Victorian Snapper Stock Assessment 2011

No. 64 June 2012

Kemp J, Conron S, Hamer P, Bruce T, Bridge N and Brown L

June 2012

Fisheries Victoria Assessment Report Series No. 64

If you would like to receive this Author Contact Details: Dr. Jodie Kemp information/publication in an Fisheries Victoria accessible format (such as large Fisheries Research Branch print or audio) please call the PO Box 114, Queenscliff Vic 3223 Customer Service Centre on: Authorised by the Victorian Government, 136 186, TTY: 1800 122 969, 1 Spring Street, Melbourne or email Printed by Fisheries Victoria, Queenscliff, [email protected] Victoria Published by the Department of Primary © The State of Victoria, Department of Primary Industries. Industries, 2012. Copies are available from the website: This publication is copyright. No part may be www.dpi.vic.gov.au/fishing reproduced by any process except in accordance with the provisions of the Copyright Act 1968. General disclaimer This publication may be of assistance to you but Preferred way to cite this publication: the State of Victoria and its employees do not Kemp J, Conron S, Hamer P, Bruce T, Bridge N guarantee that the publication is without flaw of and Brown L (2012). Victorian Snapper Stock any kind or is wholly appropriate for your Assessment 2011. Fisheries Victoria Assessment particular purposes and therefore disclaims all Report Series No. 64. liability for any error, loss or other consequence which may arise from you relying on any ISSN 1329‐7287 information in this publication. ISBN 978‐1‐74326‐219‐1 (print)

Snapper Stock Assessment 2011

Snapper Assessment Summary 2011

Victoria’s snapper stocks Two separate stocks (i.e. populations) of snapper (Chrysophrys auratus) occur in Victorian waters (see map): • The fisheries to the east of Wilsons Promontory, including Corner Inlet, are based on the eastern snapper stock o The eastern stock is distributed up the eastern coast of Australia through NSW and into southern Queensland waters • The fisheries to the west of Wilsons Promontory including Port Phillip Bay and Western Port, are based on the western Snapper, Chrysophrys auratus. Photo credit: snapper stock Lauren Brown o Port Phillip Bay provides critical spawning and nursery habitat for the western snapper stock o Most of the adult snapper found west of Wilsons Promontory were spawned and raised in Port Phillip Bay. The fisheries based on the eastern and western snapper stocks are managed separately. Victoria’s snapper fisheries Port Phillip Bay In Victoria snapper are caught in: • Port Phillip Bay • Corner Inlet • Coastal waters Western Stock Eastern Stock • Western Port.

In Victoria most of the snapper are caught from The location of western and eastern snapper bays, inlets and coastal waters to the west of fisheries in Victoria. Wilsons Promontory (i.e. they belong to the western stock). Types of fisheries Both commercial and recreational fisheries for snapper occur in Victoria. Commercial fisheries Commercial fishers catch snapper using long‐ lines (65%) and haul seines (24%). Snapper are also caught in inshore coastal waters by trawlers. Commercial fisheries operate mainly in Port Phillip Bay (suppling 92% of the catch), coastal waters (5%) and Corner Inlet (3%). A small catch Port Phillip Bay snapper long line operations. comes from the Western Port long‐line fishery. Photo credit: Lauren Brown

Snapper Stock Assessment 2011

Recreational anglers prize snapper. Recreational fisheries Recreational fishers catch snapper mostly from boats using baited hooks and lines, though some shore‐based line fishing occurs. Most of the recreational catch of snapper comes from Port Phillip Bay, though small fisheries operate in coastal waters to both the west and east of Wilsons Promontory and in Western Port. Management of Fisheries Fisheries Victoria is responsible for managing fisheries and fish resources under the provisions of the Fisheries Act 1995 and the Fisheries Regulations 2009. National guidelines for ecologically sustainable Assessing information about the condition of development (ESD) of fisheries are used to identify environmental, biological, economic, social and governance dimensions for individual fisheries. These ESD principles underpin the three key strategic goals of Fisheries Victoria: • ‘Securing’ fisheries resources • ‘Sharing’ fisheries resources • ‘Growing’ or developing the value of the resource for the benefit of the community. Stock assessments Stock assessments are designed primarily to provide information on the status of fish stocks in Victoria’s bays and inlets to help address the fish stocks and the impacts of fishing ensures biological sustainability and management sustainable fisheries. arrangements. Snapper Stock Assessment 2011 A formal assessment of Victorian snapper stocks was conducted at the Department of Primary Industries, Queenscliff, Victoria in May 2011. The assessment workshop was attended by: • Representatives of the commercial and recreational fishing sectors • Fisheries Victoria managers and scientists • Experienced recreational and commercial fishers. The stock assessment is detailed in this report Healthy Snapper stocks ensure great fisheries. and a summary presented below.

Snapper Stock Assessment 2011 ii

Status of the Western Snapper Overview of the status of the Western Snapper Fishery Stock Stock Condition ‐ Good

Stock condition Break down by fishery indicators Victoria’s western stock of adult snapper is in good condition. Recent spawning success ↓ Catch rates (Port Phillip Bay) • Moderate recruitment Catch rates in the western snapper fishery are • Average abundance expected mostly above long‐term averages. Catch rates – Port Phillip Bay Spawning success • Above the long term average for o Recreational fisheries Exceptionally strong year classes spawned in o Long‐line and haul seine 2000/01 and 2003/04 are driving current record fisheries high catch rates for both the commercial and Catch rates – Western Port Bay recreational fishing sectors. • Limited data for long‐line fisheries Despite major recruitment failures in 2005/06, • Stable or above the long‐term for and 2010/11, recent consecutive years of recreational catches moderate recruitment (2007/08, 2008/09, 2009/10) Catch rates – Coastal waters are expected to provide average abundance of • Limited data for recreational ‘pinkies’ over the next few years. fisheries • Above the long term average for Future fishery strength commercial fishers A reduction in catch rates of larger snapper is expected over the next few years; however, this Stock structure– Port Phillip Bay will be moderated by the strong 2003/04 and • Age and size class within historical 2004/05 year classes, and in the longer term by range for both commercial and the moderate 2007/08 to 2009/10 year classes. recreational fisheries Stock structure– Western Port Bay Management arrangement • Based only on data derived from the Fishery and scientific survey data presented to recreational fishery stakeholder and Departmental participants at • Age and size class within historical the May 2011 stock assessment workshop did range not indicate the need for a review of snapper management arrangements, and participants supported that the current management regime Management settings should be maintained. • Maintain current settings Flagged issues Areas of concern • Monitor recruitment in Port Phillip A recent increase and current high take of Bay snapper by commercial trawlers necessitates • Large increase in commercial catch additional data collection. of snapper in coastal waters since Data required to assess the impact of this catch 2007. on the western snapper stock include: Legend • Age and length composition of the catch Good condition. • Age and length composition of the discarded fish ↑ Improving • Catch data and effort data reported at both ↓ spatial and temporal scales. Decreasing More data on the coastal water snapper fishery Poor condition by both the commercial and recreational sectors Requires close monitoring are required to improve the western snapper stock assessment. Limited data

Snapper Stock Assessment 2011

iii

Status of the Eastern Snapper Overview of the status of the Eastern Snapper Fishery Stock Stock condition Stock Condition ‐ unknown The condition of the eastern stock of snapper is Break down by fishery indicators unknown. Recent spawning success Catches from Victorian waters in the snapper • Limited data fisheries are low and unlikely to have a major impact on a stock that extends north to Catch rates – Corner Inlet Queensland. • Limited data from the commercial fishery Spawning success • No data from the recreational Unknown. fishery.

Future fishery strength Catch rates – Coastal waters Unknown. • No data

Management arrangement Stock structure Fishery and scientific survey data presented to • No data from either sector stakeholder and Departmental participants at the May 2011 stock assessment workshop supported that the current management regime Management settings should be maintained. • Maintain current settings • Limited catch Areas of concern • Large stock extends north More data on the snapper fisheries to the east of Flagged issues Wilsons Promontory by both the commercial • No data and recreational sectors are required to improve the assessment of the eastern snapper stock. Legend Good condition.

