Search Results (69)

A quantitative literature review of restoration techniques and supporting management strategies used throughout the Caribbean and Western Atlantic from 1998 through 2024 was compiled using references from the Web of Science to highlight those with potential for reef replenishment. From 93 sources listed, 74 publications were relevant and categorized into subtopics based on the most prevalent restoration techniques. Roughly half the studies focused on three general topics: the benefits of restoring Acropora species, studies utilizing micro-fragmentation and fragment nurseries, and outplanting techniques. Other subtopics, each with at least three references, included optimizing substrates and artificial reefs, enhancing larval recruitment, emphasizing the role of herbivory, improving management practices, and addressing the impacts of tourism and community engagement. The information from the references was compiled to determine the overlap among categories and the ways in which techniques and management strategies might be applied simultaneously to enhance restoration outcomes. Additionally, sources were analyzed according to time and location of publication to better visualize the emergence of this area of research and restoration efforts. An increase in publications was observed from 2014 to 2024, associated with the rise in major events impacting coral reefs. The major locations for published research were the Florida reef tract and Puerto Rico, though restoration studies were also reported from the Bahamas and sites around the Caribbean. Criteria to assess the success of techniques included coral survival, recruitment, coral coverage, habitat structure and complexity, and biomass of marine life, including fish and invertebrates that inhabited a restored reef. Most restoration efforts utilized either fragmentation or assisted sexual breeding, followed by cultivation in nurseries or labs. Outplanting success depended on fragment size, attachment style, and site selection, with less-intrusive techniques and intermediate planting densities promoting survival. Tools like GAO maps can guide site selection based on herbivore presence and algal coverage. Monitoring is critical to ensuring coral survival, especially after the first year of outplanting, while community involvement can foster public engagement in reef conservation. Full article

Coral-reef fishes in the South China Sea play a crucial role in sustaining ecosystem stability and delivering essential ecological functions. However, widespread coral degradation has led to habitat loss, intensifying environmental stress on reef-associated fish communities. To better understand their current status and guide conservation efforts, this study conducted a comprehensive, trait-based assessment of coral-reef fish diversity across 19 reef sites in the South China Sea, spanning nearshore (Sanya, Hainan) and offshore (Xisha and Nansha Islands) systems. Significant spatial differences were observed in species composition, functional trait structure, and responses to environmental disturbance. Offshore reefs, particularly in the Nansha Islands, exhibited the highest species richness, trophic complexity, and functional diversity, while nearshore reefs showed simplified community structure dominated by small, sedentary species with high microhabitat dependence. Coral cover was only weakly correlated with fish diversity and failed to reflect functional trait complexity, highlighting the limitation of relying on structural indicators alone. Using community-weighted trait metrics, PCA, and indicator species analysis, this study established a tri-principle framework for identifying priority conservation species based on ecological function, rarity, and vulnerability. Key functional species—including Chlorurus sordidus, Siganus fuscescens, and Cephalopholis urodeta—were identified, along with representative conservation sites such as Meiji Reef, Lingyang Reef, and Luhuitou. These findings underscore the need to integrate species-level and functional diversity into coral reef monitoring and management. The proposed framework provides a science-based foundation for prioritizing species and habitats, enhancing the resilience of reef ecosystems under the dual threats of climate change and anthropogenic pressure. Full article

Bahía de Los Ángeles (BLA) is located on the peninsular coast of the Gulf of California, near to the midriff islands. It is a greatly diverse ecosystem and a marine protected area due to its importance for whale sharks, turtles, and reef fishes. The bay also supports commercial fisheries that require ecological information for the integrated management of resources. Zooplankton studies are required as is an essential link in the trophic webs. There are few zooplankton studies in BLA focused mainly on the major taxa and species of copepods and cladocerans. Only one study addressed the seasonal variation in zooplankton but with gaps in the sampling. Here, we report the monthly changes in the zooplankton abundance and the composition of the major groups and cladoceran species. Eighty-one samples were collected between September 2017 and January 2019. The holoplankton taxa identified numbered 17, which accounts for 93% of the mean abundance (range 71–100%), with copepods and cladocerans being dominant. The meroplankton consisted of 15 taxa with a greater presence during the warm months (summer–autumn), dominated by the larval stages of bivalves, gastropods, and barnacles. In contrast, many copepod nauplii were found in January associated with low temperatures. Only cladacerans were identified to the species level. They showed strong seasonal fluctuations, reaching a third of the total zooplankton from spring to autumn, with Penilia avirostris being the most abundant species. These results are compared with other temperate and tropical coastal locations of the eastern Pacific. Full article

