Wild Fish Research Articles

A comparative assessment of economic, social, and environmental performance of tilapia aquaculture in Nigeria and Ghana

Capture fisheries in many developing countries are overcapitalized and biologically overexploited, necessitating the promotion of aquaculture to mitigate the deficit in animal protein requirements, create jobs, reduce poverty, and improve the livelihoods of individuals and communities. Over the last two decades, total aquaculture output and its contribution to domestic fish production have surged, reaching 19% and 26% by 2021 (from 1% and 6% in 2000) in Ghana and Nigeria, respectively. The two main species cultivated are tilapia and catfish. While Nigeria is Africa’s second-largest aquaculture producer, Ghana experienced the fastest growth in aquaculture production between 2006 and 2019. Despite the potential benefits, the sectors in both countries face critical challenges, including high feed costs and a lack of technical expertise. In addition, aquaculture can impose a negative externality on aquatic and terrestrial ecosystems. As a result, aquaculture’s social, economic, and environmental sustainability benefits are context and species-specific, hence an empirical conundrum. This study employs the Aquaculture Performance Indicators (APIs) for a comparative assessment of tilapia farms in Nigeria and Ghana. We found that the overall economic sustainability score is similar for both countries, but Ghana outperforms Nigeria marginally in social and environmental performance.

Thyroid Endocrine Disrupting Potential of Fluoxetine in Zebrafish Larvae.

Fluoxetine (FLX), a typical selective serotonin reuptake inhibitors, has been frequently detected in aquatic environment and wild fish. However, little is known about its effect on thyroid endocrine system. In the present study, zebrafish (Danio rerio) embryos were exposed to 1, 3, 10, and 30 μg/L of FLX for 6 days. Chemical analysis demonstrated that FLX and its metabolic product (nonfluoxetine, NFLX) were accumulated in zebrafish larvae. The exposure resulted in decreased thyroid hormones (THs) levels, indicating thyroid endocrine disruption. Moreover, thyroid-stimulating hormone (TSH) content was significantly inhibited in a concentration-dependent manner after exposure to FLX. Gene transcription in the hypothalamic-pituitary-thyroid (HPT) axis was further examined, and the results showed that the genes encoding corticotrophin-releasing hormone (crh) and thyrotropin-releasing hormone (trh) were significantly up-regulated as a compensatory mechanism for the decreased TH contents accompanied with decreased tshβ mRNA expression. In addition, genes involved in thyroid hormone synthesis (sodium/iodide symporter, nis, thyroglobulin, tg) and transport (transthyretin, ttr) were down-regulated after exposure to FLX in a concentration-dependent manner. The increased gene transcription of deiodinases (dio2) and uridinediphosphate-glucuronosyltransferase (ugt1ab) might be responsible for the decrease of TH contents. In addition, a significant inhibition in thyroid hormone receptors (trα and trβ) gene expression was observed upon treatment with FLX. All these results demonstrated that FLX could alter THs and TSH content as well as gene transcription in the HPT axis, exerting an endocrine disruption of the thyroid system in zebrafish larvae.

Population Dynamic of the Shield-head Catfish Synodontis Schall (Bloch & Schneider, 1801) in Upper Atbara and Setit Dam Complex, Sudan

This study aimed to assess important population bio-parameters of Synodontis schall in the Upper Atbara and the Setit dam complex (Sudan), comprising asymptotic length, growth curvature, length at maturity, optimum length, growth performance index, and mortality rate. The study was based on the need to assess capture fisheries; whose success depends on understanding the species' population structure. For five months (September 2019 and January 2020), 500 specimens of S. schall were collected randomly using gillnet from fishermen monthly. Morphometric parameters were taken in the field. The length-weight relationship demonstrated a strong correlation coefficient of r = 0.902, indicating a negative allometric growth pattern with a b-value of 2.619. The von Bertalanffy growth function was used in estimating population parameters obtained from length-frequency data; The asymptotic length (L∞) was 36.75 cm, the growth curvature (K) was 0.78 yr.-1, and the optimum length (Lopt) was 23.09 cm. The total mortality (Z) was 2.09 yr.-1; exploitation rate (E) = 0.34 yr. -1, natural mortality (M) and fishing mortality (F) = 1.39 and 0.7 yr. -1, respectively. The overall growth performance index of 3.023 indicated a slow rate of growth. The results suggest that this species and other commercial species require further research on population dynamics.

