Abundance Of Reef Fishes Research Articles

Shallow reef fish assemblage from Fernando de Noronha Archipelago, Southwest Atlantic

The paper presents an extensive dataset of the shallow reef fish communities and habitat characteristics in the Fernando de Noronha Archipelago (Southwest Atlantic). The data were collected from August to October 2006 in the Fernando de Noronha main island. To evaluate the shallow reef fish communities, 165 visual censuses were performed in eight different localities in the Fernando de Noronha Archipelago. The dataset reports a comprehensive compilation of the shallow reef fish abundance, of eight localities of the Fernando de Noronha Archipelago. The dataset reveals spatial heterogeneity amongst the selected localities in terms of fish abundance, composition and size.

Loss of Coral Trait Diversity and Impacts on Reef Fish Assemblages on Recovering Reefs.

Understanding patterns of biodiversity change is essential as coral reefs experience recurrent cycles of disturbance and recovery. Shifts in the total cover and species composition of habitat-forming corals can have far-reaching consequences, including shifts in coral functional traits and impacts on local fish assemblages. We surveyed coral and fish assemblages along the southern coast of Hainan Island near Sanya, China, in 2006, 2010, and 2018, during a period with repeated mass bleaching events. We showed that coral biodiversity in this region is in a state of flux, with losses and gains in coral cover and an increase in species richness over time. Despite increasing species diversity, the region suffered a loss of coral trait diversity by 2010, with an incomplete recovery by 2018, owing to declines in species with key habitat-forming traits (e.g., high surface areas and fractal structure) such as corymbose corals. Concurrently, there was an increase in functional redundancy due to the proliferation of the dominant encrusting and massive corals. Coral cover was positively associated with the abundance of reef fish, indicating that the changes observed in coral abundance can impact reef-associated species. These results demonstrate that the slow recovery of coral biodiversity in southern Hainan Island has been hampered by the loss of specific coral traits and highlight the importance of protecting vulnerable coral traits in conservation and management strategies.

Environmental change and connectivity drive coral reef fish abundance in the Western Indian Ocean

Abstract Worldwide, coral reefs are facing risk from climate change. The Western Indian Ocean (WIO) harbours about 16% of global coral reefs with highly reef-dependent local communities. Coastal protection and food security depend on effective conservation management, which requires understanding species abundances. Here, we explore how fish group distribution and abundance across the WIO, categorized by their trophic function, are explained by oceanographic connectivity, sea surface temperature (SST), and chlorophyll a. We designed a proportional oceanographic connectivity metric describing the relative strength of connectivity between all WIO coral reefs and each survey site. We created statistical models for four trophic groups: grazers and detritivores, herbivorous excavators, corallivores, and primary piscivores across 51 sites in the WIO. We show that SST and chlorophyll a are strong predictors of all trophic fish groups and that the proportional oceanographic connectivity metric improved the model predictions significantly for grazers and detritivores and excavators. For excavators, peak abundances were predicted at medium connectivity, and for grazers and detritivores, at low and medium connectivity, suggesting that larvae dispersal predominates at a local scale. Decision making should include connectivity for efficient conservation area prioritization, for which our proportional oceanographic connectivity metric is a valid and useful parameter.

Reef fish biodiversity and occurrence of endangered sharks within a small marine protected area off Sint Maarten, Dutch Caribbean

AbstractMarine protected areas (MPAs) are common conservation tools supporting the protection of threatened marine fishes, such as sharks. However, the creation of shark MPAs has been less common in the Greater Caribbean region despite a growing need and opportunity. In this study, we evaluated the occurrence of shark and reef fish biodiversity off Sint Maarten, Dutch Caribbean, with a particular emphasis on endangered shark presence within the Man of War Shoal Marine Protected Area (MPA). We utilized baited remote underwater video systems (BRUVs) to gather non-invasive data on the abundance and diversity of reef fish and shark species inside and outside the local MPA. Generalized linear models (GLMs) revealed no significant effect of protection status on the presence of the endangered Caribbean reef shark (Carcharhinus perezi). However, we found a significant influence of depth on shark occurrence, as well as an effect of habitat type on shark and reef fish biodiversity, with reef habitats showing the greatest significance. These results suggest that the effect of small coastal MPAs on bolstering local endangered species conservation in the Dutch Caribbean is likely to vary according to habitat features and how those species utilize those habitats across various life stages. These findings have implications for adaptive MPA management, which should be informed by the ecology and habitat preferences of target species to achieve maximum benefits for biodiversity conservation.

