Spatial assemblage structure of shallow-water reef fish in Southwest Australia

2020 ◽  
Vol 649 ◽  
pp. 125-140
Author(s):  
DS Goldsworthy ◽  
BJ Saunders ◽  
JRC Parker ◽  
ES Harvey
Keyword(s):  
Shallow Water ◽  
Reef Fish ◽  
Marine Environment ◽  
Fish Assemblages ◽  
Canopy Cover ◽  
Reef Fishes ◽  
Reef Fish Assemblage ◽  
Reef Type ◽  
Present Distribution ◽  
Southwest Australia

Bioregional categorisation of the Australian marine environment is essential to conserve and manage entire ecosystems, including the biota and associated habitats. It is important that these regions are optimally positioned to effectively plan for the protection of distinct assemblages. Recent climatic variation and changes to the marine environment in Southwest Australia (SWA) have resulted in shifts in species ranges and changes to the composition of marine assemblages. The goal of this study was to determine if the current bioregionalisation of SWA accurately represents the present distribution of shallow-water reef fishes across 2000 km of its subtropical and temperate coastline. Data was collected in 2015 using diver-operated underwater stereo-video surveys from 7 regions between Port Gregory (north of Geraldton) to the east of Esperance. This study indicated that (1) the shallow-water reef fish of SWA formed 4 distinct assemblages along the coast: one Midwestern, one Central and 2 Southern Assemblages; (2) differences between these fish assemblages were primarily driven by sea surface temperature, Ecklonia radiata cover, non-E. radiata (canopy) cover, understorey algae cover, reef type and reef height; and (3) each of the 4 assemblages were characterised by a high number of short-range Australian and Western Australian endemic species. The findings from this study suggest that 4, rather than the existing 3 bioregions would more effectively capture the shallow-water reef fish assemblage patterns, with boundaries having shifted southwards likely associated with ocean warming.

scholarly journals Coral settlement and recruitment responses to reef fish foraging and trait diversity

2021 ◽  
Author(s):  
Cher F Y Chow ◽  
Caitlin Bolton ◽  
Nader Boutros ◽  
Viviana Brambilla ◽  
Luisa Fontoura ◽  
...  
Keyword(s):  
Reef Fish ◽  
Fish Assemblages ◽  
Reef Fishes ◽  
Foraging Strategies ◽  
Coral Recruitment ◽  
Coral Settlement ◽  
Trait Divergence ◽  
Positive Effects ◽  
Recruitment Success ◽  
Trait Diversity

The process of coral recruitment is crucial to the healthy functioning of coral reef ecosystems, as well as recovery following disturbances. Fishes are key modulators of this process by feeding on algae and other benthic taxa that compete with corals for benthic space. However, foraging strategies within reef fish assemblages are highly diverse and the effect of foraging diversity on coral recruitment success remains poorly understood. Here, we test how the foraging traits of reef fishes affect coral settlement and juvenile success at Lizard Island, Great Barrier Reef. Using a multi-model inference approach incorporating six metrics of fish assemblage foraging diversity (foraging rates, trait richness, trait evenness, trait divergence, herbivore abundance, and benthic invertivore abundance), we found that herbivore abundance had positive effects on both coral settlement and recruitment success. However, foraging trait diversity had a negative effect on coral settlement but not on recruitment. Coral settlement was higher at sites with less trait diverse fish assemblages, specifically in trait divergence and richness. Moreover, these two trait diversity metrics were stronger predictors of coral settlement success compared to herbivore abundance. Our findings provide evidence that impacts mediated by fish foraging on coral juveniles can potentially be harmful during settlement, but the space-clearing effect overall remains advantageous. We show here that the variation of fish biodiversity across reefs can be a partial driver to spatially uneven patterns of coral recruitment and reef recovery.