Current Status of Hilsa (Tenualosa ilisha) Fisheries in Bangladesh and Implications for Future Research and Development

ABSTRACTHilsa shad (Tenualosa ilisha) is an anadromous fish, making the single largest wild fishery in Bangladesh, supporting the livelihoods of about 2% of the population and contributing 1% to the national GDP. Several studies reported positive outcomes associated with its catch status, biology, ecology, nutritional profile, conservation and management and socio‐economic impacts. However, significant knowledge gaps exist in hilsa fisheries, particularly in the areas crucial for research and development. In this article, we conducted a systematic review of literature to identify and address the knowledge gaps, challenges and research priorities in hilsa fisheries to ensure their sustainable management and production. Recent data from the Department of Fisheries (DoF) indicate rising production of hilsa in Bangladesh, sparking debate about its accuracy. Reliable data are essential to avoid miscalculations that could lead to risk of overfishing or underfishing of this important fish. Hilsa matures at 6–12 months, lives 2–6 years, feeds primarily on phytoplankton and spawns mostly during full moon of September and October. The abundance of brood hilsa in the river systems before and after the peak breeding season suggests further research is needed to refine breeding period for sustainable production. Although recent molecular studies have mapped the complete genome of hilsa, there remains a lack of comprehensive knowledge on its biology, ecology, conservation and life cycle—the key areas for sustainable catches and domestication. Enhancing global demand for this species requires value addition, such as removing sharp pin bones in the flesh. DoF has implemented various policies and projects, including establishment of sanctuaries to protect and conserve hilsa fisheries for sustainable exploitation. However, these measures have sparked controversy due to their adverse impacts on income and livelihoods of fishermen. Addressing these challenges and knowledge gaps requires focused research and development initiatives to ensure sustainable hilsa fisheries in Bangladesh.

Genetic monitoring suggests ongoing genetic change in wild salmon populations due to hybridization with aquaculture escapees

Abstract Substantial domestication associated divergence of farmed from wild Atlantic salmon has raised concerns regarding the negative impacts of farm escapees on the genetic integrity and adaptability of wild salmon populations. Studies from across the North Atlantic have repeatedly demonstrated the presence of hybridization and introgression from escapees into wild salmon populations, however longer-term genetic monitoring has rarely been conducted. Here we use targeted SNP panels to evaluate the presence of hybridization and subsequent introgression of escaped farmed salmon into 18 southern Newfoundland rivers and reconstruct the number of escapees contributing to hybrids sampled over an 8-year period encompassing three reported escape events. Ongoing hybridization was observed throughout the entire time series, with F1 young-of-the-year individuals detected every year, as well as a notable increase in the proportion of backcross wild fish. Population estimates of domestic admixture were highest in smaller rivers reaching up to 78%, and the amount of aquaculture-associated European ancestry within individuals ranged as high as 39%. Spatial patterns of hybridization were closely associated with proxies of wild population size based on habitat area. Genetic analyses of relatedness indicated that at least one farm escapee parent was present each year, with the highest estimated numbers occurring after two escape events. This 8-year genetic time series, the longest monitoring period for farm escapee impacts in North America, offers valuable insight into the ongoing genetic impacts of escaped farmed salmon on wild populations.

Boat noise reduces vocalization rate and alters vocal characteristics in wild plainfin midshipman fish.

Anthropogenic noise pollution has been accelerating at an alarming rate, greatly altering aquatic soundscapes. Animals use various mechanisms to avoid acoustic masking in noisy environments, including altering calling rates or the frequency (pitch) of their vocalizations or increasing the amplitude (loudness) of their vocalizations (i.e., exhibiting the Lombard effect), but few studies have examined this vocal plasticity in fishes. We tested the effects of in situ motorboat noise on the agonistic and mating vocalizations of nesting plainfin midshipman fish (Porichthys notatus), and found that midshipman fish reduce and alter their vocalizations in the presence of boat noise. During boat noise, fish produced four times fewer agonistic vocalizations compared to ambient control periods. The fish also increased the frequency of mating hums and the amplitude of grunts and growls during boat noise. This study is the first to experimentally demonstrate the Lombard effect in fishes using real motorboat noise.

Distribution of Temperature and Salinity on Fishing Zone in The Regional Fisheries Management of Indonesia (WPP-RI) 573

The Fisheries Management Republik Indonesia (WPP-RI) 573 encompasses strategic waters in the southern Indian Ocean of Indonesia, playing a critical role in global ocean circulation through the Indonesian Throughflow (ITF). This study aims to examine the physical oceanographic characteristics, particularly sea surface temperature (SST), salinity, and marine ecosystem productivity in WPP 573, as well as the impacts of ITF variability on these parameters. Data utilized include SST, salinity, and current velocity obtained from satellite observations and numerical models. The analysis reveals that the ITF transports tropical water masses from the Pacific Ocean to the Indian Ocean, significantly influencing the spatial and temporal distribution of temperature and salinity in the region.