↑ Improving

↓ Decreasing

Poor condition

Requires close monitoring

Limited data / unknown

Snapper Stock Assessment 2011 iv

Table of Contents

Snapper Assessment Summary 2011 ...... i Victoria’s snapper stocks...... i Victoria’s snapper fisheries ...... i Types of fisheries...... i Commercial fisheries...... i Recreational fisheries...... ii Management of Fisheries ...... ii Stock assessments...... ii Snapper Stock Assessment 2011 ...... ii Status of the Western Snapper Fishery...... iii Stock condition...... iii Catch rates...... iii Spawning success ...... iii Future fishery strength...... iii Management arrangement ...... iii Areas of concern...... iii Status of the Eastern Snapper Fishery ...... iv Stock condition...... iv Spawning success ...... iv Future fishery strength...... iv Management arrangement ...... iv Areas of concern...... iv

Introduction...... 1 This report...... 1

Description of the snapper stocks...... 2

Description of the fisheries ...... 3

Management arrangements ...... 4

Assessment data and methods...... 5 Snapper beam trawl survey...... 5 Multi‐species otter‐board trawl survey ...... 5 Volunteer research angler diary program (RAD)...... 5

Snapper Stock Assessment 2011

Offsite telephone diary surveys ...... 5 Onsite access point creel surveys...... 5 Volunteer general angler diary program (RAD)...... 5

Assessment indicators and status ...... 6

Acknowledgements ...... 11

References ...... 12

Appendix I: Data figures and tables...... 13

Appendix II: 2011 Workshop participant perspectives...... 28

Appendix III: Previous assessments...... 29 Snapper stock assessment 2002 ...... 29 Stakeholder perspectives...... 29 Snapper stock assessment 2008 ...... 29 Stakeholder perspectives...... 29

Appendix IV: Snapper life‐history information...... 30

Appendix V: Data collection methods ...... 31 Commercial fishery...... 31 Recreational fishery...... 31

Appendix VI: Fishing methods ...... 33 Long‐line...... 33 Haul seine...... 33

Snapper Stock Assessment 2011 vi

List of figures Figure 1. Annual commercial catch (tonnes) and catch rate (kg/day) of snapper, and effort (days) targeting both snapper and other species in Victoria from 1978/79 to 2009/10, presented by financial year...... 13 Figure 2. The relative abundance of a) 0+ snapper taken by fisheries‐independent snapper beam trawl survey; b) 1+ snapper taken by fisheries‐independent multi‐species trawl survey; and, c) 1+ snapper taken by a recreational research angler from the angler diary program...... 14 Figure 3. Average annual recreational targeted catch rates (fish/angler hour ± standard error) of snapper taken by general angler diarists in Port Phillip Bay, Western Port, and the coastal waters west of Wilsons Promontory...... 15 Figure 4. Average annual recreational targeted catch rates (fish/angler hour ± standard error) of snapper taken by research angler diarists in Port Phillip Bay in October to December and January to April, from 2007/08 to 2010/11...... 15 Figure 5. Snapper long‐line annual commercial catch (tonnes) and catch rate (kg/200‐hook‐lifts) of snapper, and effort (shots) targeting both snapper and other species in Port Phillip Bay from 1978/79 to 2009/10, presented by financial year...... 16 Figure 6. Haul seine annual commercial catch (tonnes) and catch rate (kg/shot) of snapper, and effort (shots) targeting both snapper and other species in Port Phillip Bay from 1978/79 to 2009/10, presented by financial year...... 16 Figure 7. Annual commercial catch (tonnes) and catch rate (kg/day) of snapper, and effort (days) targeting both snapper and other species in Western Port from 1978/79 to 2009/10, all gear types, presented by financial year...... 17 Figure 8. Annual commercial catch (tonnes) of snapper taken from Commonwealth waters adjacent to Victoria from 1997 to 2009, presented by calendar year...... 17 Figure 9. Average annual recreational targeted retained catch rates from October to December and January to April (fish/angler hour ± standard error) of snapper taken by avid anglers in Port Phillip Bay from onsite access point surveys...... 18 Figure 10. Average annual recreational targeted retained catch rates from October to December and January to April (fish/angler hour ± standard error) of snapper taken by avid anglers in Western Port from onsite access point surveys...... 18 Figure 11. Length frequency distributions of snapper taken by commercial long‐lines in Port Phillip Bay from 2002/03 to 2009/10...... 19 Figure 12. Age frequency distribution of snapper taken by commercial long‐lines in Port Phillip Bay from 2008/09 to 2010/11...... 20 Figure 13. Length frequency distributions of snapper from recreational onsite access point surveys from January to April, 2008 to 2010, in Port Phillip Bay...... 21 Figure 14. Length frequency distributions of snapper from recreational onsite access point surveys from October to December, 2008 to 2010, in Port Phillip Bay...... 21 Figure 15. Age‐frequency distributions from recreational onsite surveys for January to April and October to December 2010 in Port Phillip Bay...... 22 Figure 16. Length frequency distributions of snapper taken by recreational research anglers from January to April, 2008 to 2010, in Port Phillip Bay...... 23 Figure 17. Length frequency distributions of snapper taken by recreational research anglers from October to December, 2008 to 2010, in Port Phillip Bay...... 23

Snapper Stock Assessment 2011

vii

Figure 18. Age‐frequency distributions of snapper taken by research anglers for January to April and October to December 2010 in Port Phillip Bay...... 24 Figure 19. Length frequency distributions of snapper from recreational onsite access point surveys from January‐April and October‐December 2010 in Western Port...... 25 Figure 20. Annual commercial catch (tonnes) and catch rate (kg/day) of snapper, and effort (days) targeting both snapper and other species in Corner Inlet from 1978/79 to 2009/10, all gear types, presented by financial year...... 25 Figure 21. Annual commercial catch (tonnes) and catch rate (kg/day) of snapper, and effort (days) targeting both snapper and other species in the coastal waters of Victoria from 1978/79 to 2009/10, all gear types, presented by financial year...... 26 Figure 22. Age‐specific catch rates of spawning year classes from recreational onsite surveys for January to April and October to December in Port Phillip Bay...... 27 List of tables Table 1. Stock status determination using catch rate indicators of Victoria’s western snapper stock. The data to support the following classifications are presented in Appendix I...... 7 Table 2. Stock status determination using length and age indicators of Victoria’s western snapper stock. The data to support the following classifications are presented in Appendix I...... 8 Table 3. Stock status determination using catch rate indicators of Victoria’s eastern snapper stock. The data to support the following classification are presented in Appendix I...... 9 Table 4. Overall stock status classification matrix for snapper in Victorian waters...... 10 Table 5. Summary of the commercial catch of snapper and effort targeting snapper and other species in Victorian bays and inlets...... 26

Snapper Stock Assessment 2011 viii

Introduction

Fisheries Victoria has developed a process to conduct periodic formal assessments of the This report status of key marine and estuarine finfish stocks This report assesses the status of the western and the fisheries they support. This process and eastern snapper stocks using data collected involves: from the fisheries (both recreational and • The synthesis of all relevant fisheries data commercial) and from fishery independent scientific monitoring. • Evaluation of fisheries‐independent monitoring and research data, where The report is structured as a series of tables available which describes: • Convening of a workshop involving • The stock structure of snapper in Victoria scientists, resource users and resource • The snapper fisheries that operate in managers to assess the status of the Victorian coastal waters stock/fishery in question • Fisheries management arrangements • Production of an assessment report which currently in place to control fishing effort provides scientific information and advice to facilitate fishery management decision • The types of data used in the assessment making. • The indicators of performance against which the status of the stocks are assessed The assessment process: • The trends in the data for each indicator • Provides scientific evidence on the status of the fish stocks and the environmental factors • The status matrix for each snapper stock in and harvest pressures that influence stock Victoria. abundance These tables are underpinned by a series of • Provides opportunity to draw on the appendices which: knowledge of stakeholder groups • Detail the data used in the assessment • Underpins evidence‐based decisions in an • Outline the stakeholders assessment of the

ecologically sustainable management snapper fishery context • Describe the major findings of previous • Complements Victorian fisheries assessments management planning processes • Summarise the life history of snapper • Ensures the fishery assessment process is accountable and transparent. • Detail data collection methods • A formal assessment of Victorian snapper Details commercial fishing activities used in the snapper fisheries. (Chrysophrys auratus) stocks was conducted at the Department of Primary Industries, Queenscliff, Victoria in May 2011. The assessment workshop was attended by representatives of the commercial and recreational fishing sectors, Fisheries Victoria managers and scientists, and experienced recreational and commercial fishers.

Snapper Stock Assessment 2011

Description of the snapper stocks

General Two separate stocks (i.e. populations) of snapper occur in Victorian waters (see map): description • The fisheries to the east Wilsons Promontory including Corner Inlet are based on the eastern snapper stock. The eastern stock is distributed up the east coast of Australia through NSW and southern Queensland waters • The fisheries to the west of Wilsons Promontory including Port Phillip Bay and Western Port, are based on the western snapper stock. Port Phillip Bay provides critical spawning and nursery habitat for the western snapper stock. Most of the adult snapper found west of Wilsons Promontory, were spawned and raised in Port Phillip Bay. The fisheries based on the eastern and western snapper stocks are managed separately. Fishing In Victoria snapper is harvested from the marine waters of: areas • Port Phillip Bay • Corner Inlet • Western Port • Coastal waters.

