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Re: Shell bed reefs
Posted: Wed Dec 04, 2019 7:19 pm
by CarlG
hornet wrote: ↑Tue Dec 03, 2019 2:28 pm
re-tyred wrote: ↑Sun Dec 01, 2019 12:08 pm
https://www.abc.net.au/news/2019-11-09/ ... a/11681904
This is needed in the Gippsland lakes and other estuaries around Vic. It would be particularly beneficial in the deep sand channels between Metung and Lakes Entrance.
There used to be many areas in the lake that had mussel beds on the bottom, they along with the seagrass are almost gone.
Any thoughts or data on why the disappearance of mussel and weed ?
Bottom trawling for demersal species would have nothing to do with it of course.
Re: Shell bed reefs
Posted: Wed Dec 04, 2019 10:17 pm
by Tackleberry
CarlG wrote: ↑Wed Dec 04, 2019 7:19 pm
hornet wrote: ↑Tue Dec 03, 2019 2:28 pm
re-tyred wrote: ↑Sun Dec 01, 2019 12:08 pm
https://www.abc.net.au/news/2019-11-09/ ... a/11681904
This is needed in the Gippsland lakes and other estuaries around Vic. It would be particularly beneficial in the deep sand channels between Metung and Lakes Entrance.
There used to be many areas in the lake that had mussel beds on the bottom, they along with the seagrass are almost gone.
Any thoughts or data on why the disappearance of mussel and weed ?
Bottom trawling for demersal species would have nothing to do with it of course.
Yes you are right that has nothing to do with it ......
Re: Shell bed reefs
Posted: Wed Dec 04, 2019 11:36 pm
by seedy
Landline on ABC did a segment on this a little while ago .... I will try to find it .
Re: Shell bed reefs
Posted: Thu Dec 05, 2019 12:05 am
by seedy
https://youtu.be/_vIhYd9WsSc
Could not find the landline segment , but found this . Pretty sure its the same footage and info .
Re: Shell bed reefs
Posted: Thu Dec 05, 2019 4:34 am
by re-tyred
There is no bottom trawling in the Gippsland lakes or any other Vic estuary. Only place there was ever "trawling" is scallop dredging in PPB. It certainly destroyed the shell bed reefs there. That is why the project started. I am saying it should be done to enhance the Gippsland lakes.
As the Gippsland lakes have become an almost ocean water estuary, due to us all using most of the fresh that used to flow down the rivers. It is time to enhance the system pro actively. The lower end of the lake will support KGW and possibly gummy and snapper if the habitat is there. We already have school whiting and some KGW on the couple of small areas that have this type of bottom.
Re: Shell bed reefs
Posted: Thu Dec 05, 2019 4:47 am
by re-tyred
Bottom trawling for fish only occurs in water deeper than 100mtrs off the coast of Vic. The other types of fishing are. Prawn trawling on the beach off lakes. If prawn gear was towed over a shell bed it would destroy the net. Other fishing is danish seineing, again can't be done on anything other than mud! Sand type bottom. There is also crayfishing , shark netting and octopus potting. None of these change the bottom structure. All this has nothing to do with the topic.
Re: Shell bed reefs
Posted: Thu Dec 05, 2019 5:00 am
by re-tyred
Shell bed reefs do occur off the coast of Vic. In fact the majority of areas that we rec fish for snapper are on or close to this sort of bottom. Nearly all of the snapper grounds from lakes to corner inlet have this type of bottom.
Just to repeat myself, I am saying , it would be a good way enhance the Gippsland lakes fishing.
Re: Shell bed reefs
Posted: Thu Dec 05, 2019 8:47 am
by CarlG
re-tyred wrote: ↑Thu Dec 05, 2019 4:34 am
There is no bottom trawling in the Gippsland lakes or any other Vic estuary. Only place there was ever "trawling" is scallop dredging in PPB. It certainly destroyed the shell bed reefs there. That is why the project started. I am saying it should be done to enhance the Gippsland lakes.
As the Gippsland lakes have become an almost ocean water estuary, due to us all using most of the fresh that used to flow down the rivers. It is time to enhance the system pro actively. The lower end of the lake will support KGW and possibly gummy and snapper if the habitat is there. We already have school whiting and some KGW on the couple of small areas that have this type of bottom.
The scallop dredging is pretty much what I'm refering to. Smashed the bottom in Port Phillip, (which trawling anywhere tends to do). Could seagrass be affected by salinity or temprature change.?
Re: Shell bed reefs
Posted: Thu Dec 05, 2019 9:18 am
by re-tyred
Sea grass has a very wide range of habitat from QLD to Tassie and grows well in brackish to pure seawater, so I think it would at best be a minor issue. It grows best in areas with soft bottom and low current flow. It needs a lot of sunlight so is restricted to shallow water 1-4 mtrs.
Re: Shell bed reefs
Posted: Thu Dec 05, 2019 9:25 am
by re-tyred
When people talk about Trawling they need to be aware that most fishing in Australia does not involve heavy bottom trawling. There are less that 20 scallop dredging vessels left in the Vic/ Tassie scallop industry. There are a similar number of deep water trawlers. These operate in 100- 800 mtrs on the continental slope. The majority of the commercial industry does not involve bottom trawling despite media calling most commercial fishing boats trawlers