Fishing Trawl Netting: Composition, Classification, and Industrial Applications

Materials of Fishing Trawl Netting

The selection of materials for fishing trawl netting is critical to the efficiency, durability, and sustainability of commercial fishing operations. These materials are chosen based on their performance in strength, flexibility, resistance to abrasion, and chemical stability in harsh marine environments. The right choice can significantly impact catch efficiency, net longevity, operational costs, and environmental compliance.

This guide explores the most widely used materials in modern trawl net construction, highlighting their mechanical properties, advantages, limitations, and ideal applications.

Nylon (Polyamide)

Renowned for its exceptional elasticity and tensile strength, nylon is the most widely used synthetic fiber in commercial fishing trawl nets.

Advantages

• High elasticity – stretches under load and returns to shape, absorbing shock during towing
• Excellent strength-to-weight ratio – strong yet lightweight for easier handling
• Good UV and chemical resistance – performs well in saltwater environments
• Durable in dynamic conditions – ideal for deep-sea and high-tension trawling
• Superior knot strength – maintains integrity when knotted or spliced

Limitations

• Prone to abrasion – wears faster on rough seabeds or rocky terrain
• Absorbs water – can lose up to 10% strength when wet and increases net weight
• Higher cost – more expensive than polyethylene or polypropylene
• Requires maintenance – frequent inspection and repair needed in abrasive conditions

Best for: Heavy-duty trawling, deep-water operations, high-performance fishing vessels

Polyethylene (HDPE & LDPE)

High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE) are cost-effective, buoyant materials commonly used in mid-range trawl nets.

Advantages

• Low cost – economical choice for large-scale or budget-conscious operations
• Excellent chemical and UV resistance – resists salt, algae, and sunlight degradation
• Water-resistant – does not absorb moisture, maintaining consistent weight and strength
• Buoyant – naturally floats, useful in certain net configurations
• Good abrasion resistance – outperforms nylon on rough seabeds

Limitations

• Lower elasticity – less shock absorption, increasing stress on gear
• Reduced tensile strength – not ideal for high-tension or deep-sea trawling
• Poor knot retention – knots can slip or weaken over time
• Stiff in cold temperatures – becomes brittle in colder waters

Best for: Shallow-water trawling, coastal fisheries, lightweight nets, and temporary deployments

Polypropylene

A lightweight, low-cost synthetic fiber often used in less intensive fishing applications due to its buoyancy and chemical resistance.

Advantages

• Extremely lightweight and buoyant – stays afloat, reducing ballast needs
• Resists UV and chemicals – durable in marine environments with minimal degradation
• Low cost – one of the most affordable synthetic netting materials
• Moisture-resistant – does not absorb water, maintaining performance

Limitations

• Low elasticity – minimal stretch, leading to higher stress on net structure
• Lower strength – unsuitable for heavy-duty or deep-sea trawling
• Poor abrasion resistance – degrades quickly on rough surfaces
• Shorter lifespan – degrades faster than nylon or HDPE under constant use

Best for: Light commercial fishing, aquaculture, seine nets, and short-duration trawling

Low-Headroom Trawl (LHT) Netting

A specialized trawl design optimized for prawn and shrimp fisheries, featuring a reduced vertical opening to target bottom-dwelling species.

Advantages

• Improved selectivity – incorporates escape panels or sorting grids (e.g., TEDs, BRDs)
• Enhanced prawn catch efficiency – low profile keeps net close to seabed where prawns dwell
• Reduces bycatch – allows non-target species to escape, supporting sustainable fishing
• Regulatory compliance – meets international standards for bycatch reduction
• Customizable design – can be made with nylon, polyethylene, or hybrid materials

Limitations

• Specialized use – not suitable for pelagic or mid-water trawling
• Requires precise deployment – needs careful handling to maintain low headroom
• Higher initial cost – complex design and added components increase price
• Maintenance-intensive – sorting devices require regular inspection and cleaning

Best for: Prawn/shrimp trawling, environmentally regulated fisheries, bycatch-sensitive zones

Expert Tip: For mixed-use operations, consider hybrid nets that combine nylon in high-stress zones with polyethylene in abrasion-prone areas. This approach balances performance, durability, and cost-effectiveness while extending net lifespan.

