12th International Coral Reef Symposium 9-13 July 2012 • Cairns • Queensland • Australia
Book of Abstracts
www.icrs2012.com
Theme 13. Fish & fisheries
ranging across several size classes, were collected using trammel net, spear gun, and hand net. The differences in standard length between individuals in a pair, were less than 12.0 mm, indicating individuals are biased towards choosing a mate of a similar size. Using sections of otolith, the maximum age for female and males were estimated to be 19 and 17 years, respectively. No difference in growth patterns could be detected between males and females, and fish older than 4 years didn't grow noticeably. Pair forming appeared first at an age of 2 years. Females and males didn't choose partners randomly, and the differences between partners’ ages were generally less than 2 years (0-1 years difference: 51.9%; 0-2 years difference: 77.8%); only a few pairs had large age gaps, up to 7 years. We suggest that C. vagabundus maintain their partner for a lifetime, and changes of partner only occurred when a partner was lost. This lifecycle strategy has the risk of missing the chance to gain a more competent partner. On the other hand, the fish minimises energy use for selection and competition for partners, among the same species. 13A Fish Tuesday 10 July, 1545, Hall A
Life history characteristics of Picasso triggerfish, Rhinecanthus aculeatus 1
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KĂźnzli, Fabienne , Katsunori Tachihara fabienne.kuenzli@bluewin.ch 1 Graduate School of Engineering and Science, University of the Ryukyus, 1 Senbaru, Okinawa, Japan 2 Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0121, Japan The strikingly colored Picasso triggerfish, R. aculeatus is distributed in tropical and subtropical waters around the world and is strongly associated with coral reefs. On Okinawa Island, R. aculeatus is one of the most abundant species of the family Balistidae. Adults establish territories in reef flats with males maintaining up to several females. The spawning behavior has previously been reported but nothing is known about detailed life history characteristics. The purpose of this study was to describe age and growth from sections of dorsal spine and abdominal vertebra. To understand the reproductive biology, gonads were histologically analyzed. Mature individuals occurred from May to September, while the gonadosomatic index peaked in June and July. These results indicate that the spawning period was restricted to the warm season. Fish ranged between 20.9 and 209.5 mm in standard length, with males attaining larger sizes. Annual growth marks consisted of opaque-translucent band depositions. Small recruits were found from August in the rocky intertidal shore area.
Settled recruits formed a first translucent band during the following cold season and were therefore aged 0.5 years old. The von Bertalanffy growth equation was fitted for observed length-at-age data. Maximum age for females and males was 8.5 and 9.5 years, respectively. Picasso triggerfish are viewed as one of the most successive and competitive balistids inhabiting the coral reefs of Okinawa Island. The territorial behavior, mating system and feeding habit may favor longevity, since this fish is capable of establishing territories over many years. 13A Fish Tuesday 10 July, 1715, Hall A
Description of different color displays of Goliath Grouper on aggregations in Santa Catarina, Brazil 1
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Leite, Jonas , Leonardo Bueno , Johnatas 2 3 4 Alves , Felippe Daros , Athila Bertoncini , 5 6 Fabiano Grecco , Maurico Hostim-silva , 7 Jamile Benica jonasipaq@yahoo.com.br 1 PPGOAM - UFES 2 PPGSAT - UESC 3 PGSISCO- UFPR 4 ECOPESCA - UFF 5 PPGECO - UFPR 6 CEUNES - UFES 7 Instituto COMAR Several studies around the world show that fishes from the Serranidae family display body color variations, as a tool to communicate and socialize with others fishes of the same species. These variations are more common during aggregations. The rarity, and the difficulty of observing an Epinephelus itajara aggregation, could be the reason that the different color displays of the Goliath grouper have not yet been described. The 'Meros do Brasil' project have been studying an E. itajara aggregation in southern Brazil for the last four years. During dives, the researchers recorded seven different color patterns displayed by individuals, standard, fully dark, fully light, dark body with light head, dark back and light belly, light bars, and divided face half dark half light. In addition, some instantaneous colour changes were observed. 13A Fish P114
Sampling reef fish communities in the remote waters of Micronesia 1
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Lindfield, Steve , Brett Taylor , Jennifer 3 1 McIlwain , Euan Harvey steve.lindfield@yahoo.com 1 University of Western Australia 2 James Cook University 3 University of Guam Marine Laboratory
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Theme 13. Fish & fisheries
