Costero vs. litoral vs. del litoral
While costero, litoral, and del litoral all relate to the concept of the coast, they vary in register and focus. Costero is the general adjective, litoral is a more technical or geographical term often used as a noun, and del litoral indicates possession or origin specifically related to the coastline.
Costero
B1This is the most common and versatile adjective used to describe anything located on, related to, or having the characteristics of the coast. It is used in everyday conversation for things like towns, weather, roads, or tourism.
El pueblo costero se llena de turistas en agosto.
(The coastal town fills up with tourists in August.)
La mañana estaba fresca gracias a la brisa costera.
(The morning was cool thanks to the coastal breeze.)
Tomamos la carretera costera para ver el mar.
(We took the coastal road to see the sea.)
La pesca costera es la principal actividad económica aquí.
(Coastal fishing is the main economic activity here.)
Litoral
B2This word functions both as a noun meaning coastline and an adjective referring to the shore. It is more formal, technical, or geographical than costero, often focusing on the physical boundary where legal jurisdiction, biology, or geography defines the meeting of land and water.
El gobierno aprobó una ley para la protección del litoral.
(The government passed a law for the protection of the coastline.)
Estamos estudiando la fauna de la zona litoral.
(We are studying the fauna of the littoral zone.)
El buque patrulla las aguas del litoral.
(The ship patrols the littoral waters.)
La erosión litoral es un problema grave en esta región.
(Littoral erosion is a serious problem in this region.)
Del litoral
B2This consists of the preposition de (of/from) combined with el litoral. It translates to of the coastline or from the littoral region. It is mostly used to indicate that a custom, product, person, or feature belongs specifically to that geographic strip.
La gastronomía del litoral destaca por sus mariscos frescos.
(The gastronomy of the coastline stands out for its fresh seafood.)
Las tradiciones del litoral son muy diferentes a las de la montaña.
(The traditions of the coastline are very different from those of the mountains.)
Es una planta típica del litoral mediterráneo.
(It is a plant typical of the Mediterranean coastline.)
Los habitantes del litoral están acostumbrados a la humedad.
(The inhabitants of the littoral are used to the humidity.)
Summary
In short, use costero for general descriptions concerning the coast (weather, towns, roads). Use litoral when discussing geography, law, or the physical coastline itself. Use del litoral to describe something that originates from or belongs specifically to that region.