Community structure and biomass of reef fish concerning coral cover in Sempu Strait, East Java, Indonesia

Abstract. Isdianto A, Ariefandi MF, Asadi MA, Yamindago A, Setyawan FO, Bintoro G, Setyanto A, Lelono TD, Tumulyadi A, Adhihapsari W, Setyoningrum D, Fathah AL, Putri BM, Supriyadi, Luthfi OM. 2024. Community structure and biomass of reef fish concerning coral cover in Sempu Strait, East Java, Indonesia. Biodiversitas 25: 3376-3385. Reef fishes were used as bioindicators of biodiversity in coral reef ecosystems. However, coral cover and reef fish abundance around Sempu Strait tended to decrease. The study aims to obtain reef fish's community structure and biomass and their correlation to coral cover. We observed significant variability in reef fish populations through bi-monthly monitoring using an underwater visual census and underwater photo transect conducted from December 2022 to April 2023. Based on these observations, the average range of coral fish abundance was 0.453 to 0.577 individuals per square meter, with the highest value at Rumah Apung station (0.577 ind/m2). The community structure included 81 reef fish species, categorized into major (50 species), indicator (10 species), and target (21 species) groups, demonstrating a community with moderate diversity, stable evenness, and low dominance across the observed stations. Further, the research quantified fish biomass, recording an average of 0.0207 kg/m2 or 207.571 kg/Ha, categorized as low, with the highest biomass measurements at Rumah Apung station (0.0054 kg/m2). Strong correlations were identified between coral cover and both fish abundance (correlation coefficient = 0.741) and biomass (correlation coefficient = 0.666). These results emphasize the profound impact of coral health on the conditions and sustainability of reef fish populations. These findings underscore the critical dependency of reef fish on coral ecosystems and provide essential data for conservation efforts to maintain and restore these vital marine habitats.

Kelimpahan dan Biomassa Ikan Karang di Kawasan Konservasi Perairan Gili Balu, Kabupaten Sumbawa, Nusa Tenggara Barat

The Gili Balu Marine Conservation Area (KKP), located in Sumbawa Regency, West Nusa Tenggara, is ecologically and economically significant due to its rich coral reef ecosystems. This research aims to measure the abundance and biomass of reef fish in the KKP Gili Balu, which can be used as a basis for evaluating the effectiveness of conservation efforts in maintaining marine biodiversity. The Underwater Visual Census (UVC) method was used, recording types of reef fish at ten observation points. The results showed that the highest abundance was found on Mandiki Island, with functional fish abundance reaching 2973 ind/ha, followed by Pasareang Barat Island (1903 ind/ha) and South Kalong (1600 ind/ha). The biomass of functional fish also reflects their important role in maintaining the balance of the coral reef ecosystem. This research contributes to the scientific understanding of marine biodiversity in the KKP Gili Balu and provides a basis for sustainable conservation management efforts. Additionally, the research recorded the presence of several coralivorous and economically important fish species, although they tend to be smaller compared to functional fish. Economically important fish in the KKP Gili Balu waters were found only at four observation locations: East Belang Island, North Belang, Kenawa, and Southwest Namo. The highest value was recorded at Kenawa Island, with 93 ind/ha. These fish tend to be rare in this area, possibly due to past fishing practices.

Can juvenile supply predict future abundance of large-bodied reef fishes?

The extent to which juvenile abundance can predict future populations of lethrinids at Ningaloo Reef was assessed using size frequency data collected over 13 consecutive years. Annual abundance of juvenile lethrinids (<5 cm TL) was highest in northern Ningaloo during La Niña years, when seawater is warmer and oceanic currents stronger. Juvenile lethrinid abundance explained 35% of the variance in 1–2 year-old Lethrinus nebulosus abundance the following year, a steeper relationship in the north suggesting greater survival of juveniles. Juvenile lethrinid abundance was also positively correlated to abundance of 1–2 year-old L. atkinsoni in the southern region of Ningaloo. Abundance of juvenile lethrinids were however poor predictors of L. nebulosus and L. atkinsoni older than 2 years of age. Post settlement processes likely weaken the link between juvenile supply and abundance of lethrinids >2 years old making it difficult to accurately quantify the overall size of future lethrinid populations.

