AQUACULTURE AND FISHERIES MANAGEMENT .

This study was carried out to evaluate the effects of selected aromatic pepper spices on the organoleptic and microbial qualities of oven-dried Oreochromis niloticus (Nile tilapia) fillets stored at ambient temperature. Fresh fillets were seasoned with 2% (w/w)
of three different pepper spices Scotch Bonnet (Capsicum chinense), Cayenne (Capsicum annuum), and Bell Pepper (Capsicum annuum) and compared with not spiced (control) samples. The spiced and not-spiced fillets were oven-dried at 100°C for 5 ours, packaged in sterile ziploc bags, and stored at room temperature (28 ± 2 °C) for 14 days. Microbiological, and sensory analyses were conducted at 7-day intervals to assess changes during storage. Results revealed that the spice treatments and storage durations significantly (P < 0.05) affected the sensory and microbial qualities of the fish samples. On Day 1, all samples exhibited high sensory ratings across appearance, aroma, taste, and overall acceptability (3.8 – 4.6), but these values declined progressively by Day 14. Cayenne and Bell Peppertreated samples retained relatively higher flavour and acceptability scores than Scotch Bonnet and the control, suggesting mild preservative or antioxidant effects. Microbial counts increased with storage time, with bacterial loads ranging from 7.0 × 10⁻³ cfu/g in Bell Pepper-treated samples to 240.0 × 10⁻³ cfu/g in Cayenne-treated fillets samples after
14 days. Proteus sp., Staphylococcus aureus, and Bacillus sp. were among the predominant bacterial isolates, while Aspergillus flavus, Mucor sp., and Penicillium species were the most common detected fungi. Ultimately, bell Pepper proved to be the most effective in inhibiting microbial proliferation and maintaining product acceptability

This study was carried out to assess the bacterial and fungal load of selected frozen and smoked-dried fish species sold in the New Benin Market, Oredo Local Government Area, Benin City, and to isolate and characterize the associated microorganisms. A total of fourteen (14) fish samples were randomly purchased from the market in Benin, Edo State, Nigeria. The samples were collected in sterile polythene bags to prevent contamination and transported for microbial analysis. Smoked-dried fish samples were obtained from various fish sellers, while frozen fish samples were sourced from different cold rooms. Frozen fresh smoked-dried samples were used as control. All samples were handled carefully to avoid contamination with dirt or other microorganisms. Microbiological analysis was conducted using Nutrient Agar to determine bacterial load and Potato Dextrose Agar for fungal load estimation. The results revealed that smoked-dried fish samples for Scomber scombrus had a high bacterial counts (9.6x10 3 cfu/g) compared to the frozen samples (8.0x10 3 cfu/g) and the control samples recorded the lowest bacterial load (3.4x10 3 cfu/g). Similarly, the smoked- dried fish samples showed higher fungal counts (7.0x10 2 cfu/g) than the frozen ones (6.33x10 2 cfu/g). The elevated microbial levels observed in smoked fish from the market are likely due to poor handling practices, inadequate smoking techniques employed by processors and sellers, exposure to contaminated air and septic environments. For Merluccius merluccius, the frozen fish samples had a high bacterial counts (1.5x10 4 cfu/g) compared to the smoke dried fish samples (3.4x10 3 cfu/g) and the control samples recorded the lowest bacterial load (2.0x10 3 cfu/g). Similarly, the frozen fish samples showed higher fungal counts (5.67x10 2cfu/g) than the smoke dried ones (2.0x10 2 cfu/g). The level of microbes observed in the frozen fish depends heavily on the initial contamination level, the speed of freezing, temperature fluctuations during storage, and handling practices during thawing. Frozen fish contains a residual microbial population from its initial state (harvesting, handling, processing), once the fish thaws, these surviving microbes can become active again and multiply rapidly if the temperature is favorable, potentially reaching levels that cause spoilage or illness. A total of ten (10) microorganisms, five (5) bacterial species and five (5) fungal species were isolated from both frozen and smoked-dried fish samples. The bacterial isolates included Bacillus sp., Staphylococcus sp., Proteus sp., Pseudomonas sp., and Enterobacter sp., while the fungal isolates included Aspergillus sp., accharomyces sp., Penicillium sp., Mucor sp., and Rhizopus stolonifer. Most of he fungal isolates identified are known producers of mycotoxins. There were significant differences (P > 0.05) between the frozen and smoked- dried fish amples collected from the same market, varying from one fish seller to another. This variation indicates that different handling, preservation, and marketing practices are used by fish vendors. Consequently, the microbial load reflects the hygiene standards and processing methods adopted. To ensure consumer safety, it is recommended that mechanized smoking systems be employed to completely dehydrate fish and reduce contamination risks associated with esidual moisture and the need for proper hygienic conditions during processing, handling, distribution, packaging and storage of the fish

