An assessment of the American Lobster (Homarus americanus) stock status in Newfoundland (LFAs 3–14C)

Abstract

The American Lobster (Homarus americanus) is distributed near shore around the island of Newfoundland and along the Strait of Belle Isle portion of the Labrador coast. Major life-history events (i.e., molting, mating, egg extrusion, and hatching) generally take place during mid-July to mid-September, following the fishing season. The fishery is localized and prosecuted from small open boats during an 8–10 week spring fishing season. Traps are set close to shore, at depths generally less than 20 m. Fishing effort is controlled through restrictive licensing and daily trap limits. Regulations prohibit the harvest of undersized (<82.5 mm carapace length [CL]) and ovigerous (egg-bearing) lobster. In addition, there is a voluntary practice called v-notching, which involves cutting a shallow mark in the tail fan of an ovigerous female. The mark is retained for multiple molts and notched females cannot be retained in the fishery. The practice serves to protect mature females from harvest even when they are not brooding eggs externally. The number of licenses is currently around 2,300 and trap limits range from 100 to 300 depending on the Lobster Fishing Area (LFA). This stock was last assessed in 2016 and is currently assessed every three years. The present assessment of this stock was requested by Fisheries and Oceans Canada (DFO) Resource Management to provide current information on the status of the resource to be used in an updated Integrated Fisheries Management Plan. The LFAs were assessed based on four regions: Northeast Coast (LFAs 3–6), Avalon (LFAs 7–10), South Coast (LFAs 11–12), and West Coast (LFAs 13–14). The key indicators for the assessment are reported landings, fishery catch per unit effort (CPUE), and annual survival index. Total reported landings in 2019 were at their highest level in a century (4,400 t); this reflects increasing trends in the South and West regions, while reported landings in the Northeast and Avalon regions remained near historic lows. Since 2004, the CPUE index (unstandardized) has steadily increased to recent highs in the South and West Coast regions, while it has remained unchanged and at low levels in the Northeast Coast and Avalon regions. Most size frequency distributions clearly show a sharp drop at legal size and few lobsters surviving to larger sizes, suggesting higher fishing pressure on the South and West Coast regions, relative to the Northeast Coast and Avalon regions. The annual survival index of females is higher in all regions except for the South Coast, where both females and males follow the same trend. In the South and West Coast regions, where fishing pressure is stronger, the survival of both sexes is lower overall. V-notching was shown to have a high level of efficacy in protecting egg-bearing females from fishing mortality. In all regions, the majority of large surviving lobster in the population were v-notched females.