Distribution and abundance of herbivorous reef fishes on a barrier reef system in the Florida Keys and Dry Tortugas, Florida

Herbivorous reef fishes control algal growth and are critical for maintaining reef health. Grazing effects vary due to community composition, so a diverse herbivore community is important for preventing phase shifts from coral to algal-dominated reefs. However, herbivore communities and grazing effects vary spatially, resulting in non-uniform distribution of algal mitigation across the seascape. Therefore, understanding how habitat influences herbivore communities is essential for predicting the spatial distribution of these species' ecological services. This study used underwater visual surveys (n = 5455) to examine how habitat influences spatial patterns of herbivorous fish densities and species richness in the Florida Keys and Dry Tortugas, Florida. Herbivorous fishes were ubiquitous, and communities were dominated by small herbivores such as damselfishes (Pomacentridae), gobies (Gobiidae), surgeonfishes (Acanthuridae), and small- to medium-bodied parrotfishes (subfamily Scarinae). A suite of factors influenced herbivorous fish communities but boosted regression tree results showed that habitat relief, depth, and spatial location within the Florida Keys and Dry Tortugas were the most important factors. In general, herbivore occurrence, density, and species richness increased as percent of low relief hardbottom habitat (&lt;0.2 m high) decreased. In addition, density and occurrence of herbivores generally increased at shallower depths. Spatial location influenced the density of herbivores with potential hotspots predominantly located in the Upper Keys and the Dry Tortugas Bank. These data provide a valuable understanding of the spatial distribution of herbivorous reef fishes, and aid management decisions regarding the protection and sustainability of herbivore resources and the ecosystems that rely on them.

High response diversity and conspecific density-dependence, not species interactions, drive dynamics of coral reef fish communities.

Species-to-species and species-to-environment interactions are key drivers of community dynamics. Disentangling these drivers in species-rich assemblages is challenging due to the high number of potentially interacting species (the 'curse of dimensionality'). We develop a process-based model that quantifies how intraspecific and interspecific interactions, and species' covarying responses to environmental fluctuations, jointly drive community dynamics. We fit the model to reef fish abundance time series from 41 reefs of Australia's Great Barrier Reef. We found that fluctuating relative abundances are driven by species' heterogenous responses to environmental fluctuations, whereas interspecific interactions are negligible. Species differences in long-term average abundances are driven by interspecific variation in the magnitudes of both conspecific density-dependence and density-independent growth rates. This study introduces a novel approach to overcoming the curse of dimensionality, which reveals highly individualistic dynamics in coral reef fish communities that imply a high level of niche structure.

Reef fish community structure in the waters of small islands Central Bangka Regency

This study aimed to analyze the community structure of reef fish in the small island waters of Central Bangka. The research was conducted in March 2022 in the waters of Bebuar Island, Ketugar Island, Ketawai Island, and Gusung Asam Central Bangka Regency, Bangka Belitung Islands Province. The coral reef survey method uses purposive sampling and the coral reef fish visual census with data analysis of abundance, diversity index, uniformity, and dominance. In-site water quality measurements included six parameters: temperature, salinity, current, brightness, depth, and pH. The results showed that coral reef cover from 44.60 - 87.00% with the medium to very good category. The abundance of reef fish from 1 to 3 individuals/m2 was dominated by 18 species of the Pomacentridae family. The reef fish diversity index ranged from 2.47 to 2.90, including the medium category. The uniformity index value ranged from 0.79 - 0.94, including the high category, indicating that the species found were evenly distributed across all stations. The dominance index value ranges from 0.07 to 0.15, including low, where no species dominates significantly and the fish are evenly distributed. Temperature, brightness, pH, and salinity are factors that support the growth of coral and reef fish. A water current speed of 0.05 – 0.20 m/s is quite helpful in cleaning coral reefs from mud and can supply oxygen. Water conditions were categorized as good and fulfilled the seawater quality standards.

