In an effort to ensure the sustainability of the scallop fisherymembers of the Fishermen's Organization Rescuing the Inlet (OPRE), of El Manglitohave adopted an innovative, non-extractive methodology to assess the abundance of the fishery resource in the Ensenada de La Paz.

Silvia Ramirezcoordinator of NOS Sustainable Northwestexplained that the conventional assessments of population abundance of bivalve mollusks usually involve extraction, to be later counted and measured, however, the methodology employed by OPRE fishermen is different, taking advantage of the benthic characteristics of the ax callus.

"With their experience, what they do is to identify the axes that are on the seabed, they uncover the mouth a little bit by moving their hand so that the sand moves and the widest part of the shells is exposed," he said.

"By diving and walking transects of 50 meters long by 2 meters wide, they count and measure the width of the axe shells within the transect area (one meter on and one meter off)".

To determine whether an animal is within the catchable stock, the width of the shells must measure more than 14 centimeters, he added.

Evaluation is crucial for sustainability

It was in the period from 2011 to 2017 when fishermen from El Manglito decided to suspend the extraction of axe callus with a view to recovering the population of this resource.

The population assessment of the resource is carried out annually and since 2017, the year in which fishermen received their fishing concession, it is an indispensable activity to request the fishing quota from the National Commission of Aquaculture and Fisheries (CONAPESCA) and that the sustainable use of the resource. The results of the annual evaluations allow visualizing the changes over time in the population dynamics of the resource, either the increase or decrease in abundance, as well as the size structure.

This year, the assessment was carried out during the month of April in eight fishing banks. The assessment involves the active and self-organized participation of the fishermen, with support from NOS Sustainable Northwest and with the supervision of Mexican Institute for Research in Sustainable Fisheries and Aquaculture (IMIPAS), to guarantee the correct execution of the process, said Silvia Ramírez.

"Based on the estimated abundance, the authority establishes a quota per bank, taking into account what is known as 'precautionary criteria', which is a percentage between 15 to 20% of the organisms that are commercially sized," he explained.

The NOS coordinator stressed that the fishermen have adopted this methodology of non-extractive evaluation and good utilization practices. Since 2017, when OPRE obtained the fishing concession, has maintained an authorized effort of five vessels, respecting the quota per bank and the sizes.

In spite of efforts to protect and restore the population of ax callusThe resource has had to face challenges that have caused significant mortalities throughout the years of the restoration initiative, such as the presence of illegal fishing, or the effect of sediment dragging due to torrential rainfall caused by hurricanes, but undoubtedly none as detrimental as the presence of a species of invasive exotic ascidian which resulted in the mortality of more than 80% of the hatchet population, between 2016 and 2017.

These ascidians are colonial organisms that were detected in 2015 and were establishing themselves on the axe shells, covering them and causing massive mortality of the axes, by suffocating them and preventing them from feeding. On these occasions, the population assessment made it possible to measure the magnitude of the population decline.

The information generated through resource assessments undoubtedly provides producers with better decision-making capacity. It has also made it possible to identify that the resource (callo de hacha) has not been able to recover from the mortality caused by the invasion of tunicate and, therefore, the volume available for the fishery can only support a limited use, which up to now has been limited to a limited amount. OPRE has been respected, despite the economic pressures and livelihood needs of producers and their families.

He also made visible the need to detonate productive diversification and the transition to other economies that favor the development and prosperity of the families of this fishing community. This process requires the development of entrepreneurial skills and abilities, which the women and men of OPRE are currently preparing for.

Finally, it is important to recognize the gradual importance that fishermen and women from OPREto the generation of information and the evaluation not only of the ax callusbut of the resources available in the Ensenada de La Paz. And how this sustainable approachhas changed the fishermen's relationship with their resources, motivating them to protect and restore both the resources and the Ensenada de La Paz system, despite the current challenges, considered Silvia Ramírez.

The community hopes that their efforts in the evaluation and management of the resource will be recognized and supported by the authorities and society, in order to continue with their work of restoration and responsible fishing.