A seaport is usually an important backbone of country's economy. Look at the power that such a relatively small country as Portugal achieved through exploring, expanding and trading in some ...th century. The same suits for big countries, for example England.
Apart from usual cargo, and passenger ships, it also is a load/unload point for light oil (for example petroleum) products, while raw oil is transferred via Būtingė (Butinge) terminal, close to border with Latvia.
Again, it is difficult to underestimate the economical importance of such an entity, but we have to somehow manage and make it a good balance between economy and ecology. Otherwise, it will be a dead black cold water, without any life in it. Otherwise, these guys will be either dead, or living in some remote location where we will not be able to adore their liveliness and social interactions with a bunch of ferry passengers, feeding them with breadcrumbs.