6. Conclusion

It is now a fact that large quantities of plastics enter our oceans every year, where they transform and accumulate, remaining there for as yet undefined periods of time. Their cycle is still poorly understood (figure 10 ). Those that remain on the surface are the most degraded, as they are mainly found in the form of microplastics. However, the total mass of this small debris constitutes only a small percentage of the plastic present in the oceans, and it is very likely that immense stocks cover the ocean floor, even in areas farthest from any human life. These plastics travel fast and far, carrying pollutants and various micro-organisms, some of them pathogenic, to contaminate all compartments of the aquatic environment.