Age, growth, and fishery assessment of spotted sand bass in the Northern Gulf of California, Mexico

Abstract

Spotted sand bass (Paralabrax maculatofasciatus) is one of the most common inshore reef fishes in the northern Gulf of California (GOC), Mexico, but has rarely been studied. Objectives of this study were to estimate age and growth parameters of this species from two areas in the northern GOC and use an age-structured model to assess fishery yield and Spawning Potential Ratio (SPR) over a wide range of exploitations. Samples yielded fish up to age 8, although most were between age 2 and 5. Growth was extremely rapid, with most of the growth in length achieved in the first year, followed by much slower growth. Conditional rates of natural mortality averaged 0.37. Yield models predicted that spotted sand bass in the GOC were less vulnerable to fishing than those in the Pacific Ocean, likely due to faster growth and higher natural mortality. Growth overfishing and SPR values below 0.20 were only predicted at the lowest natural mortality and high (>0.50) exploitation rates. Results suggested that the species could support a commercial fishery in the GOC that might alleviate some of the conservation issues currently facing biologists in this unique marine ecosystem.