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Sectorization, self-closures and fattening zones for the sustainable exploitation of the black shell

Published: 26 September 2018
Last edited: 28 March 2019
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Since 2009, the mangrove concession of Las Huacas Association has faced a problem with low productivity due to the fact that it coonsists only of thin mangrove barriers between shrimp farms.

To ensure the sustainability of the exploitation of the black shell - a main resource within their concession - the following strategies were implemented:

  • Increase of the minimum catch size: from ≥ 4.5 cm (current standard) to ≥ 4.7 cm, considering the improvement in the size of the shell and more development time
  • Use of an area for ​​fattening undersized shells: when shells that are smaller  than the established size (<4.7cm) are caught, "size controls" at the end of the day are used to detect them. Undersized shells are released in the fattening area to grow and is captured later when there is a social purpose (festivity) within the community.
  • Establishment of temporal clousures for recollection of the black shell, to avoid over-exploitation.


South America
Scale of implementation
Coastal forest
Marine and coastal ecosystems
Ecosystem services
Fisheries and aquaculture
Food security
Gender mainstreaming
Indigenous people
Species management
Traditional knowledge
Land and Forest degradation
Climate Challenges (Hazards)
Ecosystem loss
Ecological Challenges
Lack of alternative income opportunities
Economic Challenges
Lack of public and decision maker’s awareness
Social Challenges
Poor monitoring and enforcement
Sustainable development goals
SDG 1 – No poverty
SDG 2 – Zero hunger
SDG 12 – Responsible consumption and production
SDG 14 – Life below water
Aichi targets
Target 4: Sustainable production and consumption
Target 6: Sustainable management of aquatic living resources
Target 7: Sustainable agriculture, aquaculture and forestry
Target 15: Ecosystem restoration and resilience
Target 17: Biodiversity strategies and action plans
Target 18: Traditional knowledge
Target 19: Sharing information and knowledge


Las Huacas, Santa Rosa - Ecuador | Las Huacas, Pongalillo


  • There is little added value for quality products from the sustainable use of mangroves.
  • Absence of alternatives for other productive activities increases the exploitation pressure on the black shell.
  • Demand for resources for the subsistence of a growing population: temporal-clousures and rotation of capture areas allow the black shell population to increase.
  • The number of members of the association has doubled.
  • Pressure on the black shell resource: Areas of fattening allows the seeding of undersized  shells,which become a product reserve for times of need.
  • Degradation of the environment (mangrove) because of the shrimp farms.
  • Entry of outsiders to the concession area: Fishermen who do not belong to the association do not respect capture sizes or non-destructive extraction techniques.


Main beneficiaries are the families of the members of the association, who have improved their life quality.

Other concession areas are benefited too because the good health of the black shell population delivers more 'seeds' to mangrove areas around.

How do the building blocks interact?

The building blocks create the base conditions to better understand the problem, better capabilities to face them and to propose potential solutions  (even its long term potential consequences), and the strong enough to deal with the conflicts, diversity of views and interests, creating a more resilient community.

This is a step by step process that allows to face issues that affects the quality of life of the community, and its own experiences serves as inspiration for next steps to develop.


The impact of the initiatives is a greatly increased availability of high quality resource (larger size equals higher value), improving the total revenue, and the efficiency of the fishery. The additional resources have served in part to financing the improvements in our quality of life, and to help the asociation to invest to ensure the implementation of our management plan in the area (custody and conservation).


Aso. Las Huacas

The Association of "Las Huacas", was founded on July 4, 2007 and brings together seafood collectors and artisanal fishermen for residents of the commune of Las Huacas, in the Jambelí parish, Santa Rosa canton , Province of El Oro. They have Agreement No. SGMC-003-2015, which grants them concession for the sustainable use and custody of mangrove 1,070.5 ha. To assure the future availability of the black shell (main source of income), the Association of Las Huacas established: Increase the catch size from ≥ 4.5 cm (limit allowed by law) to ≥ 4.7 cm; auto-clousures cycles, which delimit harvesting sectors and harvesting cycles in each sector, enabling a rotating sequenced harvesting calendar, in order to avoid over-exploitation and at the same time, to assure the availability of better sized product, generating increased revenues for the fishermen. Fattening area complement the efforts, reserving a special area for captured shell that does not comply with the catch size. Once confiscated and registered in the log, undersized blackshell is taken to the fattening area, where it continues its natural cycle and remains as a reserve for future uses. This management plan establishes a total new way to manage the blach shell in the region, where neighbors used aggressive catching arts (rakes) to catch all individuals on the estuary no matter the size or its life-stage, letting devastatted populations that can not recover, killing their source of food and income.

Contributed by

Fabrizzio Tapia

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