How To Choose Long Fishing Nets: A Complete Buying Guide

Long fishing nets—also known as gillnets, set nets, or drift nets—are among the most effective passive capture tools in both commercial and small-scale fisheries. Yet their power demands precision: a poorly chosen net can mean reduced catch, damaged gear, unintended bycatch, regulatory penalties, or even ecosystem harm. Unlike casting rods or traps, long nets operate silently beneath the surface—relying entirely on correct specifications, local conditions, and responsible use. This guide distills decades of fisheries practice, gear engineering insights, and field-tested experience into actionable criteria. It’s written for fishers, aquaculture managers, conservation officers, and community co-ops who need clarity—not marketing claims—when investing in this critical piece of equipment.

1. Understand the Core Types—and Why They’re Not Interchangeable

“Long net” is a functional descriptor, not a technical category. What matters is how the net functions in water, which depends on its design, deployment method, and target species. Three primary configurations dominate real-world use:

• Gillnets: Vertical panels suspended by floats and weights; fish swim into them and become entangled by gills or body parts. Ideal for pelagic or mid-water species like herring, salmon, or cod.
• Entanglement nets (tangle nets): Looser, more elastic mesh with less tension—designed to snare fins, tails, or heads rather than gills. Often used for toothed fish (e.g., striped bass) where gillnetting is restricted.
• Trap-style set nets: Anchored horizontally near structure (reefs, drop-offs, riverbanks), forming funnel-like enclosures. Less common but highly selective for bottom-dwelling species like flounder or crab.

The distinction isn’t academic—it dictates everything from mesh stretch, twine strength, and float-to-weight ratio to legal compliance. A gillnet deployed in shallow estuaries without proper buoyancy control will sink, lose selectivity, and increase benthic impact. Conversely, using an entanglement net for fast-moving schooling fish often yields low retention rates.

2. Mesh Size: The Single Most Critical Specification

Mesh size determines species selectivity, legal compliance, and ecological impact. It’s measured as the distance between opposite knots when the mesh is stretched diagonally (called “bar measure”). A 100 mm bar-measured mesh does not equal a 100 mm square opening—it’s approximately 70.7 mm across the shortest span. Confusing these leads to illegal undersized catches and wasted effort.

Regulatory agencies set minimum mesh sizes to protect juveniles. For example:

• Atlantic salmon gillnets require ≥130 mm bar measure in many Canadian rivers;
• EU herring fisheries mandate ≥45 mm for coastal drift nets;
• U.S. Gulf shrimp trawl exclusion requires ≤114 mm in certain gillnet zones to reduce sea turtle bycatch.

But legality alone isn’t enough. Optimal mesh must account for target fish morphology. A 120 mm mesh may retain 90% of mature walleye (average girth: 18–22 cm) but only 40% of similarly sized perch due to differences in head-to-body ratio and flexibility. Field biologists consistently recommend testing mesh against live-sampled populations—not relying solely on published tables.

“Mesh selection isn’t about catching ‘more fish���—it’s about catching the *right* fish at the *right* size. One millimeter too small can trigger a season-long closure.” — Dr. Lena Torres, Fisheries Biologist, NOAA Northeast Fisheries Science Center

3. Material Selection: Strength, Durability, and Environmental Tradeoffs

Twine material affects longevity, visibility, abrasion resistance, and environmental persistence. Nylon (polyamide) remains the industry standard—but alternatives are gaining traction where sustainability or stealth matters.

For commercial operations, nylon offers the best balance of performance and service life—if properly maintained. For community-based or ecotourism fisheries, biodegradable synthetics increasingly meet both operational and stewardship goals. Avoid untreated natural fibers in tidal or warm reservoir environments: they degrade unpredictably and invite biofouling that alters sink rate and visibility.

4. Length, Height, and Configuration: Matching Gear to Habitat

A “long” net isn’t defined by absolute length—it’s defined by proportion to the water column and current dynamics. A 500-meter net is appropriate for open-coast drift fishing but dangerously unwieldy in a narrow river channel with variable flow. Key dimensions to evaluate:

1. Total length: Standard commercial gillnets range from 100 m to 2,000 m. For small-scale use, 100–300 m is manageable without mechanized hauling. Longer nets require winch systems and trained crew.
2. Vertical height (depth): Should cover 60–80% of the target zone’s depth. In a 10-meter-deep river pool targeting mid-water trout, a 7-meter-high net ensures optimal coverage while minimizing snagging on substrate.
3. Float-to-weight ratio: Critical for maintaining vertical orientation. Standard ratio is 1:1.2 (float lift : weight pull). In strong currents (>1 knot), increase to 1:1.5. Use stainless steel or lead-core weights—not concrete blocks—to prevent corrosion and sediment disturbance.
4. Leadline construction: Must be flexible enough to conform to bottom contours without kinking. Braided monofilament with integrated sinker pockets outperforms twisted rope with external weights for consistent contact.