Marine protected areas promote stability of reef fish communities under climate warming

Protection from direct human impacts can safeguard marine life, yet ocean warming crosses marine protected area boundaries. Here, we test whether protection offers resilience to marine heatwaves from local to network scales. We examine 71,269 timeseries of population abundances for 2269 reef fish species surveyed in 357 protected versus 747 open sites worldwide. We quantify the stability of reef fish abundance from populations to metacommunities, considering responses of species and functional diversity including thermal affinity of different trophic groups. Overall, protection mitigates adverse effects of marine heatwaves on fish abundance, community stability, asynchronous fluctuations and functional richness. We find that local stability is positively related to distance from centers of high human density only in protected areas. We provide evidence that networks of protected areas have persistent reef fish communities in warming oceans by maintaining large populations and promoting stability at different levels of biological organization.

Intact shallow and mesophotic assemblages of large carnivorous reef fishes underscore the importance of large and remote protected areas in the Coral Triangle

Abstract Overfishing remains a threat to coral reef fishes worldwide, with large carnivores often disproportionately vulnerable. Marine protected areas (MPAs) can restore fish populations and biodiversity, but their effect has been understudied in mesophotic coral ecosystems (MCEs), particularly in the Coral Triangle. Videos were analysed from baited remote underwater video systems deployed in 2016 to investigate the assemblage structure of large carnivorous fishes at shallow (4–12 m) and mesophotic (45–96 m) depths in two of the largest and most isolated MPAs in the Philippines: an uninhabited, fully no‐take MPA enacted in 1988 (Tubbataha Reefs Natural Park) and an archipelagic municipality surrounded by an extensive but not fully no‐take MPA declared in 2016 (Cagayancillo). Taxa focused on were groupers (Serranidae), snappers (Lutjanidae), emperors (Lethrinidae), jacks (Carangidae) and the endangered Cheilinus undulatus (Labridae). Mean abundance and species richness were not greater in TRNP than in Cagayancillo regardless of depth despite long‐term protection in the former. Limited impacts of fishing in Cagayancillo may explain this result. Differentiation of fish assemblages was evident between TRNP and Cagayancillo but more obvious between depths at each location, probably due more to habitat than MPA effects. In Cagayancillo, overall carnivorous reef fish, grouper and jack mean abundance were 2, 2 and 10 times higher, respectively, at mesophotic depths, suggesting that MCEs can serve as deep refugia from fishing. These findings of differentiation between depths and higher abundance of certain taxa in mesophotic depths emphasize that MCEs are distinct from shallow reefs, serve as important habitat for species susceptible to overfishing and, thus, must be explicitly included in the design of MPAs. This study also highlights the value of maintaining strict protection of MPAs like TRNP for the Coral Triangle and an opportunity to safeguard intact fish assemblages in Cagayancillo by expanding its no‐take zones.

Substrate Characteristics Determine the Distribution and Abundance of Reef and Reef-Associated Fish: A Comprehensive Study in Protected and Non-protected Coral Ecosystems of Sri Lanka

Substrate Characteristics Determine the Distribution and Abundance of Reef and Reef-Associated Fish: A Comprehensive Study in Protected and Non-protected Coral Ecosystems of Sri Lanka

Sampling design modifications to a fishery-independent monitoring survey balance the maintenance of long-term data with emerging management needs and funding limitations

Development of Florida’s marine Fisheries-Independent Monitoring (FIM) program began in 1985, and it initiated long-term monitoring in Tampa Bay in 1989 with the purpose of providing timely fishery-independent data and analyses to fishery managers for the conservation and protection of the species that support Florida’s fisheries. Over time, the program expanded sampling in other Florida estuaries. Data from this monitoring program are integral to the assessment and management of numerous state and federally managed fishes, so long-term consistency is of paramount importance, but sampling design modifications have been necessary over time. This review presents three case studies in which the estuarine component of the FIM program was changed to address emerging data needs in management of Florida’s fishery resources, while maintaining standardization and consistency with long-term surveys statewide. In the first case study, survey changes increased the amount of data on juvenile common snook, Centropomus undecimalis, on the Gulf of Mexico and Atlantic coasts and improved indices of abundance, survival estimates, and age-length keys for state management purposes. In the second case study, the FIM program improved estimates of abundance of juvenile reef fishes by initiating a complementary survey that expanded FIM sampling to new regions of the Florida Gulf coast and targeted a unique habitat (polyhaline seagrass beds along estuarine shoal habitats) not previously sampled in the standard long-term survey. In the third case study, the FIM program addressed a data limitation for regional management of spotted seatrout, Cynoscion nebulosus, by initiating seasonal sampling in western Florida. In each case study, the standard long-term survey design was modified to include sampling of new and unique areas and habitats, providing valuable data on estuarine fish assemblages that support analyses at the broader, ecosystem level. Survey amendments were designed to maintain standardization and consistency, all with limited additional funding. The success of these survey modifications was the result of several key factors: mission-focused programmatic goals, geographically dispersed laboratories, standardized protocols, ongoing critical analysis of the data, grant award success, and high-level data management. Although each case study originated with a survey expansion, all were followed by survey reductions or streamlining, so expansion and reduction scenarios are presented in this review. Regardless of these modifications, the mission of the FIM program remains the same: to provide timely data and analysis for the use of fishery managers, including state and federal partners.