Snapper Stock Assessment 2011

Description of the fisheries

Commercial fisheries Recreational fishery General In 2009/10, the total catch of snapper taken by Victorian For 2000/01, it was estimated that ~474 000 description licensed commercial fishers was 90 tonnes (3% of the total snapper (~330 tonnes) were taken by the Victorian finfish catch) (Figure 1). Victorian recreational fishery, constituting 5% of the total state‐wide recreational catch (by This had a wholesale market value of $0.7 million (8% of the numbers) in marine waters (Henry and Lyle total Victorian finfish market value). Victorian commercial 2003). snapper catches have ranged between 90 and 115 tonnes for the For 2006/07, it was estimated that ~612 000 past five years. snapper (~332 tonnes) were taken by the Victorian recreational fishery (Ryan et al. 2009). The majority of the recreational catch of snapper is taken from Port Phillip Bay, followed by coastal waters west of Wilsons Promontory, Western Port, and the coastal waters east of Wilsons Promontory.

Fishing In 2009/10, commercial catches of snapper in Victorian waters Snapper are caught by anglers from the shore‐ methods were primarily taken using long‐lines (65%) and haul seines line, but are most commonly targeted by (24%). anglers from boats. Anglers targeting snapper, use: • Chemically sharpened hooks • A range of hook sizes (2/0‒6/0); depending on bait size • A range of lines (4‒10 kg); depending on the depth and substrate, and size of fish being targeted • Squid, cuttlefish, octopus, silver whiting, garfish and pilchard as bait. Fishing In 2009/10, the majority of Victoria’s commercial catch of The majority of the recreational catch of areas snapper was taken from Port Phillip Bay (92%), followed by snapper harvested from Port Phillip Bay and coastal waters (5%), and Corner Inlet (3%). Catches from within this bay is caught is from the Bellarine Western Port in 2009/10 were <0.1 tonnes. Peninsula, Mornington Peninsula and the The majority of the commercial catch of snapper harvested northern and eastern region of the bay from from Port Phillip Bay by long‐lines comes from the centre and Frankston to Altona. west of the bay, and the Geelong Arm, typically in waters >10 m. The majority of the snapper catch by haul seines comes from areas in the north west of Port Phillip Bay, in waters <10 m deep. Seasonality Commercial catches of snapper from Port Phillip Bay (all gear Recreational catches of snapper from Port types combined) are highest during November/December (late Phillip Bay are highest during late spring and spring /early summer). early summer. This peak in catches coincides with the seasonal movement of This peak in catches coincides with the snapper into Port Phillip Bay for spawning. seasonal movement of adult snapper into Port Phillip Bay for spawning.

Snapper Stock Assessment 2011

Management arrangements

Commercial fishery Recreational fishery Commercial snapper catches occur as a component of a Recreational fishing licence multi‐species commercial finfish fishery. Since 15 July 1999, recreational fishers have been required to hold a recreational fishing licence The commercial fishery is currently managed primarily (RFL) to fish in marine and inland waters. by: Recreational fishers under 18 years of age or over • Input (effort) controls (including limited entry 70 years of age, or those holding one of a range of licensing, restrictions on fishing equipment and concession cards are not required to hold a methods, and closed areas/seasons) licence. • Indirect catch controls such as legal minimum size Gear restrictions limits. Recreational fishing remained unrestricted, other The number of licensed commercial fishers in Victorian than size limits, until 1992, when regulations waters was reduced by a third between 1986/87 and specified a maximum of four lines per person and 2010/11. The majority of the licence removals occurred two hooks per line when fishing in marine as a result of voluntary licence buy‐back schemes waters, and a maximum of two lines with two conducted in 1999/00 and 2005/06. hooks per line in inland waters (MacDonald 1997). In 2011, there were: • 42 commercial licence holders in Port Phillip Bay and This regulation was modified in 2009 to include Western Port two hooks per line or one bait jig when fishing in both marine and inland waters. • 18 licence holders in Corner Inlet • 246 licences holders in Victorian coastal waters (ocean Bag and size limits general) A daily bag limit (DBL) and possession limit of 10 snapper per person (of which no more than three • 60 inshore trawl licence holders. fish may be equal to or exceed 40 cm TL) applies In 2009/10, the number of commercial boats (not to recreational fishing for snapper in all Victorian licences) reporting catches of snapper were as follows: waters. • 47 in Port Phillip Bay The minimum legal size for snapper is 28 cm TL. • 3 in Western Port No more than three fish may be equal to or • 11 in Corner Inlet exceed 40 cm TL. • 38 in the coastal waters west of Wilsons Promontory • 9 in the coastal waters east of Wilsons Promontory. Western Port was closed to commercial haul seine and mesh net fishing in December 2007. Long line fishing continues in this bay, although is considered to be exceptionally rare.

Snapper Stock Assessment 2011

Assessment data and methods

Source Description Fishery‐ Snapper beam trawl survey independent A small beam trawl (Hamer and Jenkins 2004) has been used to survey the relative abundance of 2‒4 month old snapper (i.e. age 0+, 4‒10 cm TL) in Port Phillip Bay since 2000. This survey is ongoing, and involves sampling at nine areas around the bay in March to coincide with the end of the larval settlement period. Each sampling event consists of five non‐overlapping trawls of 10 minutes bottom time within each of the nine sampling areas. The survey is conducted at night. Multi‐species otter‐board trawl survey This survey of fish communities in Port Phillip Bay involved a large wing‐ or otter‐board trawl net (Parry et al. 2002) .The survey has occurred from 1994 to 2011, but recently ceased. Trawl samples were taken at 22 fixed sites stratified by depth (7, 12, 17, and 22 m) along 6 transects spread around the bay. Sites were sampled typically in March. At each site two trawls were undertaken, so that a total of 44 trawl samples were completed annually. The duration of each trawl shot was ~5 minutes. Most of the snapper taken by the otter‐board trawl survey are 1 year old. Volunteer research angler diary program (RAD) A voluntary research angler diary program was established in 1997 provides time‐series data on recreational angler catch rates, and the size/age composition of key target species. Commercial Victorian commercial fishers are required as a condition of their licence to record their fishing fishery‐ activities in a logbook and to submit this information to DPI. Commercial fishers provide the

dependent following information: • Gear code and net length/number of hooks/jigs • Area code • Number of shots • Fishing time • Weight of species caught and not returned to the water. Recreational Offsite telephone diary surveys fishery‐ Off‐site telephone diary surveys of recreational fishing were carried out in 2000/01 (Henry and

dependent Lyle 2003) and 2006/07 (Ryan et al. 2009) to provide regional and State‐wide estimates of total recreational catches of key target species, including snapper. Onsite access point creel surveys Onsite access point surveys of recreational fishing are carried out to provide time‐series of information on catch rates and the size structure of a range of fish species, including snapper. Volunteer general angler diary program (RAD) A voluntary general angler diary program was established in 1997 provides time‐series data on recreational angler catch rates, and the size/age composition of key target species. Length and Since the 1990s there has been routine sampling of length and age frequency distributions of age snapper landed by commercial and recreational fishers. Otoliths used for snapper ageing are monitoring prepared and aged following standard procedures outlined in Morison et al. (1998).

Snapper Stock Assessment 2011

Assessment indicators and status

The snapper fisheries east and west of Wilson’s Promontory in Victoria are based on separate snapper stocks and are treated as separate management units.

Port Phillip Bay

Western Stock Eastern Stock

The following ‘traffic light’ classification system has been developed to classify the status of individual snapper stocks.

Stock status Description Trend in five‐ Is the most recent classification year moving year above the long‐ average* term average** The indicator suggests that the stock is in good ↑↔ Yes condition. Current management arrangements are considered appropriate. ↑ The indicator suggests that the stock is improving. ↑ No Current management arrangements are considered appropriate. ↓ The indicator suggests that the stock is decreasing. ↓ Yes/No Current management arrangements may need to be assessed. Where appropriate, management responses to promote stock recovery need to be investigated. The status of the stock is considered poor. Current ↓ No management arrangements need to be assessed. Management responses to promote stock recovery need to be investigated. There is a need to closely monitor this indicator. Current management arrangements may need to be assessed. A limited amount of information has been collected; or, there are inconsistent or contradictory signals in the data that preclude determination of stock status. * Trend refers to a significant (P<0.1) linear change (ordinary least‐squares regression model) in the five‐year moving average of an indicator over the past 5 years; non‐significant trends were considered stable. Analysis of residuals was carried out to determine whether statistical assumptions were met. ** Long‐term refers to the duration of the time‐series.

