Density decrease in an exploited population of brown sea cucumber Isostichopus fuscus in a biosphere reserve from the Baja California peninsula, Mexico

• Published in: Ocean & coastal management 2016-03, Vol.121, p.49-59
• Main Authors: Glockner-Fagetti, Andrea, Calderon-Aguilera, Luis E., Herrero-Pérezrul, María D.
• Format: Article
• Language: English
• Subjects: Endangered species; Growth rate; Gulf of California; Holothurioidea; Isostichopus fuscus; Marine; Marine protected area; Size structure; Stakeholders' involvement
• ISSN: 0964-5691; 1873-524X
• DOI: 10.1016/j.ocecoaman.2015.12.009

The sea cucumber Isostichopus fuscus (Ludwig, 1875) has been exploited, legally, and illegally, on the Baja California peninsula since 1988. The fishery was closed in 1994 due to overfishing symptoms but reopened in 2007 under management strategies and harvesting permits. Nocturnal samplings surveyed abundance, size and weight of I. fuscus. Density, proportion of individuals above the minimum size for fishing (MSF), weight–length relationship parameters, relative condition index (Kn), parameters of the von Bertalanffy growth equation (VBGE), individual and average age from the VBGE, natural mortality rate (M) and survival percentage cohort were estimated from the data set for the population in 2005–2007, and compared with the same population in 2013 at the Biosphere Reserve Bahía de los Ángeles. Semi-structured interviews were also conducted to obtain the stakeholders' perspectives and opinions about the fishery. There were no significant differences in the weight–length relationship (W = 7.17·L1.29), relative condition index (Kn = 1.08), and parameters of the von Bertalanffy growth equation (L∞ = 35.74 cm, K = 0.26 y−1), between the study periods. The population in the 2005–2007 period was mainly constituted by individuals