Coupling and de-coupling of the El Niño Southern Oscillation to the supply of larval fishes to benthic populations in the Hawaiian Islands.

Several recent high intensity ENSO events have caused strong negative impacts on the adult phases of foundational species in coral reef ecosystems, but comparatively little is known about how climatic variables related to recent ENSOs are impacting the supply of larvae to benthic populations. In marine fishes and invertebrates, reproductive adults and planktonic larvae are generally more sensitive to environmental variability than older, non-reproductive adults. Further, the transport of larvae in ocean currents may also be strongly ENSO dependent. The interactions between the dynamics of larval survivorship and larval transport could lead to population bottlenecks as stronger ENSO events become more common. We tested the predictions of this hypothesis around the Main Hawaiian Islands (MHI) by constructing a correlation matrix of physical and biological time series variables that spanned 11 years (2007-2017) and multiple ENSO events. Our correlation matrix included four types of variables: i. published ENSO indices, ii. satellite-derived sea surface temperature (SST) and chlorophyll variables, iii. abundance and diversity of larval fishes sampled during the late winter spawning season off Oahu, and iv. abundance and diversity of coral reef fish recruits sampled on the western shore of the Big Island of Hawaii. We found that the abundance and diversity of larval fishes was negatively correlated with the Multivariate El Niño Index (MEI), and that larval variables were positively correlated with measures of fall recruitment (September & November), but not correlated with spring-summer recruitment (May & July). In the MHI, SST variables were not correlated with the MEI, but two successive El Niño events of 2014-15 and 2015-2016 were characterized by SST maxima approaching 30°C. Two large pulses of benthic recruitment occurred in the 2009 and 2014 recruitment seasons, with > 8000 recruits observed by divers over the summer and fall months. Both events were characterized by either neutral or negative MEI indices measured during the preceding winter months. These patterns suggest that La Niña and the neutral phases of the ENSO cycle are generally favorable for adult reproduction and larval development in the spring and summer, while El Niño phases may limit recruitment in the late summer and fall. We hypothesize that episodic recruitment during non-El Niño phases is related to favorable survivorship and transport dynamics that are associated with the formation of pairs of anticyclonic and cyclonic eddies on the leeward sides (western shores) of the Main Hawaiian Islands.

Abundance and diversity of reef fish species in the Core Zone of Tinabo Kecil Taka bonerate national park selayar islands

The abundance, diversity, and dominance of reef fish vary in each island cluster, resulting in different reef fish distribution. The purpose of this study was to assess the abundance, diversity, and dominance index of reef fish species in the core zone of Tinabo Kecil Island, Selayar Islands. This study used an underwater visual enumeration method approach (Underwater Visual Census). The results showed three categories of reef fish, namely indicator, target, and major fish, with 18 families, 94 species, and 817 fish individuals identified. Based on the analysis, it was found that the fish population abundance index value was 0.60 ind/m2, diversity was 4.17 (high category), and dominance was 0.02 (low category).