Evaluation of the effect of closed areas on a unique and shallow water coral reef fish assemblage reveals complex responses

Coral Reefs ◽  
2014 ◽  
Vol 33 (3) ◽  
pp. 579-591 ◽  
Author(s):  
G. Shedrawi ◽  
E. S. Harvey ◽  
D. L. McLean ◽  
J. Prince ◽  
L. M. Bellchambers ◽  
...  
Keyword(s):  
Coral Reef ◽  
Shallow Water ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Fish Assemblage ◽  
Reef Fish Assemblage ◽  
Water Coral

scholarly journals Olfactory responses of coral-reef fishes to coral degradation and crown-of-thorns (Acanthaster planci)

2016 ◽  
Vol 67 (5) ◽  
pp. 605 ◽  
Author(s):  
Amy G. Coppock ◽  
Naomi M. Gardiner ◽  
Geoffrey P. Jones
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Chemical Cues ◽  
Fish Assemblages ◽  
Reef Fishes ◽  
Live Coral ◽  
Acanthaster Planci ◽  
Olfactory Responses ◽  
Olfactory Stimuli ◽  
Coral Reef Ecosystems

Coral degradation is a major threat towards the biodiversity of coral-reef ecosystems, either through the physical effects of environmental change, or biological agents such as crown-of-thorns (Acanthaster planci). Coral loss is leading to significant declines in reef-fish assemblages, particularly those dependent on live coral as settlement sites. Most reef fishes use olfactory stimuli at settlement; however, their ability to detect chemical stimuli from degraded corals or A. planci is unknown. Here, olfactory responses of juvenile reef fishes to the presence of stressed corals and A. planci were tested. Juveniles of eight common coral-associated species were subjected to a series of pair-wise choice tests, where the period of time spent in two differing water sources was noted. All species demonstrated a significant attraction towards healthy coral (≥76%), avoiding cues emitted by stressed coral colonies. When given the choice between a control water (untreated reef water) and water containing chemical cues from A. planci, most species elicited no response. Finally, when given the choice between chemical cues derived from feeding A. planci or the control, all species avoided A. planci (≥70%). Our results indicated that juvenile reef fish are capable of distinguishing the state of coral health, but not directly from disturbance agents.

scholarly journals The influence of depth on the Mediterranean reef fish assemblage revealed by the new video on underwater scooter method

2020 ◽  
Vol 61 (2) ◽  
pp. 145-162
Author(s):  
Igor Glavičić ◽  
Marcelo Kovačić ◽  
Dejan Paliska ◽  
Dani Laslo
Keyword(s):  
Reef Fish ◽  
Fish Assemblage ◽  
Environmental Variables ◽  
Fish Assemblages ◽  
Average Density ◽  
Depth Range ◽  
Fish Assemblage Structure ◽  
Visual Census ◽  
Reef Fish Assemblage ◽  
Significant Difference

The new video on underwater scooter method in combination with rebreather diving techniques was introduced and applied for visual census of fish assemblages. The presently applied method facilitates deeper visual census studies below 40 m, where they have rarely been done before due to the increasing research challenges with depth. The video on underwater scooter method is also expected to be less disturbing and faster compared to swimming divers. The method was applied in visual census study of fish assemblages from 8 to 50 m depth conducted at two locations in the east Adriatic using 102 video transects. The environmental variables contributing to the variation of the reef fish community in the depth range of the infralittoral and upper circalittoral bottoms were also recorded. Thirty-one fish species were recorded on transects and 10.3% of all individuals were not identified to the species level. The average density on transects was 0.8 individuals/m², with C. chromis, C. julis and G. auratus being both the most abundant and the most frequent species. Three environmental variables, depth, bottom with zoocover and eastern orientation of the coast, were identified as highly significant for species occurrence. Abundance and species richness of fish assemblages showed no significant variation with depths, inclinations, orientations and sites. A significant difference in the fish assemblage structure was found among orientations, depths and inclinations with the gradient change of species composition with increasing depth and with increasing inclination.

scholarly journals Tropical rhodolith beds are a major and belittled reef fish habitat

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rodrigo L. Moura ◽  
Maria L. Abieri ◽  
Guilherme M. Castro ◽  
Lélis A. Carlos-Júnior ◽  
Pamela M. Chiroque-Solano ◽  
...  
Keyword(s):  
Reef Fish ◽  
Trophic Structure ◽  
Fish Assemblages ◽  
Fish Habitat ◽  
Reef Fishes ◽  
Marine Biodiversity ◽  
Resources Management ◽  
Abundance And Distribution ◽  
Fish Habitats ◽  
Energy Pathways