Overview of Fish Diseases and Their Treatment.

Fish diseases present substantial challenges to both aquaculture industries and wild fish populations, causing biodiversity loss and economic impacts. These diseases stem from a variety of factors, including bacterial, viral, fungal, parasitic infections, and environmental stress. This paper offers an overview of prevalent fish diseases, their causes, symptoms, and available diagnostic tools and treatments. It also addresses the growing concern over antibiotic resistance and the exploration of alternative therapies like probiotics and plant-based treatments in managing fish health. An integrated approach—combining pharmacological treatments, vaccines, environmental monitoring, and biosecurity measures—is vital for effective disease management in fish populations.

Price interactions between capture fisheries and aquaculture: Evidence from India

Fish is probably the only major food product in the modern human food system for which wild harvests are still important in the market supply despite the rapid growth in production of farmed fish/aquaculture. The issue of substitution, or competitive interaction, between capture fisheries and aquaculture is of immense interest due to its role in determining market prices, livelihoods, and welfare in the two sectors. This is particularly true for a developing country like India where fisheries and aquaculture play an important role in livelihood creation, export revenues, and food security. India has also witnessed a remarkable increase in inland aquaculture production which is now the largest contributor to the country’s total fish production. In this article, we employ recursive cointegration analysis and time-varying copula estimations to analyze a novel dataset to describe the evolution in the relationship between the prices of inland capture fisheries and aquaculture products in India over time. Our results suggest an increased degree of market integration for inland fish products in India over time, though the degree of integration is lower for the capture fisheries products compared to the aquaculture products.

Exploring freshwater soundscapes of tropical marshland habitats in Southeast Asia: insights into auditory sensory adaptation of wild Siamese fighting fish Betta splendens.

While soundscapes shape the structure and function of auditory systems over evolutionary timescales, there is limited information regarding the adaptation of wild fish populations to their natural acoustic environments. This is particularly relevant for freshwater ecosystems, which are extremely diverse and face escalating pressures from human activities and associated noise pollution. The Siamese fighting fish Betta splendens is one of the most important cultured species in the global ornamental fish market and is increasingly recognized as a model organism for genetics and behavioural studies. This air-breathing species (Anabantoidei), characterized by the presence of a suprabranchial labyrinth organ that enhances auditory sensitivity, is native to Southeast Asia and inhabits low flow freshwater ecosystems that are increasingly threatened due to habitat destruction and pollution. We characterized the underwater soundscape, along with various ecological parameters, across five marshland habitats of B. splendens, from lentic waterbodies to small canals near a lake in Chiang Rai province (Thailand). All habitats exhibited common traits of low dissolved oxygen and dense herbaceous vegetation. Soundscapes were relatively quiet with Sound Pressure Level (SPL) around 102-105 dB re 1 µPa and most spectral energy below 1,000 Hz. Sound recordings captured diverse biological sounds, including potential fish vocalizations, but primarily insect sounds. Hearing thresholds were determined using auditory evoked potential (AEP) recordings, revealing best hearing range within 100-400 Hz. Males exhibited lower hearing thresholds than females at 400 and 600 Hz. This low-frequency tuning highlights the potential susceptibility of B. splendens to anthropogenic noise activities. This study provides first characterization of the auditory sensitivity and natural soundscape of B. splendens, establishing an important ground for future hearing research in this species. The information provided on the auditory sensory adaptation of B. splendens emphasizes the importance of preserving quiet soundscapes from lentic freshwater ecosystems.

Morphology and Phylogenetic Analysis of Henneguya sp. Infecting the Orange-Spotted Snakehead (Channa Aurantimaculata) from Tamil Nadu, India.