Snapper Stock Assessment 2011

Table 1. Stock status determination using catch rate indicators of Victoria’s western snapper stock. The data to support the following classifications are presented in Appendix I.

Source Location Indicator Status year term ‐ ‐ recent

average average

five long Minimum Maximum

in Most

year average year average ‐ ‐ moving Above Ten Five Trend

Fishery‐ Port Beam‐trawl catch rate 0.02 15.16 3.37 1.37 2010/11: ↓ No Decreasing independent Phillip (mean number/1000m2) 0.23 Bay of 0+ snapper (across all ↓ sites), 11‐year time‐series (Figure 2) Multi‐species otter‐ 0.00 143.64 42.34 22.17 2009/10: ↓ Yes Decreasing board trawl catch rate 61.89 (mean number/5 min ↓ tow) of 1+ snapper, 17 year time‐series ( Figure 2) RAD program catch rate 0.00 3.39 0.98 0.68 1.00 ↓ No Decreasing (fish/angler hour) of 1+ snapper, 13‐year time‐ ↓ series (Figure 2) RAD program catch rate Oct‒Dec: Oct‒Dec: N/A N/A Oct‒Dec N/A Yes Good (fish/angler hour) 3‐year 0.93 1.28 2009/10: condition time‐series (Figure 4) Jan‒Apr: Jan‒Apr: 1.28 1.31 3.22 Jan‒Apr 2010/11: 3.22 Commercial Port Long‐line catch rate 21 76 54 67 2009/10: 76 ↑ Yes Good fishery‐ Phillip (kg/200 hook‐lifts) 30‐ condition dependent Bay year time‐series (Figure 5) Haul‐seine catch rate <1 14 10 11 2009/10: 9 ↓ Yes Good (kg/shot) 30‐year time‐ condition† series (Figure 6) Western Catch rate (kg/day) 30‐ 0.02 6 1 2 2009/10: 6 ↑ Yes Limited Port year time‐series (all gear‐ data types) (Figure 7) Oceanic Commonwealth 0.5 89.5 42.1 76.6 2009: 85 ↑ Yes Good waters catch (tonnes/year) condition 13‐year time‐series

(Figure 8)

Recreational Port GAD program catch rate 0.93 3.61 1.60 1.68 2010: 2.88 ↔ Yes Good ‐fishery‐ Phillip (fish/angler hour) 13‐ condition dependent Bay year time‐series (Figure 3) ↔ Onsite survey Oct‒Dec: Oct‒Dec: N/A Oct‒Dec: Oct‒Dec Yes Good retained catch rate 0.21 0.26 0.23 2009/10: condition (fish/angler hour) Jan‒Apr: Jan‒Apr: Jan‒Apr: 0.25 eight‐year time‐ 0.19 0.29 0.26 Jan‒Apr series (Figure 9) 2010/11: 0.26 Western Retained catch rate Oct‒Dec: Oct‒Dec: Oct‒Dec: Oct‒Dec: Oct‒Dec ↔ Oct‒Dec: Good Port (fish/angler hour) 13‐ 0.08 0.35 0.21 0.27 2009/10: Yes condition†† year time‐series from Jan‒Apr: Jan‒Apr: Jan‒Apr: Jan‒Apr: 0.25 Jan‒Apr: onsite surveys (Figure 0.08 0.36 0.25 0.25 Jan‒Apr No 10) 2010/11: 0.21 GAD program catch rate 0.16 0.48 0.29 0.29 2010: 0.18 ↓ No Limited (fish/angler hour) 13‐ data year time‐series (Figure 3) Oceanic GAD program catch rate 0.10 1.56 0.38 0.30 2010: 0.10 ↓ No Limited waters (fish/angler hour) 13‐ data year time‐series (Figure 3)

† Despite a significant negative trend observed in the five‐year moving average, the indicator is well above the long‐term average; there is no clear indication that the stock is decreasing. †† Despite being below the long‐term average, the indicator is stable; there is no clear indication that the stock is decreasing

Snapper Stock Assessment 2011

Table 2. Stock status determination using length and age indicators of Victoria’s western snapper stock. The data to support the following classifications are presented in Appendix I.

Stock Western Source Commercial Recreational Fishery Fishery Location Port Phillip Bay Port Phillip Bay Western Port

)

Indicator ‐

to ‐ ‐ 18) time 16; series series

‐ ‐ length length Figure (Figure size (Figure

(2008 angler 2009/10)

(years) (years) Figure 12 14; Figure

time time

(TL)/age to line frequency

15) 19)

‐ ‐ 2010) (Figure

11; 17; survey survey

(2010)

series

to ‐

frequency ‐ Figure Long

length Research (FL)/age 2010) (TL)/age (years) time (1994/95 series 13; Figure Onsite Onsite (TL) frequency frequency (2003 (Figure

Minimum 2009/10: Oct‒Dec 2010: Oct‒Dec 2010: Oct‒Dec 2010: 34 cm/6 yrs 27 cm/1 yrs 10 cm/0 yrs 26 cm Jan‒Apr 2011: Jan‒Apr 2011: Jan‒Apr 2011: 20 cm/1 yrs 9 cm/1 yrs 25 cm Maximum 94 cm/32 yrs Oct‒Dec: 92 cm/24 yrs Oct‒Dec: 100 cm/27 yrs Oct‒Dec: 95 cm Jan‒Apr: 88 cm/25 yrs Jan‒Apr: 85 cm/15 yrs Jan‒Apr: 120 cm

2009/10: Oct‒Dec 2010: Oct‒Dec 2010: Oct‒Dec 2010: 80 cm 77 cm/15 yrs 88 cm/15 yrs 100 cm/15 yrs Jan‒Apr 2011: 54 cm Jan‒Apr 2011: Jan‒Apr 2011: 88 cm/16 yrs 78 cm/16 yrs Ten‐year average 52 cm/9 yrs N/A N/A Oct‒Dec: 43 cm Jan‒Apr: 38cm Five‐year average 55 cm/10 yrs Oct‒Dec: 52 cm/7 yrs N/A Oct‒Dec: 43 cm Jan‒Apr: 37 cm/5 yrs Jan‒Apr: 35 cm Most recent mean 2009/10: Oct‒Dec 2010 mean: Oct‒Dec 2010: Jan‒Apr 2010: 35 cm 59 cm/11 yrs 53 cm/9 yrs 46 cm/6 yrs Oct‒Dec 2010: 47 cm Jan‒Apr 2011 mean: Jan‒Apr 2011: 38 cm/6 yrs 26 cm/3 yrs Most recent mode 2009/10: Oct‒Dec 2010: Oct‒Dec 2010: Jan‒Apr 2010: 35 cm 61 cm/9 yrs 57 cm/9 yrs 23 cm/9 yrs Oct‒Dec 2010: 44 cm Jan‒Apr 2011: Jan‒Apr 2011: 34 cm/6 yrs 25 cm/2 yrs Status Good Condition Good Condition Good Condition Good Condition

Snapper Stock Assessment 2011

Table 3. Stock status determination using catch rate indicators of Victoria’s eastern snapper stock. The data to support the following classification are presented in Appendix I.

Source Commercial fishery‐dependent Indicator Corner Inlet catch rate time‐series (Figure 20) Minimum 0 kg/day Maximum 6 kg/day Ten‐year average 1 kg/day Five‐year average 2 kg/day 2009/10 1 kg/day Trend in five‐year ↑ moving average Above long‐term No average Status Limited Data

Snapper Stock Assessment 2011

Table 4. Overall stock status classification matrix for snapper in Victorian waters.

