Theoretical size at the onset of maturity and its density-dependent variability as an option in crustacean fisheries management. (12th March 2021)

• Record Type: Journal Article
• Authors: da Silva Santana, Cesar Augusto; Lordan, Colm; Power, Anne Marie
• Editors: Siddeek, M S M
• Is Part Of: ICES journal of marine science. Volume 78:Number 4(2021)
• Page Start: 1421
• Page End: 1433
• Publication Date: 2021-03-12
• Subjects: density dependence -- Norway lobster -- Nephrops -- onset of maturity -- spawning -- stock assessment; Ocean -- Periodicals; Fisheries -- Periodicals; Fishes -- Periodicals; Marine biology -- Bibliography -- Periodicals; 551.4605
• DOI: 10.1093/icesjms/fsab040
• Languages: English
• ISSNs: 1054-3139

Abstract

Abstract: Theoretical size at the onset of maturity (TSOM) for female Norway lobster was estimated by a new methodology based on the probability distributions of mature individuals built on physiological maturity measures. Onset of maturity using TSOM varied from 18.4- to 33.7-mm carapace length for the Irish functional management units (FUs). These estimates showed a significant negative linear relationship ( R 2 = 0.60) with population density and a significant positive linear relationship with average size in females ( R 2 = 0.84). The size class at which 50% of the females are sexually mature ( L 50 ) was linked to the new TSOM metric by a significant positive linear relationship ( R 2 = 0.40). This set of linear relationships ultimately allowed TSOM and L 50 to be estimated without a requirement for maturity stages to be distinguished. As well as contributing to the stock assessment and management of Nephrops (e.g. in data-limited FUs) and its potential for the calibration of more routinely used estimates, TSOM might be applied in new species and meta-analyses where size of maturity data are scarce. This new metric also better-defines the maturity process since, taken together, TSOM, L 50, and smallest berried female represent sequential maturity events: (i) onset of maturity, (ii) 50% mature (from gonad staging), and (iii) berried females.