open water also happens