Therefore, research is necessary to achieve the sustainability of this fishery; it must be determined to decide if shark species can tolerate these levels of fishing without affecting their abundances. Worldwide, there is concern about the status of many shark species because declines in their populations put them at risk of extinction \citep{white2014}, and local extinctions have already been documented \citep{jc2014}. This is because, in general, sharks are very vulnerable to intense and prolonged periods of fishing due to their biological characteristics such as slow growth rates, late sexual maturity, low fertility and long reproductive cycles, which result in low population growth rates \citep{fordham2000}.

However, despite the over-fishing of some shark species (i.e. fishing intensity exceeds the recovery potential capacity of their populations), it does not seem feasible to prohibit this fishery as coastal fishing communities depend on this marine resource, and due to the demand for shark meat in Mexico. Simpfendorfer and Dulvy \citep{dulvy2016} indicate that prohibiting shark fishing is not a solution to the over-fishing problem faced by some shark populations in the world, as most of the species are caught incidentally (i.e. the species are not the objective of the fishery), and because they play an important role for worldwide food security. These researchers highlight that a feasible solution is to move towards sustainable fishing, because the current capturing of at least 33 species of shark is sustainable. In some regions of Mexico, research can make some shark fisheries sustainable, combining knowledge of the biology of the species and the dynamics of the fishing communities \citep{mndez-loeza2015}.

Shiffman and Hueter \citep{hueter2017} indicate that some lessons, which guide shark fisheries towards sustainability, are to protect those species with the lowest biological productivity. In Mexico, NOM-029-PESC-2006 \citep{federacin2007} establishes the protection of some of these species such as white, basking and whale sharks. Such international treaties contribute to the sustainability of fisheries, and Mexico meets the guidelines of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Meanwhile, developed countries support the transition towards the sustainability of fisheries in developing countries and in Mexico, researchers collaborate with different international institutions to receive training and improve the assessments of the status of shark species.

En los mares mexicanos habitan 111 especies de tiburones \citep{2015}, que representan el 21.8% de todas las registradas a nivel mundial \citep{s2016}. Esto es posible por la gran diversidad de hábitats costeros y oceánicos en ambos litorales del país. De esas especies, al menos 33 son de interés comercial (\citep{federacin2010} and \citep{federacin2018}), y son capturadas para el consumo de su carne y aletas. La carne tiene una gran aceptación en el mercado nacional y las aletas son un producto de exportación para el mercado asiático.

En México, existen registros de captura de tiburones desde finales de la década de los 1930´s. Fue en la década de los 1970´s que la pesca de tiburones incrementó de forma exponencial por la demanda nacional de carne e internacional de aletas, hasta alcanzar 35,000 toneladas anuales en la década de los 1990´s  \citep{a1998}. Después de una disminución de las capturas en la década pasada, con menos de 30,000 toneladas anuales, en la actual década ha incrementado gradualmente hasta alcanzar 42,704 toneladas en 2017 \citep{sagarpa2017}.