dc.contributor.advisor |
Jeffs, Andrew |
en |
dc.contributor.author |
Radford, Craig A |
en |
dc.date.accessioned |
2011-06-19T22:22:10Z |
en |
dc.date.available |
2011-06-19T22:22:10Z |
en |
dc.date.issued |
2007 |
en |
dc.identifier.citation |
2007 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/6829 |
en |
dc.description.abstract |
Underwater sound may act as an orientation cue for guiding the long range movements of the
larvae of some fishes and crabs toward suitable settlement habitats on the coast. Experimental
evidence for this claim has been hard to secure due to the virtual impossibility of controlling
sound in experimental aquaria, and difficulties of conducting field experiments. However, a
number of different approaches, including the use of diver observation, have found behavioural
evidence in support of orientation to underwater sound. The present study examined the use of in
situ SCUBA observations as a research tool, and found it produced high intensity noise in the
frequency range to which fish and decapods are most sensitive. These findings raised questions
about the appropriateness of diver observation as a tool. Consequently, an in situ behavioural
binary choice chamber was used to demonstrate that crab post-larvae of five species showed an
orientation response toward a sound cue. These results add to earlier behavioural data indicating
that acoustic orientation could be of considerable ecological importance in influencing the
settlement success of coastal fish and crustaceans.
Evaluation of the importance of sound as an orientation cue also requires a better characterisation
of reef sound. A systematic investigation into the temporal and spatial (scales< 2 km) variation
of ambient underwater sound in a shallow coastal environment found there were remarkable
daily, lunar and seasonal variation in ambient underwater noise power levels. Dusk was the
loudest time of day, the new moon was significantly louder than the full moon, and summer was
the loudest season. Snapping shrimp are a ubiquitous source of ambient underwater noise
between 5 - 20 kHz, with the number of snaps produced having the same significant daily, lunar
and seasonal variations as the power levels. Snapping shrimp activity also varied between habitat
types. Additional to snapping shrimp sounds, there was a significant rise in intensity between
500 - 3000 Hz caused by an unknown source. Laboratory experiments provided conclusive
evidence that Evechinus chloroticus produce feeding noises in this frequency band, while field
recordings from different reefs indicated power level in this frequency band reflected the size
frequency and density of E. chloroticus populations. These results highlight the potential importance of sea urchins as a significant source of biological noise in temperate shallow coastal
waters.
Overall, the results have provided additional behavioural evidence for the orientation of
crustacean to reef sound, and significantly extended our understanding of reef noise
characteristics and origins. It is argued that the temporal, spatial and biological characteristics of
ambient underwater sound could play a significant role in structuring coastal communities. |
en |
dc.publisher |
ResearchSpace@Auckland |
en |
dc.relation.ispartof |
PhD Thesis - University of Auckland |
en |
dc.relation.isreferencedby |
UoA99179378514002091 |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.rights.uri |
http://creativecommons.org/licenses/by-nc-sa/3.0/nz/ |
en |
dc.title |
Ambient underwater sound : understanding its origins, variations and biological role |
en |
dc.type |
Thesis |
en |
thesis.degree.discipline |
Biological Science |
en |
thesis.degree.grantor |
The University of Auckland |
en |
thesis.degree.level |
Doctoral |
en |
thesis.degree.name |
PhD |
en |
dc.date.updated |
2011-06-17T00:24:04Z |
en |
dc.rights.holder |
Copyright: The Author |
en |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/OpenAccess |
en |
dc.identifier.wikidata |
Q111963664 |
|