Microplastics (MPs), defined as synthetic polymer particles less than 5 mm in diameter, are widely acknowledged as ubiquitous contaminants in aquatic ecosystems, including freshwater, marine, and polar environments. Global concern with MPs has significantly increased; nevertheless, much of the current knowledge remains fragmented and, at times, limited to specific regions or ecological compartments. This study emphasizes the necessity of a thorough synthesis by critically analyzing global microplastics’ dispersion patterns, ecological consequences, and associated human health concerns. A systematic approach was employed, integrating specific search terms and establishing inclusion and exclusion criteria across various scientific databases to obtain a representative collection of literature. The study covers important topics such as the classification of MPs, their distribution, environmental impacts, and interactions with other pollutants, including heavy metals, pharmaceuticals and endocrine-disrupting chemicals. Particular emphasis is placed on comparing ecosystem-specific vulnerabilities, such as those found in tropical wetlands, marine gyres, and polar systems. The review examines potential human exposure pathways, via contaminated seafood, water, and air, while also compiling new information about cellular and physiological damage, including oxidative stress, inflammation, hormone disruption, and possible genetic effects. This investigation highlights the value of collaborative monitoring, the adoption of biodegradable alternatives, policy development, and interdisciplinary research by integrating knowledge from ecology and public health. The primary objective is to advance ecosystem-specific mitigation techniques and promote evidence-based policy development in addressing this intricate environmental issue.

The ability of aquatic organisms to sense the surrounding environment chemically and interpret such signals correctly is crucial for their ecological niche and survival. Although it is an oversimplification of the ecological interactions, we could consider that a significant part of the decisions taken by organisms are, to some extent, chemically driven. Accordingly, chemical contamination might interfere in the way organisms behave and interact with the environment. Just as any environmental factor, contamination can make a habitat less attractive or even unsuitable to accommodate life, conditioning to some degree the decision of organisms to stay in, or move from, an ecosystem. If we consider that contamination is not always spatially homogeneous and that many organisms can avoid it, the ability of contaminants to repel organisms should also be of concern. Thus, in this critical review, we have discussed the dual role of contamination: toxicity (disruption of the physiological and behavioral homeostasis) vs. repellency (contamination-driven changes in spatial distribution/habitat selection). The discussion is centered on methodologies (forced exposure against non-forced multi-compartmented exposure systems) and conceptual improvements (individual stress due to the toxic effects caused by a continuous exposure against contamination-driven spatial distribution). Finally, we propose an approach in which Stress and Landscape Ecology could be integrated with each other to improve our understanding of the threat contaminants represent to aquatic ecosystems.

The Haor region in northeastern Bangladesh, characterized by seasonal wetlands and a heavy reliance on fisheries, faces significant challenges due to climate change. Erratic rainfall, prolonged flooding, and ecosystem degradation threaten traditional fishing practices and community livelihoods. This study investigates the potential of climate-resilient cage aquaculture as a sustainable, alternative income-generating solution for vulnerable Haor communities. An 80-day experiment was conducted in five villages of Sunamganj district, Sylhet division, Bangladesh, where tilapia (Oreochromis niloticus) fry were reared in climate-resilient floating cages at five stocking densities: T1 (800 fry/m³), T2 (900 fry/m³), T3 (1000 fry/m³), T4 (1100 fry/m³), and T5 (1200 fry/m³). Key environmental parameters, including temperature (28.12–29.55 °C), dissolved oxygen (4.61–6.55 mg/L), pH (7.53–7.72), and ammonia (0.05–0.76 mg/L), remained within optimal ranges across treatments. Growth performance, survival rate, and economic feasibility were evaluated with T5 yielding the highest gross production (51.77 ± 4.80 kg/m³) and net benefits (7500 ± 500 BDT/m³), achieving a benefit–cost ratio of 1:2.86. The survey findings revealed that a majority of fishers (82%) identified tilapia cage culture as a promising alternative livelihood, yet financial constraints and limited access to credit hinder adoption. Despite these socioeconomic challenges, our findings suggest that tilapia cage culture offers a viable income-generating solution, particularly during flood periods. The study highlights floating cage aquaculture as a climate-resilient strategy to mitigate climate impacts, enhance food security, and improve economic resilience in flood-prone and ecologically sensitive regions.