Fish is a major source of protein in Asia–Pacific countries. Ciguatera fish poisoning (CFP), caused by consuming reef fish contaminated with ciguatoxins (CTXs), poses a significant health risk, affecting the neurological, gastrointestinal, and cardiovascular systems. Climate change and the global food trade are potentially major factors contributing to the expanding geographical range and frequency of CFP outbreaks. Therefore, the surveillance and monitoring of CTXs in fishery products are essential to safeguard food safety. In this study, liquid chromatography–high-resolution mass spectrometry (LC-HRMS) was used to screen for CTXs in wild-caught fish from the region. Analysis of two grouper fish samples from Okinawa, Japan, detected CTX-1B, a major CTX known to incur in fish from the Asia–Pacific region. Additionally, putative Indian Ocean CTXs (I-CTXs) were also identified. Further study with HRMS on wild-caught red emperor fish from Southeast Asia waters revealed low levels of I-CTXs as well. These findings underscore the urgent need for enhanced food safety measures and expansion of monitoring protocols to include I-CTXs. This research contributes to the global understanding of CTX distribution and confirms the importance of HRMS application in routine surveillance to mitigate the risks associated with ciguatera fish poisoning (CFP). Full article

The limited research in Utría Cove has hindered our understanding of marginal coral areas in a rapidly changing ocean. To better understand how marginal reefs could serve as coral reservoirs where local communities could actively be involved, we assessed the ecological attributes of Utría’s coral areas, documented the impact of the 2023–2024 El Niño event, and conducted a SWOT analysis to frame the restoration potential. The current state shows a reduction of 1.4 ha in La Chola reef, where the average live coral cover is 24% and algal cover is 41%. The other two coral communities assessed (Diego and Punta Diego) showed coral cover between 14% and 17%, and algal cover between 42% and 50%, respectively. No significant differences were found in structural complexity, benthic cover, and macroinvertebrates; only fish richness was significantly higher at Punta Diego. Based on previously documented higher coral cover, the three areas need interventions (i.e., active restoration), especially considering the widespread bleaching recorded (temperatures up to 31.4 °C; sustained mean temperatures of ~30 °C ± 0.43), associated with El Niño. The SWOT analysis identified four weaknesses (e.g., logistical challenges), four threats (e.g., illegal fishing), six strengths, and six opportunities that highlight the potential to engage locals in restoration by providing economic alternatives and boosting regional initiatives. Full article

Oceanic tuna fisheries are a major contributor to the economic health of Pacific Island countries (PICs), with coastal fisheries underpinning the livelihoods of locals, providing food security, significant employment, culture, and human welfare. Livelihood development across various PICs is hindered by the inability to harness the maximum potential of coastal fishery resources, particularly through the lack of identifying targeted development needs. Development of coastal value chains facilitates resilience by reducing local reliance on tuna fisheries and associated vulnerability to tuna industry dynamics to support socio-economic development throughout the PICs while maintaining food security. The aim of this paper is to identify priority opportunities for developing coastal resource value chains in PICs, targeting increased local economic resilience and food security. A methodology developed by the World Bank was used to assist stakeholders and policymakers to coalesce around common strategies for the value chains. Six value chains were identified: beche-de-mer; ornamental black pearls and Trochus shell; fresh fish for the domestic market; reef fish exports; export of live lobsters; and export of aquarium fish products. Porter’s Five Forces framework was used for value chain analysis, and strategic repositioning considerations and areas for investment support within high-priority value chains were identified. Fisheries data collection, community-based sustainable management and aquaculture restocking programmes, habitat restoration, development of the cold chain, air freight logistics for export, and facilitating international market connections and market access were identified for external investment support. Full article

