Fishing Techniques That Don’t Harm Aquatic Ecosystems

Fishing is a vital activity for food, income, and culture in many parts of the world—especially in the Amazon, where rivers and lakes provide for millions of people. However, not all fishing methods are created equal. Some can cause severe damage to aquatic ecosystems, affecting not only fish populations but also plants, mammals, birds, and entire food webs. In contrast, sustainable fishing techniques aim to meet human needs without compromising the health of the environment.

In this article, we’ll explore fishing techniques that are ecologically responsible, how they differ from harmful practices, and why their adoption is essential for the preservation of ecosystems—particularly in sensitive regions like the Amazon.

The Need for Sustainable Fishing Methods

The use of destructive fishing methods has led to numerous problems in aquatic ecosystems worldwide:

• Overfishing and population collapse of key species
• Habitat destruction, especially of breeding and nursery grounds
• Bycatch, or the unintentional capture of non-target species
• Water pollution from equipment and waste
• Disruption of food chains and biodiversity loss

To reverse these impacts, sustainable fishing requires not just new rules, but also a shift toward low-impact techniques that protect both biodiversity and livelihoods.

Characteristics of Eco-Friendly Fishing Techniques

Sustainable fishing techniques typically share the following characteristics:

• Selectivity: Targeting specific species or sizes to avoid overharvesting juveniles or endangered fish
• Minimal habitat damage: Avoiding methods that destroy the riverbed or aquatic plants
• Low bycatch: Reducing accidental capture of other fish or animals
• Human scale: Techniques that can be performed by individuals or small groups, often using traditional knowledge
• Compatibility with ecosystem cycles, such as spawning seasons and migration patterns

Let’s now take a closer look at some of the techniques that fit these criteria.

1. Handlines and Rods

Handlining is a simple, traditional method where a single fishing line with a baited hook is dropped into the water and managed by hand. In more modern forms, fishing rods with reels are used.

Benefits:

• Extremely selective—only one fish is caught at a time
• No bycatch
• Minimal disturbance to the environment
• Easy to regulate and monitor

This method is commonly used in sport fishing and small-scale subsistence fishing, particularly for species like tucunaré (peacock bass) and tambaqui in the Amazon.

2. Cast Nets (Tarrafa)

Cast nets are circular nets with weights on the edges, thrown by hand into shallow waters. When pulled in, they trap fish in a small area.

Benefits:

• Effective in catching a variety of small to medium-sized fish
• Selective based on technique and net size
• Can be controlled to avoid overfishing or harming juveniles

In the Amazon, cast nets are used by traditional fishers who understand the river’s rhythms and fish behavior, minimizing environmental impact.

3. Fish Traps (Covos and Tapiris)

Fish traps are stationary devices that use the fish’s natural movements to capture them. In the Amazon, tapiris (small enclosures made from branches) are used near flooded forest areas to catch fish as waters recede.

Benefits:

• Low energy and non-destructive
• Very low bycatch
• Traps can be checked regularly, allowing live release of non-target species
• Made from biodegradable or natural materials

Fish traps are deeply rooted in indigenous and traditional knowledge, making them excellent models for culturally appropriate sustainable fishing.

4. Selective Gillnets

Gillnets have a bad reputation when misused, but when designed correctly—especially with large mesh sizes—they can be selective and relatively sustainable.

Best practices:

• Use legal mesh sizes to avoid capturing juveniles
• Avoid setting nets in sensitive areas like spawning grounds
• Remove nets quickly to reduce bycatch or fish suffering

In managed contexts, regulated gillnets can provide food and income while maintaining healthy fish populations.

5. Seasonal and Rotational Fishing

While not a technique per se, when and where fishing happens is as important as how it’s done. Seasonal restrictions protect breeding cycles, while rotating fishing areas gives ecosystems time to recover.

This method is practiced in many Amazon reserves and co-managed areas, where communities agree on no-fishing zones or seasonal bans during piracema (fish migration and spawning season).

Techniques to Avoid

To understand why sustainable fishing matters, it’s helpful to know which techniques are especially destructive:

• Bottom trawling: Drags heavy nets across the riverbed, destroying plants and habitat
• Explosives (dynamite fishing): Kills all aquatic life in the blast radius
• Poisoning: Introduces toxins that harm fish, other animals, and people
• Electrofishing: Stuns or kills indiscriminately, often used illegally
• Fine-mesh nets: Catch even the smallest fish, disrupting regeneration cycles

These methods not only threaten biodiversity, but often result in short-term gains and long-term collapses.

The Role of Traditional Knowledge

In many Amazonian communities, fishing techniques have been passed down for generations. These often reflect a deep understanding of local species, seasons, and habitats. When combined with modern conservation science, traditional methods can be incredibly effective for sustainability.

For example, indigenous communities often:

• Avoid fishing during reproduction months
• Rotate between fishing spots based on moon phases or water levels
• Use natural materials that decompose and don’t pollute rivers
• Apply community-enforced rules to limit overfishing

Supporting these communities and recognizing their ancestral knowledge is a critical strategy in protecting aquatic ecosystems.

Innovation and Modern Adaptations

Some innovative tools are helping make traditional methods even more sustainable:

• Eco-friendly hooks that dissolve over time if lost
• Solar-powered fish finders that help locate mature schools
• Smart buoys that track fish movement and alert when certain species pass
• Drones and GPS to monitor protected areas and fishing boundaries

When adopted thoughtfully, technology can complement traditional fishing, not replace it.

Education and Community Engagement

Sustainable fishing practices only work when communities understand and support them. Many successful conservation programs invest heavily in:

• Fisher education on species identification, regulations, and techniques
• School programs that teach young people about aquatic biodiversity
• Workshops on fish processing and value-added products to reduce pressure on wild stocks
• Women-led initiatives that expand income opportunities without overfishing

Engaging all members of the community—young and old, men and women—helps foster a shared sense of responsibility for the river’s future.

Policy and Enforcement

No technique is sustainable without rules and enforcement to back it up. This includes:

• Clear legal definitions of allowed gear and practices
• Community agreements that regulate behavior locally
• Government monitoring and support, including funding for eco-fishing projects
• Penalties for illegal techniques like dynamite or poisoning

The best systems combine top-down policy with bottom-up local enforcement, especially in regions like the Amazon where central oversight is limited.

Conclusion: Fishing in Harmony With Nature

Fishing will always be part of life along rivers, lakes, and coastlines. The goal is not to stop fishing—but to do it in a way that preserves nature, supports communities, and ensures abundance for future generations.

By choosing and promoting techniques that respect aquatic ecosystems, we can build a sustainable fishing culture that honors both tradition and science. Whether you’re a policymaker, a fisher, or simply a consumer, your choices help shape the future of our waterways.

The Amazon’s rivers are generous. Let’s fish them with care.