Henneguya sp. is a crucial myxosporean parasite known to cause milky flesh or tapioca disease in the freshwater fish population, leading to heavy mortality. Studies to investigate its host range and to monitor their prevalence in wild and aquacultured fish are necessary. The infected orange-spotted snakehead (Channa aurantimaculata) fish samples showing clinical signs such as severe ulceration and open wounds on the mouth and operculum were collected from an ornamental fish-rearing unit in Chennai, Tamil Nadu. The sample was diagnosed with myxosporean infection by microscopic observation, morphological records and DNA sequencing followed by phylogenetic analysis. The Henneguya infection was identified in C. aurantimaculata for the first time. Necropsy of the infected fish revealed characteristic multifocal whitish-yellow, oval-shaped cysts measuring 3-5mm in length on the liver and spleen. The wet mount of cysts showed numerous mature Henneguya spores that were uninucleate, elongated, lenticular and ellipsoidal with the bluntly rounded anterior end gradually tapering off to the posterior with a caudal elongation. The spore body measured 12.1 ± 0.9μm (10.1-14.7μm) × 7.1 ± 0.6μm (5.3-8.5μm) with two slightly unequal pyriform polar capsules of 6.1 ± 0.5μm (5.1-7.4 )× 2.5 ± 0.4μm (1.6-3.9) (large); 6.0 ± 0.4μm (5.2-6.4) × 2.5 ± 0.3μm (1.7-3.1) (small) and a caudal elongation of 16.1 ± 1.2μm in length. The parasite was confirmed to be a Henneguya sp. by PCR amplification of SSrRNA followed by gene sequencing. The sequence generated was submitted in the GenBank under accession number PP852214.1 The maximum likelihood analysis revealed that the obtained sequence is a close relative of H. exilis with pairwise sequence variation of 3.3% and a homology of 99.04%. The findings highlight the potential impact of Henneguya sp. on ornamental fish health, underscoring the need for vigilant monitoring and management in India.

Fatty Acid Content and Profile in Ulva lactuca in Response to Exposure to Variable Growth Conditions in Indoor Photobioreactors.

Seaweed presents a sustainable alternative source of valuable fatty acids (FAs) involving omega-3 (n-3) and omega-6 (n-6). As such, there is great potential to reduce pressure on wild fish populations, helping to combat overfishing and its associated global impacts. This study explored the effect of various environmental factors on the FA content and profile of Ulva lactuca using indoor photobioreactors. The taxonomic identity of U. lactuca was confirmed through DNA sequencing using 3 markers (rbcL, ITS, and tufa). The effects of temperature (8, 20, and 30 °C), seawater salinity (3.5, 3.0, 2.5, and 2.0% w/v), nutrient type and concentration (0 or 6.4 ppm, consisting of 50% w/w N-NO3, 50% w/w N-NH4, and 0-1 ppm P-PO4), and irradiance (50, 100, and 150 μmol photons m-2 s-1) were evaluated. This study assessed their influence on U. lactuca's biomass production rate (BPR), dry weight (DW), ash content (AC), and FA composition after 7 and 21 days. The results revealed that after 21 days, the polyunsaturated FA (PUFA) content decreased with the increasing seawater salinity (i.e., 38.9% ± 0.7, 33.8% ± 0.4, and 27.0% ± 0.4, and 6.6% ± 0.1 for a salinity of 2.0, 2.5, 3.0, and 3.5% w/v, respectively). The content of n-3 after 21 days increased significantly under the following conditions: 8 °C, a salinity of 2.5% w/v, 6.4 ppm of nitrogen without the addition of phosphorous, and an irradiation of 50 and 150 μmol photons m-2 s-1, affording a low n-6/n-3 proportion that fits a desirable level of an n6/n3 ratio (1-10) for a balanced nutritional diet.

Individual Behavioral Syndromes and Shoal Characteristics in Farmed and Wild Acrossocheilus fasciatus

This study investigates the individual behavioral syndromes and shoal characteristics of farmed and wild populations of the cyprinid Acrossocheilus fasciatus to elucidate the factors influencing the efficacy of fish stock enhancement. We examined two wild populations from Quzhou and Lishui, in Zhejiang Province, China, and one farmed population from the same geographical location as the Quzhou wild population. Individual behavioral syndromes were thoroughly evaluated alongside shoal characteristics. Results indicated that farmed A. fasciatus exhibited greater boldness, exploratory behavior, and sociability compared to their wild counterparts. Wild populations demonstrated distinct behavioral traits, with the Quzhou population showing reduced locomotor activity and sociability, and the Lishui population displaying timidity. Shoal analysis revealed that wild fish had higher cohesion and shoal synchronization compared to farmed fish. Additionally, mixed groups exhibited intermediate locomotor behaviors but decreased cohesion, particularly in the Quzhou population. These findings underscore significant behavioral differences between farmed and wild fish, as well as among wild fish from different geographical locations, emphasizing the need for tailored training and environmental modifications in stock enhancement programs to improve survival.

