Bycatch & Entanglement

Two of the most serious ecological problems in commercial crab fishing are bycatch mortality and large whale entanglement in buoy lines. Both are direct consequences of how conventional gear works — and both are addressable with better technology.

Bycatch

Crab pots catch more than crabs. Finfish, undersized crabs, non-target crab species, sea stars, and other organisms enter through the funnel entries and can’t easily escape. When a pot is hauled to the surface, the crew sorts through the catch, keeps what’s legal, and throws back everything else.

The problem: many of those discarded animals are already dead or dying. The pressure change from depth to surface, handling stress, air exposure, and the time spent in the pot all contribute to discard mortality. Estimates vary by species, but discard mortality rates of 5–30% are common.

At scale, this adds up. A 500-pot operation pulling every pot every 2–3 days generates thousands of bycatch events per season.

How SmartPot Helps

The submerged unit’s on-device vision system classifies every animal that enters the pot. When it identifies bycatch or an undersized crab:

1. The servo-driven door unlocks
2. The animal exits through the opened door
3. The door re-locks after a timeout
4. The event is logged and reported

This happens at depth, in the animal’s natural environment, with no handling, no pressure change, and no air exposure. Survival rates approach 100%.

Note

Autonomous bycatch release addresses non-target species, but keepers that remain in the pot also degrade over time — cannibalism, injury accumulation, and metabolic stress all increase with soak duration. See Soak Time Biology for how extended soak time affects the animals that stay.

Whale Entanglement

North Atlantic right whales are critically endangered — approximately 360 individuals remain, with roughly 70 reproductively active females. The species is approaching extinction, and entanglement in vertical buoy lines from lobster and crab fishing gear accounts for 82% of documented right whale deaths.

The damage is pervasive: 85% of all right whales bear entanglement scars. Since the Unusual Mortality Event began in 2017, at least 45 right whales have been confirmed dead or seriously injured from entanglement — with the true number estimated closer to 100 due to unobserved deaths at sea.

When a whale swims through a field of buoy lines, the ropes can wrap around flippers, flukes, or mouths. The whale may drag gear for weeks or months, leading to exhaustion, starvation, infection, and death. Even non-lethal entanglements cause chronic stress and reduce reproductive success.

Right whales aren’t the only victims. Humpback, fin, sei, and minke whales, basking sharks, and sea turtles all suffer regular entanglement injuries in fixed-gear fishing lines.

Regulatory Response

NOAA and state regulators have responded with:

• Seasonal fishery closures in right whale habitat
• Weak link requirements (breakaway connections)
• Gear marking requirements
• Reduced vertical line caps
• Congress has directed NOAA to finalize entanglement risk reduction rules by December 31, 2028

These measures help whales but devastate fishermen’s livelihoods. Closures during peak season can mean losing 30–40% of annual income.

The Ropeless Alternative

SmartPot’s ropeless recovery eliminates the vertical buoy line entirely. The pot sits on the bottom with no line to the surface. When the operator wants to retrieve it, they send a SURFACE command via LoRa, which triggers a ballast release mechanism. The pot becomes positively buoyant and rises to the surface.

No line in the water = no entanglement risk = no regulatory need for closures.

Note

Several ropeless technologies exist (timed releases, acoustic triggers, inflatable lift bags), but they cost $1,500–$4,000 per acoustic release plus $8,000–$9,000 for a deck unit — and none of them know what’s in the trap. SmartPot is the first to combine ropeless recovery with on-device intelligence. The pot doesn’t just surface when told — it knows what’s inside and can advise the operator whether retrieval is worthwhile.

For a detailed comparison of existing ropeless technologies, see The Ropeless Landscape.