Crustaceans and Mollusks Monitoring

Melanie Aleman

In 2016, Cardno ENTRIX completed the Environmental Impact Study and Environmental Management Plan for the Development, Construction, and Maintenance of the Facilities; Dredging, Navigation Channel; and the Operation of the Public Deep Water Port located in the Guayas province, near Guayaquil, in Posorja. This strategic development project undertakes international standards in operations and sustainability, and as such, seeks to conserve the local mangrove ecosystems, among others.

Aligned with this goal, Cardno ENTRIX conducted the biotic monitoring of crustaceans and mollusks in the mangrove areas near the port’s building site in December 2018. This monitoring project complies with the Environmental Management Plan and the terms of the project’s environmental license, as well as analyzes the populations of existing crustaceans and mollusks in the area.

Monitoring crustaceans and mollusks is important to measure and control any impact that the port’s construction could have on these delicate species. If any changes are detected, information gathered through biotic monitoring can be used to make corrections and modifications to mitigate the impact, minimizing or eliminating it, if possible.

Monitoring Objectives

In the monitoring, Cardno ENTRIX had the following objectives:

  • Evaluate the conservation status of crustaceans and mollusks in the existing mangrove remnant near the project’s site.
  • Establish a baseline on the density and demographic characteristics of the crab and mollusk populations found in the mangrove areas near the project.

Entrance to the monitoring area

Entrance to mollusk sampling point

Monitoring Activities

During the biotic monitoring, Cardno ENTRIX specialists obtained the research permit for sample mobilization, in accordance with Ecuador’s environmental laws. Additionally, the team:

  1. Selected the sampling quadrants
  2. Determined the coverage of vegetation and number of organisms found
  3. Photographed the areas and specimens being monitored
  4. Took samples and identified individuals

In monitoring crabs, the team recorded information on its specie, sex, carapace size, and reproductive data for each individual collected.

Measuring an Anadara grandis. (pustulose ark)Measuring an Ucides occidentalis (red crab)

In monitoring mollusks, the team recorded information on its specie, morphometric sizes, color, shell shape, shell opening, presence or absence of the siphonal canal, paneal line and abductor muscle scar.

Measuring an Anadara grandis (pustulose ark)

Collaboration with the Manglares Porteños Cooperative

Cardno ENTRIX conducted the monitoring with its specialist biologists, who worked together with the association of local crabbers, the Manglares Porteños Cooperative.

These local crabbers supported Cardno ENTRIX in the capacity of community guides, sharing their knowledge on the methods of capture, handling, and locating the crustacean and mollusk harbors. At the same time, our biologist specialized in aquatic fauna, Maria Jose Racines, trained the local guides on the importance of the crustacean and mollusk biodiversity, and taught about the species characteristics, recorded during the monitoring.

This exchange was critical for mutual learning between environmental specialists and local crabbers. In addition, it contributed to building local capacity and providing local labor opportunities in this important development project in the country.

Locating crustaceans for study


Weighing and measuring crabs

Weighing and measuring mollusks