NZ Pilchard Guide: (Sardinops sagax) – Bait Fish Facts

NZ Pilchard Guide: Sardinops sagax

Bait Fish Facts

Pilchard is also called Mohimohi, Sardine, and Picton herring

By Allan Burgess

Looking for the ultimate New Zealand baitfish that consistently brings home snapper and kingfish? The New Zealand pilchard Sardinops sagax, locally known as mohimohi or Picton herring, is a powerhouse in our coastal waters. Whether you are rigging them up whole for big predators or trying to identify that flash of silver and blue in your berley trail, understanding this species is key to local fishing success. This guide covers everything from identifying their distinct spots to how they fuel the entire marine food chain.

Identification

This small fish averages 10 to 20cm in length but can reach 25cm. It is blue above, greenish on the sides, and silver underneath. There is a row of between 8 and 14 black spots down each side that distinguishes the pilchard from other small pelagic fishes. The body of the pilchard is almost round. There don’t appear to be any teeth, which suits the pilchard as it feeds mostly on plankton.

The late David H. Graham, in A Treasury of New Zealand Fishes, describes fishing off Cape Saunders, Otago, and seeing the following incredible sight. “As far as the eye could see, these small fish were swimming in a northern direction, accompanied by flocks of predatory birds, such as Mutton Birds (sooty shearwaters), Cape Pigeons, Gulls and others. They were so abundant that when the launch was moving, it seemed as though we were speeding over a floor of silver…” Such was the vastness of the pilchard schools seen in Otago in the 1930s.

Graham found that although pilchards are a pelagic (surface) fish, he often found them in the stomachs of commercially caught fish that had been caught in very deep water, over 80 fathoms down. He couldn’t say whether the pilchards had dived to that depth or if the deep-water predators had come up to the surface to catch them.

Pilchards also come close to shore, and also into harbours where they are preyed upon by red cod, kahawai and many other species.

Sometimes large numbers of pilchards were washed ashore in Otago and collected by residents who considered them good eating. Graham also reported that in 1900-1902, huge numbers were washed ashore off Oamaru and sold to retailers at 3 or 4 shillings a kerosene case. They retailed at 3d a dozen fresh and 4d a dozen smoked, and were much in demand.

Spawning and Age by Length

• Spawning takes place in late spring and early summer in the South Island, but all year roundfast-growing a  in the North Island. Each female releases between 30,000 and 50,000 eggs in a season. Collins Guide To The Sea Fishes of New Zealand
                
  
• According to readings of the otolith bones in the head, the pilchard is a relatively fast-growing and short-lived species. They reach a maximum length of about 25 cm, and perhaps 9 years, but the main size range is of 10−20 cm fish, 2 to 6 years old. Maturity is probably reached at 2 years of age. fs.fish.govt.nz/Doc/21767/69_PIL_09

Distribution Around New Zealand

Pilchards are a schooling pelagic species found in surface inshore waters around the North Island and the upper South Island. They are also a common and popular baitfish caught around southern Australia

Pilchards were caught in the Marlborough Sounds from 1939 and canned during the war years to be sent over seas for the armed forces. However they have never been caught commercially on a large scale in New Zealand. Total annual landings by commercial fishing boats increased steadily from 1990 as the fishery developed in northeastern NZ waters, reaching over 1200 t in 1999−2000.

Recreational anglers catch pilchards from time to time when fishing from wharves or when netting for other baitfish like mullet.

Pilchards form compact schools often referred to by anglers as ‘meatballs,’ particularly during summer. These meatballs are heavily preyed upon by larger fishes, seabirds, and marine mammals and are thought to form an important part of the diet for many species. Sport anglers can become very excited by such sightings as there can be sort-after predatory fish feeding on them including snapper, kingfish, tuna, and even marlin.  

What do pilchards eat?

• Pilchards eat small crustaceans, particularly in the larval stages, including crabs, krill, and shrimps, together with microscopic marine algae.
  
  
• It could be that the abundance or otherwise of pilchards is affected by the annual fluctuations of their food supply.
  
  

Pilchards are preyed upon by barracouta, kahawai and many other species. Graham reports large shoals of pilchards around Cape Saunders being set upon by large shoals of the barracouta. The barracouta were forcing the pilchards onto the rocky coastline. They were so abundant that it was no trouble to dip a hand net into the sea and scoop up a full net.

Even in June and October off Cape Saunders, and as far as Puketeraki, shoals of pilchards were seen a mile wide and almost continuous in length. All the while, the pilchards were bubbling on the surface of the sea as they attempted to evade the barracouta and other fish that were pursuing and devouring them. Barracouta caught at such times were found to contain three or four dozen pilchards in their stomachs.

Fish species known to prey on pilchards

The vast schools of pilchards are preyed upon by a surprisingly large number of other species. Graham found the following species to have been feeding on pilchards: sevengill shark, tope, smoothhound, spiny dogfish, thresher shark, porbeagle shark, javelin-fish, whip-tail, hake, red cod, megrim, lemon sole, common sole, warehou, groper, kahawai, yellowtail kingfish, snapper, mackerel, and red gurnard. Tope, Smoothhound, Spiny dogfish, and powerful open-ocean predators like bluefin tuna heavily rely on pilchards. No doubt there are many others!

Tips for buying and using frozen Pilchards

Taxonomy of pilchards changed after 1996 DNA studies

The name change from Sardinops neopilchardus to Sardinops sagax occurred because taxonomists and marine biologists determined that the pilchards and sardines previously thought to be separate species are actually part of a single, globally widespread species.

References

Collins Guide To The Sea Fishes of New Zealand by Tony Ayling, illustrated by Geoffrey J. Cox.

The Fishes of New Zealand – Edited by Clive C Roberts, Andrew L Stewart, and Carl D Struthers.

Sea Anglers Fishes of New Zealand – By Arthur W. Parrott.

fs.fish.govt.nz/Doc/21767/69_PIL_09