AbstractUnderstanding habitat-level variation in community structure provides an informed basis for natural resources’ management. Reef fishes are a major component of tropical marine biodiversity, but their abundance and distribution are poorly assessed beyond conventional SCUBA diving depths. Based on a baited-video survey of fish assemblages in Southwestern Atlantic’s most biodiverse region we show that species composition responded mainly to the two major hard-bottom megahabitats (reefs and rhodolith beds) and to the amount of light reaching the bottom. Both megahabitats encompassed typical reef fish assemblages but, unexpectedly, richness in rhodolith beds and reefs was equivalent. The dissimilar fish biomass and trophic structure in reefs and rhodolith beds indicates that these systems function based on contrasting energy pathways, such as the much lower herbivory recorded in the latter. Rhodolith beds, the dominant benthic megahabitat in the tropical Southwestern Atlantic shelf, play an underrated role as fish habitats, and it is critical that they are considered in conservation planning.

scholarly journals Reef fish communities are spooked by scuba surveys and may take hours to recover

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4886 ◽  
Author(s):  
Michael J. Emslie ◽  
Alistair J. Cheal ◽  
M. Aaron MacNeil ◽  
Ian R. Miller ◽  
Hugh P.A. Sweatman
Keyword(s):  
Species Richness ◽  
Reef Fish ◽  
Fish Assemblages ◽  
Ecological Monitoring ◽  
Reef Fishes ◽  
Fish Length ◽  
Initial Contact ◽  
Monitoring Programs ◽  
Species Of Conservation Concern ◽  
Initial Attraction

Ecological monitoring programs typically aim to detect changes in the abundance of species of conservation concern or which reflect system status. Coral reef fish assemblages are functionally important for reef health and these are most commonly monitored using underwater visual surveys (UVS) by divers. In addition to estimating numbers, most programs also collect estimates of fish lengths to allow calculation of biomass, an important determinant of a fish’s functional impact. However, diver surveys may be biased because fishes may either avoid or are attracted to divers and the process of estimating fish length could result in fish counts that differ from those made without length estimations. Here we investigated whether (1) general diver disturbance and (2) the additional task of estimating fish lengths affected estimates of reef fish abundance and species richness during UVS, and for how long. Initial estimates of abundance and species richness were significantly higher than those made on the same section of reef after diver disturbance. However, there was no evidence that estimating fish lengths at the same time as abundance resulted in counts different from those made when estimating abundance alone. Similarly, there was little consistent bias among observers. Estimates of the time for fish taxa that avoided divers after initial contact to return to initial levels of abundance varied from three to 17 h, with one group of exploited fishes showing initial attraction to divers that declined over the study period. Our finding that many reef fishes may disperse for such long periods after initial contact with divers suggests that monitoring programs should take great care to minimise diver disturbance prior to surveys.

scholarly journals Two waves of colonization straddling the K–Pg boundary formed the modern reef fish fauna

2014 ◽  
Vol 281 (1783) ◽  
pp. 20140321 ◽  
Author(s):  
S. A. Price ◽  
L. Schmitz ◽  
C. E. Oufiero ◽  
R. I. Eytan ◽  
A. Dornburg ◽  
...  
Keyword(s):  
Reef Fish ◽  
Late Cretaceous ◽  
Evolutionary Dynamics ◽  
Fish Fauna ◽  
Reef Fishes ◽  
Causal Mechanism ◽  
Reef Fish Assemblage ◽  
Ecological Importance ◽  
Modern Reef ◽  
Oceanic Currents

Living reef fishes are one of the most diverse vertebrate assemblages on Earth. Despite its prominence and ecological importance, the origins and assembly of the reef fish fauna is poorly described. A patchy fossil record suggests that the major colonization of reef habitats must have occurred in the Late Cretaceous and early Palaeogene, with the earliest known modern fossil coral reef fish assemblage dated to 50 Ma. Using a phylogenetic approach, we analysed the early evolutionary dynamics of modern reef fishes. We find that reef lineages successively colonized reef habitats throughout the Late Cretaceous and early Palaeogene. Two waves of invasion were accompanied by increasing morphological convergence: one in the Late Cretaceous from 90 to 72 Ma and the other immediately following the end-Cretaceous mass extinction. The surge in reef invasions after the Cretaceous–Palaeogene boundary continued for 10 Myr, after which the pace of transitions to reef habitats slowed. Combined, these patterns match a classic niche-filling scenario: early transitions to reefs were made rapidly by morphologically distinct lineages and were followed by a decrease in the rate of invasions and eventual saturation of morphospace. Major alterations in reef composition, distribution and abundance, along with shifts in climate and oceanic currents, occurred during the Late Cretaceous and early Palaeogene interval. A causal mechanism between these changes and concurrent episodes of reef invasion remains obscure, but what is clear is that the broad framework of the modern reef fish fauna was in place within 10 Myr of the end-Cretaceous extinction.