Stock Source Location Indicator Description of Current Status Status Classification Western Fishery‐ Port Beam‐trawl 0+ age Since the recruitment failure of the 2005/06 Decreasing independent Phillip catch rate (Figure 2) year class, recruitment of new year class has Bay been moderate or low; catch rate of 0+ pre‐ ↓ recruits in 2010/11 were very low Otter‐board trawl 1+ Catch rates of 1+ age pre‐recruits have been Decreasing age catch rate moderate or low since 2005/06. The increased

(Figure 2) catch rate in 2010/11 is inconsistent with the ↓ decrease recorded for the 0+ pre‐recruits in 2009/10 RAD program 1+ Catch rates of 1+ age pre‐recruits have been Decreasing age catch rate moderate or low since 2005/06. The increased

(Figure 2) catch rate in 2010/11 is inconsistent with the ↓ decrease recorded for the 0+ pre‐recruits in 2009/10 RAD program catch Recreational catch rates have been increasing Good rate (Figure 4) since 2008 Condition

Commercial Port Commercial long‐ Long‐line catch rates have been stable since Good fishery‐ Phillip line catch rate 2005/06, with a notable increase in 2009/10 Condition dependent Bay (Figure 5) Commercial haul Haul seine catch rates increased from 2005/06 Good seine catch rate until 2007/08, and have since fluctuated. Condition (Figure 6) Catch rates are well above the long‐term average Commercial long‐ The 2000/01 year class is currently Good line age‐frequency dominating the commercial fishery. It is Condition distributions expected that the strong 2000/01 and 2003/04 (Figure 12) year classes, and the moderate 2004/05 year class will support the fishery over the next few years Oceanic Commercial Significant commercial catches of snapper Good waters Commonwealth (65‐90 tonnes annually) were harvested Condition catch (Figure 7, between 2007 and 2010; annual reported Figure 8) prior to 2004 were <10 tonnes Recreational‐ Port GAD program catch Catch rates have been increasing since 2008 Good fishery Phillip rate (Figure 3) and are above the long‐term average Condition dependent Bay Recreational onsite Catch rates are stable and above the long‐ Good survey retained term average Condition catch rate (Figure 9) Recreational onsite The 2000/01, 2003/04 and 2004/05 year classes Good survey and angler are dominating the recreational fishery. It is Condition diary age‐frequency expected that the 2003/04 and 2004/05 year distributions classes will support the fishery over the next (Figure 15; Figure few years 18) Western Recreational Recreational catch rates are stable Good Port retained catch rate Condition from onsite surveys (Figure 10) Eastern There are no indicators available for Limited Data specifically assessing the status of Victoria’s eastern snapper stock

Snapper Stock Assessment 2011

Acknowledgements

This report could not have been undertaken without contributions from a number of people:

The Catch and Effort Unit processed and summarised the commercial fishery data: Paula Baker, Ursula Koliba and Monique Nellis. Karina Ryan produced programs for routine reporting of data.

Commercial catch sampling was assisted by Pam Oliveiro, Melissa Beazley and White Fisheries. Fishery‐ independent research surveys were assisted by Kade Mills.

Thank you to Alistair Hirst for providing data from the Port Phillip Bay trawl survey. Thank you also to the people who participated and provided information in the stock assessment workshop held at the Fisheries Research Branch, Department of Primary Industries, Queenscliff, May 2011. Their assistance in the development and review of this report is gratefully acknowledged. Thank you to Pam Oliveiro, Katrina Halse, Tina, Whillock and Pieta Lindberg for data editing and entry.

Thankyou to the our field staff for their many hours interviewing anglers during onsite access point surveys

Thank you to recreational angler diarists who generously return records of their snapper fishing for analysis. Thank you to Jon Presser, James Andrews and Leanne Gunthorpe for comments on this report.

Snapper Stock Assessment 2011

References

Coutin P.C. (1997). Snapper ‐ 1996. Compiled by Murphy H.M., Jenkins G.P., Hamer P.A., Swearer the Bay and Inlet Fisheries and Stock Assessment S.E. (2011). Diel vertical migration related to Group. Department of Natural Resources and foraging success in snapper Chrysophrys auratus Environment, Marine and Freshwater Resources larvae. Marine Ecology Progress Series 433, 185‐194. Institute, Fisheries Victoria Assessment Report Ryan K.L., Morison A.K., Conron S. (2009). No. 12, 52pp. Evaluating methods of obtaining total catch Coutin, P. (2000). Snapper ‐ 1998. Compiled by estimates for individual Victorian bay and inlet the Bay and Inlet Fisheries and Stock Assessment recreational fisheries, FRDC Final Report Group. Fisheries Victoria Assessment Report No. 2003/047. 19. p. 24. Queenscliff: Fisheries Victoria. Saunders R.J. (2009). The reproductive biology Coutin, P.C., Cashmore, S., Sivakumuran, K.P. and recruitment dynamics of snapper, (2003). Assessment of the snapper fishery in Chrysophyrys auratus. PhD Thesis, University of Victoria. Final report to Fisheries Research and Adelaide. Development Corporation, Australia. Project No

97/127., p. 210. Queenscliff, Victoria.: Marine and Freshwater Resources Institute. Efron, B., Tibshirani, R. (1993). An introduciton to the bootstrap. Chapman and Hall, New York.

Gomon, M., Bray, D. & Kuiter, R. (2008). Fishes of

Australiaʹs southern coast. Sydney: Reed New Holland. Hamer, P.A., Acevedo, S., Jenkins, G.P. & Newman, A. (2011). Connectivity of a large embayment and coastal fishery: spawning aggregations in one bay source local and broad‐ scale fishery replenishment. Journal of Fish Biology, 78, 1090‐1109. Hamer, P.A., Jenkins, G.P. (2007). Migratory dynamics and recruitment of snapper, Pagrus auratus, in Victorian waters. Final report to Fisheries Research and Development Corporation Project 1999/134, 90. Hamer, P.A., Jenkins, G.P., Acevedo, S. (2010). Importance of spawning in Port Phillip Bay to local snapper stocks. p. 27. Queenscliff: Fisheries Research Branch. Henry, G.W., Lyle, J.M. (2003). National recreational and indigenous fishing survey. FRDC Project 99/158. Cronulla: NSW Fisheries. Jones C.M., Robson D.S., Lakkis, H.D., Kressel, J. (1995). Properties of catch rates used in the analysis of angler surveys. Transactions of the Amercian Fisheries Society 124, 911‐928.

Snapper Stock Assessment 2011

Appendix I: Data figures and tables

All - Snapper - All Gear: All Catch (tonnes) Effort (days) Catch rate (kg/day) 250--25000 15

200--20000

ate 150--15000 10 h R Effort Catch 100--10000 Catc 5 50--5000

78/79 79/80 80/81 81/82 82/83 83/84 84/85 85/86 86/87 87/88 88/89 89/90 90/91 91/92 92/93 93/94 94/95 95/96 96/97 97/98 98/98 99/00 00/01 01/02 02/03 03/04 04/05 05/06 06/07 07/08 08/09 09/10

Financial year Prepared by the Fisheries Research Branch, Fisheries Victoria (October 2010)

Figure 1. Annual commercial catch (tonnes) and catch rate (kg/day) of snapper, and effort (days) targeting both snapper and other species in Victoria from 1978/79 to 2009/10, presented by financial year.

Snapper Stock Assessment 2011

16 0+ snapper ‒ beam trawl Strong 2003/04 14 Five-year moving average year-class

) 2 12 Strong 2000/01 year-class 10 Recruitment 8 failure of 2005/06 year-class Recruitment 6 failure of 2010/11 year-class (Number/1000 m (Number/1000 abundance Relative 4 2

2010 2011 2008 2003 2004 2005 2006 2007 2009 2000 2001 2002 1998 1999 1997 1995 1996 160

1+ snapper – multi-species trawl Five-year moving average Strong 2003/04 140 Strong 2000/01 year-class year-class 120

100 Recruitment 80 failure of 2005/06 year-class 60

Relative abundance abundance Relative 40 minute tow) (Number/five 20

0 2010 2011 2008 2004 2007 2003 2006 2005 2009 2000 2001 2002 1998 1999 1997 1995 1996 4 1+ snapper – recreational research 3.5 Five-l year moving average Strong 2000/01 Strong 2003/04 year-class year-class 3 2.5 Recruitment 2 failure of 2005/06 year-class 1.5

hour) (fish/angler Relative abundance abundance Relative 1

0.5

2010 2008 2004 2005 2003 2007 2006

2009 2000 2001 2002 1998 1999 1997 1995 1996 Sampling year

Figure 2. The relative abundance of a) 0+ snapper taken by fisheries‐independent snapper beam trawl survey; b) 1+ snapper taken by fisheries‐independent multi‐species trawl survey; and, c) 1+ snapper taken by a recreational research angler from the angler diary program.

Snapper Stock Assessment 2011

8 Port Phillip Bay Five-year moving average 6

1998 1999 2000 2001 2003 2004 2005 2006 2007 2008 2009 2010 2002 1997 0.8 Western Port 0.6

0.4

0.2

0.0

hour) Catch rate (fish/angler 2002 2000 2001 2003 2004 2005 2006 1999 2010 1998 2007 2008 2009 3 Coastal waters west of Wilsons Promontory

2005 2006 1998 1999 2000 2001 2002 2003 2004 2007 2008 2009 2010 1997

Figure 3. Average annual recreational targeted catch rates (fish/angler hour ± standard error) of snapper taken by general angler diarists in Port Phillip Bay, Western Port, and the coastal waters west of Wilsons Promontory.

