WARMING, PRODUCTIVITY SHIFTS AND HABITAT RISK FOR OIL SARDINE IN THE SOUTHEASTERN ARABIAN SEA: AHP–PCA BASED VULNERABILITY ASSESSMENT

Oil sardine (Sardinella longiceps) is a climate-sensitive pelagic species supporting major coastal fisheries in the southeastern Arabian Sea. This study assesses its climate vulnerability using a 20-year (2005–2024) dataset and an integrated AHP–PCA framework. Environmental variables including SST, chlorophyll-a, salinity, dissolved oxygen, mixed layer depth, pH, nutrients, and major climate indices (ENSO, IOD, PDO) were extracted and analysed using Python. PCA identified dominant environmental drivers, while AHP generated weighted exposure, sensitivity, and adaptive capacity indices. The present study shows a clear warming trend across the region, with higher SST coinciding with reduced habitat stability and shifts in sardine suitability zones. Declining chlorophyll and changes in nutrient availability indicate weakening productivity, directly influencing potential feeding conditions and spawning environments. Increased salinity variability was found to coincide with periods of lower predicted suitability, suggesting sensitivity during early life stages. Variability in mixed layer depth and upwelling intensity further highlights fluctuating nutrient supply and consequent changes in favourable habitats. Collectively, SST anomalies, productivity decline, and altered upwelling emerged as the strongest drivers influencing sardine vulnerability. The composite vulnerability index indicates moderate to high vulnerability in core fishing grounds, underscoring the need for climate-ready fisheries management aligned with SDG-14.

Presentation Preference: Standard Oral (12 Minutes)

Primary Presenter: Shijin Ameri, Amrita Vishwa Vidyapeetham (shijinameri@am.amrita.edu)

Authors:

Shijin Ameri, Amrita Vishwa Vidyapeetham  (shijinameri@am.amrita.edu)

Vysakh S, Amrita Vishwa Vidyapeetham  (ammasvysakh21@gmail.com)