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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.

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.

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%.

North Atlantic right whales are critically endangered — fewer than 350 individuals remain. The leading human cause of right whale mortality is entanglement in vertical buoy lines from lobster and crab fishing gear.

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.

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

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

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.