scholarly journals Incorporating reef fish avoidance behavior improves accuracy of species distribution models

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9246
Author(s):  
Kostantinos A. Stamoulis ◽  
Jade M.S. Delevaux ◽  
Ivor D. Williams ◽  
Alan M. Friedlander ◽  
Jake Reichard ◽  
...  
Keyword(s):  
Reef Fish ◽  
Species Distribution ◽  
Avoidance Behavior ◽  
Species Distribution Models ◽  
Fish Assemblages ◽  
Reef Fishes ◽  
Distribution Models ◽  
Approach Distance ◽  
Fish Avoidance ◽  
Habitat Variables

Species distribution models (SDMs) are used to interpret and map fish distributions based on habitat variables and other drivers. Reef fish avoidance behavior has been shown to vary in the presence of divers and is primarily driven by spearfishing pressure. Diver avoidance behavior or fish wariness may spatially influence counts and other descriptive measures of fish assemblages. Because fish assemblage metrics are response variables for SDMs, measures of fish wariness may be useful as predictors in SDMs of fishes targeted by spearfishing. We used a diver operated stereo-video system to conduct fish surveys and record minimum approach distance (MAD) of targeted reef fishes inside and outside of two marine reserves on the island of Oʻahu in the main Hawaiian Islands. By comparing MAD between sites and management types we tested the assumption that it provides a proxy for fish wariness related to spearfishing pressure. We then compared the accuracy of SDMs which included MAD as a predictor with SDMs that did not. Individual measures of MAD differed between sites though not management types. When included as a predictor, MAD averaged at the transect level greatly improved the accuracy of SDMs of targeted fish biomass.

scholarly journals Comparing mesophotic and shallow reef fish assemblages in the 'Au'au Channel, Hawaii: fish size, feeding guild composition, species richness, and endemism

2020 ◽  
Vol 96 (4) ◽  
pp. 577-592
Author(s):  
Raymond C Boland ◽  
K David Hyrenbach ◽  
Edward E DeMartini ◽  
Frank A Parrish ◽  
John J Rooney
Keyword(s):  
Species Richness ◽  
Reef Fish ◽  
Fish Assemblages ◽  
Reef Fishes ◽  
Feeding Guild ◽  
Shallow Reef ◽  
Guild Composition ◽  
High Conservation ◽  
Herbivore Species ◽  
Foraging Guilds

Mesophotic (30–150 m) reef fish assemblages in the 'Au'au Channel, between the Hawaiian Islands of Maui and Lanai, were compared visually with neighboring shallow (<30 m depth) reef fish assemblages for differences in structure. Between 2007 and 2011, approximately 7000 mesophotic and 4000 shallow reef fishes were identified, sized (standard length), and assigned to seven foraging guilds. The shallow water zone had more species than the mesophotic zone (99 vs 80, respectively). Mesophotic planktivores and two herbivore species were significantly larger than their shallow reef counterparts. Shallow reef fish assemblages had a higher Chao1 estimated species richness for herbivores and corallivores but not the other five foraging guilds. The differences between mesophotic and shallow fish assemblages indicate that both have unique communities of high conservation importance.

Reef fish assemblage and zoogeographic affinities of a scarcely known region of the western equatorial Atlantic

2014 ◽  
Vol 95 (3) ◽  
pp. 623-633 ◽  
Author(s):  
João Eduardo Pereira Freitas ◽  
Tito Monteiro Cruz Lotufo
Keyword(s):  
Reef Fish ◽  
Fish Assemblages ◽  
Fish Fauna ◽  
Ecological Factors ◽  
Brazilian Coast ◽  
Equatorial Atlantic ◽  
The North ◽  
Reef Fish Assemblage ◽  
North Eastern ◽  
Strong Resemblance

Based on data from 151 underwater surveys (scuba) between 2002 and 2007, the present study assessed the reef fish fauna from a scarcely known region on the north-eastern Brazilian coast (Ceará State). A checklist of 179 taxa is provided and the zoogeographic patterns are analysed and discussed, including six other localities. Based only on assemblage composition, the reef fish fauna from Ceará showed a strong resemblance (73%) with the reefs of Risca do Zumbi (RN) and Paraiba (PB). The data from the visual censuses including abundance values corroborate the evaluation based only on composition and suggest ecological factors as the main drivers of the fish assemblages in the region.

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