The seasonal and interannual temporal variation in the composition, richness, diversity, and similarity of fish larval assemblages associated with an Eastern Tropical Pacific (ETP) coral reef system was studied in March (cold water) and September (warm water) during the years 2017, 2018, and 2019. Throughout the study period, we collected 4779 fish larvae and identified 88 taxa, encompassing 46 families. This increased the total number of recorded fish taxa for the region to 146. Fish larvae were collected by daytime and nighttime surface trawls, using a bongo net 30 cm in diameter and 180 cm in length, equipped with mesh sizes of 300 and 500 μm. The species diversity and abundance of ichthyoplankton over this ETP coral reef changed by intra-annual variation of the hydrological conditions of the upper layer of the sea. Six significant assemblages were identified (SIMPROF, p < 0.05), each one associated with each sampling period (ANOSIM, R = 0.764); Cetengraulis mysticetus, Diaphus pacificus, Anchoa sp., Anisotremus sp., Bremaceros bathymaster, Oligoplites saurus, Caranx sp., Seriola sp., Gobiidae sp., Microgobius sp., and Synodus evermanni were the species that contributed to dissimilitude between groups. Canonical correspondence analysis revealed significant associations between specific larval fish taxa abundance and temperature, salinity, dissolved oxygen, and zooplankton biomass. Overall, the assemblage of ichthyoplankton in this ETP coral reef system is sensitive to seasonal changes in water column hydrographic conditions. Full article

Biological reference points are key quantities provided by stock assessments and used in fishery management for evaluating fishery status and setting future catch levels. For many fisheries worldwide, biological reference points are based on the spawning potential ratio (SPR), which measures per-recruit reproductive output as a function of the fishing rate relative to that when fishing is absent. SPR depends on the biological characteristics of the stock, which in turn can be influenced by the environment. A fishing rate based on SPR is often used as a proxy for the fishing rate that provides maximum sustainable yield. Here, we evaluate variability in the fishing rate (F₄₀) that provides an SPR of 40%, a commonly used limit reference point, given plausible variability in biological characteristics. Using eight case-study species from marine waters off the southeast United States, we consider both simple random variability and directional variability, both of which might result from climate change. We test the sensitivity of F₄₀ to various life-history traits and compute distributions of F₄₀, given the expected variability in those traits. Based on those distributions, we evaluate the probabilities of overfishing given a target fishing rate (here, 75%F₄₀) that is based on prevailing conditions without considering future variability in F₄₀, consistent with common, current practice. Analyses also considered an SPR of 30% and 50% to evaluate the generality of conclusions. Results support that SPR-reference points are generally robust to plausible levels of variability in life-history traits that might be induced by environmental nonstationarity and that associated target fishing rates can provide meaningful buffers to prevent overfishing. Full article

This research explored the influence of seasonal and environmental variables on the variation and density of ichthyoplankton in the Thermaikos Gulf and the adjacent marine protected area of the Litochoro artificial reef in Pieria, northern Greece. The objective was to assess the condition of existing ichthyoplankton communities, understand their relationship with seasonal environmental parameters, and ascertain whether the area plays the role of a fish nursery site. Observations were carried out on the boundary of the marine protected area near Litochoro, with collection sessions occurring during the spring, summer, and fall seasons from 2018 to 2021. Ichthyoplankton was collected using a bongo net sampler across 16 stations, identifying seventy larval fish species. Measurements of physico-chemical parameters were taken as well as community and population metrics such as species abundances. In the Litochoro area, the interplay between environmental conditions and the dynamics of ichthyoplankton species highlights significant ecological trends. Notably, commercially important species such as Engraulis encrasicholus (anchovy) and Sardina pilchardus (sardine) exhibited peaks in abundances, with anchovies reaching up to 544/10 m² in May 2021 and sardines peaking at 383/10 m² in April 2020. These species are crucial both ecologically, as integral components of the marine food web, and economically, serving as primary targets in local fisheries. Spearman analysis showed some species like anchovy having a negative trend with chl-a values. Also, diversity indices had strong negative correlations with chl-a values, suggesting that higher chl-a concentrations might be associated with lower biodiversity whereas most diversity indices, apart from Pielou’s normality index (J) and Simpson’s diversity index (1–lambda), showed a significant positive correlation with surface salinity. This suggests that increased salinity levels might boost certain facets of biodiversity during the summer and early autumn months. Full article