Trophic levels of reef fish community in Badul Island waters after Sunda Strait tsunami

The Sunda Strait tsunami in December 2018 damaged coral reef ecosystems in the Banten coastal area, including Badul Island waters. This condition potentially affects directly to the trophic level of the reef fish community. The purpose of this study was to determine the trophic level of the reef fish community in the waters of Badul Island after a tsunami. The research was conducted in April 2022 at four sampling stations (North, West, South and East) in the Badul Island waters. Reef fish survey using Underwater Visual Census with a 50 m line transect at a depth of 3 – 5 m. Reef fish identified during the study were grouped based on trophic level (carnivore, planktivore, omnivore, herbivore and corallivore). From this research identify 264 individu with 30 species from 17 Family of reef fish. Small waters area around Badul Island made possible reef fish from 4 sampling stations still in same population. The highest abundance of reef fish was found on the west side of Badul Island (128 ind/250 m2). Number species of reef fish founded the highest in East side with 14 species. The highest abundance of reef fish, based on trophic level, was approximately 74 ind/250 m2 of carnivore fish on the western side of the island.

The abundance of reef fish based on ecological role and trophic level on Kaliage Island, Seribu Archipelago, DKI Jakarta

A popular tourist destination known for its colorful coral reefs is Kaliage Island, part of the Seribu Archipelago. The UVC (Underwater Visual Census) method was used in a recent study to examine reef fishes’ trophic levels, ecological roles, and community structure. Dominance, evenness, and diversity indices were used to investigate community structure. The results revealed 3,117 fish from 54 species, 16 families, and 32 genera on the reef. The two most notable species within the family Pomacentridae were Pomacentrus alexanderae and Amblyglyphidodon curacao. Fish with major, target, and indicator functions accounted for 85.98 percent, 11.29 percent, and 2.73 percent of the fish population with ecological roles, respectively. The trophic distribution of fishes revealed that 45.01 percent were omnivores, 23.10 percent were planktivores, 19.19 percent were carnivores, 9.46 percent were herbivores, and 3.24 percent were coral eaters. The analysis showed that the reef fish community was balanced and not dominated by any species, with diversity, evenness, and dominance indices of 2.53, 0.87, and 0.01, respectively. For conservation efforts throughout the Seribu Archipelago, this study provides important insights into the stability and health of the reef ecosystem on Kaliage Island.

Change in Reef Fish Assemblages along Depth Gradient at Gili Rakit and Gili Lipan Marine Protected Areas (MPAs)

Since 2010, Marine Protected Areas (MPAs) have been established in Indonesia to ensure the sustainable management of coral reef ecosystems. This study examines fish assemblages across varying depths and MPAs management areas, specifically assessing the suitability of Gili Rakit and Gili Lipan MPAs. The study concludes that deeper coral reefs have higher reef fish abundance, with a majority of carnivores, planktivores, and omnivores. Gili Taekebo has the lowest abundance and species richness, while Pulau Lipan has the highest. The target reef fish are primarily found in the core zone, rehabilitation, and open access management types. Based on the findings, MPAs should prioritize sites with gradient depth coral reefs and complex habitats to enhance reef fish biodiversity richness. Takad Tabampang and Pulau Bedil are recommended as sustainable fisheries management types, while Gili Taekebo could benefit from rehabilitation or open access management. Pulau Lipan and Labajo may benefit from target fish re-stocking programs.

Reef Fish Community Structure in Penyusuk Waters, Bangka Regency, Indonesia (Case Study of Artificial Reef in PT. Artha Cipta Langgeng)

Reef fishes are important components of a healthy coral ecosystem. However, when coral reefs are degraded, reef fishes also lose their habitat resulting in a decline in reef fish production and sustainable livelihood for the communities depending on it. In this study, we determined the status of reef fish communities in an artificial reef at PT Artha Cipta Langgeng in the Penyusuk waters of Bangka Regency, Indonesia. Data on reef fish communities were collected using the underwater visual census (UVC) method, including in situ and ex-situ environmental parameters. A total of 2,987 individuals belonging to 12 reef fish species and five families were recorded across three stations. The abundance of reef fish ranges from 45 to 60 ind/m², categorized as highly abundant. Diversity, evenness, and dominance indices were calculated at 1.18-1.49, 0.56-0.65, and 0.26 -0.36, respectively which are categorized as low to moderate. The environmental parameters in the artificial reef are still within the standard limit for a reef ecosystem. The study emphasizes the importance of artificial reefs as an alternative to a degraded coral reef ecosystem in supporting the thriving existence of reef fishes in the Penyusuk waters.