11th ICRS Abstract book - Nova Southeastern University

Oral Mini-Symposium 16: Ecosystem Assessment and Monitoring of Coral Reefs - New Technologies and Approaches
16-30
Listening To The Reefs Of Oman: Can Sound Be Used As A Predictor Of Marine
Fauna?
Mark PRIEST* 1 , Stephen SIMPSON 2 , Jenny MCILWAIN 1 , Andrew HALFORD 1
1 University of Guam, Mangilao, Guam, 2 University of Edinburgh, Edinburgh, United
Kingdom
Coral reefs are noisy places which can be detected from 10’s of kilometres away. A
cacophony of sound is produced by a variety of reef dwelling organisms; fish drum on
their swim bladders and grind their teeth, urchins scrape across algae covered rocks, and
snapping shrimp implode bubbles of air fired from their claws. Settlement-stage reef fish
have been shown to respond to reef noise, implying it is not haphazard, and transfers
useful information regarding the surrounding environment. If we can decipher nature’s
song what will we are able to learn from the tune?
The coastal waters of Oman contain an unusual variety of reef habitats, both tropical and
temperate in nature. We used a hydrophone to record the sounds of differing reefs,
spanning the Arabian Sea and Gulf of Oman, and used standard UVC techniques to
assess the fish assemblages and benthic communities. Reef noise proved to be consistent
over time and varied in composition between geographic locations, with each site
producing unique sound profiles. This was also the case for fish and benthic
communities, which also showed remarkable levels of dissimilarity. We investigate the
degree to which properties of reef noise can be translated and used to predict reef
quantity, quality, and species composition. Results suggest this is possible and with
further refinement sound may have an application as a monitoring tool.
16-31
Coral Reef Soundscapes: The Underwater Acoustic World From A Larval Reef
Fish’s Perspective
Adel HEENAN* 1 , Stephen SIMPSON 1 , Mark PREIST 2 , Emma KENNEDY 3 , Chantal
HUIJBERS 4 , Ivan NAGELKERKEN 4 , Victoria BRAITHWAITE 5
1 The University of Edinburgh, Edinburgh, United Kingdom, 2 University of Guam,
Mangilao, Guam, 3 Heriot-Watt University, Edinburgh, United Kingdom, 4 Radboud
University Nijmegen, Nijmegen, Netherlands, 5 Penn State University, University Park,
PA
Previous work in temperate and tropical marine reef systems has found that larval fish are
attracted to generic biological reef noise during settlement (the period of transition from
the plankton to the reef benthos which precedes metamorphosis into the adult form). As
we develop our understanding of how sound functions in larval coral reef fish navigation,
a more intriguing and complex picture unfolds. Larval fish are able to detect and locate
sound sources and distinguish between artificial sounds and those they would encounter
in their natural environment. Furthermore, fish larvae are selectively attracted to different
components of reef noise, dependent on their life history stage. After presenting an
overview of the behavioural function sound plays in the settlement process of coral reef
fish, the focus of the talk will shift towards the actual acoustic environment of the reef,
and what information this could potentially portray to a settlement stage fish. The results
of a worldwide study of reef noise shall be presented, where we compared different
tropical habitats in Curaçao and Aruba (reefs, mangroves, seagrass), different quality
habitats in the Philippines (pristine, protected, overfished, decimated), and different
periods of the lunar cycle at Lizard Island. Reef noise is mainly biological noise
produced by resident fish and invertebrates, as such it is a clear indicator of reef type,
quality, and even species composition and density. Sound is transmitted at intensities
above ambient levels for kilometres, and would be audible by fishes and other migrating
animals. This work highlights the value of reef noise as a cue for larval fish orientation
and habitat discrimination. It also suggests that through human activity altering the
natural soundscapes around reefs, there is a whole suite of anthropogenic impacts on
marine systems that are currently poorly understood and largely unmitigated.
