Worldwide, the fisheries sector is growing with improved technologies to meet the ever-growing demand for seafood. However, with climate change and increasing marine pollution, there are also significant concerns about declining biodiversity and its impact on income and livelihoods for small-scale fishers. There is a significant shift from traditional fishing methods to mechanization and aquaculture in India. However, the new alternatives have come with many downsides which often go unnoticed. Mechanized fishing contributes to GHGs emissions, destruction of the seabed, overexploitation, and disrupting the ocean food chain. Likewise, coastal aquaculture emits GHGs during feed production, discharges organic and inorganic wastes, involves LULC changes and destroys ecologically sensitive areas (ESAs), leading to loss of various ecosystem services that increase environmental vulnerability and leads to higher ecological footprint. The impacts of climate change on the fishing sector and coastal areas are well established. However, there is a need to understand the impact of changes in fishing techniques on coastal zones and climate change. In this paper, the changes in the fishing sector are evaluated, followed by the development of a framework to assess the impacts of those changes on coastal zones and climate change. The changes in commercial fishing techniques are assessed by determining the dominant fishing techniques prevailing across India, along with reasons for a shift from traditional methods. A Life-Cycle Cost Assessment (LCCA) of the dominant techniques, aquaculture and mechanized fishing, helped to verify the need for such a shift. Two case study areas are selected for sample data collection for computing LCCA of aquaculture and mechanized fishing - Worli in Mumbai and Bhimavaram in Andhra Pradesh for studying mechanized fishing and aquaculture respectively. LCCA of the dominant techniques against traditional techniques showed that economic viability is one of the major reasons for the shift, which was later confirmed during the interviews with fishermen. These methods though profitable have various impacts on coastal ecosystems and emit GHGs making them unsustainable. The paper develops a framework to categorize the impacts of these changes on coastal zones and climate change and suggests appropriate methods to compute those impacts.