Brodifacoum causes coagulopathy, hemorrhages, and mortality in rainbow trout (Oncorhynchus mykiss) at environmentally relevant hepatic residue concentrations.

Widely used second-generation anticoagulant rodenticides like brodifacoum are classified as persistent, bioaccumulative, and toxic. Widespread exposure of terrestrial and avian non-target species is well-known and recently hepatic anticoagulant rodenticide residues have been detected in wild fish. However, no sufficient data exist to interpret the effects of these findings on fish health. In order to assess the potential impact of rodenticide residues on fish, we exposed rainbow trout (Oncorhynchus mykiss) to brodifacoum-spiked feed. In a first experiment, individually kept trout (body weight ca. 200 g) were exposed to a single dose of brodifacoum and observed for 15 days. In a second experiment, fish (body weight ca. 330 g) were kept in groups and fed every 7 or 8 days with brodifacoum-spiked feed for up to 60 days. Sampling of trout every 15 days over the 60 days period allowed monitoring of brodifacoum concentrations in serum, liver, and muscle tissue, as well as occurring effects over the course of the experiment. In both experiments, brodifacoum doses of ≥ 75 µg/kg body weight caused prolonged or non-measurable blood coagulation times. Disturbed hemostasis led to hemorrhages and anemia with significantly decreased albumin levels. In the 60 days-experiment, brodifacoum doses ≥ 100 µg/kg body weight caused additionally discoloration, apathy, and anorexia, resulting in reduced weight gain, and ultimately mortality. The delay until the onset of overt symptoms (14-17 days) highlights the importance of test duration while investigating effects of anticoagulant rodenticides in fish. The lowest hepatic brodifacoum concentration associated with effects in trout was on average 122.6 ng/g liver wet weight, which is in the range of previously reported brodifacoum residues in wild fish. These findings illustrate the risks associated with the use of anticoagulant rodenticides for freshwater fish and reinforce the need to stipulate all available and appropriate risk mitigation measures to prevent emissions at source.

Indigenous Technical Knowledge on Use of Plants in Capture Fisheries in Northeast Region of India: A Review

Indigenous Technical Knowledge on Use of Plants in Capture Fisheries in Northeast Region of India: A Review

The effect of structural enrichment and increased water flow on the opportunity for domestication selection in hatchery-reared steelhead (Oncorhynchus mykiss)

Hatchery-reared salmon often have lower fitness in the wild than wild fish, a difference that appears to result from rapid adaptation to the hatchery environment. Size at release is heritable and positively correlated with survival at sea. Therefore, selection should favor traits that promote fast growth in the hatchery even if those traits are maladaptive in the wild. Modifying hatchery conditions to reduce the variation in size among families should decrease the opportunity for selection. Using a mix of 15 full-sibling families of winter run steelhead ( Oncorhynchus mykiss), we tested two modifications designed to benefit the normally slower-growing fish: (1) the addition of structure to rearing tanks and (2) increased water flow. Neither treatment substantially changed the variance in size at release relative to controls. Furthermore, there was a very high correlation among family mean size across all environments. We conclude that simple changes to the hatchery environment such as those tested here cannot overcome the large family effects and are unlikely to substantially reduce the opportunity for selection on size at release.

Cleaner cuts: Farmed fish and skin-off fillets are lower in per- and polyfluoroalkyl substances (PFAS).

The ubiquitous occurrence and persistence of per- and polyfluoroalkyl substances (PFAS) in all environmental matrices and biota poses significant health risks to humans. Fish consumption is one of the main pathways humans are exposed to PFAS, yet general patterns in factors influencing PFAS content in fish fillets remain unknown. We assembled information on PFAS content (total quantified PFAS, PFOS, PFOA, and others) in fish fillets to assess the effect of fish origin (marine, freshwater, wild, or farmed), fillet type (skin-on or skin-off), and lipid content on PFAS variation across environments at a global scale. We found that these factors influenced PFAS contents in fish fillets, with concentrations reaching up to 2149ng•g wet mass-1 (WM). Specifically, PFOS and PFOA in skin-off fillets were consistently lower in farmed than wild fish across freshwater and marine environments. In freshwater wild fish, PFOS was lower in skin-off fillets than skin-on fillets at group and species levels, and multiple PFAS showed an inverse relationship with the lipid content of skin-off fillets, though the slopes showed varying steepness depending on the carbon chain length and functional group of the PFAS. However, the high variability of PFAS content across sites in aquatic environments and the complexity of PFAS bioaccumulation mechanisms in fish tissues may lead to variable results at a fine scale (i.e., species level); this highlights general patterns of factors influencing PFAS bioaccumulation that may inform the management of human exposure to PFAS through dietary consumption.

