The Ondo State coastal waters , face increasing heavy metal pollution from human activities, posing risks to ecosystems and public health. This study investigated seasonal and spatial variations of eight heavy metals: Lead (Pb), Cadmium (Cd), Chromium (Cr), Iron (Fe), Zinc (Zn), copper (Cu), Nickel (Ni), and Cobalt (Co) in water, sediment, and Pseudotolithus species from Awoye and Idi-Ogba. Metal levels were measured using Buck Scientific Atomic Absorption Spectrophotometer, with pollution indices and health risks evaluated. Most water quality parameters met USEPA standards, except turbidity, dissolved oxygen and nitrate. Significant seasonal metal peaks included Cd (0.19 mg/L, wet season, Awoye), Cr (0.10 mg/L, dry, Idi-Ogba), Fe (4.44 mg/L, dry, Idi-Ogba), and Pb (0.10 mg/L, wet, Awoye), with Pb exceeding WHO limits. Sediment metal levels were below Effect Range Low guidelines, indicating low ecological risk. Geo-accumulation Index showed unpolluted conditions at Awoye (wet: all metals negative; dry: Cd 0.42) and Idi-Ogba (all seasons negative). Enrichment Factor indicated extreme enrichment, especially Cd (Awoye dry season: 9330.67). Contamination Factor was moderate for Cd at Awoye dry season (2.00), others < 1. Nemerow Pollution Index revealed unpolluted status (Awoye: 0.05–0.21; Idi-Ogba: 0.03–0.04). In Pseudotolithus tissues, the liver and kidney accumulated the most metals, especially Fe and Pb in the two locations. At Awoye, Cd posed significant health risks (HQ: 12.62; cancer risk: 9.5 × 10⁻2), while Idi-Ogba showed minimal concern. These findings highlight the need for regular monitoring and mitigation efforts in the region.

Polycyclic Aromatic Hydrocarbons (PAHs) are persistent pollutants that accumulate in marine organisms, posing health risks through human consumption. The Gulf of Guinea in Ondo State, Nigeria, influenced by urban runoff and petroleum effluents, provides a critical setting to assess PAH contamination in Pseudotolithus typus and P. elongatus, with implications for food security and public health. Despite their dietary value, species-specific PAH risks remain poorly understood. This study assessed seasonal PAH bioaccumulation in edible tissues and associated human health risks, hypothesizing that accumulation varies by species and season. Sixty specimens per species were collected during the wet (June–August) and dry (November–January) seasons from Awoye, Ayetoro, and Idi-Ogba. Muscle tissues were analyzed for PAHs using Gas Chromatography–Mass Spectrometry. Risk assessment employed Estimated Daily Intake (EDI), Toxic Equivalency Quotients (TEQ), and Screening Values (SV). EDI revealed elevated intake levels of carcinogenic PAHs, particularly benzo[a]anthracene, benzo[a]pyrene, dibenz[a, h]anthracene, indeno[1,2,3-cd] pyrene, and benzo[g, h,i] perylene. The ∑PAH concentrations in P. typus ranged from 0.134 ng/g (Awoye, wet season) to 0.437 ng/g (Ayetoro, dry season), while P. elongatus ranged from 0.269 ng/g (Awoye, wet season) to 0.921 ng/g (Idi-Ogba, dry season). Although concentrations were below the European Commission permissible limit (12.00 µg/kg), TEQ values (0.116–86.10 µg/kg for P. typus; 0.25–87.30 µg/kg for P. elongatus) exceeded the SV threshold of 0.00690 µg/kg, indicating potential carcinogenic risks. These findings suggest that consumption of P. typus and P. elongatus may pose long-term health concerns. Continuous monitoring and consumption advisories are recommended to safeguard coastal communities.

The integrity of certification processes in the agrifood and fishing industries is essential for combating fraud, ensuring food safety, and meeting rising consumer expectations for transparency and sustainability. Yet, current certification systems remain fragmented, and they are vulnerable to tampering and highly dependent on manual or centralized procedures. This study addresses these gaps by providing a comprehensive survey that systematically classifies blockchain-based certification technologies and methodologies applied to the fisheries sector. The survey examines how the blockchain enhances trust through immutable record-keeping, smart contracts, and decentralized verification mechanisms, ensuring authenticity and accountability across the supply chain. Special attention is given to case studies and implementations that focus on ensuring food safety, verifying sustainability claims, and fostering consumer trust through transparent labeling. Furthermore, the paper identifies technological barriers, such as scalability and interoperability, and puts forward a collection of functional and non-functional requirements for holistic blockchain implementation. By providing a detailed overview of current trends and gaps, this study aims to guide researchers, industry stakeholders, and policymakers in adopting and optimizing blockchain technologies for certification. The findings highlight the potential of blockchain to innovate certification systems, easing the way for more resilient, sustainable, and consumer-centric agrifood and fishing industries.

Coastal ecosystems along Nigeria’s Gulf of Guinea face increasing pollution from industrial discharges and oil-related activities, posing serious thr