{"id":352467,"date":"2025-12-16T20:44:11","date_gmt":"2025-12-16T20:44:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/au\/352467\/"},"modified":"2025-12-16T20:44:11","modified_gmt":"2025-12-16T20:44:11","slug":"mary-river-cod-thriving-in-brisbane-river-catchment-century-after-relative-went-extinct","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/au\/352467\/","title":{"rendered":"Mary River cod thriving in Brisbane River catchment, century after relative went extinct"},"content":{"rendered":"

A major, but endangered, apex predator has been reeled back to a south-east Queensland river catchment a century after its close relative became extinct in the area.<\/p>\n

The Brisbane River catchment, which stretches from Brisbane to Ipswich and the Somerset region, used to be home to the Brisbane River cod.<\/p>\n

Now, its close relative, the endangered Mary River cod, is thriving in the waters, five years after thousands of fingerlings were introduced.\u00a0<\/p>\n

Ecologist and Ipswich City Council waterway health officer Jack McCann said the Brisbane River cod went extinct sometime in the 1920s or 1930s.<\/p>\n

\"The<\/p>\n

A Mary River cod, a close relative of the Brisbane River cod.\u00a0 (ABC Rural: Jennifer Nichols)<\/p>\n

“Early settlers of the region knew this fish was quite easy to catch and quite a large species. They grew up to 20 kilograms, maybe even bigger, and were up to a metre in length,” he said.<\/p>\n

“There was a lot of them around and they were a great source of protein for early settlers.<\/p>\n

“They were also used as fodder in piggeries and things like that.”<\/p>\n

Habitat decline<\/p>\n

Mr McCann said along with overfishing, habitat destruction led to the species’ decline.<\/p>\n

“There was a lot of logging, timber harvesting from our riparian zones and clearing,” he said.<\/p>\n

Their disappearance led to the river losing one of its key apex predators.<\/p>\n

“They played a really important role in managing the food web in waterways,” he said.<\/p>\n

“Here in Ipswich, where pest fish can be quite a problem, they can help mediate pest fish numbers.<\/p>\n

“They help keep the balance of keeping other native fish communities in place.”\"a<\/p>\n

The Mary River cod has been released in Ipswich and researchers are regularly counting how many there are.\u00a0 (Supplied: Ipswich City Council)<\/p>\n

Apex predator returns<\/p>\n

But 100 years on, the Mary River cod has been reintroduced to the catchment and Mr McCann said it was doing well.<\/p>\n

It’s been subject to a species recovery plan in its native environment, which runs from the Sunshine Coast to Hervey Bay.<\/p>\n

How gelignite blasts decimated the Mary River cod<\/a><\/p>\n

Mary River cod were fished to the brink of extinction, their habitat destroyed, even blasted with gelignite, but a recovery plan is being updated.<\/p>\n

Its endangered status was one of the key reasons the controversial Traveston Crossing Dam project, near Gympie, was scrapped.<\/p>\n

“We’re not exactly sure if [the Brisbane River cod is] the exact same fish as the Mary River cod. We don’t have any genetic samples of the Brisbane River cod, but there’s a chance and potentially even a likelihood they were the same fish genetically,” he said.<\/p>\n

Since 2020, about 30,000 Mary River cod fingerlings have been released into the catchment as part of a collaboration between the Ipswich, Brisbane and Somerset councils, along with local fish stocking associations and state government organisations.<\/p>\n

It’s also involved the construction of a fish ladder at a weir on the Bremer River, so the species can migrate to various parts of the river more easily.<\/p>\n

In September, a Mary River cod was found using that fishway for the first time.<\/p>\n

\"A<\/p>\n

A fish ladder, or fishway, was built on a Bremer River weir, to help the Mary River cod swim upstream. (Supplied: Ipswich City Council)<\/p>\n

“This is the first formal recapture, and we’re about to put a tag in that fish so we can now monitor its movement and growth moving forward,” Mr McCann said.<\/p>\n

“That’s a great result \u2026 something that’s been years in the making.”‘Real hope’ for future<\/p>\n

Somerset and Wivenhoe Fish Stocking Association president Garry Fitzgerald said it was “incredibly rewarding” to see fingerlings grow into adults.<\/p>\n

“This gives real hope for the species’ recovery,” he said.<\/p>\n

\"A<\/p>\n

Somerset and Wivenhoe Fish Stocking Association members have been tagging and scanning Mary River Cod in the Brisbane River catchment.\u00a0 (Supplied: Ipswich City Council)<\/p>\n

Mr McCann said there was “some evidence” the species was also spawning in the catchment for the first time.<\/p>\n

“We haven’t detected any naturally spawned juveniles at this point, but that’s something that’s sort of the next phase of the recovery plan,” he said.<\/p>\n

Mr McCann said that would involve restoring more riparian habitat, which could benefit other animals that call the catchment home, such as platypus.<\/p>\n

The cod is protected, so any local fishers who catch one need to release it unharmed.<\/p>\n","protected":false},"excerpt":{"rendered":"A major, but endangered, apex predator has been reeled back to a south-east Queensland river catchment a century…\n","protected":false},"author":2,"featured_media":352468,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[64,63,193608,193607,193603,75,193605,193604,8168,6349,192902,193606,128],"class_list":{"0":"post-352467","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-au","9":"tag-australia","10":"tag-brisbane-river-catchment","11":"tag-brisbane-river-cod","12":"tag-endangered-animal","13":"tag-environment","14":"tag-exctinct-animal","15":"tag-exctinction","16":"tag-fish","17":"tag-fishing","18":"tag-mary-river-cod","19":"tag-murray-cod","20":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/352467","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=352467"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/352467\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/352468"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=352467"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=352467"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=352467"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}