This study demonstrates the first identification and characterization of acanthocephalan parasites (thorny-headed worms) infecting small pelagic fish stocks sold in Leyte, Philippines. A total of 340 small pelagic fish, representing eight distinct species across four families, were purchased from the Baybay City Public Market, with the fish collected from the territorial waters of Baybay City, Albuera, Inopacan, Hilongos, and Bato. The fish samples were aggregated into 34 pools (n = 10 fish per pool) for gastrointestinal examination. Five (14.70%) of the 34 pools tested positive for acanthocephalans, with evident infections in the scombrid species Katsuwonus pelamis and Auxis rochei. Morphometric characterization of male and female worm morphotypes indicates that the parasite is a Rhadinorhynchus sp. and is more similar to Rhadinorhynchus ganapatti. Bayesian estimation of pooled prevalence using the Gibbs sampler was employed, providing prevalence estimates for a fixed pool size and testing the uncertain sensitivity and specificity. The model yielded a posterior median individual prevalence of 0.4401 (95% PI: 0.0436-0.9304), indicating a low-intensity, latent infection directly influenced by poor level sensitivity (0.1562) and specificity (0.5727). Despite its relatively low infection rate, its public health implications can never be underestimated, especially since Filipinos have a deeply rooted culinary tradition of eating raw fish known as “kinilaw.”

This study assessed the climate vulnerability of milkfish (Chanos chanos) aquaculture in Cardona, Rizal, located in the central bay of Laguna de Bay, Philippines, using the Fisheries Vulnerability Assessment Tool (FishVool). Focus group discussions were conducted with fourteen respondents, including fish pen caretakers, aquaculture operators, municipal agriculture officers, and members of the Municipal Fisheries and Aquatic Resources Management Council. Vulnerability was evaluated across three components: sensitivity, exposure, and adaptive capacity, using indicator scores translated into categorical ranks following the FishVool rubric. Results showed that sensitivity (mean score = 2.74), exposure (3.26), and adaptive capacity (3.37) were all classified as Medium, resulting in an overall Medium vulnerability classification for milkfish aquaculture in the study area. These findings indicate that while aquaculture households are not experiencing extreme climate stress, they remain subject to recurring environmental pressures and structural constraints that limit more robust adaptation. Although the assessment is site-specific to Cardona, the study demonstrates the utility of FishVool as a practical framework for evaluating aquaculture vulnerability at the municipal level.

The pronghorn spiny lobster, Panulirus penicillatus, is a high-value reef-associated species that supports small-scale fisheries and the live seafood trade in Eastern Visayas, Philippines. However, limited local reproductive information has constrained the implementation of science-based management measures for the species. This study assessed the reproductive dynamics and maturity patterns of P. penicillatus using fishery-dependent samples collected from five major lobster-producing areas from February 2018 to December 2019. A total of 8,549 individuals with valid sex records were analyzed, consisting of 4,415 males and 4,134 females. The overall sex ratio was slightly but significantly male-biased at 1:0.94 (χ² = 9.24, df = 1, p = 0.002). Size distribution, based on 8,527 individuals with valid carapace length records, was dominated by small to intermediate individuals, with 57.2% occurring between 40 and 55 mm CL. Berried females were concentrated mainly within the 45–60 mm CL range, indicating that reproductively active females were present within commonly harvested size classes. Reproductive activity was extended but temporally variable, as shown by the occurrence of egg-bearing females, tarspot-bearing females, mature ovarian stages, and significant monthly variation in female gonadosomatic index. Berried female incidence peaked from April to August 2018, while ripe ovaries and elevated female GSI were prominent during February to June 2019. Histological examination identified six ovarian developmental stages: immature, developing, ripe, spawning, re-developing, and spent. Fecundity ranged from 41,962 to 446,782 eggs per female and increased significantly with CL, highlighting the greater reproductive contribution of larger females. Logistic maturity analysis estimated CL₅₀ at 39.28 mm and CL₉₅ at 42.33 mm based on physiological maturity.

The Philippine sardine industry is integral to national food security, rural employment, and export earnings, producing an annual average of 341,000 metric tons valued at PHP 10.74 billion since 2014. Despite its significance, the sector is becoming increasingly vulnerable to ecological pressures, climate variability, and economic risks. Thus, this study employed a value chain analysis that encompasses 86% of the country's national sardine production areas, along with interviews conducted with 421 fishers, traders, and processors. Findings revealed unequal value distribution: fishers recorded high returns on investment (83%) yet remained incomeconstrained, largely dependent on traders for operating capital. Traders earned the highest income per trading cycle but were exposed to price volatility and high operating expenses, whereas processors exhibited uneven profitability across scales and product types. Policy recommendations emphasize strengthening economic resilience through collateral-free credit, cooperative input purchasing, and risk insurance in typhoon-prone provinces. Operational adaptability requires additional investments in cold storage, ice plants, and modernized processing technologies, alongside alternative livelihood programs during closed seasons to safeguard fisher incomes.

