Structure Of Coral Reef Fish Communities Research Articles

Environmental DNA biomonitoring reveals seasonal patterns in coral reef fish community structure

Coral reef fish populations are declining due to multiple factors including habitat destruction, overfishing, and climate change. While these can include seasonal impact, seasonal changes can also be a confounding factor, so that seasonal monitoring is essential for detecting true temporal changes in fish community abundance and composition. However, seasonal monitoring is rarely implemented. The aim of this study was to detect the seasonal patterns of coral reef fish community structure around Tidung Kecil Island, Indonesia, using eDNA metabarcoding (eDNA) and underwater visual census (UVC). The UVC identified 32 species belonging to 10 families in the rainy season and 29 species belonging to 7 families in the dry seasons. The eDNA metabarcoding identified 209 species belonging to 56 families and 27 species belonging to 17 families in the rainy and dry seasons, respectively. Based on eDNA metabarcoding data, coral reef fish abundance and community composition differed significantly between seasons (Mann Whitney, p < 0.01), while the UVC method did not detect these seasonal differences (Mann Whitney, p > 0.05). UVC and eDNA data both showed a predominance of omnivorous fishes in the rainy season and carnivorous fishes in the dry season. Ecological indices did not differ significantly between seasons for the two used methods, although the species making the highest contributions to the similarity (SIMPER) analysis differed between methods. Overall, this study confirms the premise that eDNA metabarcoding can be an effective tool for monitoring seasonal variation in coral reef fish communities.

Coral Reef Fishes Biodiversity In Pahawang Island,Pesawaran District Lampung

The components of coral reef ecosystem can be described by the unique regulation in community level. Coral reef fishes use coral reef as their habitat and they highly depend on coral reef health. Otherwise, the condition of coral reef health can be predicted by the biodiversity of coral reef fishes. The research aim was describe communities differences between two explored area in marine tourism spots in Pahawang Island. This research was conducted on November 2019 at two stations on the coral reefs ecosystem of Pahawang Island represented the two quitely different area, the marine tourism and the visitor areas. The coral reef fishes were observed by using visual census method with a Line Transect length of 30 meters and a visibility of 2.5 meters left and right of the transect. Coral reef fish community structure was measured by diversity, similarity, and dominancy indexes. A total of 1.940 coral reef fish species from 13 families were recorded. Pomacentridae is the most speciose family (1.091 species), followed by Siganidae (308 species) and Labridae (166 species). Biodiversity of coral reef fishes at Pahawang Island showed results diversity index (H') in both observation stations classified as medium with a low dominance index value (C) and similarity index (E) at both stations classified as high, presumably as a result of tourism activities. The diversity index at station 2 has a greater value than station 1 as a tourist area with diving and snorkeling tourism activities, at station 2 there are more types or genus of reef fish, compared to station 1.

Long-term monitoring of coral reef fish assemblages in the Western central pacific

Throughout the tropics, coral reef ecosystems, which are critically important to people, have been greatly altered by humans. Differentiating human impacts from natural drivers of ecosystem state is essential to effective management. Here we present a dataset from a large-scale monitoring program that surveys coral reef fish assemblages and habitats encompassing the bulk of the US-affiliated tropical Pacific, and spanning wide gradients in both natural drivers and human impact. Currently, this includes >5,500 surveys from 39 islands and atolls in Hawaii (including the main and Northwestern Hawaiian Islands) and affiliated geo-political regions of American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, and the Pacific Remote Islands Areas. The dataset spans 2010–2017, during which time, each region was visited at least every three years, and ~500–1,000 surveys performed annually. This standardised dataset is a powerful resource that can be used to understand how human, environmental and oceanographic conditions influence coral reef fish community structure and function, providing a basis for research to support effective management outcomes.

