NAFO SC Studies No. 44 (2012)

Report of the Workshop on Implementation of Stock Reproductive Potential into Assessment and Management Advice for Harvested Marine Species

(pdf 4.4 MB)

M. J. Morgan¹, C. T. Marshall², L. O'Brien³, I. Mosqueira^4* and S. Cerviño⁵

¹Fisheries and Oceans Canada, PO Box 5667, St. John's, NL, A1C 5X1, Canada
²University of Aberdeen, School of Biological Sciences, Zoology Building, Tillydrone Avenue,
Aberdeen, AB24 2TZ, Scotland, UK
³National Marine Fisheries Service, Northeast Fisheries Science Center, Woods Hole Laboratory, 166 Water Street, Woods Hole, MA 02543, USA
⁴CEFAS, Lowestoft Laboratory, Pakefield Road, Lowestoft, NR33 0HT, UK
⁵Instituto Español de Oceanografía (IEO), Vigo, Spain
*Current address: European Commission, Joint Research Center, IPSC/Maritime Affairs Unit, FISHREG,
Via E. Fermi 2749, 21027 Ispra VA, Italy

Morgan, M. J., C. T. Marshall, L. O'Brien, I. Mosqueira and S. Cerviño. 2012. Report of the Workshop on Implementation of Stock Reproductive Potential into Assessment and Management Advice for Harvested Marine Species. NAFO Scientific Council Studies, 44: 1–75. doi:10.2960/S.v44.m1

Abstract

A workshop on Implementation of Stock Reproductive Potential into Assessment and Management Advice for Harvested Marine Species that was held at the University of Aberdeen, Scotland on April 12–14, 2011. This Workshop was a key deliverable for the NAFO WG on Reproductive Potential. This workshop was held in conjunction with the EU COST Action Fish Reproduction and Fisheries (FRESH).

The workshop was organized by Tara Marshall (UK), Joanne Morgan (Canada), Loretta O'Brien (USA), Iago Mosqueira (UK) and Santiago Cervino (Spain). The objectives were to provide workshop participants with expert advice in implementing information on reproductive potential into the assessment of their stocks and to review and recommend best practices for incorporating information about growth, maturation, condition and fecundity into management of harvested marine species.

Invited presenters were Bridget Green (Australia), Adriaan Rijnsdorp (Netherlands), Peter Wright (UK), Coby Needle (UK), Paul Spencer (USA) and Liz Brooks (USA). Presentations were also made by Joanne Morgan and Santiago Cerviño (Spain). The presentations were made under four themes: Estimating Stock Reproductive Potential; Implementing Estimates into Assessments; Are we doing it better, worse or just differently?; and Coding It Up.

The workshop concluded that it is clear that the incorporation of more complex indices of SRP can make a difference in the perception of stock status. Trends in biological parameters and the quality of the data on these parameters are both important components. Variation in weight at age and in maturity at age are both common and can have a large impact on perceived SRP. The collection of data on weight, maturity, sex ratio and fecundity is encouraged. Work on whether or not advice is improved by incorporating more biology into our estimates of SRP is only beginning. These studies should be continued and applied to more stocks and species with more varied reproductive strategies. One possible approach is likely to be within a management strategy evaluation context. This type of process would require the input of both modelling experts and experts in species biology.