The sustainable management of tropical spiny lobster (Panulirus spp.) fisheries is constrained by limited biological data and monitoring systems, particularly in the Philippines. This study investigated the population dynamics and yield-per-recruit of six Panulirus species (P. penicillatus, P. ornatus, P. versicolor, and P. femoristriga) and the two subspecies of P. longipes (P. l. longipes, and P. l. bispinosus) in Eastern Visayas using length-frequency data from 9,051 individuals sampled between February 2018 and December 2019. Sizebased stock assessment models in FISAT II estimated a pooled asymptotic length (L∞) of 180.3 mm (males) and 169.8 mm (females), with a mean growth coefficient (K) of 0.16 yr⁻¹. Pooled total mortality (Z) averaged 1.00 yr⁻¹, and fishing mortality (F) was 0.74 yr⁻¹. Exploitation rates were high, with pooled estimates of 0.70 for males and 0.69 for females, and species-level values ranging from 0.53 to 0.79, exceeding the optimal Eₘₐₓ in five of the six species. Beverton–Holt yield-per-recruit analysis revealed that current fishing practices result in suboptimal yields, with 47–90% of individuals landed below their size at first maturity. Negative allometric growth (b = 2.02–2.70) and low size at first capture, equivalent to 20–46% of L∞, further support evidence of growth overfishing.

The bigeye scad (Selar crumenophthalmus) is a major fishery resource in Fisheries Management Area (FMA) 10 and an important contributor to the Central Visayas fisheries sector. Despite its commercial and ecological importance, up-to-date studies on the stock status in this region remain limited. This study aimed to assess the species stock status based on growth, mortality, and CPUE indicators using the catch and effort and length-frequency data collected from the National Stock Assessment Program (NSAP) enumeration sites from 2020 to 2024. Results and information generated are intended to support science-based management and inform appropriate harvest control rules and other relevant measures. The estimated von Bertalanffy Growth Function (VBGF) includes an asymptotic length (L∞) of 29.56 cm total length (TL) and a growth coefficient (k) of 1.0, indicating a fast-growing species. The analysis showed that bigeye scad exploitation has increased each year. Mortality estimates showed an average exploitation ratio (E) of 0.66 and fishing mortality (F) of 3.45, breaching the 0.5 and 2.0 thresholds, respectively, indicating high fishing mortality. CPUEs generally indicate declining trends for most major gears, and percentage catches of mature fish have breached the LRP for some dominant gears catching the species. Using the Length-Based Bayesian (LBB) approach, relative biomass at Maximum Sustainable Yield (B/Bmsy) was estimated at 0.79, and current biomass at virgin biomass (B/B0) was estimated at 0.3.

Manila Bay is a critical traditional fishing ground where the small pelagic Sardinella pacifica (formerly identified as Sardinella fimbriata) plays a vital socio-economic and ecological role. However, the population faces intense fishing pressure and overexploitation from unsustainable practices. Landed catch data from various fishing gears—including gillnets, stationary liftnets, ring nets, and otter trawls—were collected from January 2017 to December 2021. A total of 4,073 individuals were analyzed for sex ratio, body length and weight, gonadosomatic index (GSI), gonad maturity stages, length at first maturity (Lm₅₀), and length at first capture (Lc50). The monthly sex ratio significantly deviated from the expected 1:1 (F: M) proportion, indicating female dominance. GSI values and gonad maturity stages showed that S. pacifica spawns year-round in Manila Bay. Spawning shows strong environmental resilience. The estimated length at first maturity (Lm₅₀) was 10.6– 11.0 cm for females and 8.8–10.1 cm for males. These values are notably lower than the previously reported 2014–2015 baselines (12.25 cm for females and 12.75 cm for males).

