How effective are straight seawalls?

Straight seawalls can be effective in protecting coastal areas from erosion and storm surge by reflecting wave energy. However, they may also lead to increased erosion in adjacent areas due to the disruption of natural sediment transport. Additionally, straight seawalls can create harsh environments for marine life and may not adapt well to changing sea levels. Overall, while they provide immediate protection, their long-term effectiveness can vary based on local conditions and environmental impacts.