Climate change impacts on coral reefs: Synergies with local effects, possibilities for acclimation, and management implications

Most reviews concerning the impact of climate change on coral reefs discuss independent effects of warming or ocean acidification. However, the interactions between these, and between these and direct local stressors are less well addressed. This review underlines that coral bleaching, acidification, and diseases are expected to interact synergistically, and will negatively influence survival, growth, reproduction, larval development, settlement, and post-settlement development of corals. Interactions with local stress factors such as pollution, sedimentation, and overfishing are further expected to compound effects of climate change.Reduced coral cover and species composition following coral bleaching events affect coral reef fish community structure, with variable outcomes depending on their habitat dependence and trophic specialisation. Ocean acidification itself impacts fish mainly indirectly through disruption of predation- and habitat-associated behavior changes.Zooxanthellate octocorals on reefs are often overlooked but are substantial occupiers of space; these also are highly susceptible to bleaching but because they tend to be more heterotrophic, climate change impacts mainly manifest in terms of changes in species composition and population structure. Non-calcifying macroalgae are expected to respond positively to ocean acidification and promote microbe-induced coral mortality via the release of dissolved compounds, thus intensifying phase-shifts from coral to macroalgal domination.Adaptation of corals to these consequences of CO2 rise through increased tolerance of corals and successful mutualistic associations between corals and zooxanthellae is likely to be insufficient to match the rate and frequency of the projected changes.Impacts are interactive and magnified, and because there is a limited capacity for corals to adapt to climate change, global targets of carbon emission reductions are insufficient for coral reefs, so lower targets should be pursued. Alleviation of most local stress factors such as nutrient discharges, sedimentation, and overfishing is also imperative if sufficient overall resilience of reefs to climate change is to be achieved.

Detection of Shifts in Coral Reef Fish Assemblage Structure Over 50 Years at Reefs of New Providence Island, the Bahamas Highlight the Value of the Academy of Natural Sciences' Collections in a Changing World

Natural history collections contain historical records that present snapshots of organisms and communities, and are now more important than ever in the face of rapidly changing environments. The world's largest collection of fishes from The Bahamas is housed at The Academy of Natural Sciences, Philadelphia. These vast Bahamas holdings primarily resulted from the collecting efforts of James Böhlke and Charles Chaplin in the 1950s–1970s. One of the many ways these historical records have been used since their collection is as baseline data for coral reef sites that were revisited decades later to answer questions about changes in coral reef fish community structure through time. Analyses of data collected from resurveys conducted in 2006 and 2010 provided evidence for a relative increase in the abundance of individuals belonging to different trophic groups and families; particularly, a relative increase in herbivores (mainly parrotfishes) and a relative decrease in planktivores. Furthermore, an interesting inverse trend was detected between two nocturnal groups of fishes, where the larger-bodied sqnirrelfishes increased while the smaller-bodied cardinalfishes decreased in relative abundance. These significant differences across trophic groups and families are consistent with the effects of a degraded reef habitat characterized by increased algal cover and fewer shelter spaces. Overall, these resurvey results suggest that neither the coral nor reef-fish communities reflect ‘baseline’ conditions. Continued monitoring of these assemblages using comparative data from multiple replicate samples across time periods will be needed to detect their further change or stabilization.

Long-term spatiotemporal variations in coral-reef fish community structure and fishing at a South Pacific atoll

In many atolls of the South Pacific, a shift has occurred in the past couple of decades from traditional to more intensive fishing practices. Increasing fishing pressure on coral reefs raises the need for long-term studies to understand how fish communities react to fishing practice changes. The objective of this study was to analyse the variations of reef fish communities (in terms of species richness, diversity, density and structure) during a long time lapse at Tikehau atoll (Tuamotu archipelago, French Polynesia). The same eight lagoon pinnacles were sampled in 1987 and 2003 at 6 and 12 m depth. Quantitative data were collected by visual census techniques (UVC) on 50 m × 5 m belt transects. Analyses were conducted using a multiple spatial scale (depth, pinnacle and whole lagoon) approach with a particular attention on commercial species such as Scaridae (parrotfish), Acanthuridae (surgeonfish), Lutjanidae (snapper), Lethrinidae (emperor), Serranidae (grouper). Despite an increased sampling effort between 1987 and 2003, the mean species richness per transect decreased significantly from 26.2 ± 6.2 to 21.6 ± 9.6. The mean diversity varied similarly. A stronger decrease happened at pinnacles close to the village, where fish density also decreased. Conversely, fish density, species richness and diversity increased at pinnacles less visited by inhabitants. The community structure shifted from commercial species to small site-attached species e.g. Pomacentridae (damselfish), Ptereleotridae (dartfish) as fishing reduced the abundance (and biomass) of targeted stocks. We argue that these spatiotemporal variations resulted from a drastic change in fishing practices over the 16 years period, that shifted a sustainable fishery using traditional fish traps to an unbalanced, species-threatening, selective fishery. This study underlines the need for management and for the implementation of marine protected areas (including no-take zones) in order to protect the coral reef ecosystem and favor sustainable fisheries at Tikehau atoll.