Sustainability Note: Increasing regulations require the use of biodegradable or recyclable netting materials. Some manufacturers now offer eco-friendly nylon variants and recycled polyethylene options to reduce marine pollution and ghost fishing risks.

Various Kinds of Fishing Trawl Netting: Types, Materials & Applications

Fishing trawl netting is a highly specialized component of modern commercial fishing operations, designed to efficiently capture fish and seafood across diverse marine environments. The design, material, and mesh configuration of trawl nets vary significantly based on the target species, fishing method (bottom or midwater), water depth, and environmental regulations. Understanding the different types of trawl netting helps ensure sustainable practices, regulatory compliance, and operational efficiency.

Otter Board Trawl Netting

Otter board trawling is one of the most common methods used in offshore demersal (bottom-dwelling) fisheries. This system uses large rectangular doors—called otter boards—that are dragged along the seabed to keep the mouth of the net open horizontally as it’s towed by a fishing vessel. These boards create hydrodynamic resistance, spreading the net wide to maximize catch area.

The netting is typically constructed from high-strength synthetic fibers such as nylon or polyethylene, chosen for their durability, abrasion resistance, and ability to withstand constant tension during towing. These materials also resist degradation from saltwater exposure, ensuring longer service life.

A key feature of otter board trawl netting is its adjustable mesh size. Larger mesh openings allow undersized or juvenile fish to escape, promoting sustainable fishing practices and compliance with international and regional regulations (e.g., EU Common Fisheries Policy). Selective mesh designs help reduce bycatch while targeting commercially valuable species like cod, haddock, pollock, and whiting.

Beam Trawl Netting

Beam trawl netting is specifically engineered for catching flatfish such as sole, plaice, and flounder that reside close to or on the seabed. Unlike otter trawls, beam trawls use a rigid horizontal beam—often made of steel or reinforced composite materials—to hold the net open across the seafloor.

To endure direct contact with rough substrates like sand, gravel, or rocky bottoms, beam trawl nets are constructed from thicker, heavier-duty nylon or even steel-reinforced netting. Additional bobbins or rollers may be attached to the footrope to reduce drag and prevent damage from scraping.

The mesh size in beam trawl netting tends to be smaller than in otter trawls, allowing for effective retention of smaller flatfish species commonly found in coastal fisheries. While this increases selectivity for market-sized fish, it can also lead to higher bycatch if not properly managed. Innovations such as square mesh panels or sorting grids are increasingly integrated into beam trawls to improve sustainability.

Midwater (Pelagic) Trawl Netting

Midwater or pelagic trawl netting targets species that swim in the upper or middle layers of the ocean, including mackerel, herring, sardines, squid, and various shrimp species. Since these nets do not touch the seabed, they require less structural reinforcement and are designed for speed and maneuverability.

The netting material is typically lightweight nylon with a streamlined profile to minimize water resistance during towing. The entire net system is often equipped with acoustic sensors and sonar-guided bridles to position the mouth precisely within fish schools detected by echolocation.

Fine mesh sizes are standard in midwater trawling to effectively capture small pelagic species. However, some configurations include larger mesh sections in the forward portion of the net to allow non-target species to escape before reaching the codend. This enhances ecological responsibility without sacrificing catch efficiency.

Bottom Trawl Netting

Bottom trawl netting is used to harvest species living on or just above the seabed, such as shrimp, scallops, monkfish, and certain groundfish. It shares similarities with otter and beam trawling but is optimized for maximum contact with the ocean floor.

Due to intense abrasion from rocks, shells, and sediment, bottom trawl nets are built with coarse, heavy-gauge mesh made from abrasion-resistant polymers. Some versions incorporate chain mats or rubber tires along the lower edge to protect the net and stir up organisms hiding in the substrate.

