2006/824 l 15/12/2009 2006/824 l 27/01/2010 Review of fisheries biology for ribaldo (Mora moro) Review fisheries biology for ribaldo (Mora moro) Lauren Veale and Kyne Krusic‐Golub Not for citation without permission January 2010 Department of Primary Industries Review of fisheries biology for ribaldo (mora moro) Published: Fisheries Research Branch Department of Primary Industries, Queenscliff PO Box 114, Queenscliff, 3225 Victoria General disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. Copyright © The State of Victoria, Department of Primary Industries, 2010. This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968. Authorised by the Victorian Government, 2a Bellarine Highway, Queenscliff 3225 Printed by DPI Queenscliff, Victoria Preferred way to cite: Veale, L., and Krusic‐Golub, K. (2010). Review of fisheries biology of ribaldo (Mora moro). Report to Australian Fisheries Management Authority. Department of Primary Industries, Queenscliff. p15 ISSN 1449‐2520 ISBN 978‐1‐74199‐554‐1 Review of fisheries biology for ribaldo (mora moro) ii Executive Summary Ribaldo (Mora moro) are a deep‐sea cod caught on bottom long‐lines and as a bycatch of deepwater trawling in the Southern and Eastern Scalefish and Shark fishery (SESSF). They are a companion species with ling in the auto long‐line (ALL) sector and of low value to the commonwealth trawl (CT) sector. Recent catches in the SESSF averaged 174 t prior to the induction of a 100 t Total Allowable Catch (TAC) in 2005. The following year, discard rates increased from 14 to 28%, prompting Australian Fisheries Management Authority (AFMA) to raise the TAC to 165 t in 2006. Very little information on the life history and biology of this species is currently available. In Australia information on age, growth and mortality is limited to approx 700 age estimates from the SESSF. The lack of ages for this species was discussed at the Slope Assessment Group (SlopeAG) meeting held in May 2006. This was seen as a component of the stock assessment process that could be improved relatively easily through the age estimation of additional species. The SlopeAG also recommended undertaking a review of the fisheries and biological information to determine future research priorities for this species. This report presents an overview of the ribaldo fishery within the SESSF, reviews the information on growth and reproduction that is currently available, and indicates research priorities required for improved assessment of this species. Review of fisheries biology for ribaldo (Mora moro) iii Table of Contents Executive Summary............................................................................................. iii Introduction............................................................................................................ 1 Objectives................................................................................................................................................................... 1 Taxonomy................................................................................................................ 1 Classification ............................................................................................................................................................. 1 Morphology................................................................................................................................................................ 1 Distribution ............................................................................................................ 2 Fisheries................................................................................................................... 4 Ribaldo in Australia ................................................................................................................................................. 4 Ribaldo in New Zealand.......................................................................................................................................... 6 Ribaldo in the Mediterranean Sea ......................................................................................................................... 7 Previous research................................................................................................... 7 Size structure and sex ratio...................................................................................................................................... 7 Age/Growth and Length‐Weight Relationships.................................................................................................. 9 Reproduction and Life History............................................................................................................................. 10 Mortality ................................................................................................................................................................... 11 Diet ............................................................................................................................................................................ 12 Stock Structure ........................................................................................................................................................ 12 Future research needs ......................................................................................... 12 Acknowledgments .............................................................................................. 13 References ............................................................................................................. 14 Review of fisheries biology for ribaldo (Mora moro) iv List of Tables Table 1. Generas of the moridae family, examples of species within each genera and relative distribution and maximum size............................................................................................................................................. 3 Table 2. Maximum and mean lengths of female/male ribaldo and other morids from various authors....... 8 Table 3. Age and growth information for ribaldo and other morids estimated by various authors............ 10 Table 4. Reproduction and spawning information for ribaldo and other morids, collected by various authors............................................................................................................................................................... 11 List of Figures Figure 1. Ribaldo (Mora moro) .................................................................................................................................. 2 Figure 2. Distribution of ribaldo with corresponding probability of occurrence. ............................................ 2 Figure 3. Map of the Southern and Eastern Shark and Scalefish Fishery .......................................................... 4 Figure 4. Annual retained and discarded catch for ribaldo (1994–2006) from different sectors of the SESSF. (Source: Koopman, unpublished)..................................................................................................................... 5 Figure 5. Standardised CPUE (kg/km tow) of ribaldo for period 1994–2005. Note: Data collected by onboard observers where catch refers to total (retained and discarded)................................................... 5 Figure 6. Ribaldo CPUE (kg/km) at different depths for period 1994‐05. Error bars represent 95% confidence intervals. Note: Data collection by onboard observers where catch refers to total (retained and discarded).................................................................................................................................................... 6 Figure 7. Length frequency of ribaldo for period 2004–06, using species stock assessment data from the SESSF. .................................................................................................................................................................. 7 Figure 8. Mean length (±SE) and size range of ribaldo (SESSF) according to depth, measured by onboard ISMP observers on trawl and non‐trawl vessels in the SESSF (1985–06). .................................................. 9 Figure 9. Age frequency of ribaldo for period 2004–06. ....................................................................................... 9 Review of fisheries biology for ribaldo (Mora moro) v Introduction Ribaldo (Mora moro) are a recently exploited deep‐sea cod caught as bycatch by bottom long‐line and bottom gear in Australia, New Zealand, Iceland, the Mediterranean Sea and the North Atlantic. Found at depths 300 to 2,500 m, ribaldo have been known to reach lengths of 80 cm and live to more than 57 years. Despite their wide distribution and increasing economic importance, information on the biology, reproduction and population dynamics of ribaldo remain largely unknown. This report summarises biological information available for ribaldo and provides future research priorities to assist in the development of sustainable management practices for this species. Objectives 1. Summarise available biological and fisheries