Fish rolls in Nigeria are nutritionally imbalanced, and the impact of varying fish concentrations on their microbial safety and shelf life is not well understood. This study was carried out to assess the nutritional composition and microbial quality of fish rolls made with Scomberjaponicus concentrate. Five formulations were prepared with S. japonicus fish concentrate (0%,10%, 20%, 30%, 40%), Standard analytical methods (AOAC, 2020) were used to determine the proximate composition, while microbial analysis was performed using standard microbial techniques to determine microbial and fungal contamination levels. There was significant (P<0.05) increases in protein, fat, ash, and moisture contents with higher levels of inclusion. Protein content increased from 9.77% to 25.54%, while carbohydrate content decreased correspondingly from 58.64% to 25.48%. Bacterial counts ranged from 3.7 × 10² to 1.0 × 10³ cfu/g, and fungal counts from 0.2 × 10² to 1.7 × 10² cfu/g, all below the recommended limits of 5 × 10⁵ cfu/g set by the FAO. (ICMS, 2002). The major bacterial isolates included Bacillus sp., Staphylococcus sp., Pseudomonas sp., and Enterobacter sp., while Aspergillus sp., Saccharomyces sp., and Penicillium sp. were the predominant fungi. The study suggest that fish rolls made with S. japonicus significantly enhances their nutritional value, without exceeding acceptable microbial limits. An optimal fortification level of 20% fish concentrate was recommended to balance nutritional quality, sensory acceptability, affordability and microbial safety.

High feed costs and poor water quality hinder sustainable Oreochromis niloticus production, requiring affordable natural alternatives. This study evaluated the influence of Lemna minor on water quality and the reproductive performance of O. niloticus broodstock. A 12-week experiment was conducted using a completely randomized design comprising four treatments: T₀ (control commercial feed only), T₁ (½ of Commercial feed + L. minor coverage), T₂ (same quantity of T0 feed + L. minor coverage), and T₃ (L. minor only). Water quality parameters (dissolved oxygen; T0; 1.111, T1;1.251, T2;1.493, T3;3.825, pH; T0; 6.053, T1;6.128, T2; 6.102, T3;6.328, and total ammonia nitrogen; T0; 0.4356, T1;0.3267, T2; 0.3111, T3; 0.0344) and reproductive indices (number of fry and larval survival rate) were monitored throughout the study. It was revealed that treatments containing Lemna minor significantly improved water quality, with higher dissolved oxygen and lower total ammonia nitrogen compared to the control. However, excessive coverage of L. minor slightly reduced fry output, with the highest number of fry (43.33) in T₀ and the lowest (23.33) in T₂. Fry survival showed no significant difference (p > 0.05) among treatments. The study suggests that the integration of Lemna minor in O. niloticus broodstock system enhance water quality and reduce dependence on costly commercial feed without compromising Reproductive efficiency.

