Researchers dive into their catch on the banks of the Harvey River hoping to see marron migration signs

A bucket full of yabbies, a couple of cobblers, and even an elusive mudskipper were just some of the underwater creatures pulled from the Harvey River last week.

On Friday, the Harvey River Restoration Taskforce and researchers from Murdoch University’s Harry Butler Institute returned to the waterway after setting traps the night before with hopes of finding some marron.

The team has been conducting research in the river since 2021 in an effort to restore the declining biodiversity of the waterway as part of the HRRT’s project Marron, More Than A Meal — Revive Our Rivers.

The push to bolster the river’s natural habitat saw the team adding logs to the waterway in early 2021, which showed signs of success after two adult marron were found at the site in spring that year.

Earlier this year, the researchers saw more reason to be excited after a juvenile marron was found in the waterway, showing the species was starting to breed in the area.

This month, the team hoped to find more marron success, but came up empty-handed.

They did find various other creatures in the water which had Murdoch University’s Associate Professor Stephen Beatty optimistic their efforts were bearing fruit.

“We know they are breeding, and we know they like these restoration sites, so that’s a really good thing,” he said.

“We monitor the native fish and they haven’t really changed much around the logs compared to upstream control sites, but the macro invertebrates — all the bugs in the water which are really important for the food web and an indicator of aquatic health — have increased significantly.”

He said when adding the logs to the river the team hoped the current would create deeper pockets along the river’s journey, able to better withstand the hotter and drier seasons brought on by climate change.

“It hasn’t really happened yet, so we’re going to rethink that for future projects, but in terms of diversity of habitat, it has certainly increased,” Dr Beatty said.

“Because we should be doing everything we can to protect and restore these waterways.”