Endeavour Prawns Metapenaeus endeavouri, M. ensis

Northern Prawn Fishery (Commonwealth) Blue Endeavour Prawn management unit

Blue Endeavour Prawn is assessed as part of the integrated bioeconomic model constructed for the Northern Prawn Fishery (Commonwealth) Tiger Prawn sector². Commercial catch of Endeavour Prawn is disaggregated into separate species using a model incorporating historical fishery-independent survey data³. Blue Endeavour Prawn is assessed using a biomass dynamic model that estimated the spawner stock size at the end of 2012 to be 88.5 per cent of the spawner stock size (S) that would be required for maximum sustainable yield (S_MSY)². This is above the limit reference point of 50 per cent (0.5S_MSY). As a result, the management unit is not considered to be recruitment overfished⁴. The commercial catch in 2012 (approximately 343 tonnes [t]) was below the estimate of maximum sustainable yield (base case 836 t). This level of effort is unlikely to cause the management unit to become recruitment overfished.

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

Northern Prawn Fishery (Commonwealth) Red Endeavour Prawn management unit

Although stock assessments have been attempted for Red Endeavour Prawn, there is currently no reliable assessment to confidently classify the status of this stock⁴. Catches over recent years have been quite low compared with historical highs. This is most likely related to a fall in fishing effort directed at Tiger Prawn (Red Endeavour Prawn is a byproduct species from effort directed at Tiger Prawn), rather than any indication of a fall in Red Endeavour Prawn biomass. Insufficient information is available to confidently classify the status of this stock.

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

Torres Strait Prawn Fishery (Commonwealth) Blue Endeavour Prawn management unit

The most recent assessment⁵ for Blue Endeavour Prawn in the Torres Strait Prawn Fishery (Commonwealth) estimated that biomass in 2007 ranged from 71 to 85 per cent of the unfished (1967) level. Maximum sustainable yield was estimated at approximately 1100 t, and recent annual catches have been well below this level: catch in 2013 was 103 t, and catches since 2007 have been below 500 t. As a result, the management unit is not considered to be recruitment overfished⁶. Catch and effort levels, which have been well below maximum sustainable yield and maximum sustainable effort estimates for more than 10 years, are unlikely to cause the management unit to become recruitment overfished.

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

East Coast Otter Trawl Fishery (Queensland) Red and Blue Endeavour Prawn management unit

Since 1998, there has been a general upward trend in the nominal catch rate⁷ for Endeavour Prawns (species combined, as they are not differentiated in commercial logbooks) in the East Coast Otter Trawl Fishery (Queensland). Effort in this fishery stabilised in 2007 following management changes, marine park closures and the economic impact of rising operational costs. The average annual catch rate for the past 5 years (2009 to 2013) was 69 kg per day, which is 55 per cent higher than the long-term average (1990 to 2006). Current harvest levels are significantly lower than levels in 2001, when an assessment concluded that Endeavour Prawns were fully exploited⁸. The above evidence indicates that the biomass of the management unit is unlikely to be recruitment overfished. The average annual commercial harvest of Endeavour Prawns in the past 5 years (2009 to 2013) was 540 t, which is half the long-term average of 1112 t for the years 1990 to 2006. The fishing effort associated with the 2013 catch (7924 days) was only 30 per cent of the long-term average of 25 939 fishing days. This level of fishing pressure (catch and effort) is unlikely to cause the management unit to become recruitment overfished.

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

Exmouth Gulf Prawn Managed Fishery (Western Australia) Blue Endeavour Prawn management unit

The Exmouth Gulf Prawn Managed Fishery (Western Australia) contributes the majority of the commercial landings of Blue Endeavour Prawns in Western Australia. There is no formal assessment for Blue Endeavour Prawn, which is a byproduct species whose distribution partly overlaps that of both Brown Tiger Prawn (Penaeus esculentus) and Western King Prawn (Melicertus latisulcatus); Blue Endeavour Prawns are caught when fishers are targeting these two species. Fishery-independent recruitment surveys of Brown Tiger Prawns and Western King Prawns (at standardised sites on separate key fishing grounds for the two species) also record the abundance of Endeavour Prawns on these grounds, providing an annual recruitment abundance index for this species. In 2013, the mean abundance index (catch rate) for Blue Endeavour Prawns on the Brown Tiger Prawn grounds of 9 kg/hour was below the 15 year mean (13 kg/hour), but within the range observed during these years (6–35 kg/hour). On the Western King Prawn grounds, the mean abundance index for Blue Endeavour Prawns of 7 kg/hour was also below the 6-year (2007 to 2012) mean of 14 kg/hour, but within the range observed during those years (2–38 kg/hour). There has been no declining trend in the fishery-independent survey catch rates over the periods sampled in either of these fishing grounds. As a result, the biomass of the management unit is not considered to be recruitment overfished.

With respect to fishing mortality, a target catch range is set at 120–300 t, based on historical catches between 1989 and 1998. Total catch in 2013 (85 t) was below the target catch range and below the average catch over the past 15 years (201 t)⁹. Low overall effort was expended in this fishery in 2013 (33 per cent less effort than the mean annual effort recorded between 2007 and 2011) due to low Brown Tiger Prawn stock abundance. The level of fishing effort on the Brown Tiger Prawn fishing grounds is normally around 60 per cent of the total annual effort; in 2013, it was only 25 per cent of total effort, and this reduced effort translated to a lower-than-average effort on Blue Endeavour Prawns. In the Exmouth Gulf Prawn Managed Fishery (Western Australia) management unit, the breeding biomass of Blue Endeavour Prawns is considered to be adequate because a significant portion of the breeding biomass is protected by the Brown Tiger Prawn spawning closures. As well, an additional portion of the Blue Endeavour Prawn biomass occurs inshore of the key fishing grounds for Brown Tiger Prawns, which are permanently closed. Hence, the current level of effort is unlikely to cause the management unit to become recruitment overfished.

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

Shark Bay Prawn Managed Fishery (Western Australia) Blue Endeavour Prawn management unit

Blue Endeavour Prawns are landed in low numbers in the Shark Bay Prawn Managed Fishery (Western Australia), since they are not the target species. Therefore, catch-and-effort data cannot be used to determine the status of the species in this fishery. In 2013, 15 t were reported as landed, compared with a mean landing during the past 15 years of 9 t. Insufficient information is available to confidently classify the status of this stock.

North Coast Prawn Managed Fisheries (Western Australia) Blue Endeavour Prawn management unit

Blue Endeavour Prawns are landed in low numbers in the North Coast Prawn Managed Fisheries (Western Australia), since they are not the target species. Therefore, catch-and-effort data cannot be used to determine the status of the species in these fisheries. Insufficient information is available to confidently classify the status of this stock.

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