While the mesh is generally coarser than midwater trawls to reduce wear and tear, modern designs increasingly integrate bycatch reduction devices (BRDs) and turtle excluder devices (TEDs) to meet conservation standards. These modifications allow non-target species to escape while retaining the desired catch, balancing economic needs with environmental stewardship.

Key Considerations in Trawl Net Selection

Important: Improper use of trawl netting can lead to habitat destruction, overfishing, and legal penalties. Always consult fisheries management authorities and adhere to best practices for sustainable harvesting. Regular inspection and maintenance of netting—repairing tears, replacing worn sections, and cleaning biofouling—extend equipment life and maintain optimal performance.

Commercial Significance of Fishing Trawl Netting

Fishing trawl netting plays a pivotal role in the global seafood industry, serving as a cornerstone for commercial fishing operations. Its significance extends beyond simple catch collection—it influences profitability, regulatory compliance, environmental sustainability, and long-term operational efficiency. As demand for seafood continues to rise, the design, durability, and selectivity of trawl netting directly impact the economic viability and ecological responsibility of modern fisheries.

Bycatch Reduction and Eco-Friendly Netting

One of the most transformative advancements in trawl netting technology is its ability to significantly reduce bycatch—the unintentional capture of non-target species such as juvenile fish, endangered marine animals, or non-commercial species. Traditional trawling methods have long been criticized for high bycatch rates, but innovations like Low-Headroom Trawl (LHT) and SELEC-NET™ systems are revolutionizing sustainable fishing practices.

• Low-Headroom (LHT) Netting: Specifically engineered for prawn fisheries, LHT nets utilize a reduced vertical opening that allows smaller prawns and non-target species to escape through the top or sides while retaining market-sized prawns in the cod end.
• SELEC-NET™ Technology: Designed with precision-cut escape panels and selective mesh patterns, these nets enable undersized fish to exit safely while maintaining high retention of target species, improving stock sustainability.
• Environmental Compliance: Many countries now mandate the use of bycatch reduction devices (BRDs) and turtle excluder devices (TEDs), making compliant netting essential for legal operation.

Commercial Advantage: Fisheries using eco-friendly trawl designs benefit from reduced penalties, improved public image, eligibility for eco-certifications (e.g., MSC), and access to premium markets that prioritize sustainable sourcing.

Increased Catch Efficiency

Modern trawl netting is engineered to maximize catch efficiency by targeting specific species at precise depths—whether near the seabed (bottom trawling) or within the water column (midwater trawling). This targeted approach ensures higher yields of commercially valuable species such as shrimp, cod, haddock, and other finfish.

• Bottom Trawl Nets: Ideal for demersal species like flatfish and scallops; designed to glide along the seafloor with reinforced ground gears to withstand abrasion.
• Midwater Trawl Nets: Used for pelagic species such as mackerel, herring, and squid; these nets avoid seabed contact, reducing habitat disruption and increasing selectivity.
• Hydrodynamic Design: Advanced net shapes and towing configurations improve net spread and stability, enhancing sweep area and capture rates.

Economic Impact: Higher catch efficiency translates into greater revenue per haul, reduced fuel consumption per ton of catch, and optimized vessel utilization—key metrics for profitability in competitive fishing markets.

Durability and Cost-Effectiveness

The economic sustainability of a fishing operation heavily depends on equipment longevity. Trawl nets are subjected to extreme conditions—including abrasive seabeds, strong currents, and heavy loads—making material resilience critical.

• High-Strength Materials: Constructed from abrasion-resistant synthetic fibers like nylon, polyethylene (PE), and polyester, modern trawl nets offer superior tensile strength and resistance to wear, UV degradation, and chemical exposure.
• Long Service Life: Premium nets can endure hundreds of tows before requiring major repairs, significantly lowering replacement frequency and associated downtime.
• Reduced Maintenance Costs: Durable construction minimizes tears and mesh deformation, decreasing repair labor and material expenses over time.
• Cost Per Use Optimization: While initial investment may be higher for advanced netting, the long-term cost per fishing hour is substantially lower compared to cheaper, less durable alternatives.

Operational Benefit: Extended net lifespan enhances fleet availability, reduces operational interruptions, and improves overall return on investment (ROI) for fishing enterprises.

