Sowing seeds for snapper habitat

January 7, 2019 by Teresa Belcher, Particle

In an Australian first, recreational fishers will have a crack at restoring the lost seagrass meadows of Cockburn Sound.

Hundreds of recreational fishers have volunteered to release one million seagrass seeds into the sea as part of the Seeds for Snapper project.

Recfishwest, OzFish and the University of Western Australia have teamed up to reseed Cockburn Sound with seagrass that has been lost over the past 60 years.

Seagrass in danger

OzFish Unlimited's Andrew Matthews says Cockburn Sound has lost around 80% of its original 4000-hectare habitat.

There's now only 900 hectares left.

"That's a massive 2600 football fields worth of seagrass habitat lost over the past few decades," Andrew says.

He says the seagrass meadows of Cockburn Sound are well recognised as critical foraging and nursery grounds for pink snapper.

Other species affected by the seagrass loss include King George whiting, squid, garfish and blue swimmer crabs—all popular recreational fishing species.

And after Shark Bay, Cockburn Sound is WA's second-largest pink snapper spawning ground.

So why has the seagrass been lost?

Read more at: 

Scientists have found a shark that can survive on a mostly vegetable diet

Bonnethead species is able to survive on a diet of plants, despite reputation as a predator

Josh Gabbatiss Science Correspondent 

Bonnethead sharks were experimentally fed with a diet of 90 per cent seagrass, which they were able to digest YouTube/Science Magazine

A species of shark that is able to survive on a diet consisting largely of plants, has been identified by scientists. 

Despite their reputation as carnivores Bonnethead sharks were able to survive when they were fed a diet of seagrass, a plant that grows on the ocean floor.

The study, led by Samantha Leigh, a doctoral candidate at the University of California, Irvine, built on research conducted 10-years ago, which examined the creatures stomach contents.

That study revealed large quantities of seagrass. In some young sharks, scientists found over 60 per cent of the material in their stomachs was plant-based.

In order to establish whether sharks were intentionally feeding on plant material, or whether it was accidental, Ms Leigh and her colleagues fed captive sharks a 90 per cent seagrass diet for three weeks. The final 10 per cent was made up of squid. 

Continued  

Scientists have found a shark that can survive on a mostly vegetable diet

Bonnethead species is able to survive on a diet of plants, despite reputation as a predator

Josh Gabbatiss Science Correspondent 

Bonnethead sharks were experimentally fed with a diet of 90 per cent seagrass, which they were able to digest YouTube/Science Magazine

A species of shark that is able to survive on a diet consisting largely of plants, has been identified by scientists. 

Despite their reputation as carnivores Bonnethead sharks were able to survive when they were fed a diet of seagrass, a plant that grows on the ocean floor.

The study, led by Samantha Leigh, a doctoral candidate at the University of California, Irvine, built on research conducted 10-years ago, which examined the creatures stomach contents.

That study revealed large quantities of seagrass. In some young sharks, scientists found over 60 per cent of the material in their stomachs was plant-based.

In order to establish whether sharks were intentionally feeding on plant material, or whether it was accidental, Ms Leigh and her colleagues fed captive sharks a 90 per cent seagrass diet for three weeks. The final 10 per cent was made up of squid. 

Continued  

Call for more protection for seagrass meadows

By Helen BriggsBBC Environment correspondent

27 June 2015 

Seagrasses - the underwater plants that act as nursery grounds for young fish - need more protection, say scientists.

Monitoring of seagrass meadows off the North Wales coast found areas damaged by the likes of boat moorings, anchors and vehicles crossing at low tide had reduced value to the ecosystem.

Fewer species of fish were found where seagrass was degraded, according to research published in PeerJ journal.

The seagrass studied was near the village of Porthdinllaen, in Gwynedd.

Researchers at Swansea University studied areas with both high and low cover over a 28-hectare stretch of sea bed.

They also sampled fish living in the underwater meadows of flowering plants.

There was a three-fold reduction in the diversity of fish species and invertebrates, such as prawns, shrimp, juvenile cod and juvenile plaice, in areas of low cover, said lead researcher Dr Richard Unsworth.

Continued ...

Seagrass fish feeding grounds 'lost like rain forests'

12 August 2014 Last updated at 08:12

Seagrass is found just off the shoreline so is vulnerable to pollution and disturbance by marine anchors

Underwater fish "meadows" are being lost at the same rate as the Amazon rain forests, researchers have warned.

Seagrass is a key habitat for feeding and sheltering young fish, including plaice, haddock and pollock.

But every hour an area the size of two football pitches is destroyed.

Scientists from Swansea University believe the habitats need to be protected otherwise fishing stocks could be affected.

Lead researcher Dr Richard Unsworth says more sensitive boat mooring could help

"The rate of loss is equal to that occurring in tropical rainforests and on coral reefs yet it receives a fraction of the attention," said Dr Richard Unsworth, lead researcher.

"If you're a small fish, like a juvenile cod, then you need food and shelter. Seagrass meadows provide both."

Continued ...

Sea otter return boosts ailing seagrass in California

The return of sea otters to an estuary on the central Californian coast has significantly improved the health of seagrass, new research has found.

Seagrass was deemed to be heading for extinction in this region before the otters returned.

But scientists found that the animals triggered a chain reaction of events that boosted the water-dwelling plants.

The research is published in the journal, PNAS.

The urbanisation of California has led to a huge increase in nutrient pollution in coastal waters, from increasing use of nitrogen-rich fertilizers.

“It's almost like these sea otters are fighting the effects of poor water quality, ”Brent Hughes University of California

This is said to be the reason for the dieback of seagrass, which has also been declining worldwide.

This research suggests that the hunting to near-extinction of sea otters in the late 19th and early 20th Century may have exacerbated the problem, and conversely that their reintroduction is helping revive ailing seagrass populations, even in the face of hugely nutrient-rich water.

continued