Real-world deployment reveals subtle mismatches. In the Columbia River, fishers reported 35% lower chinook retention when switching from 5-meter to 8-meter height nets—despite identical mesh—because deeper nets sagged excessively in slack water, allowing fish to pass underneath unimpeded.

Mini Case Study: The Klamath River Adaptation

In 2021, Karuk Tribal fishers observed declining spring-run Chinook catches despite stable stock assessments. Net surveys revealed that standard 120-mm gillnets were capturing mostly sublegal fish—while larger, mature fish swam above or below the net’s effective zone. Working with USFWS biologists, they tested three configurations: a 150-mm mesh at 6 m height (standard), a 140-mm mesh at 4.5 m height (shallower), and a 160-mm mesh at 7.5 m height (deeper). The 140-mm/4.5-m combination increased retention of legal-sized adults by 62%—because it aligned precisely with the thermocline layer where mature Chinook concentrated during peak migration. This wasn’t about “bigger net”—it was about precise spatial matching.

5. Legal, Ethical, and Operational Compliance Checklist

Even the most technically sound net fails if it violates jurisdictional rules or undermines community trust. Use this field-proven checklist before purchase or deployment:

• ✅ Verify mesh size meets *both* federal and state/provincial minimums—and confirm measurement method (bar vs. stretch vs. knot-to-knot).
• ✅ Confirm net color is permitted (many jurisdictions ban fluorescent or high-visibility colors to reduce bird bycatch).
• ✅ Ensure floats are marked with vessel ID per Coast Guard or fisheries authority requirements.
• ✅ Check if time-gear restrictions apply (e.g., maximum soak time of 48 hours in EU waters).
• ✅ Review bycatch mitigation mandates: Do you need pingers for marine mammals? Turtle excluder devices? Acoustic deterrents?
• ✅ Document chain-of-custody if sourcing biodegradable netting—some certifications require traceability to manufacturer.

6. Maintenance, Storage, and Realistic Lifespan Expectations

A long net is a capital investment—not disposable gear. Its lifespan hinges less on initial quality and more on post-use care. Salt crystallization, UV exposure, and improper drying cause 70% of premature failures.

After each use:

1. Rinse thoroughly with fresh water—inside and out—to remove salt, silt, and organic residue.
2. Hang vertically in shade (never direct sun) on wide-mesh racks to ensure full airflow through every panel.
3. Inspect for broken twine, frayed knots, or corroded hardware. Repair small sections immediately; don’t wait for “next season.”
4. Store loosely coiled—not tightly wound—in ventilated, climate-controlled space (ideally 10–20°C, <60% RH).
5. Re-tension floats and weights annually; replace rubber grommets every 18 months.

Contrary to common belief, soaking nets in bleach or vinegar “sanitizes” them—this accelerates nylon hydrolysis and weakens molecular bonds. Instead, use enzymatic cleaners designed for fishing gear (e.g., NetWash Pro) to break down biofilm without chemical damage.

FAQ

Can I modify mesh size after purchase?

No—mesh is determined during weaving and cannot be safely altered. Cutting and re-knotting destroys structural integrity and voids regulatory compliance. If your target changes, purchase a new net calibrated to the new species’ requirements.

Are LED-lit nets legal?

Generally no. Lighted nets are banned in over 42 countries and all U.S. federal waters under the Magnuson-Stevens Act, as they disrupt natural predator-prey behavior and increase non-target mortality. Some research trials use low-intensity red LEDs for selective attraction—but these require explicit scientific permits and are not commercially approved.

How do I verify if a supplier is reputable?

Look for ISO 20400-compliant sustainable procurement policies, third-party certification (e.g., MSC Chain of Custody), and transparency about twine source and manufacturing location. Reputable suppliers provide full test reports—including wet-strength retention, abrasion cycles, and knot efficiency—not just marketing brochures.

Conclusion

Choosing a long fishing net is an act of stewardship. It reflects your understanding of local ecology, respect for regulatory frameworks, and commitment to future harvests. There is no universal “best” net—only the right net for your water, your species, your values, and your responsibilities. Start by measuring your site’s depth, current speed, and temperature stratification. Then consult your regional fisheries office—not just catalogs—for mesh and configuration guidance rooted in local data. Inspect every spool for uniform twine diameter and knot consistency. Test one panel before committing to bulk purchase. And never deploy without verifying buoyancy and sink rate in situ.

Your net doesn’t just catch fish—it shapes relationships: with regulators, with neighboring fishers, with Indigenous knowledge holders, and with the water itself. Choose deliberately. Maintain rigorously. Adapt intelligently. The most successful long-net users aren’t those with the longest gear—they’re those who understand that every meter of mesh carries intention, consequence, and opportunity.