Coastal and marine plants are species adapted to life in or near saltwater environments, including shorelines, tidal zones, seagrass beds, and underwater ecosystems. These plants thrive in sandy, saline, or submerged habitats where few others can survive. Marine plants such as seagrasses grow entirely underwater, while coastal species like salt-tolerant grasses, algae, and dune vegetation occupy intertidal and supratidal zones.

Over time, they evolved unique mechanisms to manage salt exposure, shifting tides, and low nutrient availability. Many developed tolerance to wind, waves, and sand movement, enabling them to anchor ecosystems that are constantly changing. Their ecological niche is essential for stabilizing coastlines, supporting marine life, and cycling nutrients. Distributed globally, these plants have independently evolved across different plant groups to meet the challenges of life in marine and coastal environments.

Coastal and marine plants grow with specialized features that help them survive in salty, shifting environments. Many have thick, waxy leaves or salt-excreting surfaces to manage excess salt. Seagrasses, which live fully underwater, have long, ribbon-like leaves and roots that anchor them in soft seabeds. Dune plants and salt marsh grasses often develop deep or spreading roots to hold onto sandy or muddy ground.

Some coastal plants grow low to the ground to resist wind, while others stand tall to compete for light. Many reproduce through both seeds and underground runners, allowing them to spread and quickly stabilize exposed areas. Some float their seeds on tides, while others drop them nearby. These adaptations help coastal and marine plants survive waves, salt spray, and constant changes in water levels.

Coastal and marine plants have supported human communities for centuries, providing resources, protection, and ecological services. Seagrasses and algae have been harvested for food, fertilizer, and animal feed, while coastal plants like beach grasses and mangroves help protect shorelines from storms and erosion. In traditional coastal cultures, seaweeds hold culinary and ceremonial value, and dune vegetation often marks territory or guides seasonal land use.

Today, scientists and environmental planners rely on these plants in habitat restoration, shoreline stabilization, and carbon sequestration efforts. In daily life, beachgoers may not notice their presence, but these plants quietly buffer coastlines and maintain water quality. As climate concerns grow, their role in mitigating sea-level rise and supporting marine biodiversity has gained renewed attention, positioning them as key players in global conservation and coastal resilience strategies.