Queen triggerfish Balistes vetula is an important reef-associated species for commercial fisheries in the U.S. Caribbean. It exhibits a relatively unique reproductive strategy as a nesting benthic spawner, investing substantial energy in territorial defense, building and maintaining nests, and caring for fertilized eggs during the reproductive season. Prior to this study, no comprehensive life history information existed in the literature for queen triggerfish. This study provides the first comprehensive documentation of age, growth, size/age at sexual maturity, reproductive seasonality, and reproductive output for a Balistes species in the Caribbean. From 2013 to 2023, we collected 2190 fish samples from fisheries-dependent and -independent sources from the waters of Puerto Rico and the U.S. Virgin Islands. Fish ranged from 67 to 477 mm fork length (FL). We documented that queen triggerfish is sexually dimorphic with males attaining larger mean sizes-at-age compared to females and the species is characterized by a moderately young age at median sexual maturity (A₅₀ = 3.3 y). The maximum age for our U.S. Caribbean samples was 23 y based on increment counts from otoliths. Spawning season encompassed the months of December to August in the region, and female spawning frequency ranged from an estimated 2 to 84 times per year; female spawning frequency increased with increasing size and age of fish. We documented that commercial fishers in the U.S. Caribbean mainly target “plate-size” individuals, defined in our study as 235–405 mm FL, which appears to act as a self-imposed slot size range limit and results in the fishery not removing individuals in the smallest and largest size groups at high rates. The percentage of immature fish from fisheries-dependent sources was close to 0 (0.8%). Commercial fishing for queen triggerfish in the region currently appears to be sustainable, but monitoring of the population should continue. Full article

This paper provides a review of toxic algal blooms in the Philippine and Malaysian coastal and marine systems, considering relevant available knowledge, including climate change dimension/s in the assessment of their recorded recent expansion. The first record of human toxicity in the Philippines associated with HABs/toxic algal blooms specifically was during the bloom of Pyrodinium bahamense in the Sorsogon, Samar, and Leyte waters in 1983. Since then, the species has been identified to occur and cause blooms in about 44 sites/areas in the country. Recent government reports, i.e., 2021, 2022, and 2023, have also identified other paralytic shellfish poisoning (PSP) causative organisms (Gymnodinium catenatum, Alexandrium spp.) in the country. New records indicate that the presence of PSP causative species has been reported almost year-round in the Philippines. In Malaysia, PSP caused by P. bahamense was initially confined in 1981 to the state of Sabah, Malaysia Borneo, but since then, blooms of this species have been reported almost annually at different scales across the coastal waters of Sabah. P. bahamense and other cyst-forming dinoflagellates could be transported naturally or through human activities. Other eco-physiological and environment factors from the field and the laboratory have been used to study the bloom dynamics and transport of PSP causative species in several areas in the Philippines and Malaysia. More recently, plastics and other marine litter have been considered potential vectors of invasion/transport or expansion of dinoflagellates with other microorganisms. ENSO events have been observed to be stronger since 1950 compared with those recorded from 1850 to 1950. The extreme phases of the ENSO phenomenon have a strong modulating effect based on seasonal rainfall in the Philippines, with extreme ENSO warm events (El Niño) often associated with drought and stresses on water resources and agriculture/aquaculture. In contrast, cold events (La Niña) often result in excessive rainfall. The La Nina Advisories from 2021 to 2023 (18 advisories) showed the persistence of this part of ENSO, particularly in regions with recurrent and new records of HABs/toxic algal blooms. More studies and monitoring of another type of toxic algal bloom, Ciguatera Fish Poisoning (CFP), are recommended in tropical countries such as the Philippines and Malaysia, which have extensive reef areas that harvest and culture marine fish for local and export purposes, as accelerating reports of this type of poisoning have apparently increased and causative organisms have been identified in several areas. There is an urgent need to enhance HAB/toxic algal bloom research and monitoring, particularly those related to climate change, which has apparently impacted these blooms/occurrences directly or indirectly. Local researchers and managers should be made aware of the knowledge and tools already available for their utilization and enhancement to meet local conditions and challenges for potential recurrence and expansion of HABs/toxic algal blooms. Regional and international HAB research and collaboration should be further advanced for the protection of public health and marine resources. Full article

In May 2023, oceanic and atmospheric anomalies indicated El Niño conditions in the eastern Pacific, followed by coral bleaching in coral communities and reefs of Huatulco. We conducted surveys and sampled coral reef communities from late June to mid–August of 2023 to evaluate the intensity and extent of the changes associated with the warming event. From January of 2023, Huatulco experienced positive sea surface temperature (SST) anomalies; however, beginning in June, the high-temperature anomalies became extreme (>31 °C; ~2 °C above historical records). These high temperatures resulted in extensive coral bleaching in middle–late June and mortality from middle–late July (>50–93%). In addition, the area experienced significant reductions in echinoderm abundance and fish biomass. In 2023, severe bleaching affected coral systems in the Central Mexican Pacific, Gulf of Mexico, and Mexican Caribbean, making this the most devastating marine heatwave event, simultaneously impacting coral reefs across Mexico’s Pacific and Atlantic coasts. Full article

