Lobster Weight vs. Carapace Length Study

This study is conducted to determine the relationship between the length of carapace and the weight of lobsters in various Lobster Fishing Areas (LFA).

Lobster carapace length has historically been the deciding factor for the size of lobster being captured from particular areas. Since carapace length regulations are of major importance to the commercial fishery and there is some disagreement in the weight of lobsters versus carapace lengths, the Fishermen and Scientists Research Society (FSRS) will be researching this issue further.

Increased knowledge of basic lobster biology can only benefit the conservation of the resource.

Measuring

Measuring the lobsters involves using Vernier calipers. The front end of the caliper goes in along side the eye of the lobster and the back end of the caliper hooks around the carapace. Read at the zero mark on the left end of the small ruler on the caliper. The carapace is to be measured in mm and the value will be rounded down to the nearest mm. For example, you measure lobster A 's carapace and the calipers show 81.99 mm, on the data record sheet you would put 81 mm under the length column. Rounding down is the standard convention for measuring lobsters.

Sexing

The sex of the lobster must be recorded.

The sexes are determined by looking at the first pair of pleopods (swimmerets). The female appendage has a feathery appearance and the structures are usually crossed next to the body. The male's structures have a more ridged appearance and are straight, (not crossed).

Numerical values: 1 for male and 2 for female.

Weighing

Place the lobster on the center of the scale and record the weight to the nearest gram. If the lobster is larger than the scale, place a larger tray on the scale, tare it, then weigh the lobster in the larger tray.

When handling lobsters it is important not to pick them up by the claws. They can drop them as a defense mechanism, and the buyer or fisherman will be furious with you.

Soft Shell

When the lobster has shed its exoskeleton during the molting process, the new carapace is not completely water hardened for several months and will be soft to the touch. The lobsters should be handled carefully to avoid damage to the flesh and organs. If the lobster appears to have a "soft shell" please indicate in the column using Y, and give as much of an explanation as possible in the "comments" section at the end of the data sheets. For example: how soft does it feel, what colour is the exoskeleton, any damage to the lobster, etc.

Berried Lobsters

Spawning lobsters cannot be used in this study, as the weight of the eggs will produce inconsistent results.