6.6.00 Oct-Dec JanJan-Apr- Apr 5.5.00

4.4.00

3.3.00

2.2.00

1.1.00 CCaattcch rh raattee ((ffiissh/ah/anngglleerr hohourur)) ((ffiissh/ah/anngglleerr raattee rh CCaattcch 0.0.00 22007007//0088 22000088//0909 20200909//1100 22001100//1111

Figure 4. Average annual recreational targeted catch rates (fish/angler hour ± standard error) of snapper taken by research angler diarists in Port Phillip Bay in October to December and January to April, from 2007/08 to 2010/11.

Snapper Stock Assessment 2011

Port Phillip Bay - Snapper - Snapper longline Gear: SN

Catch (tonnes) Effort (1000-hook-lifts) Catch rate (kg/200-hk-lfts) 200--1500 80

150- 60

-1000 ate

h R 100- Effort Catch 40

Catc -500 50- 20

09/10 09/10 78/79 79/80 80/81 81/82 82/83 83/84 84/85 85/86 86/87 87/88 88/89 89/90 90/91 91/92 92/93 93/94 94/95 95/96 96/97 97/98 98/98 99/00 00/01 01/02 02/03 03/04 04/05 05/06 06/07 07/08 08/09

Financial year

Prepared by the Fisheries Research Branch, Fisheries Victoria (October 2010)

Figure 5. Snapper long‐line annual commercial catch (tonnes) and catch rate (kg/200‐hook‐lifts) of snapper, and effort (shots) targeting both snapper and other species in Port Phillip Bay from 1978/79 to 2009/10, presented by financial year.

Port Phillip Bay - Snapper - Haul seine Gear: ES, BS, GS, RN, H1, H2, H3, H4, H5, H6 Catch (tonnes) Effort (shots) Catch rate (kg/shot) 40--5000 15 -4000 30- ate -3000 10 h R 20- Effort Catch -2000 Catc 5 10- -1000

78/79 79/80 80/81 81/82 82/83 83/84 84/85 85/86 86/87 87/88 88/89 89/90 90/91 91/92 92/93 93/94 94/95 95/96 96/97 97/98 98/98 99/00 00/01 01/02 02/03 03/04 04/05 05/06 06/07 07/08 08/09 09/10 Financial year

Prepared by the Fisheries Research Branch, Fisheries Victoria (October 2010)

Figure 6. Haul seine annual commercial catch (tonnes) and catch rate (kg/shot) of snapper, and effort (shots) targeting both snapper and other species in Port Phillip Bay from 1978/79 to 2009/10, presented by financial year.

Snapper Stock Assessment 2011

Western Port - Snapper - All Gear: All Catch (tonnes) Effort (days) Catch rate (kg/day) 6--4000 6

-3000

4- ate 4 h R -2000 Effort Catch Catc 2- 2 -1000

Prepared by the Fisheries Research Branch, Fisheries Victoria (October 2010)

Figure 7. Annual commercial catch (tonnes) and catch rate (kg/day) of snapper, and effort (days) targeting both snapper and other species in Western Port from 1978/79 to 2009/10, all gear types, presented by financial year.

101000 9090 8080 7070 6060 5050 4040 3030 Catch (tonnes) 2020 1010 00

20200808 20032003 20042004 19919999 20200099 20200099 20200055 20200066 20200077 20200000 20200011 20200022 11997997 19199988

Year

Figure 8. Annual commercial catch (tonnes) of snapper taken from Commonwealth waters adjacent to Victoria from 1997 to 2009, presented by calendar year.

Snapper Stock Assessment 2011

Oct-Dec Jan-Apr 0.5

0.4

0.3

0.2 0.1

0 Catch rate (fish/angler hour) Catch rate (fish/angler

2002/03 2003/04 2004/05 2005/06 2006/07 2007/08 2008/09 2009/10 2010/11

Figure 9. Average annual recreational targeted retained catch rates from October to December and January to April (fish/angler hour ± standard error) of snapper taken by avid anglers in Port Phillip Bay from onsite access point surveys.

Oct-Dec Jan-Apr 0.5 0.4 0.3

0.2

0.1

0.0

hour) Catch rate (fish/angler

2004/05 2001/02 2002/03 2003/04 2005/06 2006/07 2007/08 2008/09 2009/10 2000/01 2010/11 1998/99 1999/00

Figure 10. Average annual recreational targeted retained catch rates from October to December and January to April (fish/angler hour ± standard error) of snapper taken by avid anglers in Western Port from onsite access point surveys.

Snapper Stock Assessment 2011

10 2002/03 10 2006/07 8 8 6 6 4 4 2 2 0 0 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 2025 30 35 4045 50 55 6065 70 75 80 85 90 95100 12 2007/08 10 2003/04 10 8 8 6 6 4 4 2 2 0 0 20 25 30 35 40 45 50 55 60 65 7075 80 85 90 95 100 2025 3035 40 4550 55 60 65 7075 80 85 90 95100 8 2008/09 10 2004/05 6 8 6 4 4 Weighted frequency (%) frequency Weighted 2 2 0 0 20 25 3035 40 45 5055 6065 70 7580 8590 95100 2025 3035 40 45 50 55 60 65 70 75 80 85 90 95100

10 2005/06 15 2009/10 8 6 10

4 5 2 0 0 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 20 25 30 35 4045 5055 6065 70 7580 85 90 95100 Fork length (mm)

Figure 11. Length frequency distributions of snapper taken by commercial long‐lines in Port Phillip Bay from 2002/03 to 2009/10.

Snapper Stock Assessment 2011

7070 202008/008/099 6060

5050 4040 3030 2020 1010 00

8383//8844 8484//8855 8383//8844 0808//0099 0707//0088 0606//0077 0404//0055 0303//0044 0202//0033 0101//0022 0000//0011 9999//0000 9898//9999 9797//9988 9696//9977 9595//9966 9494//9955 9393//9944 8686//8877 8585//8866 0505//0066 9292//9933 9191//9922 9090//9911 8989//9900 8888//8899 8787//8888 7070 20200909//1100 6060 5050 4040 3030 2020

(%) Frequency 1010

0011 8787//8888 8686//8877 8585//8866 9191//9922 9090//9911 8989//9900 8888//8899 9797//9988 9696//9977 9595//9966 9494//9955 9393//9944 9292//9933 0909//1100 0808//0099 0707//0088 0606//0077 0505//0066 0404//0055 0303//0044 0202//0033 0101//0022 0000// 9999//0000 9898//9999 8585//8866 7070 6060 2010/11 (Jul-Dec) 5050 4040 3030 2020

1010

8989//9900 88/888/899 8787//8888 86/86/8787 85/85/8686 1010//1111 09/109/100 08/08/0909 07/007/088 0606//0077 05/05/0606 04/04/0505 0303/04/04 0202/03/03 01/01/0202 0000//0011 9999/00/00 9898//9999 97/997/988 9696//9977 95/995/966 9494//9955 93/93/9494 92/992/933 9191/92/92 90/90/9191 Estimated age (spawning year)

Figure 12. Age frequency distribution of snapper taken by commercial long‐lines in Port Phillip Bay from 2008/09 to 2010/11.

Snapper Stock Assessment 2011

1515 202008 (08 (nn==3346)46)

1010

00 1010 1515 2020 2255 3300 35354400445555005555 6060 6565 7070 7575 8080 8855 9900 9519510000 1515 20200099 ((nn==551199))

1010

(%) Frequency 00 1010 1515 2020 2255 3300 353544004455550055556060 6565 7070 7575 8080 8855 9900 9595100100

1515 202010 (nn==338877))(10

1010

00 1010 1515 2020 2525 3030 353544004455550055556060 6565 7700 7755 8080 8585 9090 9595100100 Total Length (mm)

Figure 13. Length frequency distributions of snapper from recreational onsite access point surveys from January to April, 2008 to 2010, in Port Phillip Bay.

15 2008 (n=829)

5 0 1010115520202525330033554400 4545505055556060656577007755808088559900 9955110000

15 2009 (n=625)

Frequency (%) Frequency 0 1100115522002255 3300 35354040454550505555660066557070757580808585 99009955110000

15 2010 (n=635)

0 1010 151522002525 3030353544004455550055556060 6565707075758800885599009595101000 Total Length (mm)

Figure 14. Length frequency distributions of snapper from recreational onsite access point surveys from October to December, 2008 to 2010, in Port Phillip Bay.

