Plebidonax deltoides

Plebidonax deltoides
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Veneroida
Superfamily:	Tellinoidea
Family:	Donacidae
Genus:	Plebidonax
Species:	P. deltoides
Binomial name
Plebidonax deltoides Lamarck, 1818

Plebidonax deltoides, known as pipi in the eastern Australian states, and Goolwa cockle in South Australia, is a small, edible saltwater clam or marine bivalve mollusc of the family Donacidae, endemic to Australia. It was previously known as Donax deltoides. Other names for the shellfish are Coorong cockle, ugari and eugarie.

Not to be confused with Paphies australis, a bivalve mollusc of the family Mesodesmatidae which is endemic to New Zealand. P. australis are also known as Pipi.

Life cycle

P. deltoides is an edible bivalve mollusc primarily found from the Eyre Peninsula to Kingston in South Australia and from Tasmania to Fraser Island in Queensland, with Younghusband Peninsula (Coorong Beach) in South Australian the site of the largest stock abundance in Australia where cockles make up 85% of the total biomass. The Sir Richard Peninsula (Goolwa Beach) and Younghusband Peninsula sand dunes are composed mainly of cockle shell sediments that have formed over the last 6,600 years.^[1]

P. deltoides cockles live on high-energy beaches, the juveniles in the intertidal and the adults in the subtidal zone. The cockles use a strong foot to bury into the sand to an average depth of 100 mm and feed by filtering phytoplankton from the water. Cockles mature at around one year of age and live from four to five years reaching a maximum size of 80 mm. They are dioecious serial broadcast spawners with spawning taking place over a long period of time peaking in the spring. Larvae drift as plankton for four to eight weeks in the coastal currents, often travelling large distances. Cockles need heavy surf to live as the surf concentrates the phytoplankton they feed on and increases the oxygen in the water. After periods of calm weather cockles begin to die off.^[2]

South Australia

The cockle was primarily used as bait in South Australia and it was not until Italian immigrants introduced vongole into restaurants in the 1990s that prices increased to where they became viable for commercial fishing. In 2004, regulations regarding the human consumption of cockles were included into the 1982 Fisheries Act and 32 licenses to harvest unlimited quantities were offered at $150,000 each. Imported Asian cockles have since largely replaced the Goolwa cockle as bait due to the lower cost.

The Cockle Train, the oldest steel-tracked railway in Australia, was built in 1854 from Port Elliot to Goolwa in order to transfer cargo from ocean going vessels to river boats. The train acquired it name due to its extensive use by colonists to collect cockles from beaches near the River Murray Mouth. Originally 11 km (6.8 mi) in length the line was extended to Victor Harbor in 1864 and is now a popular tourist attraction^[3]

Cockle controversy

During the 2008 season, due to surging demand and decreasing catches,^[4] a quota of 36,800 tonnes was introduced to manage the resource and commercial fishing was restricted to the Younghusband Peninsula, from a point 2 km east of the centre of the Murray Mouth to Kingston with recreational fishers banned from catching in these areas.^[5] The quota became controversial when it was found that 11 of the licenses, primarily multi generational local family fishing companies, were allocated only 1% of the quota each which would fail to cover their overheads while licenses supplying European markets were allocated up to 15% each. Two groups were formed to lobby Parliament to protect their interests, the Goolwa Cockle Working Group to represent the 10 large quota holders and the Southern Fisherman’s Association representing the small quotas. A politician supporting the small quota holders, Mitch Williams, claimed the government was deliberately trying to cut the number of people in the industry to possibly just five or six. The South Australian Legislative Council overturned the quotas on 23 June 2008 citing that "they tip the balance in favour of some fishers to the detriment of others". The Fisheries Minister, Rory McEwen threatened to re-promulgate the quotas and the Legislative Council has still to decide whether to disallow the regulation a second time if it is re-introduced. Due to the controversy it remains unknown whether fishermen would harvest as many cockles as they can as fast as they can until the total quota limit is reached or abide by their existing share allocation for the 2009 season.^[6]

2009 season

The November 2008 to May 2009 cockle season was closed after the fishery dramatically collapsed with more than 95% of the catch consisting of undersize juveniles. A Parliamentary enquiry is investigating Department of Primary Industries and Resources (PIRSA) for its failure to manage the fishery.^[7] An independent organisation, The Goolwa Pipi Harvesters Association was inaugurated in October 2009 and tasked with ensuring the sustainable development of the cockle retail and export industry. The initial quota for future seasons has been set at 600 tonnes annually, which is less than 2% of the 2008 quota.^[8]

