WILDCOAST on the Front Lines: Our Global Fight Against River Plastic Pollution

July 24, 2025

By Angela Kemsley 

At WILDCOAST, we’ve always believed in the power of community, science, and direct action to protect our most precious coastal and marine ecosystems. That’s why we are incredibly proud to announce the recent publication of groundbreaking research in the Journal of Environmental Management (Brewster et al., 2025), a leading peer-reviewed scientific journal. This isn’t just any paper; it’s a testament to years of dedicated effort, collaboration, and the vital role WILDCOAST plays in understanding and tackling the global plastic pollution crisis, particularly in our own backyard: the Tijuana River Watershed.

You might know us for our work protecting coastlines, conserving marine wildlife, or establishing protected areas. But for years, a significant part of our mission has been focused on stopping plastic pollution at its source, before it ever reaches our beautiful beaches and the ocean. We’ve been on the front lines, working tirelessly to intercept plastic debris in the Tijuana River, and this new scientific paper shines a spotlight on the impact of these efforts, including our pioneering work with the trash boom in Los Laureles Canyon, Tijuana.

The Global Plastic Problem: A River Runs Through It

Plastic pollution is a massive, urgent threat to both human health and the health of our planet. We see it every day: plastic bags tangled in mangroves, bottles washing up on shore, and tiny plastic fragments making their way into the food we eat. While the images of plastic-choked oceans are powerful, the truth is, most of this plastic starts its journey much further upstream, in our rivers. Rivers act like highways, transporting vast amounts of plastic from land-based sources directly into our oceans.

Despite this critical role, there’s been a real lack of hands-on, on-the-ground research about plastic in rivers, especially over long periods and in diverse locations. That’s where this incredible new study comes in. It’s one of the most comprehensive efforts to date, bringing together community-led research teams from eight different river systems across four continents – Mexico, Jamaica, Panama, Ecuador, Kenya, Vietnam, Thailand, and Indonesia. For over three years (2020-2023), these teams worked synchronously, collecting and analyzing macroplastic debris (plastic pieces larger than 5mm).

WILDCOAST’s Critical Role: Leading the Charge in Tijuana

WILDCOAST was a key partner in this ambitious global project, leading the data collection efforts in the Los Laureles Canyon in Tijuana, Mexico. This isn’t just a research site for us; it’s a community we’ve been working with for years, tackling the very real and immediate problem of transboundary pollution in the Tijuana River Watershed.

Los Laureles Canyon is unique. It’s an ephemeral drainage, meaning it only flows during the rainy season. But when it does, it carries a significant amount of debris, including a staggering amount of plastic, directly towards the Tijuana Estuary and eventually the Pacific Ocean. Our team, working closely with local communities, deployed a specialized trash boom in the canyon. This wasn’t a high-tech, multi-million-dollar machine, but a manually serviced boom, complemented by land-based community waste collection points. This approach highlights a crucial finding of the study: while advanced technology has its place, effective plastic collection is often more about strategic local tailoring and consistent operational approaches than just technological complexity.

Over the 35 months of data collection in Los Laureles Canyon, our team, alongside our global partners, collected and analyzed an astounding 8.4 million pounds of debris, with a whopping 66% of that being plastic! This massive dataset provides unprecedented insights into what kind of plastic is flowing into our oceans and where it’s coming from.

What We Learned: Insights from the Front Lines

The study revealed some fascinating and important patterns, and our work in Los Laureles Canyon contributed significantly to these findings:

• It’s Not Just About Technology: We found that the sheer complexity of the collection technology wasn’t the main driver of how much plastic was collected. Instead, factors like how strategically the collection efforts were tailored to the local environment and the consistent operational approaches were more impactful. Our Los Laureles boom, a simpler, community-serviced system, proved highly effective for its context.
• Population Matters: The study showed a strong link between the size of nearby urban populations and the amount of plastic debris collected. This makes sense – more people often means more consumption and, unfortunately, more mismanaged waste. This insight is crucial for deciding where to focus future collection efforts for maximum impact.
• The “Other” Plastic Problem: Tires in Tijuana: One of the most striking findings from Los Laureles Canyon was the high proportion of “Other” plastics, predominantly waste automotive tires (41.4% of the plastic collected!). While tires were found at other sites, nowhere was their prevalence as high as in Tijuana. This highlights a specific and well-documented transboundary problem in the Mexico-U.S. border region, where used tires from the U.S. often end up. This finding underscores the urgent need for stronger policies like extended producer responsibility and fees to tackle this unique form of plastic waste.
• Recycling Challenges and Opportunities: The study revealed that a significant portion of collected plastic, including in Los Laureles Canyon, was made of readily recyclable polymers like PET (38.7% in Los Laureles). However, the overall recycling rate across all sites was low (only 14%). In Tijuana, to achieve a 56.2% recycling rate for the collected plastic, it had to be trucked nearly 1,700 miles to a recycling plant in Toluca (near Mexico City) because local infrastructure is lacking. This clearly shows the immense need for investment in local, accessible, and affordable recycling infrastructure, especially in communities like those in the Tijuana River Watershed. It also highlights the economic opportunity that exists in developing these systems.

Looking Ahead: Our Commitment to a Plastic-Free Future

This paper is more than just a collection of data; it’s a powerful tool that informs our strategies and reinforces the importance of our community-led approach. The insights gained from Los Laureles Canyon and the other study sites will help us, and the global community, better understand the sources of plastic pollution and develop more effective upstream solutions.

We are committed to continuing our work in the Tijuana River Watershed, advocating for stronger policies, investing in local solutions, and empowering communities to be part of the solution. This publication in the Journal of Environmental Management is a significant milestone, validating our efforts and providing a robust scientific foundation for the ongoing fight against plastic pollution. We are proud to be at the forefront of this critical research, turning scientific insights into tangible action for healthier oceans and communities.

Join us in celebrating this achievement and in our ongoing mission to protect our planet from plastic pollution!