1 About this document
This is a prototype of an automatic report that documents how the user specified the operating model and their various justifications.
2 Introduction
This MERA questionnaire was population primarily from a recent stock assessment of tiger flathead (referred to as ‘the assessment’ herein):
Day Jemery (2016) Tiger flathead (Neoplatycephalus richardsoni) stock assessment based on data up to 2015. Technical report presented at SERAG, Hobart, 24 November 2016.
https://drive.google.com/open?id=18kPzoKFMqTsErnPN3tyS3q32wDK5uNw4
- Describe the history and current status of the fishery, including fleets, sectors, vessel types and practices/gear by vessel type, landing ports, economics/markets, whether targeted/bycatch, other stocks caught in the fishery.
(from the assessment) “Tiger flathead have been caught commercially in the south eastern region of Australia since the development of the trawl fishery in 1915… Historical records (e.g. Fairbridge, 1948; Allen, 1989; Klaer, 2005) show that steam trawlers caught tiger flathead from 1915 to about 1960. A Danish seine trawl fishery developed in the 1930s (Allen, 1989) and continues to the present day. Modern diesel trawling commenced in the 1970s”.
- Describe the stock’s ecosystem functions, dependencies, and habitat types.
(from the assessment) “[Tiger flathead] are endemic to Australian waters and are caught mainly on the continental shelf and upper slope waters from northern NSW to Tasmania and through Bass Strait”
- Provide all relevant reference materials, such as assessments, research, and other analysis.
Day (2016) referenced above.
A fully specified OMx (DLMtool, MSEtool) operating model was also specified from the stock synthesis assessment and is available here:
https://drive.google.com/open?id=1PshBHUTtniuFyw_yUZq_B57VfrE__Fbp
This includes some details not present in the assessment report (Day 2016)
3 Fishery Characteristics
3.1 Longevity
| Answered |
|---|
| Very short-lived (5 < maximum age < 7) |
| Short-lived (7 < maximum age < 10) |
| Moderate life span (10 < maximum age < 20) |
| Moderately long-lived (20 < maximum age < 40) |
| Long-lived (40 < maximum age < 80) |
| Very long-lived (80 < maximum age < 160) |
| Justification |
|---|
| The assessment document (page 27) states a base-case assumption of M = 0.27 per year |
3.2 Stock depletion
| Answered |
|---|
| Crashed (D < 0.05) |
| Very depleted (0.05 < D < 0.1) |
| Depleted (0.1 < D < 0.15) |
| Moderately depleted (0.15 < D < 0.3) |
| Healthy (0.3 < D < 0.5) |
| Underexploited (0.5 < D) |
| Justification |
|---|
| The assessment (Figure 16, page 40) estimates SSB relative to unfished of between 0.3 and 0.5 (95% CI) with a mean estimate of 0.43. |
3.3 Resilence
| Answered |
|---|
| Not resilient (steepness < 0.3) |
| Low resilience (0.3 < steepness < 0.5) |
| Moderate resilence (0.5 < steepness < 0.7) |
| Resilient (0.7 < steepness < 0.9) |
| Very Resilient (0.9 < steepness) |
| Justification |
|---|
| Steepness estimates from the assessment (Table 19, page 45) ranged from 0.61 to 0.75. |