Small pelagic fishes, including sardines, anchovies, and mackerel, form the backbone of the Philippines’ capture fisheries, accounting for over 44% of total production from 2018 to 2023. Among these, Sardinella lemuru (Bali sardine) is the leading species, with significant contributions from Sardinella gibbosa (Goldstripe sardine). This study assesses the population and exploitation of S. lemuru and S. gibbosa using catch and effort data collected through the National Stock Assessment Program (NSAP) from 2014 to 2023 in Fisheries Management Area (FMA) 9. Results show that commercial gears, especially bagnet and ring net, account for most sardine landings, with S. lemuru comprising 49% and S. gibbosa 2% of the total catch. Peak abundance seasons varied by species, with S. lemuru peaking from June to September and S. gibbosa from March to April, reflecting different spawning and migration patterns. Growth and mortality analyses revealed high fishing pressures on both species, with exploitation rates exceeding sustainable thresholds (E > 0.5). Only 4.8% of S. lemuru and 18.6% of S. gibbosa in the catch had reached maturity, highlighting growth overfishing and the risk of recruitment overfishing. Current catch patterns threaten long-term stock sustainability and underscore the urgent need for science-based fisheries management measures in FMA-9.

Sardinella lemuru, better known as Bali sardinella, is an important commodity in Fisheries Management Area (FMA) 7 because of its high economic value. However, overfishing threatens S. lemuru stocks. Studies of population parameters are necessary to understand their status and dynamics and to provide a foundation for developing management schemes to conserve and protect the resource. For this study in FMA 7 waters, 104,389 specimens of S. lemuru from the drift gillnet and ring net fisheries were randomly measured at different landing centers using the National Stock Assessment Program (NSAP) standard methodology from January 2019 to December 2022. Results revealed that S. lemuru is a year-round species in FMA 7, being exploited by the dominant fisheries, namely drift gillnet and ring net. The population dynamics were estimated through FiSAT II routines. The size distribution ranged from 10.25 cm to 21.25 cm. This species is fast-growing (K=0.9, K=0.77), with two recruitment pulses throughout the year. Fishing mortality (F=3.94, F=4.56) exceeded the natural mortality (M=1.79, M=1.65), revealing high fishing pressure.

This study was conducted from 2016 to 2018 to determine the reproductive capacity of selected commercially important small pelagic species in Region I. This includes the determination of the sex ratio of females and males, seasonal patterns of gonadal maturity development, gonado-somatic index (GSI), comparative values of length at first maturity (Lm), length at full captivity (L50), mean length of catch and length at full selectivity (Lc), spawning potential ratio (SPR), and length ranges of species caught by various fishing gears with their corresponding length at first maturity (Lm) using the National Stock Assessment Program standard data gathering and gonad identification. A total of 16,097 samples were collected, and the male-to-female sex ratio was 1:1. Decapterus macarellus spawns year-round, and its performance indicators fall within the target reference points except for exploitation rate (0.70). All gears catching this species show a high frequency of catch for mature individuals. Rastrelliger brachysoma and Rastrelliger kanagurta spawn from April to November. The length at full captivity (L50) of these species is near the computed Lm, indicating a high probability of capturing first-time spawners. Additionally, gillnet (GN) and trawl (T) catches show a high frequency of mature and immature sizes, while beach seine (BS) captures a high frequency of smaller sizes for R. brachysoma.

The Visayan Sea and Guimaras Strait, which make up Fishery Management Area 11 (FMA 11) in the central Philippines, are major fishing grounds rich in marine resources and the focus of this study. FMA 11 is characterized by a multi-gear, multi-species fishery due to its shallow, highly productive waters. This study examines fishing gears that use fine mesh nets (mesh size < 3 cm) at the bunt and assesses their impact on FMA 11 productivity. The objective is to evaluate how fine-mesh nets affect stock status and the fishery’s overall health. Using catch and effort data, length frequency, and grid mapping collected from 2015 to 2024 across three regions (5, 6, and 7) within FMA 11, we estimated growth parameters, maturity, and mortality coefficients for 11 priority species. Additionally, we used the open-source applications EcoPath with EcoSim (EwE) and QuantumGIS to improve understanding of the fishery’s status. Results indicate that most species in FMA 11 have exceeded reference points for both maturity and exploitation, revealing high juvenile catches and intense fishing pressure.