Snapper Stock Assessment 2011

9 January‒April 2010

2000/01 2007/08 2001/02 1997/98 2004/05 2003/04 2002/03 1999/00 1998/99 1996/97 1995/96 1994/95 1993/94 2009/10 2008/09 2006/07 2005/06

(%) Frequency 9 October‒December 2010

2000/01 2007/08 2001/02 1997/98 2003/04 2002/03 2004/05 1999/00 1998/99 1996/97 1995/96 1994/95 1993/94 2008/09 2006/07 2005/06 2009/10 Estimated age (spawning year)

Figure 15. Age‐frequency distributions from recreational onsite surveys for January to April and October to December 2010 in Port Phillip Bay.

Snapper Stock Assessment 2011

15 2008 (n=688)

5 0 00 55 1100 1515 22002255 3030 3355 4040 4545 55005555 6060 6655 77007755 8080 8585 9900 9595101000 1515 22009009 ((nn==1105053)3)

1010

Frequency (%) Frequency 00 00 55 101015152200225530303355404045455500555560606565770077558080885599009955110000 15 2010 (n=1422)

0 00 55 110015152200225533003535440045455500555566006655707077558800858599009595101000 Total length (mm)

Figure 16. Length frequency distributions of snapper taken by recreational research anglers from January to April, 2008 to 2010, in Port Phillip Bay.

15 2008 (n=379)

0 00 55 1010115522002255 303035354040445555005555 60606565707075758080885599009955100100 15 2009 (n=672)

(%) Frequency 0 00 55 11001155 20202525303033554400 454555005555 60606565707077558800 858590909595101000 15 2010 ( n=749)

0 00 55 11001155 202025253030335544004455 5050555566006565707077558800 858590909595101000 Total length (mm)

Figure 17. Length frequency distributions of snapper taken by recreational research anglers from October to December, 2008 to 2010, in Port Phillip Bay.

Snapper Stock Assessment 2011

50 January‒April 2010 40

2000/01 2007/08 2001/02 1997/98 2004/05 2003/04 2002/03 1999/00 1998/99 1996/97 1995/96 1994/95 1993/94 2009/10 2008/09 2006/07 2005/06

Frequency (%) Frequency 50 October‒December 2010 40

2000/01 2007/08 2001/02 1997/98 2008/09 2009/10 2006/07 2005/06 2004/05 2003/04 2002/03 1999/00 1998/99 1996/97 1995/96 1994/95 1993/94 Estimated age (spawning year)

Figure 18. Age‐frequency distributions of snapper taken by research anglers for January to April and October to December 2010 in Port Phillip Bay.

Snapper Stock Assessment 2011

15 Jan-Apr 2010 (n=85) 10

0 1010 1155 2200 252530303355 40404455 5050 555560606655 7700 7755 8080 858590909955110000

1515 Frequency (%) Frequency Oct-Dec 2010 (n=103) 1010

00 1100 1155 2020252530303535 4400 4455 5500 5555 6600 6655 707075758080858590909955110000 Total length (mm)

Figure 19. Length frequency distributions of snapper from recreational onsite access point surveys from January‐April and October‐December 2010 in Western Port.

Corner Inlet - Snapper - All Gear: All

Catch (tonnes) Effort (days) Catch rate (kg/day) 15--3000 8

10--2000 ate

h R Effort Catch 4 Catc 5--1000

Figure 20. Annual commercial catch (tonnes) and catch rate (kg/day) of snapper, and effort (days) targeting both snapper and other species in Corner Inlet from 1978/79 to 2009/10, all gear types, presented by financial year.

Snapper Stock Assessment 2011

Ocean General - Snapper - All Gear: All Catch (tonnes) Effort (days) Catch rate (kg/day) 40--6000 8

30- 6

-4000 ate h R 20- Effort Catch 4 Catc -2000 10- 2

Figure 21. Annual commercial catch (tonnes) and catch rate (kg/day) of snapper, and effort (days) targeting both snapper and other species in the coastal waters of Victoria from 1978/79 to 2009/10, all gear types, presented by financial year.

Table 5. Summary of the commercial catch of snapper and effort targeting snapper and other species in Victorian bays and inlets.

Stock Western Eastern Location Port Phillip Bay Western Port Corner Inlet Fishing Long‐line Haul seine All gear types All gear types method combined combined Variable Catch Effort (1000 Catch Effort Catch Effort Catch Effort (tonnes) hook‐lifts) (tonnes) (shots) (tonnes) (days) (tonnes) (days) 10 year 47 181 24 2490 0.4 470 2 2251 average 5 year 55 161 24 2307 0.4 406 4 2161 average 2009/10 57 150 38 2194 0.08 15 2 2019 Trend ↑ ↓ ↑ ↓ ↓ ↓ ↔ ↓

Snapper Stock Assessment 2011

0.30 January‒April

0.25 2000/01 0.20 2003/04 2004/05 0.15

0.10

0.05

0.00

0 1 2 3 4 5 6 7 8 9

0.30 October‒December 0.25

hour) Catch rate (fish/angler 0.20

0.15

0.10

0.05

0.00

0 1 2 3 4 5 6 7 8 Estimated age (years)

Figure 22. Age‐specific catch rates of spawning year classes from recreational onsite surveys for January to April and October to December in Port Phillip Bay.

Snapper Stock Assessment 2011

Appendix II: 2011 Workshop participant perspectives

• Commercial fishers operating in Victorian coastal waters reported that snapper

catches had been good in recent years and were increasing. • Recreational fishers reported ‘exceptionally’ good catches of snapper in Port Phillip Bay in recent years, and that catch rates in Western Port had been

stable. • Recreational fishers reported that ‘pinkies’ were abundant inshore and around artificial reefs in Port Phillip Bay. • Recreational fishers reported that there had been a reduction in the size of snapper taken in Western Port, and that larger fish (>3 kg) were a less common occurrence than in previous years. • Fisheries officers reported evidence of

increased non‐compliance and concealment, and that this was likely due to the current high abundance of snapper.

Snapper Stock Assessment 2011

Appendix III: Previous assessments

were shallow‐hooked and 8% were deep‐ Snapper stock assessment 2002 hooked. • High levels of snapper recruitment were • In 2006, the minimum legal size for snapper noted. was increased from 27 to 28 cm TL; the daily • Catch rates in the commercial and bag limit remained at 10, however, a recreational sectors were reported as stable maximum of three snapper measuring 40 or increasing. cm TL or more was introduced to replace • Long‐line catches in Port Phillip Bay the previous allowance of three fish declined to the lowest on record in 2000/01 measuring 50 cm TL or more was (23 tonnes); this was partly the result of a introduced. These changes were reduction in effort due to a voluntary licence implemented in response to stakeholder buy‐back schemes conducted in 1999/00. feedback on a discussion paper of options Stakeholder perspectives for changes in snapper size and bag limits, and were not driven by management • Commercial fishers reported that there was decisions to constrain mortality. a reasonable number of large snapper in Port Phillip Bay during 2001/02. • A further voluntary commercial licence buy‐ back scheme was conducted in 2005/06. • Haul seine commercial fishers reported a high abundance of small snapper in Port Stakeholder perspectives Phillip Bay. • Haul seine commercial fishers reported low • Concern for post release survival of catches of snapper in Port Phillip Bay; undersize fish was expressed. juveniles, and adults >1 kg, were rarely

• Western Port recreational fishers reported being taken. that snapper catch rates had declined over • Recreational fishers reported a decrease in the last decade, but that catch rates were the amount of small fish landed in the improving. Patterson River from ~30‒40 fish to ~10 fish, and that release rates were high. Snapper stock assessment 2008 • Recreational fishers reported that they were • Commercial long‐line and haul seine catch rarely reaching the daily bag limit, and that rates in Port Phillip Bay were reported as the he abundance of pinkies in Port Phillip stable. Bay was low; one recreational fisher • The proportion of larger (≥65 cm FL) older reported that pinkies were abundant near (≥14 years) snapper taken by commercial Black Rock. fishers had declined. • More anglers reported using soft plastics • A reduction in the abundance of small and lures to target snapper. snapper in Port Phillip Bay and Western The 2002 and 2008 snapper stock assessment Port had resulted in lower release rates. workshops showed there was no evidence in the • Release rates of pinky snapper in Port available indicators for a review of snapper Phillip Bay were high when recreational management arrangements, and that the current fishers were targeting King George whiting. level of protection should be maintained. • Research into the post release survival of snapper indicated that if fish were shallow‐ hooked (in the lip) there was high post release survival (97.5%). However, deep‐ hooked fish had a low post release survival (48.4%). Survival of deep hooked fish was higher if the hook was not removed. • Angler diary and onsite survey data collected from fishers targeting King George whiting showed that 92% of snapper taken

Snapper Stock Assessment 2011

Appendix IV: Snapper life‐history information

Distribution • Northern Queensland to Carnarvon in Western Australia including Tasmania, and around New Zealand.

