In recent years, much research has focused on studying the damage caused by microplastics to the ecological environment and human health. Indeed, MPs are often consumed by shellfishes and zooplanktons due to their similarity in size to POM (particular organic matter). Especially in zooplankton, the accumulation of MPs in the body affects the reproductive system and the growth rate of juveniles. Moreover, toxins derived from MPs are continuously accumulated in predators of zooplankton and impact the whole ecosystem across the food chain. In this work, we found that even though MPs were internalized by and adherent around Daphnia magna, there were no significant differences in the survival rate of their adults and offspring. However, the population of ovigerous adults under high MPs exposure for 7 days decreased significantly, suggesting an extension of the days of sexual maturity in D. magna. The removal of MPs after 7 days’ MPs treatment resulted in an increase in D. magna juveniles and neonates which indicated their growth was reduced or inhibited in the MPs environment. Overall, the uptake of MPs led to negative effects on population reproduction and the growth of offspring in D. magna.

Aquaponic systems are made up of hydroponic beds and recycled aquaculture systems. The significant elements that determine how effectively an aquaponic system operates are the nitrogen cycle (nitrification) and the phosphorus cycle (phosphate). Because some research indicates that aquaponics systems are primarily deficient in phosphorus, phosphate-enriched nutrients were added to raise the phosphorus levels. During an eight-week experimental period, the effects of water quality parameters and microbiology, animal and plant growth performance, chlorophyll compounds in lettuce, and the bacterial community were analyzed. Phosphate concentration (1.604 ± 1.933 mg L⁻¹) and ammonia-oxidizing bacteria (AOB) (1.19 × 10² ± 1.30 CFU mL⁻¹) give significant positive reactions to the added nutrients. However, the prawn survival rate (17.00 ± 0.63%) showed a significantly negative response to nutrition modification containing phosphate, and the percentage of bacterial pathogens became more dominant (pathogen 40.51%; N_bacteria 35.05%; probiotics 24.44%). This study shows that adding phosphate increases phosphorus levels in an aquaponics system and changes the microbial community and species growth performance.

Red coloring determines the commercial value of blood parrot cichlids (Vieja melanurus × Amphilophus citrinellus). While synthetic astaxanthin (SA) is commonly used to improve hue, its expensive cost has prompted the quest for more sustainable alternatives. This 60-day study looked at shrimp waste extract (SWE) as a dietary supplement for color improvement. Fish were assigned to five diets: basal control (G1, 0 mg/kg SA: 0 mg/kg SWE), SWE alone (G2, 0 mg/kg SA: 7.7 mg/kg SWE), high SA (G3, 90 mg/kg SA: 0 mg/kg SWE), moderate SA (G4, 45 mg/kg SA: 0 mg/kg SWE), and mixed SA with SWE (G5, 45 mg/kg SA: 7.7 mg/kg SWE). Growth and CIELAB skin pigmentation were evaluated. Growth performance was consistent across all treatments. Colorimetric study found that while the SWE alone (G2) significantly improved pigmentation compared to the control, it was less effective than the high-SA diet. However, incorporating SWE into the moderate-SA diet (G5) resulted in a promising complementary response. Despite having half the SA concentration, G5 achieved pigmentation that was comparable or superior to the G3 diet by the end of the feeding trial. These data revealed that, while SWE has lower independent activity, it is an effective complementary additive for shortening the feeding period required to achieve a similar redness. Finally, SWE enables the partial substitution of synthetic astaxanthin, providing a cost-effective and environmentally sustainable nutritional strategy for the ornamental aquaculture business.