Efficacy of fisheries management strategies in mitigating ecological, social, and economic risks of climate warming in China.

Climate change has significantly altered fish population dynamics and marine ecosystems worldwide, resulting in multiple ecological, economic and social risks for sustainable fisheries. As a hotspot of global warming, China is anticipated to face with extensive climate-driven changes in marine fisheries and ecosystems, but a clear and adaptative management strategy has not been established. In this study, we assessed the climate adaptiveness of current fisheries management and alternative strategies with diverse management priorities. Dynamic ecosystem model, Ecosim, was used to quantify the effectiveness of these management options in mitigating ecological, social, and economic risks of climate change, as well as the potential trade-offs. Results showed that under the status quo fisheries management, climate warming would dramatically impair ecosystem structure and function, leading to declines in fishery yields, economic losses in the fishing industry, and potential food security crises. However, these climate-driven risks could be mitigated, or at least minimized, through improved fisheries management. The harvest control rule (HCR) strategy, which responds to climate-induced biomass variations, would be most effective in promoting sustainable fisheries production but limited in offsetting climate-driven economic losses; while multispecies strategies can, in a balanced way, help mitigate climate change impacts on sustainable fishery production, ecosystem health, seafood security, and economic profitability. Furthermore, their capability to offset climate-driven risks would be largely compromised with increasing greenhouse emissions, as no management strategy could sustain current ecological, economic and social levels of fisheries under the high-emission scenario. We emphasize the need to pursue a dual approach that incorporates both reducing greenhouse gas emissions and taking adaptive fisheries management strategies to realize fisheries potential and ensure ecological and socio-economic resilience. Although the dynamic model cannot incorporate climate-driven spatial variations, the insights and framework from this work can support the identification of climate-resilient management strategies over long-term and provide guidance on achieving climate-ready fisheries in China and other regions.

Relations between microplastic contamination and stress biomarkers under two seasonal conditions in wild carps, mullets and flounders.

Potential effects of microplastics (MP, plastic particles <5mm) on the levels of multiple stress biomarkers were investigated in wild fish populations of Cyprinus carpio, Mugil cephalus, Platichthys flesus captured in the Minho River estuary located in the Iberian Peninsula. Specimens were collected in March and September 2018, corresponding to the end of winter and summer, respectively. Based on the concentration of MP determined by FT-IR analysis and morphological inspection, fishes from each species were divided into two groups: ≤0.1MPg-1 and >0.1MPg-1. Biomarkers (general condition, neurotoxicity, biotransformation, oxidative stress) and the Integrated Biomarker Response (IBR) indicating fish general stress were determined. Fishes with more than 0.1MPg-1 showed elevated general stress (1.2- to 1.8-fold) relative to fish with ≤0.1MPg-1. Founders captured in March were the exception. Mullets were the most susceptible fishes to MP contamination by exhibiting poor physical condition, neurotoxicity, oxidative stress or damage, and carps were the most resilient. Low temperature and less chlorophylls (a proxy of food availability) observed in March appear to enhance the biological effects of MP.

Mapping the fine spatial distribution of global offshore surface seawater mariculture using remote sensing big data

ABSTRACT Against the backdrop of near-saturation in global marine capture fisheries, current mariculture production now exceeds one-third of capture production and continues to hold significant growth potential. However, the lack of spatially detailed global offshore surface seawater mariculture (OSSM) data hampers scientific understanding and management from a spatial perspective. In this study, utilizing multi-source remote sensing time-series imagery, we achieve the world’s first spatially detailed mapping of both raft and cage mariculture types. The results show that (1) in 2020, the total global OSSM area was 20,079.97 km², comprising 85.04% raft mariculture and 14.96% cage mariculture. 95.33% of the OSSM was concentrated in Asia. (2) The interpreted national OSSM areas align well with the FAO production statistics trends. Obtaining these areas using remote sensing offers greater timeliness compared to production statistics, which is advantageous for dynamic monitoring and production estimation. (3) Through analysis of global pond aquaculture data, it was found that most coastal areas worldwide had a single-type of aquaculture. However, in parts of Asia, regions with both OSSM and pond aquaculture coexisted. The data acquired in this study, characterized by detailed spatial information, provide significant insights for constructing spatial models of mariculture, researching resource-environment effects, and informing management practices.