Stock • The snapper fisheries east and west of Wilsons Promontory in Victoria are based on separate snapper stocks structure and are treated as separate management units • The snapper east of Wilson’s promontory though to be part of a larger widely dispersed snapper stock distributed from eastern Victoria to southern Queensland • Victorian commercial catches are predominantly from the western stock • Port Phillip Bay is an important snapper spawning and nursery area for Victoria’s western snapper stock; the majority of adults recruiting to Port Phillip Bay, Western Port and coastal waters in western Victoria are the product of localised spawning and juvenile recruitment in Port Phillip Bay. Movement • After a pelagic larval phase (20–25 days), snapper settle to bottom habitats in sheltered bays and estuaries • Juveniles mostly remain in sheltered waters for at least their first year of life, but beyond this age they can display a variety of movement behaviours, ranging from local residency to movements of 100’s km in coastal waters • Adult snapper make mass migrations into Port Phillip Bay from coastal waters each spring‐summer to breed, and most are thought to leave the bay by autumn. However, long‐term residency of adult snapper in Port Phillip Bay and coastal waters is also thought to occur. Habitats • Juvenile and adult snapper are demersal (i.e. occurring mostly near the bottom) • Small juveniles (< 1 year old, < 20 cm length) are most commonly associated with sediment habitats • Older juveniles and adults can be associated with both reef and sediment habitats Longevity • Up to 40 years of age Reproduction • Small individuals <35 cm TL (<3 years of age) are mostly immature • Snapper between 35 and 44 cm TL (~3‒5 years of age) are mostly maturing • Sexual maturity in Port Phillip Bay occurs at ~5years of age at ~42 cm TL (36 cm FL) • Spawning occurs from late spring to summer (November–February) with a common peak in December/early January, and can occur in bays and coastal waters • Adults move into bays, most notably, Port Phillip, and aggregate to spawn during late spring and summer (October–December) and return to coastal waters in late summer/autumn • Snapper are serial batch spawners; which means that individual fish can spawn many times during the spawning season. • Spawning is thought to occur in the evening (as per studies in South Australia) • The number of eggs produced by adult snapper increase exponentially with size, with a large adult snapper capable of releasing millions of eggs during a spawning season. Recruitment • Spawning success as measured by the successful recruitment of juvenile snapper is highly variable from year to year • This variation appears to be related to highly variable survival rates of larvae, which may be linked to environmental influences. Growth • Growth rates are similar in Port Phillip Bay, Western Port and Corner Inlet • Most snapper at 40 cm TL are typically 4‒6 years of age • Individuals recruit to the commercial and recreational fisheries at 28 cm TL (the legal minimum length) and 2‒3 years of age. Diet • Snapper are considered generalist predators, and their diet varies with fish size • Larvae feed on a range of tiny zooplankton and invertebrate eggs • Small individuals (5–15 cm TL) feed mainly on polychaete worms and small crustaceans • Individuals from 15–25 cm TL mostly consume crustaceans , molluscs and small fish • Large individuals consume crustaceans, molluscs, cephalopods (i.e. squid and octopus) and fish References: Coutin et al. 2003; Hamer and Jenkins 2007; Gomon et al. 2008; Saunders 2009; Hamer et al. 2010; Hamer et al. 2011; Murphy et al. 2011 ;

Snapper Stock Assessment 2011

Appendix V: Data collection methods

This section further describes relevant research The National Recreational Fishing Survey in and monitoring used to provide information for 2000/01 provided State‐wide and regional the 2011 snapper stock assessment. estimates of both retained and discarded catches of key target species by recreational fishers Commercial fishery (Henry and Lyle 2003). Anglers were identified and recruited for the survey using a State‐wide Recording of commercial catches from bay and inlet fisheries commenced in 1914. telephone screening method.

Catch information was recorded in this manner State‐wide and regional recreational catches of key Victorian marine and estuarine species were by calendar year until 1963. estimated again in 2006/07 using a telephone Fishers provided more detailed monthly catch diary survey (Ryan et al. 2009). The 2006/07 data to the Victorian Department of Fisheries survey used the Recreational Fishing Licence and Game between 1964/65 and 1972/73. This database as a sampling frame to identify and catch information was forwarded to the recruit anglers. Commonwealth Bureau of Census and Statistics Data from onsite access point surveys provides a for processing and reporting. Throughout this period, fishing effort data were not detailed and time‐series of information on species targeted have not been summarised. and caught by anglers, discard rates, catch rates and the length and age composition of the Between 1973/74 and 1977/78, the same type of retained catch of key target species. Seasonal data were recorded and collected but were boat ramp access point surveys have been processed and summarised by the Victorian conducted every year since 2003. A variable Fisheries and Wildlife Division. number of interviews occur on any sample day. Avid anglers are anglers who recalled fishing at More detailed daily records of fishing method, least five days in the previous 12 months. area, catch and effort (and therefore catch rate) Calculating mean catch rates from these anglers have been collected and entered into databases increases consistency in the sampling effort and since 1978/79. reliability of the analyses. These data have been checked for major errors The access point angler survey covers a large by a series of range tests and other validation number of anglers with sampling bias towards routines that are part of the normal data entry fine weather weekend days in order to maximise procedures of the Catch and Effort Unit at the the number of interviews. Discard rates are Department of Primary Industries, Queenscliff. potentially subject to recall bias. The precision of A review of logbook data quality has indicated the annual and seasonal catch rate estimate is that more than 95% of monthly catch/effort influenced by sampling intensity (survey days). returns have been submitted. There is potential Fork length measurements are made by trained for some errors in catch rate due to unrecorded interviewers. effort and/or errors in coding effort data. Volunteer angler diarists have been operating in No attempt has been made to independently Victoria since 1997. Experienced volunteer verify the accuracy of catch weight, fishing anglers contributed to either the ‘general’ or location or effort values supplied by fishers. ‘research’ angler diary program. All anglers Effort values are not standardised as no attempt recorded: has been made to make any adjustment for changes in fishing power over the period for • Time spent fishing which catch/effort statistics have been collected. • Fishing location • Species targeted and caught Recreational fishery • Fish lengths There have been two large‐scale, telephone‐ • Number of rods diary surveys of recreational fishing in Victoria • Bait and hook type/sizes used. aimed at estimating total recreational catch. In addition, research anglers were required to alter their fishing techniques (hook sizes, baits

Snapper Stock Assessment 2011

and fishing locations) in order to catch the largest possible size range of the key species they were targeting. All catches, including under‐size fish, were recorded in diaries, and all fish caught were measured. Otolith samples were collected for ageing.

The general angler diary program requires anglers to record results from their ‘normal’ fishing activities and represents a completely fishery dependent method of collecting data. The research angler diary program is also considered to be a fishery independent method, as anglers that participate are bound by prescribed gear (hook sizes), times and locations. The main advantage of the research angler diary program over the general angler diary program is the standardisation of effort, enabling a more rigorous assessment of trends over time. These angler diary data are not representative of all anglers, but are collected in a consistent manner and are therefore comparable from year to year. Average recreational catch rates were calculated using the ratio of the means estimator (Jones et al. 1995). This estimator allows for the fact that information obtained from interviews with recreational fishers represents complete trips. Confidence limits were estimated using bootstrapping methods (Efron and Tibshirani 1993).

Snapper Stock Assessment 2011

Appendix VI: Fishing methods

Long‐line Long‐lining involves a long length of fishing line, often several kilometers long, to which short lengths of line carrying baited hooks are attached. The long‐lines are hauled up periodically. The gear is often set on the bottom where it is held by anchors. The start and finish of the long‐ line is marked with buoys and flags. A long‐line can also be set just below the surface where the target species is pelagic, or suspended at the required depth using regularly spaced buoys along the line. In Victorian waters, long‐lining is used to catch snapper, along with school shark, gummy shark and tuna.

Haul seine

Haul seining involves the setting of a net, with long ropes at both ends from a boat. The nets travel a semicircular course. Both ropes and then ends of the net are winched in so that the area enclosed by the net continually decreases until it is small enough for the fish to be removed.

Under‐sized and unwanted fish are then released. Fish are sorted before the net is removed from the water so that the by‐catch of undersize or unwanted fish can be released back into the sea alive. The ropes are up to one kilometer long. There are floats on the rope and weights at the bottom so the net hangs vertically in the water. In shallow, protected areas which have sandy substrate; long warps are often attached to the ends of the ropes to increase the area being encircled. Modifications to haul seine nets during the 2000s have enabled seine fishing to occur over hard substrates. In Victorian waters, haul seining is used to catch snapper, King George whiting, flounder, bream, garfish, calamari and rock flathead. Small boats are commonly used with one or two fishers.

Snapper Stock Assessment 2011