Regulatory and Market Advantages

Beyond physical performance, trawl netting influences a fishery’s regulatory standing and market competitiveness. Governments and international bodies are increasingly enforcing sustainable fishing standards, and gear choice is central to compliance.

• Compliance with Fisheries Regulations: Use of certified bycatch-reducing gear helps operators meet national and EU Common Fisheries Policy (CFP) requirements, avoiding fines or license suspensions.
• Access to Global Markets: Retailers and exporters increasingly require proof of sustainable practices; eco-conscious trawl systems support certification under programs like MSC, ASC, or Friend of the Sea.
• Brand Reputation: Companies investing in responsible fishing technologies enhance their brand value among environmentally aware consumers and business partners.
• Fleet Modernization Incentives: Some governments offer subsidies or grants for upgrading to selective, low-impact gear, further improving cost-efficiency.

Strategic Insight: Forward-thinking fisheries view trawl netting not just as a tool, but as a strategic asset that aligns operational success with environmental stewardship.

Industry Recommendation: When selecting trawl netting, balance initial cost with long-term performance. Prioritize designs that offer proven bycatch reduction, durability in local fishing conditions, and compliance with current and anticipated regulations. Partnering with reputable manufacturers who provide technical support and performance data can significantly enhance decision-making and operational outcomes.

Additional Considerations for Commercial Success

• Customization Options: Nets can be tailored to vessel size, trawling speed, and target species for optimal performance.
• Repair and Maintenance Services: Access to professional net mending extends service life and maintains structural integrity.
• Data Integration: Some modern nets include sensors to monitor catch composition and environmental conditions in real time.
• Training and Support: Proper handling and deployment techniques are crucial—manufacturer training improves safety and efficiency.
• Future-Proofing: Investing in adaptable net systems prepares fleets for evolving regulations and market demands.

How to Choose the Right Fishing Trawl Netting: A Comprehensive Guide

Selecting the appropriate fishing trawl netting is essential for maximizing catch efficiency, minimizing environmental impact, and ensuring durability under demanding marine conditions. The choice depends on several interrelated factors including the target species, mesh size, fishing method, water environment, and material composition. This guide provides detailed insights into each factor to help commercial fishermen and aquaculture professionals make informed decisions when purchasing or upgrading trawl nets.

Important Note: Always comply with local fisheries regulations regarding mesh sizes and bycatch reduction. Using non-compliant netting can result in fines, gear confiscation, or suspension of fishing licenses.

1. Target Species: Matching Net Design to Fish Behavior

The species you intend to catch directly influences the design, structure, and netting type of your trawl system. Different fish inhabit various water columns and exhibit distinct behaviors, requiring specialized net configurations.

• Prawns and Shrimp: Require low-headrope trawl nets with fine, prawn-specific netting. These nets are designed to skim just above or along the seabed, capturing small crustaceans while minimizing contact with rough terrain. The netting must be tightly woven to prevent escape but flexible enough to handle sandy or muddy substrates.
• Pelagic Fish (e.g., mackerel, herring, sardines): Found in midwater columns, these species demand midwater trawl nets with finer mesh to contain fast-swimming schools. The netting should form a large, funnel-shaped mouth to herd fish efficiently into the codend without causing excessive turbulence.
• Demersal/Bottom-Dwelling Fish (e.g., cod, haddock, pollock): These species live near or on the ocean floor and require bottom trawl nets made from heavy-duty materials. The net must withstand constant abrasion from rocks, shells, and debris.
• Flatfish (e.g., sole, plaice): Best caught using beam trawls equipped with sturdy, wide-opening netting. Beam trawls use a rigid horizontal beam to keep the net open and often include tickler chains to stir up fish from the sediment. The netting must be both strong and slightly finer than standard bottom trawls to avoid catching undersized flatfish unnecessarily.

2. Mesh Size: Balancing Selectivity and Efficiency

Mesh size is one of the most critical specifications in trawl netting, affecting both legal compliance and ecological sustainability. It determines which fish can enter and retain within the net, allowing juvenile fish to escape and promoting responsible fishing practices.

