Management strategies proposal for reducing the abundance of small organisms in the small pelagic fishery catch from the Gulf of California

Abstract

Background: Results indicate the fishery might be catching small California sardine in some fishing areas that could produce growth overfishing. Objectives: To estimate the percentage of organisms caught below the minimum size and determining the potential variables affecting the organisms size caught by the fishery. Methods: we did data exploratory analysis, correlation analysis and explored the size´s seasonal and interannual variability. We used ANCOVA and ANOVA to find out the main driver determining sardine´s size. The response variable was the standard length, the ANCOVA model included six covariates, six factors and the first level interactions. Results: the standard length ranged from 64 mm to 230 mm, the mean was 158.6 ± 19.8 mm. Results suggest 32.9% of the organisms caught are below the minimum size, 12.9% above the tolerance limit (20%). Regarding the seasonal variation, results suggest the lower standard length value occurred during June and July, while the highest occurred in March. The ANCOVA model included 60 significant predictors; it explained 82.2% of the observed variability. ANOVA results suggested that the predictor variable explaining the majority of the variability was the factor Month (31.5%); the second was the factor year (9.5%) and the third was Boat (7.2%). Conclusions: Compliance with regulations would require reducing operations during June and July in zones IV-G and VI-G; this would help to avoid growth overfishing. However, it could face fishermen opposition that already face a close season. Regulations compliance would require that CONAPESCA and fishermen reach a consensus. Our results contribute to provide information to avoid growth overfishing and yield overfishing. They support the efforts that managers and fishermen are making to assure the sustainable exploitation of this fishing resource.