Foodborne diseases, especially among school children who often consume ready-to-eat (RTE) foods, pose a significant Health risk. This study was carried out to assess the microbial load of fish roll snacks sold in eight randomly selected primary schools within Oredo Local Government Area, Benin City, Nigeria. Fish roll samples were collected and analyzed using standard microbiological techniques to determine bacterial and fungal contamination levels. The bacterial counts ranged from 5.9 × 10² CFU/g (Sample 5) to 7.6 × 10³ CFU/g (Sample 6), while fungal counts varied from 2.9 × 10² CFU/g (Sample 6) to 1.0 × 10³ CFU/g (Sample 2). Some of the bacterial species identified were Bacillus sp. (4.32%), Streptococcus sp. (9.43%), Pseudomonas sp. (5.66%), and Enterobacter aerogenes 5.66%), while some fungal species such as Aspergillus oryzae (9.43%), Saccharomyces sp. (9.43%), Penicillium sp. (11.32%), and Mucor piriformis (9.43%) were also detected. Sample 6, from Adesua Primary School (public sector), had the highest bacterial count (7.6 × 10³ CFU/g), while Sample 5 from Ogboe Primary School (public sector) had the lowest bacterial count (5.9 × 10² CFU/g). Sample 2 from Phelim Primary School (private sector) recorded the highest fungal count (1.0 × 10³ CFU/g), while Sample 6 from Adesua Primary School had the lowest fungal count (2.9 × 10² CFU/g). The high microbial load observed suggests contamination due to poor hygiene practices, improper food handling, and inadequate storage conditions. However, all values were within the recommended limit of 5 × 10⁵ CFU/g set by the FAO.

Polycyclic aromatic hydrocarbons (PAHs) have received significant attention due to their potential health and environmental impacts. Some are toxic and pose risks to human health and ecosystems. This study was conducted to determine the levels of PAHs in Oreochromis niloticus from Ogun river in Ajegunle, South-West Nigeria. Gas Chromatography with Flame Ionization Detector (GC/FID) was used to measure the concentrations of PAHs in the fish tissues, following United State Environmental Protection Agency (USEPA) methods. The objectives of the research evaluated the toxic equivalency (TEQ) of PAHs, toxic/hazard
quotient for PAHs, estimated daily intake with annual intake and cancer risk factor for PAHs in O.niloticus. Naphthalene had a low value in the fish sample analyzed and could be related to the fish species inability to absorb it irrespective of its presence in the water and sediments. Total PAH concentrations found in the fish sample exceeded the acceptable limit set by the European Commission (2 µg/kg Fluroanthene and Benzo(a)pyrene) for fish considered safe for human consumption. The quota for PAHs
ranged from 0.037% for Naphthalene to 73.97% for Fluroanthene. The continual consumption of fish from the river by the inhabitants could lead to bioaccumulation with adverse health implications since PAHs are carcinogenic, mutagenic and teratogenic. Furthermore, the high concentrations and the persistent nature of PAHs make the fish that inhabit the river unfit for human consumption.

This study investigated the nutritional value and organoleptic assessment of bread fortified with
fish concentrate from commercially important fish species. Fish is a highly nutritious source of
protein and essential fatty acids, but its incorporation into staple foods like bread remains
underexplored. The research aimed to evaluate the impact of fish concentrate on the proximate
composition and sensory characteristics of bread. Bread samples were produced with varying
levels of fish concentrate (0%, 10%, 20%, and 30%) and analyzed for moisture, protein, fat, ash, fiber, and carbohydrate content. Organoleptic properties, including appearance, taste, texture, and aroma, were also assessed. The results showed that fortification with fish concentrate significantly enhanced protein, fat, and
ash content while reducing carbohydrate levels. Sample D (30% fish concentrate) had the highest
protein (20.18%) and fat (9.16%) content, whereas the control sample (0% fish concentrate)
exhibited the highest carbohydrate content (63.44%). Sensory evaluation indicated that moderate
fortification (10–20%) improved taste, aroma, and texture without negatively affecting consumer
acceptability. However, higher levels (30%) introduced stronger flavors that may not be well
received by all consumers.