Exploring long-term variability of Nephrops norvegicus landing per unit effort (LPUE) off North Galicia (NW Spain)

• Published in: Fisheries research Vol. 165; pp. 121 - 126
• Main Authors: González Herraiz, Isabel, Fariña, A. Celso, Freire, Juan, Cancelo de la Torre, José Ramón
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2015
• Subjects: ARIMA model; Environmental factors; Landing per unit effort; Nephrops norvegicus; Northern Spain; ANE, Spain, Galicia; Landing per unit effort; Environmental factors; ARIMA model; Nephrops norvegicus; Northern Spain
• ISSN: 0165-7836; 1872-6763
• DOI: 10.1016/j.fishres.2014.12.020

•Proportion of males 4 years ago was the key factor explaining three decades Galicia (NW Spain) Nephrops catch per unit effort fluctuations. Landings of Nephrops norvegicus from North Galicia (Northwest Spain) have decreased by 80% from 1975 to 2001. Variability in the landings per unit effort (LPUE) of this stock was investigated by using time series approach. The LPUE time series (1975–2001) exhibited a seasonal pattern. The seasonal decomposition of the LPUE showed a declining in the trend-cycle component from 1987 onwards. Univariate and dynamic regression ARMA models were fitted to the LPUE time series. Population (proportion of males, proportion of ovigerous females and recruits) and environmental variables (temperature, salinity, nitrates and chlorophyll at 70m depth, upwelling and sea surface temperature) were tested at different lags as explanatory variables. The proportion of males 4 years ago was the key factor explaining LPUE fluctuations.