The Status of the Florida Spiny Lobster Fishery, 1962 - 1963

Robinson, Richard; Dimitriou, Dolores

l. The spiny lobster currently supports the fifth most valuable commercial marine fishery in Florida. 2. The lobster fishery has been studied from the standpoint of whether it exhibits the usual evidence of overfishing, i.e., declining total catch, declining catch per unit of effort, and decreasing size of individuals entering the catch. 3. There has been a general upward trend in total landings of spiny lobsters in Florida since 1950. The 1962-63 season shows the highest landings since the record 1957-58 season. 4. Catch per unit of effort figures obtained by three different methods show that there has been a decline through the 1961-62 fishing season. However, all three measures indicate a slight increase in catch per unit of effort for the 1962-63 season. 5. The average size of lobsters measured during 1962-63 is similar to the average size of those measured during 1945-4·9, suggesting that increased fishing pressure is not reducing the average size and age of lobsters entering the catch. 6. The evidence suggests that the lobster stocks of south Florida are not depleted in the biological sense. While a decline in catch per unit of effort may indicate reduced stocks, it is our view that in the lobster fishery this decline is a reflection of increasing fishing pressure upon relatively stable stocks. 7. Detailed data on the fishing patterns of a group of Key West lobster fishermen indicate that catch per trap-day decreases as the time the traps are allowed to fish increases. 8. Observations made on commercially caught lobsters during 1962-63 confirm that there is some mating and spawning activity throughout the year. 9. Spiny lobster phyllosoma larvae were removed from plankton tows taken July, 1960, through June, 1962. Phyllosoma were not numerous, although they were widely distributed geographically and seasonally. Less than seven per cent of the lobster larvae were identified as Panulirus. 10. It is recommended that the definition of the minimum legal size of lobsters be changed to not less than 3 1/8 inches from between the "horns" to the trailing edge of the carapace at the mid-dorsal line. 11. An economic- biological survey should be conducted to obtain information to formulate a management scheme. Regulations should not be instituted until a thorough understanding has been gained of lobster population dynamics, and of the economic aspects of the problem.