Gould’s Squid Nototodarus gouldi

Phil Sahlqvist^a and Jeremy Lyle^b

Table 1: Stock status determination for Gould's Squid

Jurisdiction	Commonwealth, New South Wales, Tasmania, Victoria
Stock	Southern Australian (CTS, GABTS, SESSF, SF, SSJF)
Stock status
Stock status	Sustainable
Indicators	Catch rates, total catch

CTS = Commonwealth Trawl Sector; GABTS = Great Australian Bight Trawl Sector (Commonwealth); SESSF = Southern and Eastern Scalefish and Shark Fishery (Commonwealth); SF = Scalefish Fishery (Tasmania); SSJF = Southern Squid Jig Fishery (Commonwealth)

Stock Structure

There is assumed to be a single biological stock of Gould's Squid throughout southern Australian waters. Genetic studies are limited, but support this hypothesis¹. Analysis of elements in statoliths has also shown that some Gould's Squid caught in Victorian waters and the Great Australian Bight were hatched in various regions off southern Australia².

Stock Status

Southern Australian biological stock

No formal stock assessment is available for the Gould's Squid biological stock in Australia. Gould's Squid is short lived (<1 year), spawns multiple times during its life, and displays highly variable growth and size/age at maturity¹. These characteristics mean that it can rapidly increase its numbers during favourable environmental conditions and is therefore less susceptible to overfishing than longer lived species. The total fishing effort in the Southern Squid Jig Fishery (Commonwealth) has decreased markedly since the peak fishing effort of 15 600 jig hours in 1997, to a historical low of 617 jig hours in 2010. Fishing effort from trawl fisheries has also substantially decreased since 2000. The fall in fishing effort levels is a result of economic factors (see below, under 'Catch explanation'), rather than long-term changes in Gould's Squid catch rates. This evidence indicates that the current level of fishing mortality is unlikely to cause the biological stock to become recruitment overfished.

The peak historical catch of Gould's Squid from south-eastern Australian waters (7914 tonnes [t]) was taken by foreign jig vessels in 1979–80. This supports the case that the biological stock can support a much higher annual harvest than the Australian jig and trawl vessels have removed in any season. The nominal catch rate (kg/hr) from Commonwealth Trawl Sector vessels has been stable over the past 15 years, which indicates that the biomass has not been severely depleted by fishing. This conclusion is further supported by preliminary analysis of biological stock depletion off western Victoria by foreign fishing during the early 1980s, and for the domestic fishery during 1995–2006. Testing of depletion estimation methods indicated that overfishing had not occurred in past seasons by jigging or demersal trawling³. This was because the proportion of squid escaping harvest was estimated at 30 per cent or higher in all years in the main fishing area. This evidence indicates that the biomass of this biological stock is unlikely to be recruitment overfished.

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

Table 2: Gould's Squid biology¹

Longevity and maximum size	1 year; 35–40 cm ML
Maturity (50%)	Variable (171–275 days); 17–30 cm ML

ML = mantle length

Figure 1: Distribution of reported commercial catch of Gould's Squid in Australian waters, 2010

Main features and statistics for Gould’s Squid stocks/fisheries in Australia in 2010

Gould's Squid is targeted using automatic squid jigging machines. Smaller vessels may use hand jigging methods⁴. Trawl vessels catch squid throughout the Southern and Eastern Scalefish and Shark Fishery (Commonwealth), but jig vessels tend to concentrate on the more reliable fishing grounds off western and central Victoria and south-eastern Tasmania.
A range of input and output controls have been implemented across the fisheries that target Gould's Squid:
- Input controls include limited entry licensing for all fisheries and a cap on available fishing effort, which is controlled by total allowable effort limits (Southern Squid Jig Fishery only). In the Southern Squid Jig Fishery (Commonwealth), catch is not limited unless trigger catch limits5 are exceeded and subsequent assessment of stock status requires fishing to be halted (see below, under 'Catch explanation').
- Output controls include bag limits or possession limits on recreational catch of squid species in all states. Licences are required in some states unless an exemption applies.
In 2010, 7 vessels reported Gould's Squid catch in the Southern Squid Jig Fishery (Commonwealth), 50 vessels in the Commonwealth Trawl Sector and 4 vessels in the Great Australian Bight Trawl Sector (Commonwealth). In the Scalefish Fishery (Tasmania), 18 automatic jig licences were issued in 2010, but only 4 vessels reported Gould's Squid catch.
Total commercial catch of Gould's Squid in 2010 was 623 t, comprising 483 t in the Commonwealth Trawl Sector, 62 t in the Southern Squid Jig Fishery (Commonwealth), 18 t in the Great Australian Bight Trawl Sector (Commonwealth) and 60 t in the Scalefish Fishery (Tasmania). An estimate of total recreational catch is not available because Gould's Squid was reported within a general squid–cuttlefish group in the most recent national survey; however, the recreational catch is expected to be much less than the commercial catch. The recreational catch of Gould's Squid for Tasmania was around 37 t in 2007–08⁶. Indigenous catch is unknown.

Figure 2b) nominal catch rate of Gould's Squid in the Southern Squid Jig Fishery (Commonwealth), and Commonwealth Trawl Sector

Figure 2: a) Commercial catch of Gould's Squid in Australian waters, 1990–2010 (calendar year);
b) nominal catch rate of Gould's Squid in the Southern Squid Jig Fishery (Commonwealth), and Commonwealth Trawl Sector, 1996–2010 (calendar year)

Catch Explanation

The annual catch history for Gould's Squid shows great variability between years (see Figure 2a). Most of this variability is in the Southern Squid Jig Fishery (Commonwealth) catch, which first dominated domestic landings in 1995 and reached a peak of 2001 t in 1997. In 1999 and 2007, the Scalefish Fishery (Tasmania) also contributed much of the total catch. Since 2005, the Southern Squid Jig Fishery (Commonwealth) component of the catch has decreased significantly, as a result of unreliable catch rates (see Figure 2b), the length of the season on the main fishing grounds due to the availability of squid and poor economic conditions. High costs of fishing, and low global and domestic prices for squid (and thus low profitability), are the main economic factors driving low effort in the fishery.

Effects of fishing on the marine environment

Jig fishing methods are highly selective. An ecological risk assessment of the Southern Squid Jig Fishery (Commonwealth) was completed in 2006 and did not identify any indicators of threat to the environment from jig fishing. The trawling method used in the Commonwealth Trawl Sector and Great Australian Bight Trawl Sector (Commonwealth) has potential for interactions with threatened, endangered and protected species, particularly seals, seabirds, and seahorses and pipefishes (syngnathids). These fisheries have in place bycatch and discarding workplans or bycatch catch triggers to reduce these interactions and environmental impacts.

Environmental effects on Gould’s Squid

The Gould's Squid biological stock can vary significantly in abundance between years, and environmental conditions are widely acknowledged as influences on larval and juvenile survival. Environmental factors such as sea temperature and nutrient concentrations have also been linked to growth rate, particularly for females¹.

^a Australian Bureau of Agricultural and Resource Economics and Sciences
^b Institute for Marine and Antarctic Studies, Tasmania