Saddletail Snapper Lutjanus malabaricus

Northern Australian biological stock

The cross-jurisdictional northern Australian biological stock has components in the Northern Territory and Queensland. Each jurisdiction assesses that part of the biological stock that occurs in its waters. Status presented here for the entire biological stock has been established using evidence from both jurisdictions.

For the Northern Territory component of the biological stock (where most of the commercial catch is taken), Saddletail Snapper was assessed in 2013 using a stochastic stock reduction analysis model⁴. Egg production was estimated to be around 80 per cent of that before the start of the fishery, indicating that this part of the biological stock is not recruitment overfished.

The Northern Territory manages the commercial harvest of Saddletail Snapper and Crimson Snapper together as ‘red snappers’, with a combined total allowable commercial catch of 3800 tonnes (t). Saddletail Snapper has averaged 78 per cent of the annual red snapper catch over the past 10 years; the 2013 commercial catch of this species was 1806 t. The 2013 assessment indicated that the current harvest rate of Saddletail Snapper is well below that required to achieve maximum sustainable yield. This level of fishing mortality is unlikely to cause this part of the biological stock to become recruitment overfished.

For the Queensland part of the biological stock, commercial catch in 2013 was 9 t, constituting only 0.5 per cent of the total 2013 Saddletail Snapper catch from this stock. This contrasts with catches of 150–250 t per year during the period 2006 to 2011, and is the lowest catch since 2001. This low catch of the Queensland component of the stock would not have altered the stock assessment results for the predominant Northern Territory component.

Because the Northern Territory part of the biological stock constituted the majority of the total catch in 2013, the status of this part of the biological stock is indicative of the entire biological stock.

On the basis of the evidence provided above, the biological stock is classified as a sustainable stock.

East coast Queensland biological stock

Saddletail Snapper is taken in both the commercial and recreational sectors, probably in similar numbers.

Recreational harvest estimates group Saddletail Snapper and Crimson Snapper together because these two species are often not separately identified in recreational catches. The recreational harvest of these species was estimated at approximately 65 000 fish in 2010. The relative proportions of the two species in this figure are not known.

Since 2004, commercial harvest has decreased from an average of 150 t per year to around 50 t per year. This decrease coincided with expansion of no-take marine reserves within the Great Barrier Reef Marine Park and the introduction of a quota management system for coral reef finfish species. Both factors are likely to have influenced commercial catch. Saddletail Snapper is managed as part of the ‘other species’ quota category, which comprises many other coral reef finfish species. There is a cap on the total catch for the group, but no individual cap on any one species within the group. Although recreational fishing effort is not capped, the current level of combined fishing pressure is unlikely to cause the stock to become recruitment overfished.

Current information on population composition is unavailable, and no stock assessment has been completed, so insufficient information is available to confidently classify the status of this biological stock.

On the basis of the evidence provided above, the biological stock is classified as an undefined stock.

North West Shelf biological stock

Saddletail Snapper is exploited primarily on the north-west coast of Western Australia as a component of the Pilbara Trap Managed Fishery, Pilbara Fish Trawl Interim Managed Fishery and Northern Demersal Scalefish Managed Fishery (in the Kimberley region of Western Australia)⁵. Saddletail Snapper is assessed on the basis of the status of several indicator species (for example, Red Emperor—Lutjanus sebae, and Goldband Snapper—Pristipomoides multidens in the Kimberley region) that represent the inshore demersal suite of species occurring at depths of 30–250 m. The major performance measures for these indicator species are estimates of spawning stock levels. The target level of spawning biomass is 40 per cent of the unfished level. The limit level is 30 per cent of the estimate of initial spawning biomass. Data analysis using an integrated age-structured model determined that the spawning biomass levels of the indicator species were greater than 40 per cent of the unfished level in the Pilbara Trap Managed Fishery, Pilbara Fish Trawl Interim Managed Fishery and Northern Demersal Scalefish Managed Fishery in 2007⁶. In addition, the catch of Saddletail Snapper in the Northern Demersal Scalefish Managed Fishery has been stable for the past 5 years (2009 to 2013), ranging from 87 to 126 t ⁶. Similarly, the catch of Saddletail Snapper in the Pilbara demersal fisheries has been low and stable, ranging from 64 to 73 t over the past 3 years⁶. The biological stock is therefore not considered to be recruitment overfished.

The fishing mortality (F)–based assessments⁶ indicated that the fishing levels on the indicator species were either lower than the target level or between the target and threshold levels. These assessments use reference levels based on ratios of natural mortality (M) for each species, such that F _target = 2/3M, F_threshold = M and F_limit = 3/2M. This level of fishing mortality is unlikely to cause the biological stock to become recruitment overfished.

On the basis of the evidence provided above, the biological stock is classified as a sustainable stock.