Answer:
Rich countries can be described as having consumerist society in which the increasing acquisition of goods and services is encouraged. Thus, from a society such as this, the waste produced is also extremely large. So large that in many cases the system that should handle it is not capable of doing so.
Furthermore, the people themselves do not dispose of this waste in a responsible manner. Instead, parts of it are just through into nature where it eventually ends up in aquatic and especially marine environments.
By reducing the amount of used goods or at least the amount of packaging, will be a first step in reducing this environmental danger. However, more is necessary.
The consumerist mindset is not sustainable. Instead of throwing away a product such as a plastic cup, it could be reused several times. This would also lead to a waste reduction.
Perhaps the best solution is to recycle if not all, then most of the waste produced. By recycling, the waste itself will be eliminated to a large degree. Also, the amount used will not be such a big problem anymore as the used products are recycled into new ones.
Recycling will benefit greatly the marine environments by ceasing further pollution. The waste already present could be gathered and turned once more into a useful product.
Unfortunately, this solution is also the most expensive as extensive financial resources are necessary for the creation of the infrastructure of a recycling waste management system. However, long-term this investment will show itself to be profitable as, after all, our health is dependent on Earth's health.