Impacts of Lobster Trap Fishing on Juvenile Lobsters

In the Florida spiny lobster trap fishery, fishermen bait their traps with live, sublegal-sized (less than three-inch carapace length) lobsters, also called shorts.

Shorts are live bait used to attract legal-sized lobsters (Hunt et al. 1986). While the use of shorts enhances trap catches, the long duration bait lobsters spend in traps can kill them, and in turn can reduce the number of lobsters available to commercial and recreational fisherman.

Why do Fisherman Bait with "Shorts"?

Shorts are effective bait because lobsters are social animals that live in groups. Legal- sized lobsters are attracted to traps with shorts. Using shorts as bait catches three times more lobsters than other baits such as cowhide, fish heads or cat food (Yang and Obert, 1978; Lyons and Kennedy, 1981; Heatwoleetal, 1988). Fishermen use live wells to hold the shorts while they are moved.

Traps and Shorts

Trap imacts on juvenile lobster, caption below
(A) Shorts in a trap. (B) Lobster aggregation on coral. (C) Live well on commercial boat. (D) Pile of traps ready to deploy.
  • Two or three shorts are used in each trap.
  • The number of traps was reduced from 939,000 in 1991 to about 480,000 traps in 2014.
  • Approximately 1 million lobsters are used as live bait each day (Matthews, 2001).
  • Lobster traps are checked every 7-25 days.
 


 




Fishery Effects on Short Lobsters

  • Research has determined that only 1-2 percent of lobsters escape from traps daily (Hunt et al. 1986).
  • Lobsters confined in traps begin to starve after around 4 weeks
  • Long confinement of shorts can lead to slowed growth, weight loss and injuries.
  • The high number of traps amplifies the number of short lobsters dying in traps.

Impacts to Fishery and the Lobster Population

  • An estimated 869,000 shorts die in fished traps each season.
  • If a trap is lost, it can continue to ghost fish, catching and killing lobsters until the trap breaks.
  • An estimated 643,000 lobsters die in lost traps each year.
  • Mortality caused by baiting traps with shorts and ghost traps cause losses to commercial and recreational lobster landings and the role that lobsters play in their environment.

References 

Heatwole, D.W., Hunt J.H., and Kennedy, F.S., Jr. 1988. Catch efficiencies of live lobster decoys and other attractants in the Florida spiny lobster fishery. Florida Marine Research Publication No. 44. Florida Marine Research Institute, St. Petersburg, FL. Order publication

Hunt, J. H., Lyons, W. G., and Kennedy, F. S. 1986. Effects of exposure and confinement on spiny lobsters, Panulirus argus, used as attractants in the Florida trap fishery. Fisheries Bulletin, 84: 69-76. Order publication

Lyons, W. G., and Kennedy, F. S. 1981. Effects of harvest techniques on sublegal spiny lobsters and on subsequent fishery yield. Proceedings of the Gulf and Caribbean Fisheries Institute, 33: 290–300. Order publication

Yang, M. C. K., and Obert, B. 1978. Selected statistical analyses of Key West spiny lobster data in Spiny Lobster Research Review: Proceeding of a Conference Dec. 16, 1976, Key West Florida, pp. 4–7. Ed. by R. E. Warner. Florida Sea Grant Technical Paper, Gainesville, FL. 60 pp.

Uhrin AV, Fonseca MS, DiDomenico GP. 2005. Effects of Caribbean spiny lobster traps on seagrass beds of the Florida Keys National Marine Sanctuary: Damage Assessment and evaluation of recovery. American Fisheries Society Symposium, 41: 579-588.



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