The BIOCON group at the University of La Palma (ULPGC) is launching a scientific initiative, known as GRANDES, which aims to contribute to fisheries management by identifying which parts of the genome regulate the growth and reproduction of commercially exploited fish species.
The aim is to protect the reproductive potential of populations and prevent induced fishery evolution (genetic overfishing) and its consequences on marine ecosystems.
One of the central themes will be to assess the impact of managing fisheries using as a reference the size at which 95% of individuals have reached maturity (L95), as opposed to the more widespread criterion based on the size at first maturity of 50% of the population (L50).
The ECOAQUA University Institute of the University of Las Palmas de Gran Canaria (ULPGC), through the Biodiversity and Conservation (BIOCON) group, with José Juan Castro as principal investigator, has launched a project that seeks to contribute to fisheries management by identifying which parts of the genome regulate the growth and reproduction of commercially exploited fish species.
Under the title “Implications of mass maturity size on genetic structures and reproductive and growth characteristics in fish species of fishery interest”, whose acronym is GRANDES, this scientific initiative aims to use this knowledge to generate a solid scientific basis for designing fishing regulations supported by genetic evidence, capable of protecting the reproductive potential of populations and conserving their genetic diversity, preventing induced fishing evolution (genetic overfishing) and its consequences on marine ecosystems.
Boats moored in Arrecife, Lanzarote - Photo by José Juan Castro.
This project is part of the Pleamar 2025 programme and receives competitive grants from the Fundación Biodiversidad, F.S.P., to promote the blue economy and boost sustainability in fishing and aquaculture, co-financed by the European Maritime, Fisheries and Aquaculture Fund.
Sustainability, the main challenge
The sustainability of fisheries is one of the main challenges in the management of marine ecosystems. Fishing can induce changes not only in the abundance of populations, but also in their biological and genetic characteristics, affecting key processes such as growth, maturation and reproduction.
These alterations can have long-term consequences on the recovery capacity of exploited populations and on the stability of the marine systems that sustain them. For this reason, in recent years, the need to incorporate new scientific approaches that integrate genetic information into the assessment and management of fishery resources has become apparent.
This concern has given rise to the GRANDES project, a scientific initiative based on several complementary lines of research.
Local fishermen working in Canary Island waters.
On the one hand, specific regions of the genome related to growth and sexual maturation in the selected species will be analysed. At the same time, the current status of key biological parameters — such as the reproductive season, the size at which fish reach first maturity (L50 and L95) and growth patterns — will be described and these data will be compared with available historical information.
Maturity criterion: L95 versus L50
One of the central themes of GRANDES will be to assess the impact of managing fisheries using as a reference the size at which 95% of individuals have reached maturity (L95), as opposed to the more widespread criterion based on the size at first maturity of 50% of the population (L50).
Using models of fecundity, recruitment yield and biomass under different scenarios, the team will investigate how the status of populations and catch levels would change if more conservative minimum catch sizes were adopted.
Researcher José Juan Castro, principal investigator of the GRANDES project.
Based on these results, sustainable management proposals will be developed in line with the biological and genetic characteristics of each species, assessing their relevance and viability for the competent authorities.
Likewise, the interaction between natural selection and selection exerted by extractive activity will be studied, analysing the evolution of oceanographic and climatic conditions, as well as trends in recorded catches.
This approach will make it possible to assess the adaptive capacity and genetic resilience of stocks in the face of intense and prolonged exploitation, i.e. the extent to which populations are able to withstand and recover from environmental and fishing changes.
The GRANDES project aims to generate scientific knowledge that incorporates the genetic dimension into the study and management of exploited populations, providing a solid basis for designing more rigorous and realistic fisheries management models that are aligned with the current challenges of conservation and sustainability of marine ecosystems.