Scarus forsteni, a whitespot parrotfish from the Scaridae family, is a herbivorous fish inhabiting coral reef ecosystems. The deterioration of coral reefs has highly affected the habitats of the parrotfish. The decline in genetic diversity of parrotfish emphasizes the critical importance of conserving their genetic variability to ensure the resilience and sustainability of marine ecosystems for future generations. In this study, a genome of S. forsteni was assembled de novo through using Illumina and Nanopore sequencing. The 1.71-Gb genome of S. forsteni, was assembled into 544 contigs (assembly level: contig). It exhibited an N50 length of 17.97 Mb and a GC content percentage of 39.32%. Our BUSCO analysis revealed that the complete protein of the S. forsteni genome had 98.10% integrity. Combined with structure annotation data, 34,140 (74.81%) genes were functionally annotated out of 45,638 predicted protein-coding genes. Upon comparing the genome size and TE content of teleost fishes, a roughly linear relationship was observed between these two parameters. However, TE content is not a decisive factor in determining the genome size of S. forsteni. Population history analysis results indicate that S. forsteni experienced two major population expansions, both of which occurred before the last interglacial period. In addition, through a comparative genomic analysis of the evolutionary relationship of other species, it was found that S. forsteni had the closest relationship with Cheilinus undulatus, another member of the Labridae family. Our expansion and contraction analysis of the gene family showed that the expansion genes were mainly associated with immune diseases, organismal systems, and cellular processes. At the same time, cell transcription and translation, sex hormone regulation, and other related pathways were also more prominent in the positive selection genes. The genomic sequence of S. forsteni offers valuable resources for future investigations on the conservation, evolution, and behavior of fish species. Full article

Cryptobenthic fishes make up more than half of coral reef fish fauna and contribute greatly to coral reef trophodynamics and diversity. Because of their small size, they are easily overlooked and understudied. Some of them use corals as their habitat, but this association is not well understood. In the Caribbean, two common cryptobenthic gobies, Elacatinus evelynae and Coryphopterus lipernes, are usually observed residing on corals. In order to compare their habitat use, we investigated their distributions on a range of scleractinian host-coral species at three different depths (5, 10, and 15 m) at Curaçao, southern Caribbean. The numbers of both species were relatively low at 5 m. Furthermore, we investigated the relationship between fish size and depth and found that adult E. evelynae individuals were most common at 5 m depth and juveniles at 15 m depth. Novel host corals were found for both fish species. Taking host size into account, the gobies were most abundant on large coral colonies of two host species: E. evelynae on both Colpophyllia natans and Montastraea cavernosa, and C. lipernes only on C. natans. In summary, depth, host species, and host-colony size were found to be environmental factors that may determine the occurrence of both fish species. Full article

Habitat fragmentation (HF) is an ecological process, which is potentially also one of the main causes of diversity loss. Many studies have debated the best tools to adopt for assessing the effects of HF. The traditional application of biodiversity metrics might not fully describe the biotic community associated to a particular habitat or the ongoing ecological processes. The community-weighted mean (CWM) seems to be a valid investigation index, since biological traits (BTs) of the associated community are selected by local environmental factors. Furthermore, by combining species with common BTs into Functional Groups (FGs), it is possible to account for ecological functions that are supported by the inclusion of the response of key species within the same context. In our case study, we investigated the possible effect of HF of different Sicilian vermetid reefs on the associated infralittoral fish community based on the (i) vermetid fragmentation level, (ii) nature of the infralittoral substratum and (iii) conservational level of protection. We expected HF to be the main factor in shaping the local fish community; however, the nature of the infralittoral substratum proved to be the principal driver of the ichthyofaunal community. By analysing separately the two infralittoral substrata considered in the study, we observed how HF might affect the associated fish community differently. A pristine vermetid reef seems to sustain a higher number of FGs when established on a rocky substratum. On the other hand, in the presence of a sandy substratum, a fragmented vermetid reef seems to attract a more functionally rich fish community than those accounted for a pristine status. Our results provide some evidence in support of the need to include a broad spectrum of community function descriptors for a more comprehensive characterisation of a habitat and for the assessment of the functioning of its ecosystem. Full article