Scientists Identify Charru Mussel Invasion Hotspots in Batan Estuary

UP Visayas researchers urge early action to protect fisheries and food security in Aklan

By John dela Cruz

Batan, Aklan — A newly published scientific study has identified critical invasion hotspots of the invasive Charru mussel (Mytella strigata) in the Batan Estuary, highlighting growing risks to local fisheries, aquaculture, and coastal livelihoods in Aklan.

The study, titled “Predicting the distribution of the invasive charru mussel (Mytella strigata) in estuarine environments,” was published on January 5, 2026 in ScienceDirect. It was conducted by Gency L. Guirchem-Helican, John Ray Moleno, Irvin Michael Palmos, and Harold Monteclaro of the Institute of Marine Fisheries and Oceanology (IMFO), University of the Philippines Visayas.

Year-Round Invasion Hotspots Identified

Using field surveys and environmental modeling, the researchers identified areas of the Batan Estuary that face year-round high invasion risk. These persistent hotspots are:
• New Washington
• Inner Batan
• Tinagong Dagat

According to the study, these locations consistently provide favorable conditions for the Charru mussel to survive, reproduce, and spread throughout the year.

Why These Areas Are Vulnerable

The research shows that Charru mussels thrive in estuarine sections that are:
• Warm
• Brackish, where freshwater and seawater mix
• Shallow
• Organically enriched, often due to domestic waste, agricultural runoff, and decaying vegetation

These conditions are common in inner estuaries that support fishing communities and nearby agricultural activities.

What Is an Invasion Hotspot?

An invasion hotspot refers to a specific geographic area that is highly vulnerable to biological invasion, where non-native species establish and spread rapidly. Once an invasive species dominates a hotspot, it becomes difficult and costly to restore the ecosystem.

Implications for Fisheries and Agriculture

The continued spread of Charru mussels may result in:
• Displacement of native oysters, clams, and mussels
• Loss of fish nursery grounds, affecting municipal fisheries
• Clogging of fishing gear, fish traps, and aquaculture structures
• Changes in sediment and water quality

Because estuaries connect upland farms, rivers, and coastal waters, the study also highlights how land-based activities, including farming practices and waste disposal, influence coastal ecosystem health.

Science-Based Guide for Local Policy

Unlike earlier reports that only documented presence, this UP Visayas study predicts where the invasive mussel is most likely to spread, giving local governments and agencies a valuable tool for early intervention.

The researchers emphasized that early detection and targeted action are more effective and less costly than trying to control widespread infestation.

Call for Coordinated Local Action

Based on the findings, experts recommend:
• Focused monitoring in identified hotspots
• Improved waste management and farm runoff control
• Community education for fisherfolk and shellfish gatherers
• Integration of invasive species management into coastal resource management (CRM) and local agriculture-fisheries development plans

Protecting Aklan’s Coastal Resources

With fisheries and estuaries playing a vital role in food security and rural livelihoods, the study serves as a timely warning and an opportunity for Aklan. Guided by science, local communities and policy makers can act early to protect native marine life and sustain the productivity of the Batan Estuary for future generations.