Marine Mammal Populations and Ocean Noise Determining When Noise Causes Biologically Significant Effects (2005) / Chapter Skim
Currently Skimming:
Appendix D: Draft Conceptual Plan for Workshop Discussion
Appendix D: Draft Conceptual Plan for Workshop Discussion
Pages 113-124
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 113... ...
Thus as human use of the oceans increased with a concomitant increase in anthropogenic sound in the ocean, the conflict with evolutionarily adapted marine animals sound sensing systems was inevitable. Over 90 percent of the global trade is transported by sea.
|
From page 114... ...
Although there are many documented, clearly discernable responses of marine mammals to anthropogenic sound, reactions are typically subtle, consisting of shorter surfacings, shorter dives, fewer blows per surfacing, longer intervals between blows, ceasing or increasing vocalizations, shortening or lengthening duration of vocalizations, and changing frequency or intensity of vocalizations. Although some of these changes become statistically significant in given exposures, it remains unknown when and how these changes translate into biologically significant effects at either the individual or the population level.
|
From page 115... ...
The goal of the NRC Committee on Characterizing Biologically Significant Marine Mammal Behavior is to develop a framework to relate short term acoustic dose:behavioral response relationships to potential population consequences. HISTORY OF NRC REPORTS The NRC has produced three reports on the effects of noise on marine mammals, in 1994, 2000 and 2003.
|
From page 116... ...
STATEMENT OF TASK The statement of task for the present NRC Committee, the Committee on Characterizing Biologically Significant Marine Mammal Behavior, picks up on two issues noted above: the difference between statistically significant and biologically significant changes in behavior; and linking those short-term behavioral changes to possible population level consequences. The term "biologically significant" enjoys wide use in conservation and management literature, and increasingly in regulatory agency guidelines, but has not been well defined.
|
From page 117... ...
GOAL, PROPERTIES AND OUTPUT Develop a conceptual framework and produce a practical process to help regulators assess the risk that specific acoustic sources will have negative impacts on a marine mammal population by disrupting normal behavioral patterns. Desirable properties of such a process include one that is: accurate; precautionary and becomes more precautionary with greater uncertainty in the potential population level effects of the induced behavioral changes; is simple and transparent to the public, legal staff, and congress; leads to an iterative process which will improve risk estimates as data improve; is able to evaluate cumulative impacts of multiple low level disturbances; and ends up with a small number of parameters that are easy to estimate.
|
From page 118... ...
Impacted to Factor demographic Function igration urturing Life M Feeding Breeding N Response Energy location, 2 and omeostasis/Risk X-Fcn H Time season, by weighted Change nfant relationships . Behavior rientation iving other-I oidance O Breathing Vocalizing D Resting M Spatial Av odeling M functions kshop 1 wor Transfer the X-Fcn Function at D-1 ed mation Cycle el TABLE eq uration uty emphasiz Sound Transfor Fr D Lev Source D
|
From page 119... ...
For the purposes of this report, we will need to develop a preliminary method to estimate the likelihood of population effect. SOUND Ocean acoustic sounds can have a wide range of effects on marine mammals varying from minor annoyances to potentially deleterious effects on a population level.
|
From page 120... ...
Among various parameters of acoustic signals that should be considered include bandwidth, frequency range, intensity, modulation type, modulation rate, duration and duty cycles need to be considered. However, at our current level of understanding there is little understanding how any of these parameters, whether individually or corporately can affect or modify marine mammal behavior.
|
From page 121... ...
The main costs of interference are risks of injury, opportunity costs due to not detecting a signal, and costs of lost time and extra energy expenditure. If a diving animal responds to sound in a way that pushes the limits of diving physiology, the behavioral response itself could cause injury.
|
From page 122... ...
The first two purposes derive directly from the statement of task, identifying biologically significant behavioral changes and linking those changes to population level effects. The third purpose is to assist regulators in determining the likelihood that a given stimulus will lead to a specific behavioral change affecting a defined biological function which results in a given change in an identified population parameter.
|
From page 123... ...
APPENDIX D 123 high, moderate or low. The Transfer Function Modeling expert group will help the committee turn this heuristic model into an operational one.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.