The shortfin scad Decapterus macrosoma is a major small pelagic resource in Palawan and a key contributor to landings in the Southwest Sulu Sea. This study evaluated its reproductive biology, population dynamics, and length-based stock status using National Stock Assessment Program (NSAP) monitoring data collected from commercial landings in Narra and Brooke’s Point, Palawan, from January 2018 to December 2020. A total of 7,525 specimens caught by bagnet and ringnet were measured for total length and weight, and gonads were examined to determine sex and maturity stage; spawning seasonality was inferred from monthly maturity-stage frequencies and gonadosomatic index (GSI), while length at first maturity (L50) was estimated using a logistic model. Growth and mortality parameters were derived using FiSAT II, and stock condition was assessed through exploitation indices, yield- and biomass-per-recruit analyses, LBSPR (SPR), and Froese length-based indicators. Among sexed individuals, females were significantly more abundant than males (overall ratio 1:1.17). Reproductive activity was seasonal, with peak spawning consistently occurring in April– May, supported by elevated proportions of ripe females and the highest monthly mean GSI (up to 3.03 in May). Female L50 was estimated at 15.81 cm TL. Gear selectivity indicated early capture, particularly in bagnet (Lc50 = 14.08 cm) relative to L50, while ringnet selectivity (Lc50 = 15.68 cm) was near maturity length. Estimated natural mortality (M) ranged from 1.75 to 1.88 yr⁻¹, whereas fishing mortality was high (F = 2.71 for bagnet; 3.17 for ringnet), resulting in exploitation rates of 0.61–0.64 that exceed the precautionary threshold (E = 0.5). Spawning potential ratios were low (SPR = 22% for bagnet; 26% for ringnet), and Froese indicators showed persistently low proportions of mature fish (10.4–28.9%) and mega-spawners (3.6–9.4%), indicating recruitment and growth overfishing with severe size truncation.

Blue Swimming Crab (BSC), Portunus pelagicus (Linnaeus, 1758), locally known as “Lambay,” is one of the most commercially traded seafood commodities in the Philippines. As in other BSC areas in the country, Hinatuan and Bislig Bays in Surigao del Sur, Caraga Region, in Fisheries Management Area 2 have abundant BSC; however, their current status is unknown. Therefore, an assessment is needed to support the formulation of policies for BSC management. This study used combined data from 2015 to 2021 from major crabbing areas in the said fishing grounds. Performance indicators were analyzed using various models, including the FAO ICLARM Stock Assessment Tool (FiSAT). The primary gear used was bottom-set gillnet, wherein P. pelagicus emerged as the dominant species, comprising an average of 53%. The computed length infinity (L∞) and growth coefficient (k) were 20.5 cm and 1.4 per year, respectively. Fishing mortality exceeds natural mortality, yielding an exploitation rate of 0.76 and indicating over-exploitation.

Coryphaena hippurus, locally known as “Arayu,” is a migratory fish of significant importance to Batanes Province, serving as a food source, livelihood, and cultural identity for Ivatan communities. This study assessed the stock status of the species in Batanes Waters (Fisheries Management Area 1) using standard National Stock Assessment Program (NSAP) methodology, analyzing data collected from 2014 to 2023. The results present a complex picture of the stock. Troll line is the dominant gear, contributing 97.1% of the total catch. Historical catch and Catch Per Unit Effort (CPUE) have increased steadily, while the Spawning Potential Ratio (SPR) was estimated at 43% in 2022 and 2023, indicating a healthy status. However, natural mortality (M), fishing mortality (F), and exploitation ratio (E) were estimated at 1.02, 5.89, and 0.85, respectively. This rate of F being almost five times M indicates high fishing pressure, and E suggests the stock is already beyond the sustainable level of exploitation.

This study examined the catch composition and population status of dominant small pelagic species exploited by purse seine fisheries in the Southeast Sulu Sea from 2018 to 2023. The research aimed to develop a data-driven fisheries profile of the region by generating comprehensive information on species composition, exploitation patterns, and population dynamics associated with purse seine landings. Data were collected from twelve major landing sites and analyzed using established growth models and length-based stock assessment approaches. Results indicated that Sardinella lemuru dominated the total catch, contributing 1,118,742.9 mt (85.2%), followed by Decapterus macrosoma with 76,273.2 mt (5.8%), Selar crumenophthalmus with 37,176.8 mt (2.8%), Amblygaster sirm with 21,451.7 mt (1.6%), and Decapterus macarellus with 3,671.1 mt (0.3%). Stock assessment analyses revealed persistent fishing pressure and elevated exploitation levels in S. lemuru (L∞ = 20.6 cm, k = 1.11 yr⁻¹, Ø′ = 2.673, M = 2.12 yr⁻¹, F = 2.78–4.38 yr⁻¹, Z = 4.92–6.50 yr⁻¹, E = 0.57–0.63), D. macrosoma (L∞ = 26.77 cm, k = 1.03 yr⁻¹, Ø′ = 2.868, M = 1.88 yr⁻¹, F = 1.98–3.45 yr⁻¹, Z = 3.86–5.33 yr⁻¹, E = 0.51–0.65), and S. crumenophthalmus (L∞ = 28.86 cm, k = 1.02 yr⁻¹, Ø′ = 2.929, M = 1.83 yr⁻¹, F = 1.83–3.87 yr⁻¹, Z = 3.66–5.70 yr⁻¹, E = 0.50–0.68), with exploitation ratios consistently exceeding the biological reference point for sustainable exploitation (E > 0.50). In addition, growth overfishing was evident, as the estimated lengths at first capture (L₅₀) for most species were generally below established length-at-maturity benchmarks, indicating substantial harvesting of immature individuals. In contrast, D. macarellus exhibited comparatively healthier stock conditions (L∞ = 33.9 cm, k = 0.97 yr⁻¹, Ø′ = 3.047, M = 1.69 yr⁻¹, F = 0.91–1.69 yr⁻¹, Z = 2.60–3.38 yr⁻¹, E = 0.35–0.50), characterized by lower fishing mortality and exploitation rates.

