Research Article

Causal relationships in king’s littleneck clam fisheries (Ameghinomya antiqua, P.P. King, 1832), Los Lagos Region, Chile

¹ Universidad Diego Portales, Facultad de Ingeniería y Ciencias, Instituto de Ciencias Básicas, Chile
² Universidad Santo Tomás, Centro Acuícola Pesquero Investigación Aplicada Puerto Montt, Chile

^* Corresponding author: hugo.robotham@udp.cl

Received: 12 April 2024
Accepted: 20 October 2025

Abstract

This study investigates the network of causal relationships in the king’s littleneck clam (Ameghinomya antiqua) fishery in the southern zone of the Los Lagos Region, Chile, using the Convergent Cross Mapping (CCM) method. The dynamics of the system were analysed based on four time series: abundance indices derived from landings per unit effort (LPUE), the percentage of mega-spawners (Mega) in catches, landings and sea surface temperature (SST) anomalies. The study identified a significant unidirectional causal relationship between landings and landings per unit, and between sea surface temperature and catch per unit effort. A marginally significant one-way causal relationship between landing and mega-spawners was found. A unidirectional causal relationship was also observed from temperature to landings; the extended CCM suggested that landings respond with a lag of 2-4 months to changes on SST. Landings and LPUE were driven by the shared environmental force (sea surface temperature). The results suggested that controlling landings rates can influence management decisions aimed at regulating resource conservation, using a precautionary approach and a target reference value for LPUE. The importance of incorporating indicators such as mega-spawners into management strategies is highlighted, as they can be indicators of the stock’s health status. This study improves the comprehension of how environmental and socio-economic factor interact in complex system.