2010 season

In October 2009 the government reduced the commercial quota to 300 tonnes and delayed the start of the 2010 season until December.^[9] Previously, recreational fishers had been requested to voluntarily limit their catches to 600 cockles per day however, a new recreational bag limit of 300 cockles per person was now enforceable by law. During the weekend of 9–10 January fisheries officials patrolled the Victor Harbor and Goolwa Beaches inspecting over 1000 recreational catches. Four fishers were fined for exceeding the bag limit and 10 for taking undersize cockles, 15,000 undersized cockles were returned to the water.^[10]

The Fisheries Department is currently investigating increasing the minimum cockle size from 35 millimetres (1.4 in) for the 2011 season.^[9]

2011 season

Due to a recovery of the cockle stocks, the State Government increased the commercial quota from 300 to 330 tonnes for the 2011 season, the start of which was voluntarily delayed until 1 December 2010.

Recreational fishers are now permitted to collect cockles on the Younghusband Peninsula between 28 Mile Beach and Kingston jetty. Commercial fishers who do not have a quota may take cockles for their own personal use as bait with a catch limit of 10 kg (22 lb) per day. It is illegal for commercial fishers without quotas to sell or trade cockles. The size limit was not increased but will instead be reviewed annually and the Goolwa cockle was officially renamed Pipi by PIRSA.^[11][12]

Victoria

Pipis were taken commercially from South Gippsland beaches in "masive quantities" until depletion of stocks in the 1970s reduced the fishery to recreational fishers. Recreational fishers were limited to five litres a person per day until this was reduced to two litres in 2009 due to concern over family groups collecting far in excess of regulations. Recreational fishers must have a fishing licence and are prohibited from using tools, Pipis must be dug up using hands or feet only.^[13][14]

New South Wales

A small commercial fishery with no size or catch limit has existed since the 1950s, harvesting from 100 to 450 tonnes per year in 1990s although this tonnage declined from 1997 due to contamination from algae biotoxins.^[15][16] Commercial harvesting in N.S.W. is by hand with 99% of the commercial catch being taken north of Sydney, with half from Stockton Beach. To share the resource and to minimise harvesting for sale on the black market, recreational fishers were allowed a bag limit of 50 "pipis" per day which are by law are only to be used for bait due to a number of bio-toxin poisoning cases. According to a 1999 survey, recreational fishers were estimated to take around 45 tonnes per year, 92% for consumption and 8% for bait.

In 2011 following concerns that the fishery may collapse the Department of Primary Industries implemented a partial season closure and minimum commercial size limit of 40 mm while recreational fishing has not been further constrained^[17]. The NSW Status Of Fisheries ^[18] lists the Pipi exploitation status as Uncertain.

References

1. ^ South Australia Goolwa Cockle Fishery pdf PIRSA July 2006
2. ^ Pipis Now and Forever State Government Department of Primary Industry, Victoria
3. ^ Cockle train, Victor Harbor State Library of South Australia
4. ^ From 2003 to 2008 the price of cockles increased from 80 cents per kg to $42:50 kg.
5. ^ SA mud cockle quota system begins ABC News 24 October 2008
6. ^ Warring the cockles of the heart The Independent Weekly 26 September 2008
7. ^ South Australia's cockle fishery collapses The Independent Weekly 4 April 2009
8. ^ New Pipi Chief The Advertiser 17 October 2009 Page 56
9. ^ ^{a b} Govt moves to protect Goolwa cockles ABC News 30 October 2009
10. ^ Move to protect Pipi from overfishing PIRSA January 2010
11. ^ Catch limits Pipi PIRSA
12. ^ Cockle stocks slowly recovering at Goolwa Adelaidenow 28 October 2010
13. ^ Peeved over pipi pilgrims The Age March 6, 2010
14. ^ Reduced pipi catch limit State Government Department of Primary Industry, Victoria
15. ^ NSW Fisheries
16. ^ Pipis disappear from Hunter beaches ABC News Jun 21, 2011
17. ^ Partial closure to save dwindling pipi stocks ABC June 9, 2011
18. ^ [http://www.dpi.nsw.gov.au/research/areas/systems-research/wild-fisheries/outputs/2010/1797/StatusOfFisheriesResourcesNSW2008-09.pdf

External links

• Australian Government Department of Environment
• [http://www.vliz.be/imisdocs/publications/54777.pdf A comparison between the commercial and recreational

fisheries of the surf clam, Donax deltoides]

• WikiSpecies