The study was conducted to assess the exploitation status, mortality rates, and growth parameters of sardines (Sardinella lemuru) in Fishery Management Area 4 (FMA-4) from 2018 to 2023, a region responsible for about 50% to 70% of the country's sardine production (FFTC, 2017). Using consistent monitoring from the National Stock Assessment Program (NSAP) and statistical analysis tools such as TropFishR (R), key indicators such as exploitation rate (E), fishing mortality (F), natural mortality (M), and growth parameters (Linf, K) were estimated annually. The exploitation rates ranged from 0.60 to 0.68, nearing the limit reference point of 0.70, while fishing pressure also ranged from 1.53 to 2.15, suggesting that S. lemuru stocks are under high fishing pressure or are highly exploited. The fishing mortality consistently exceeded natural mortality over the years, further emphasizing the elevated pressure exerted by commercial fisheries. Growth analysis exhibited moderately fast-growing stocks, with variations in capture probability across years influenced by fishing gears and management practices, notably closed fishing seasons. Parameter estimation methods such as Powell-Wetherall plots, K-Scan, Response Surface Analysis (RSA), Simulated Annealing (SA), and Genetic Algorithm (GA) were applied to optimize the growth models and evaluate key values for Linf and K, ensuring reliable and accurate results.

Sardinella lemuru constitutes 77% of the total landed catch in Fishery Management Area -4 from 2015 to 2024. This assessment of stock status has utilized length-based data, applying statistical models including the FAO-ICLARM Stock Assessment Tool (FiSAT), Length-Based Method and Gear (LBAR), and Froese Indicators to estimate the Exploitation Ratio (E), Length at First Maturity (Lm50), Fishing Pressure (F/M), and Catch Selectivity. FiSAT estimated E between 0.52–0.69 (average: 0.60), while LBAR ranged from 0.41–0.79. The highest exploitation ratio was recorded from 2020 to 2023, with a significant decline in 2024 (E = 0.56), down from 0.69 in 2023 (p < 0.001). This decline is attributed to the adjustment of the closed season implementation, from December 1–March 1 to November 15–February 15, in accordance with the peak seasonal spawning period of the stocks, which runs from October to February, with the highest peak in November, as reported by the results of NSAP 9 Reproductive Biology. The ratio of Fishing Mortality to Natural Mortality remained high across models: 1.48–2.19 in FiSAT and 1.60–3.74 in LBAR, with the highest values from 2020 to 2023 reflecting the increasing trend in fishing pressure; however, a significant decrease was noted in 2024 (p < 0.05). FiSAT estimated Lc50 between 14.1–15.72 cm (2015–2023), with a significant improvement in 2024 to Lc = 15.01 (p = 6.25 x 10-05), while LBAR provided a much wider range. Froese indicated that mature catches ranged from 36.89% to 63.91% over a 10-year time frame, with a highly significant mature catch in 2024 (p < 0.001).

This study presents a detailed length-based stock assessment of the mackerel scad (Decapterus macarellus) in Fisheries Management Area (FMA) 6, covering January 2014 to December 2022, to evaluate the stock’s sustainability and guide future fisheries management strategies. Using length-frequency data collected from dominant fishing gears, including purse seines, ring nets, and drive-in nets, we assessed key indicators such as fishing mortality (F), exploitation rate (E), the percentage of mature fish in the population, and the biomass index (Bcurrent/B0). The results revealed high fishing mortality (F = 4.2M), significantly exceeding the sustainable threshold. Furthermore, only 15.7% of the catch comprised mature individuals, indicating a high risk of recruitment and growth overfishing. The exploitation rate (E = 0.80) substantially exceeds the ideal level of 0.50, indicating overexploitation of the population. The computed current biomass (B_current) was 0.18, far below the limit reference point at the MSY level of 0.29.