16-32
Passive Acoustic Mapping Of Grouper Aggregation Sites
David MANN* 1 , James LOCASCIO 1 , Michelle SCHARER 2 , Michael NEMETH 2 , Richard
APPELDOORN 2
1 College of Marine Science, University of South Florida, St. Petersburg, FL, 2 Dept. of Marine
Sciences, University of Puerto Rico-Mayaguez, Mayaguez, Puerto Rico
Many fishes, including groupers, drums and damselfishes, produce sounds associated with
mating behaviors. Passive acoustic techniques can provide synoptic, long-term time series of
sound production associated with reproductive activities of these species at widely spaced sites.
Passive acoustic techniques were used to study the behavior of red hind (Epinephelus guttatus)
at spawning aggregation sites off the west coast of Puerto Rico and Mona Island, Puerto Rico.
Underwater video cameras with hydrophones were used to record red hind behavior along with
sound production. Male red hind produced sounds composed of a series of pulses that graded
into a tonal-like sound, with most of the energy below 400 Hz. Most sound production took
place during apparent patrolling of male territories. Sound production was also recorded during
interactions of males with females. Not all interactions, including male-male interactions at the
edges of territories, involved sound production. Long-term acoustic recorders (LARS) were
used to record sound production for longer periods of time than could be accomplished with the
underwater video. Two LARS were deployed on previously identified red hind aggregation
sites on the west coast of Puerto Rico and five LARS were deployed on Mona Island from
January-March 2007. Analysis of LARS data from the west coast of Puerto Rico and Mona
Island showed similar diel periodicities of sound production, but the two sites had different
peaks in sound production during the month. These results demonstrate the potential of passive
acoustics for mapping spawning aggregation sites of soniferous species over large spatial and
temporal scales.
16-33
Utilizing Acoustic Data in Establishing Reef Fish Recruit Abundance
Victor TICZON* 1 , Badi SAMANIEGO 2 , Greg FOSTER 3 , Sonia BEJERANO-CHAVARRO 4 ,
Eileen PENAFLOR 1 , Shiela MARCOS 5 , Joseph Dominic PALERMO 1 , Peter MUMBY 4 , Laura
DAVID 1
1 Ocean Color and Coastal Oceanography Lab, The Marine Science Institute, University of the
Philippines-Diliman, Quezon City, Philippines, 2 Apercu Consultants Inc., Makati City,
Philippines, 3 National Coral Reef Institute, Nova Southeastern University, Fort Lauderdale-
Davie, FL, 4 Marine Spatial Ecology Laboratory, University of Exeter, Devon, United Kingdom,
5 National Institute of Physics, University of the Philippines-Diliman, Quezon City, Philippines
Reef fish recruitment patterns have been observed to be strongly dependent on the physical and
biological habitat features of the reef. The reefs’ habitat structure mediates the process of
predation and competition by providing refuges and resources for settling recruits. Overall, the
study aims to (1) determine the influence of rugosity and shelter features on the diversity and
abundance of reef fish recruits and, (2) generate reef fish recruit diversity and abundance map
of Ngaderrak Reef, Republic of Palau. Fish visual census, habitat classification, and shelter
dimension measurements of major habitats, were conducted in Ngaderrak reef, and, Puerto
Galera and Anilao, Philippines. Acoustic habitat mapping was only conducted in Ngaderrak.
While the first three tasks were conducted in specific detail for ecological analysis, the
Biosonics DTX was used to generate broad scale spatial information on habitat type, rugosity
and shelter features of the entire reef area of Ngaderrak. Preliminary results show higher recruit
abundance in the more physically complex microhabitats. This corroborates past studies which
reflects correlation between reef fish recruit abundance and diversity with substrate complexity.
The strong correlation with reef fish recruit abundance and the physical characteristics of the
reef supports the use of remote sensing techniques such as Acoustic Ground Discrimination
Systems (AGDS), to spatially characterize habitat features of the reef and possibly, identify
areas with high recruitment potential based on the physical structure of the substratum. Acoustic
survey results demonstrate the ability of AGDS to distinguish microhabitats based on the
physical structure of the corals, rugosity, and substrate hardness. However, initial results show
that habitat information derived from acoustic remote sensing was limited to structures with
notable vertical relief. Acoustic mapping accuracy of benthic microhabitat features remains to
be determined using geo-referenced video-transects of the study area.
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