experiments and indicated fish are highly selective between individual Acropora species. The relationship between corallivore prey choice and fitness maximisation is poorly understood. This relationship was examined by comparing condition and reproductive output of O. longirostris breeding pairs maintained on exclusive diets of a preferred vs. non preferred Acropora species. Body condition of fish maintained on preferred coral was significantly better than those fed non-preferred prey. This directly affected reproductive output as pairs fed non-preferred coral did not breed. This suggests that the quality of coral as a dietary resource can vary markedly between species and patterns of prey selectivity reflect these differences. Increasing anthropogenic disturbance is predicted to decrease coral cover and diversity on reefs. The striking differences in fitness observed suggests that, while fish may have the ability to consume a variety of corals, loss of key individual species will have direct negative effects for associated corallivore populations. 13C Ecological effects of habitat degradation Thursday 12 July, 1745, Hall A
Responses of reef fish communities to large-scale habitat perturbations 1
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Brooks, Andrew , Russell Schmitt , Sally 1,2 1 4 Holbrook , Thomas Adam , Peter Edmunds , 3 Libe Washburn brooks@msi.ucsb.edu 1 Coastal Research Center, Marine Science Institute, UC Santa Barbara, CA, USA 2 Dept. of Ecology, Evolution and Marine Biology, UC Santa Barbara, CA, USA 3 Interdepartmental Graduate Program in Marine Science, UC Santa Barbara, CA, USA 4 Department of Biology, CSU Northridge, CA. USA Our ability to predict how communities of coral reef fishes will change in response to habitat alteration depends strongly on understanding the functional relationships of component species with live coral and reef structure, together with how these aspects are shaped by wave exposure and various perturbations. The forereefs of Moorea, French Polynesia, have experienced two ecologically significant pulse perturbations since 2007; a wide-scale COTS outbreak that severely reduced the cover of live coral around the island, followed by a cyclone that reduced the structural complexity of the forereef along Moorea's north shore by removing much of the dead coral. Prior to these disturbances, the fish assemblages on the forereef demonstrated consistent spatial differences in species composition that were related to differences in the wave energy incident to different localities around the island. Following the disturbances, fish communities at these localities responded in a consistent fashion independent of the initial species
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composition. Fish species strongly associated with living corals declined island-wide, and assemblages found along the usually less wave impacted north shore became more similar to those found along the more wave impacted southwestern shore. Surprisingly, fish species richness remained virtually unchanged and the total biomass of fishes increased. This counter-intuitive response resulted from the replacement of small, coral dependent species by larger-bodied, coral rubble associated species and an island-wide increase in the abundance and biomass of herbivores. 13C Ecological effects of habitat degradation Thursday 12 July, 1530, Hall A
The Goliath Grouper (Epinephelus itajara) escape from fishing in Santa Catarina, southern Brazil 1
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Bueno, Leonardo , Jonas Leite , Johnatas 2 3 4 Alves , Felippe Daros , Athila Bertoncini , 5 6 Fabiano Grecco , Maurico Hostim-Silva , 7 Jamile Benica lecobueno@hotmail.com 1 PPGOAM - UFES 2 PPGSAT - UESC 3 PGSISCO- UFPR 4 ECOPESCA - UFF 5 PPGECO - UFPR 6 CEUNES - UFES 7 Instituto COMAR The Goliath grouper occurs along the Atlantic west coast, from Florida to Santa Catarina, and in the west of Africa; inhabiting coral and artificial reefs, rocky shores and mangroves. Its slow growth and reproductive rates, and its group spawning behavior, make it particularly vulnerable to overfishing. In Brazil, the decline of populations, the loss of mangrove habitat and lack of data on the species, have resulted in maintenance of the regulation that has prohibited the harvesting of Goliath groupers since 2002. Globally, relatively little work has been conducted on spawning aggregations and few sites have been the specific focus of monitoring and management activities. In Brazil, the “Meros do Brasil” project has obtained information from old fishermen about specific historical locations of Goliath grouper aggregations in Santa Catarina state. Since 2007, diving researchers of the project have been monitoring the sites “Ilha dos Lobos” Island, Tamboretes and Graças archipelagos, and Monobóia artificial reef, which were indicated by the fishermen as having a high frequency and number of E. itajara aggregations. Over four years of research, only the Monobóia, an artificial structure used by petroleum ships to unload, which is protected by Brazilian Navy and is almost free of fishing, had a Goliath grouper aggregation, with more than 45 individuals. At the island sites, only four specimens were observed together at the same time in all the years of in-water observation, a
