Research Document - 2015/057
An assessment of American Lobster (Homarus americanus) in Newfoundland in 2012
By E. Coughlan, K. Skanes, D. Orr, G. Evans, W. Coffey, D. Stansbury, and E. Hynick
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 CL) and ovigerous (egg bearing) animals. In addition, there is a voluntary practice called V-notching, which involves cutting a shallow v-shaped notch in the tail fan of an ovigerous female. The mark is retained for 2‑3 molts and v-notched females cannot be retained in the fishery. The practice thus serves to protect proven spawners even when they are not brooding eggs externally. The number of licenses is currently around 2,700 and trap limits range from 100 to 300 depending on the Lobster Fishing Area (LFA).
These stocks were last assessed in 2009 and are currently scheduled for assessment every three years. The present assessment of these stocks was requested by Fisheries Management to provide current information on the status of the resource and provide the data to be used in the updated Integrated Fisheries Management Plan (IFMP). Consequently, a Regional Peer Review (RPA) Process was held May 15‑16, 2013. This document provides the methodology and analysis for the assessment of LFAs 3‑14 which were assessed based on four regions that are a geographical grouping of the LFAs into the Northeast region (LFAs 3‑6), Avalon region (LFAs 7‑10), South Coast region (LFAs 11‑12) and West Coast region (LFAs 13‑14). The key indicators for the assessment are reported landings, nominal effort, catch per unit effort (CPUE), size frequency distributions and survival rate indicators based on molt class ratios.
The fishery has always been a recruit-based fishery, therefore reported landings reflect abundance. Most size frequency distributions clearly show a sharp drop at legal size and few lobsters achieving the second molt class, indicating that most of the exploitable biomass is caught in the year of recruitment to the fishery. Reported landings have been decreasing in the Northeast and Avalon Regions and increasing on the South and West Coasts. Total reported landings for Newfoundland have remained relatively stable since the 1960s. Reported landings increased by 70 % from 1,760 t in 2000 to 3,000 t in 2008 before declining by 28 % to 2,150 t in 2012 resulting from a decrease in the Northeast and Avalon regions and an increase in the South and West Coasts. The reported landings have become spatially concentrated. The contribution of the most productive LFA (LFA 11) to the reported landings has increased from less than 15 % in the early 1990s to around 45 % in the last three years. Nominal effort (based on active fishers, trap limits & fishing days) has decreased by 31 % since 2008, due to license retirements, fewer active fishers, shorter seasons, and trap limit reductions. Mean catch rates of pre-recruit lobsters show little annual variation and there is no apparent relationship between these catch rates and future commercial reported landings or CPUE. CPUE has changed little over the time period for which data are available (2004‑12). Since 2008 the survival fraction has increased in all regions except for the Northeast region. Overall since 2004, the survival fraction was lowest in the South Coast region and highest in the Avalon region.
- Date modified: