Climate change and the current level of catches will deplete the fishery in 15 years

«If we continue fishing as we have done now, together with the effects of climate change, in 10 or 15 years most of the marine resources will disappear, there will be a collapse of many species such as groupers, abbots or old women. This is the main conclusion of the Moira project developed by researchers from the University of Las Palmas de Gran Canaria (ULPGC) to assess the sustainability of fisheries in Gran Canaria, for 2030 and 2050. Its principal investigator, José Juan Castro remember that in the last 50 years 90% of fishing productivity has been lost and that there is no time to lose to avoid the collapse of the system.

«The objective of the project was to establish a prediction system of how the marine resources are in Gran Canaria in the near future, in 2030 and in 2050, using an ecosystem model that allows us to see how it would evolve over time, applying fishing strategies -reducing fishing effort, increasing reserve areas, establishing catch quotas for different types of fleets or fishing areas ... -, and analyzing in turn, how climate change is going to affect all the species that are in that marine ecosystem on the island, "said Castro, a researcher at the University Institute of Sustainable Aquaculture and Marine Ecosystems (IU-Ecoaqua) of the ULPGC.

The Moira project -Modelization of recreational and artisanal fisheries developed in the spaces of the Natura 2000 Network in Gran Canaria: participatory management and evolution in future climate scenarios-, co-financed by the Biodiversity Foundation of the Ministry of Ecological Transition and Demographic Challenge, through the Pleamar Program, and the European Maritime and Fisheries Fund (FEMP), has had the participation of the fishing sector, from the Cooperativa de Pescadores de San Cristóbal, the Oleaje recreational fishing club and the Gran Canari Coastal Action Groupa, which brings together all the fishermen's associations and some recreational fishing clubs, as well as other actors who work in the marine environment. “With the information and help from the sector, we have fed the prediction model and, furthermore, the fishermen have given us what would be the solutions for the future, their strategies as fisheries managers, both professionals and recreational fishermen "Castro pointed out.

The species most threatened by overfishing are the old ones, moray eels, tunas and samas.


With all this information, the ULPGC scientific team, made up of José Juan Castro, Jorge Cabrera, Airam Guerra, Lorena Couce, Diego Gamo, Irene del Toro, Antonio Carlos Domínguez, David Jiménez, Ana Espino and Angelo Santana del Pino, researchers from the group of Biodiversity and Conservation of the IU-Ecoaqua, the Institute of Intelligent Systems and Numerical Applications in Engineering (Siani), and the Comprehensive Marine Technology Service (Sitma) of the ULPGC, developed five scenarios for predicting the future around fishing in Gran Canaria.

The first scenario was to do nothing, to see how the whole system would evolve by leaving things as they are at the moment. "If we continue working at the same level of catches, with the same boats and number of fishermen and the same ways of doing things," adding the factor of global warming based on the data raised by the intergovernmental panel on climate change, and which is the temperature increase of one degree centigrade by 2030 and one and a half degree by 2050. “With this scenario, if we continue as we are, most of the resources would disappear in 10 or 15 years. There will be a significant drop if we continue fishing as we have done before, together with the effects of climate change that would affect the growth of species, natural mortality.

The following scenarios were to reduce only professional fishing by 30%; another to reduce only recreational fishing by 30%, leaving the professional as before; combine both, reducing the two by 30%; and, finally, a fifth scenario that contemplates the reduction of 30% of each one of them, in addition to creating marine reserves.


«With these four alternatives we saw that things improve a little, but not enough to make the system recover, the collapse occurs but in a longer period of time, instead of in 15 years, it would occur in 30 years, although the trend is the same ”, emphasized Professor Castro. "These results tell us that the system is highly overexploited and that the reduction in effort that we are proposing of 30% is not enough, we must go further and establish many more measures."

Between them, the Ecoaqua researcher aims to implement actions such as catch quotas, minimum sizes for all species, a greater limitation of recreational fishing - "which is the one with the greatest impact at present, due to the number of fishermen and the volume of activity" -, or creating temporary reserves for some species related to the breeding season. "If we don't do that, in a matter of a very short time we can run out of the fishery resources that we know today."

Among the measures to be taken, they indicate catch quotas, minimum sizes or temporary reserves.


The researchers warn that "the system is not in balance" and that the most threatened species are the old ones, moray eels, tunas and samas, compared to octopuses, roosters or amberjack, which present a better situation. However, the loss of species affects the trophic chain since they are food for other animals such as turtles, sharks or birds.

“We have not tested scenarios greater than 30% reduction, but what we are seeing is that recreational fishing in Gran Canaria has a very important role, more than professional fishing where the number of active fishermen or boats is very low. However, the number of recreational fishermen can reach more than 30,000 only in Gran Canaria, and 110,000 in the entire Archipelago »

José Juan Castro points out the need to focus actions on the species that have the highest level of fishing pressure in specific periods, such as the brecas, samas or bocinegros in some months, and groupers or abbots in others. "Temporal measurements can be short in time, from a month, but they have to be located at the moment in which these species reproduce, because they are more vulnerable, they are concentrated in space and more are captured."

Researchers from the Ecoaqua and Siani institutes develop five future scenarios


The Moira research project also includes the development of technology, since to carry out the project, the Siani researchers, under the direction of Jorge Cabrera, designed an autonomous surface vehicle, with a surfboard, photovoltaic panels and an echo sounder. that tracks the sea and records data on the different species.

Once the study has been completed, the next step is to present the report to fishermen and the competent public administrations - the State, the Autonomous Government and councils - during these weeks. «Then, it will depend on the administrations, if they want to go further or start with these results to apply measures. Obviously, no more studies are needed to start implementing actions. Things have not been going well for a long time and you have to act more forcefully, hot cloths are no longer good for much, "concluded Professor José Juan Castro.

Evolution and participatory management


  • The ULPGC's Moira project has aimed to assess fishing activity and model climate change scenarios to reduce its impacts on the Canary Islands Natura 2000 Network, helping to strengthen the management, recovery and monitoring of these areas.


  • Development of a low-cost autonomous vehicle prototype for the evaluation of biomass and fish stocks; obtaining catch data with the collaboration of fishermen through meetings, surveys and interviews; pilot sampling campaigns supported by an ROV; data processing and analysis of all the information generated: evaluation of habitats, fishing species and protected species; transfer of results to the stakeholders and general dissemination of the Moira project.


  • In the Canary Islands, artisanal and recreational fisheries are characterized by large information gaps that make it difficult to establish proper management. "The use of methodologies based on citizen science, such as surveys, are a quick and low-cost tool to fill in these deficiencies." The need to separate the three recreational fishing modalities was also observed to more reliably assess recreational fishing effort.


  • The pig rooster, sea bream, abbot, octopus, parsnip, mullet and mackerel, are found on fish and continue to be exploited as extracted from the Kobe diagrams estimated from the first-sale data of the Canary Islands Government.

Good practices

  • Respect the minimum sizes in force, establish minimum sizes for all species that correspond at least to their size at first maturity; improve traceability mechanisms to eradicate the commercialization of poaching; and to strengthen ties between public administrations, fishermen's groups and the scientific community, to smooth things over and reduce the currently existing mistrust. Likewise, it is proposed to avoid the use of gear in areas where there is a high probability of capturing vulnerable species, such as elasmobranchs, that are not the target of the fishery.


  • Both artisanal and recreational fishing must be controlled by public administrations to guarantee that current regulations are being complied with; An updated census is required of the vessels authorized for recreational fishing and the obligation to report their positions, in addition to increasing their control; and establish closures according to the biological cycles of the species and create comprehensive marine protected areas.


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