InvestSMART

Spare a thought for poor jack mackerel

THE marine food chain goes something like this: sun, phytoplankton, zooplankton, shrimps, sprats, forage and demersal fish, pelagics and apex predators. Remove any one link and the whole web collapses.
By · 12 Feb 2012
By ·
12 Feb 2012
comments Comments
THE marine food chain goes something like this: sun, phytoplankton, zooplankton, shrimps, sprats, forage and demersal fish, pelagics and apex predators. Remove any one link and the whole web collapses.

It's against this premise we can thank our lucky stars the foreign-owned factory ships that eyed our blue mackerel fisheries a few years back were sent packing. Consider, on the other hand, the jack mackerel fishery in the Southern Pacific.

A similar fish to our small mackerel species, the jack mackerel has been plundered to the point of collapse.

Where stocks were estimated at 30 million tonnes two decades ago, they have been reduced to 3 million tonnes today. A University of British Columbia oceanographer, Daniel Pauly likened the overfishing to the last of the buffaloes. "When they're gone, everything will be gone ... this is the closing of the frontier," he said.

Factory ships from around the world have descended on the waters off Chile and Peru for years and unleashed their massive nets. While a staple of some cultures, jack mackerel mainly ends up as fishmeal to sate the aquaculture industry.

The largest of the factory ships, the Russian-flagged Lafayette, a rebuilt 50,000-tonne oil tanker, is longer than two football fields. The mother ship sucks fish from its fleet of super trawlers using giant hoses. The mackerel, as many as 1500 tonnes a day, are frozen in blocks.

When the ship set sail for the Southern Pacific at the end of November, its target was to catch 300,000 tonnes of fish. That's twice what Hong Kong consumes in a year.

Meanwhile, delegates from 20 countries have gathered to try to stop the plunder. Australia and New Zealand have initiated a South Pacific Regional Fisheries Management Organisation to apply unilateral leverage on the renegade factory ships.

Thankfully, our fisheries managers had the good sense to prevent factory fishing of our blue or slimy mackerel stocks after a trial some year ago.

Game fishers hunting around the slimy mackerel schools off Port Stephens have enjoyed world-class marlin fishing. The stellar fishing is directly attributable to the abundance of baitfish.

Charter skipper Scott Thorrington said it was still going "nuts" when we spoke to him on Friday.

"There's bait everywhere, oodles of slimy mackerel, and they're the key to the fishery. You can see the marlin rounding up the bait and smashing it," Thorrington said from behind the wheel of his boat Flying Fisher.

Then our call was cut short by the wail of a fishing reel and yet another marlin hook-up.

In last weekend's Lake Macquarie Billfish Bonanza, Thorrington tagged an incredible 17 marlin using 24 kilogram tackle. However, he ended up playing bridesmaid to winning boat Diversion whose crew tagged 17 marlin using lighter 15 kilogram tackle.

There are plenty of fish for the frying back inshore.

Broken Bay and Pittwater are littered with surface fish including Australian salmon, bonito and frigate mackerel. Flathead are lurking beneath the feeding schools and bream are starting to gather.

The rain should help the school jewfish in the Hawkesbury. Blue swimmer crabs are hot one day and skulking the next, but there are big whiting over the flats in Brisbane Water.

Harbour guide Craig McGill conveys another amazing shark story. An angler was fighting an Australian salmon from his boat anchored off Clifton Gardens when a big bull shark launched from the water, grabbed the jumping fish, and landed back down with an almighty splash.

Otherwise, the action includes kingfish to 80 centimetres, abundant salmon, tailor, bonito and frigate mackerel. The flathead are lining up over the flats in North Harbour.

Southside guide Scotty Lyons has been scoring plenty of salmon, tailor and bonito in Botany Bay.

Offshore, Lyons and crew landed an impressive bag of morwong reminiscent of the kind of catches my grandfather made in the good old days.

Google News
Follow us on Google News
Go to Google News, then click "Follow" button to add us.
Share this article and show your support
Free Membership
Free Membership
InvestSMART
InvestSMART
Keep on reading more articles from InvestSMART. See more articles
Join the conversation
Join the conversation...
There are comments posted so far. Join the conversation, please login or Sign up.

Frequently Asked Questions about this Article…

The article says overfishing by large factory ships and their fleets of super trawlers has driven jack mackerel stocks down. These factory vessels used massive nets and a mother ship system to harvest huge volumes, reducing estimated stocks from about 30 million tonnes two decades ago to roughly 3 million tonnes today.

The piece highlights the Russian‑flagged Lafayette as an example: a rebuilt 50,000‑tonne tanker longer than two football fields that acts as a mother ship. Its fleet can suck fish aboard using giant hoses, freezing as much as 1,500 tonnes a day, and the Lafayette reportedly set a target of 300,000 tonnes on a recent voyage.

The article notes jack mackerel is mainly processed into fishmeal for the aquaculture industry, so steep stock declines could tighten the supply of a key raw material for fish farming. More broadly, the piece warns that removing forage fish from the marine food chain can destabilise ecosystems, which has implications for industries tied to healthy fisheries and coastal economies.

Delegates from about 20 countries have gathered to try to stop the overfishing, and Australia and New Zealand have initiated a South Pacific Regional Fisheries Management Organisation to exert unilateral leverage on the renegade factory ships, according to the article.

The article opens with a simple marine food‑chain reminder—sun → phytoplankton → zooplankton → small forage fish → larger predators—and quotes UBC oceanographer Daniel Pauly likening the overfishing to the ‘last of the buffaloes,’ warning that when these forage fish are gone, broader ecosystems can collapse.

The article praises Australian fisheries managers for preventing factory fishing of blue and slimy mackerel after a trial, suggesting that this protection helped maintain baitfish abundance that supports strong local recreational and game fishing.

The article describes world‑class marlin fishing off Port Stephens driven by abundant slimy mackerel baitfish, strong catches in the Lake Macquarie Billfish Bonanza, and plenty of inshore surface fish such as Australian salmon, bonito, frigate mackerel, flathead, bream, kingfish and whiting in various local spots.

Based on the article, investors may want to monitor international fisheries management efforts (like the South Pacific Regional Fisheries Management Organisation), reports on forage fish stock levels (jack mackerel and mackerel species), and regulatory moves that limit factory fishing—because these factors influence fishmeal supply for aquaculture and the health of commercial and recreational fisheries.