Theme 13. Fish & fisheries
very different result from the thirty individuals related by the old fishermen. This evidence indicates a refuge for the fish at Monob贸ia, where they do not suffer from fishing. 13C Ecological effects of habitat degradation P123
Modeling the impact of decreasing coral reef complexity on fish distributions 1
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Caldow, Chris , Simon Pittman , Bryan 1 Costa chris.caldow@noaa.gov 1 Biogeography Branch, National Ocean Service, NOAA 2 University of the Virgin Islands, St. Thomas, USVI Coral reef ecosystems exhibit complex vertical and horizontal structural heterogeneity at a range of spatial scales. This heterogeneity plays an important ecological role in influencing the distribution, abundance and behavior of marine organisms. Shallow-water coral reefs, however, are proving vulnerable to rapid environmental change. Topographic complexity of Caribbean coral reefs is reported to have declined by 50% during the last 40 years. This 'flattening' of seafloor structure is likely to continue due to stress from land-based sources of pollution, hurricanes and climate change that combine to degrade coral reefs. Loss of topographic complexity will have major consequences for fish communities because suitable habitat disappears or is impaired with suboptimal ecological function. Ecological impacts will need to be anticipated to ensure that management actions are well targeted and that expectations for recovery after protection are ecologically realistic. To address this crucial knowledge gap, we modeled the distribution of several fish species under a range of reef flattening scenarios for a shallowwater coral reef ecosystem in southwestern Puerto Rico. Preliminary results show that the area of suitable habitat for several common fish species contracted and then fragmented across the seascape. We highlight species-specific vulnerability to loss of structural complexity. Our forecasting techniques provide resource managers with spatially-explicit information that can help anticipate future changes to essential fish habitat, fisheries catch, marine protected area performance, biodiversity patterns and population viability of endangered species associated with coral reef ecosystems. 13C Ecological effects of habitat degradation Thursday 12 July, 1545, Hall A
Cardiorespiratory physiology and energetics of reef fishes Clark, Timothy timothy.clark.mail@gmail.com
Australian Institute of Marine Science, PMB 3, Townsville MC, Australia 4810 Reef fishes are experiencing a changing environment. Water temperatures are progressively increasing in many locations around the world, and the oceans are becoming more acidic. While much research focuses on the role of coral health and reef structure in determining the resilience of reef fishes to climate change, little is known of the direct impacts of temperature and acidification on fish populations. Indeed, it is possible that some fish species will prove less resilient to climate change than the corals that surround them. This presentation outlines how climate change directly influences the physiology of reef fishes and thus their capacity to function and survive. Using large (coral trout) and small (pomacentrids) species as models, this presentation highlights how a fundamental process - oxygen transport from the environment to the tissues of the body - may underlie interspecific differences in resilience to environmental change. 13C Ecological effects of habitat degradation Friday 13 July, 1000, Hall A
Recovery of fish communities following habitat degradation 1,2
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Coker, Darren , Nicholas Graham , Morgan 1 Pratchett darren.coker@my.jcu.edu.au 1 ARC Centre of Excellence for Coral Reef Studies, James Cook University 2 AIMS@JCU, Australian Insititute of Marine Science Corals reefs are subjected to multiple disturbances that impact levels of coral cover and the complexity of the reef matrix, and in turn influence the structure of associated fish communities. With disturbances predicted to increase, an understanding of how impacts, through the change in substrate health, will influence the recruitment of many fishes, is essential for understanding the recovery of reefs following biological and physical disturbances. While studies have revealed that live coral and habitat complexity is important for many recruiting fishes, there is a lack of evidence stating how a combination of changes will impact the recruitment of fishes. By using manipulated man-made patch reefs consisting of 6 different habitat treatments; 3 levels of live coral cover (high, medium, low) crossed with 2 levels of habitat complexity (high, low), we were able to investigate the independent and combined effect of varying levels of live coral cover and structural complexity on the recruitment and recovery of fish communities. Our results show that there were little differences in abundance and species richness between the 6 habitat treatments. Although, we found using multivariate techniques, significant
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