• Fine Mesh (10–40 mm): Ideal for pelagic species like sardines, anchovies, and juvenile shrimp. Fine mesh prevents small, fast-moving fish from escaping while enabling selective harvesting. However, it increases drag and requires more towing power.
• Medium Mesh (40–80 mm): Commonly used in midwater trawling for species such as mackerel and hake. Offers a balance between selectivity and hydrodynamic efficiency.
• Coarse Mesh (80+ mm): Typically used in bottom trawling for larger demersal fish like cod and halibut. Allows smaller, non-target species and juveniles to escape, reducing bycatch. Despite being coarser, the netting must still be robust to endure seabed friction.
• Specialty Mesh for Bycatch Reduction: Some fisheries use square mesh panels or sorting grids in the extension section of the net to allow flatfish or small fish to escape while retaining target species.

Expert Tip: Regularly inspect mesh for stretching or wear. Over time, diamond-shaped meshes can elongate, effectively increasing the opening size and reducing selectivity. Replace or repair damaged sections promptly to maintain compliance and efficiency.

3. Fishing Method: Tailoring Netting to Operational Conditions

The fishing technique employed determines the physical demands placed on the netting material and overall trawl structure.

• Bottom Trawling: Involves dragging the net across the seafloor, exposing it to extreme abrasion from rocks, coral, and sediment. Netting must be constructed from high-tenacity, abrasion-resistant materials such as reinforced nylon. Bottom trawls are typically heavier and require stronger towing cables and winch systems.
• Midwater (Pelagic) Trawling: Conducted in open water, away from the seabed. This method uses lightweight, streamlined netting (often polyethylene or polypropylene) to reduce drag and fuel consumption. The net maintains its shape through hydrodynamic forces rather than contact with the bottom.
• Nearshore/Inshore Trawling: Performed in shallow coastal waters with less severe seabed conditions. Nets used here benefit from durable yet lightweight materials, making them easier to deploy and retrieve from smaller vessels. UV resistance is particularly important due to prolonged sun exposure during storage and operation.

4. Durability and Material: Choosing the Right Netting Fiber

The longevity and performance of trawl netting depend heavily on the synthetic fiber used. Each material offers unique advantages and trade-offs in strength, weight, cost, and resistance to environmental factors.

For maximum lifespan, look for trawl netting with reinforced seams, double-twisted twines, and protective coatings. Some manufacturers offer hybrid netting that combines materials—such as nylon in high-wear zones and polyethylene in lighter sections—to optimize performance and cost.

Maintenance Tip: After each use, rinse trawl nets with fresh water to remove salt, sand, and organic matter. Dry nets completely in the shade to prevent UV damage and store them in a cool, dry place to extend their service life.

Additional Considerations

• Net Shape and Configuration: Consider whether you need a single- or multi-segment net, with or without sorting panels or escape windows.
• Regulatory Compliance: Check regional fisheries management organizations (RFMOs) for mandated mesh sizes, minimum fish sizes, and bycatch mitigation requirements.
• Environmental Impact: Opt for eco-friendly designs that reduce seabed disturbance and bycatch, supporting sustainable fishing practices.
• Cost vs. Longevity: While polypropylene may be cheaper upfront, nylon often provides better long-term value in demanding conditions due to its superior durability.

Choosing the right fishing trawl netting is a strategic decision that affects catch quality, operational costs, regulatory compliance, and environmental stewardship. By carefully evaluating your target species, fishing method, and environmental conditions—and selecting materials accordingly—you can optimize both productivity and sustainability in your fishing operations.