Do ectoparasites determine cleaner fish abundance? Evidence on two spatial scales

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 263:189-196 (2003) - doi:10.3354/meps263189 Do ectoparasites determine cleaner fish abundance? Evidence on two spatial scales Karen L. Cheney, Isabelle M. Côté* Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK *Corresponding author. Email: i.cote@uea.ac.uk ABSTRACT: Cleaner fish on coral reefs can have a significant impact on the diversity and distribution of their fish clients. Understanding the factors affecting the distribution of cleaners themselves therefore becomes an important consideration for elucidating the mechanisms controlling coral reef fish community structure. We hypothesised that obligate cleaner fish, which rely almost exclusively on ectoparasites gleaned from clients, should be more abundant in areas rich in their preferred prey, namely parasitic gnathiid isopod larvae. We tested predictions from this hypothesis on 2 spatial scales in the Caribbean: among reefs within Barbados, and among 6 islands spanning the Greater and Lesser Antilles. As predicted, densities of coral-dwelling cleaning gobies Elacatinus spp., which are active cleaners, were higher in areas of high rates of emergence of gnathiid larvae from the benthos. This relationship was not observed in sponge-dwelling cleaning gobies, which rely mainly on non-client-gleaned food sources. The density of coral-dwelling cleaners was also correlated with client density, but contrary to our prediction was not related to ectoparasite loads of a common reef fish client. Cleaning goby abundance is more likely to be a consequence than a cause of ectoparasite availability, since cleaning goby recruitment is usually linked to factors related to foraging, and territorial clients do not preferentially settle near cleaning gobies. Whether the link between cleaner abundance and ectoparasite availability is mediated through differential recruitment or differential survival of cleaners in parasite-rich and parasite-poor areas remains to be determined. KEY WORDS: Cleaning symbiosis · Reef fish community structure · Gobiosoma spp. Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 263. Online publication date: November 28, 2003 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2003 Inter-Research.

Aggression in damselfish: habituation by adults of Pomacentous parritus to juvenile intruders

Successful recruitment of juvenile coral reef fishes may depend, in part, upon the aggressive behavior of adults already on the reef. In addition to initial levels of aggression, changes in aggressive behavior of adults, e.g., due to habituation, may have an even greater influence on recruiting juveniles. Adult males of the bicolor damselfish, Pomacentrus partitus, were used as subjects to study habituation of aggression toward conspecific and congeneric (P. variabilis) juveniles. Adults, held in a 1000 liter aquarium, habituated after 4 hours of constant exposure to juveniles restrained in a 1 liter ‘model bottle’. Stimulus strength of the juveniles depended on their species identity, size and proximity to the resident adult's shelter. There was a recovery of aggression with a change in stimulus location, but at the same location, a stimulus of greater strength was required to bring about recovery. The implications of these findings for coral reef fish community structure are discussed.

Colonization by nearshore fish on small artificial reefs in Barkley Sound, British Columbia

We investigated the structure of a temperate nearshore fish community by examining the development of fish assemblages on small artificial reefs of concrete blocks constructed in two series 6 months apart. In each series, a species equilibrium, of approximately six species, was rapidly reached within 6 months. Eight of the 30 species which had colonized the reefs from the surrounding rocky habitats were common on the reefs. Both juveniles and adults of all species were present, except for the rockfishes (Sebastes spp.) which were represented only by young individuals (1 to 3 years of age). Tagging indicated that the bottom-dwelling species (Gobiidae, Cottidae) remained permanently on the reefs, whereas a seasonal turnover in rockfish occurred.The communities inhabiting the reefs usually did not differ from each other within each series, whereas significant differences occurred between series. This difference was attributed to the differential colonizing ability of species. No evidence of interspecific competition was apparent among the species inhabiting the reefs.The results are discussed in light of some current models of coral reef fish community structure. Some possible factors affecting the differences observed between tropical and temperate waters are also discussed.