Frequently Asked Questions About Fishing Trawl Netting

A: Yes, fishing trawl netting can be used to target various species, but its design must be tailored to specific fish types and fishing environments to maximize efficiency and minimize ecological impact. Different configurations are optimized for distinct habitats and target species:

• Mid-Water (Pelagic) Trawl Netting: Designed to catch schooling fish that inhabit the upper and middle layers of the ocean, such as tuna, mackerel, sardines, and herring. These nets are typically buoyant and deployed at various depths without touching the seabed.
• Bottom (Demersal) Trawl Netting: Built to skim or drag along the seafloor to capture bottom-dwelling species like cod, haddock, pollock, and flatfish. These nets are reinforced to withstand abrasion from rocks and rough terrain.
• Low-Headroom Trawl Netting: Specifically engineered for prawn and shrimp fisheries. This design includes a small vertical opening that allows smaller marine organisms to escape while retaining target crustaceans, significantly reducing bycatch of juvenile fish and non-target species.

Modern trawl designs often incorporate bycatch reduction devices (BRDs) and turtle excluder devices (TEDs) to promote sustainable fishing practices and comply with environmental regulations.

A: The lifespan of fishing trawl netting varies widely—typically ranging from 6 months to 3 years—depending on several key factors:

• Material Type: Nets made from high-quality nylon or polyethylene tend to last longer due to superior strength and elasticity.
• Fishing Method: Mid-water trawls experience less wear and can last 2–3 years with proper care. In contrast, bottom trawls face constant abrasion against the seabed, reducing their effective life to 6–18 months.
• Environmental Exposure: Prolonged exposure to saltwater, ultraviolet (UV) radiation, and extreme temperatures degrades fibers over time. UV rays, in particular, weaken nylon strands, leading to fraying and reduced tensile strength.
• Operational Conditions: Trawling over rocky or coral-rich seabeds accelerates wear. Frequent hauling, improper handling, and entanglement with debris also shorten net longevity.

To extend the service life of trawl nets, fishermen should conduct regular inspections for tears or weak spots, perform timely repairs, rinse nets with fresh water after use, and store them in shaded, dry areas away from direct sunlight.

A: Nylon is the most widely used material in fishing trawl netting due to its excellent balance of durability, flexibility, and cost-effectiveness. Key advantages include:

• High Strength and Elasticity: Nylon can stretch under load and return to its original shape, making it ideal for withstanding the dynamic forces of trawling.
• Tear and Abrasion Resistance: It resists damage from fish teeth, debris, and contact with the ocean floor better than many alternatives.
• Lightweight and Easy to Handle: Compared to older materials like hemp or cotton, nylon is much lighter, reducing labor and fuel costs during deployment and retrieval.
• Cost-Effective Production: Nylon is relatively inexpensive to manufacture and readily available globally, making it accessible to commercial and small-scale fisheries alike.

However, nylon has a notable drawback: it is highly susceptible to degradation from prolonged UV exposure. Continuous sunlight breaks down the polymer chains, leading to brittleness and fiber failure. To combat this, many manufacturers apply UV-resistant coatings or incorporate additives during production. Some fisheries also use polyethylene or polyester blends for enhanced UV stability, especially in surface or shallow-water operations.

A: Not necessarily. The effectiveness of mesh size depends on the target species, their size, and sustainability goals. Finer mesh does not mean "more fish"—it means "different fish," often with a focus on selectivity and conservation:

• Fine Mesh (Small Openings): Used in mid-water trawling for small pelagic species like sardines, anchovies, and juvenile tuna. It also helps in prawn fisheries where capturing smaller crustaceans is desired. Importantly, fine mesh can inadvertently trap juvenile fish, raising concerns about overfishing if not regulated.
• Coarse Mesh (Larger Openings): Common in bottom trawling for larger demersal species such as cod, haddock, and pollock. Larger mesh allows undersized fish and non-target species to escape, supporting sustainable fishing practices and compliance with minimum landing size regulations.
• Species-Specific Needs: Flatfish like sole and plaice may require moderately fine mesh to ensure capture, while adult tuna or halibut are best caught with coarser, stronger netting.

Regulatory bodies often mandate minimum mesh sizes to protect juvenile populations and reduce bycatch. Innovations such as square mesh panels or escape windows further improve selectivity, allowing smaller fish to exit while retaining market-sized catches.

In summary, mesh size should be carefully selected based on ecological, regulatory, and economic factors—not simply to maximize catch volume, but to ensure long-term fishery health and profitability.