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Mangroves


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This is quite interesting, I've always thought they were bloody invasive 'pests', and according to this guy that would be correct.

 

https://www.nzgeo.com/stories/mangroves-allies-or-invaders/

 

New Zealand is the only country in the world where the mangrove is expanding its area of occupation. Is this expansion good for New Zealand’s marine environment? We don’t believe it is, because it appears to be occurring at the expense of other habitats, such as shellfish beds, sea-grass beds, flounder habitat and wading-bird habitat, as well as recreational areas such as sandy beaches and stretches of open water

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The hint of someone removing a mangrove a few years ago was enough to get a body charged and fined. Friends of mine with coastal property were warned and very wary.

Now you see local gummint or who? steam cleaning/killing the seedlings off mud flats. As seen at mahunga drive  around the pylons in the upper manukau harbour

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Have a read up re mangroves. There is a NZ native species that have been here for thousands of years. They offer a habitat to breading fish, where the eggs are laid and then the little fellows live in relative safety till they are big enough to roam out into deeper less protected waters. They also stabilize the silt within esturies to stop it being washed away.
The fact that they are spreading may well be due to other factors perhaps. Like something else has been removed from the waterway to allow the space for them to spread. I don't know, just a thought.

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I was under the impression Mangroves flourished when silt runs into the estuary and harbour.  The additional silt makes it easier for the Mangroves to take hold.  

Whangamata Harbour is an example of this with the forestry surrounding it.  

We an encouraging Mangroves with our use (misuse) of land.  

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I was under the impression Mangroves flourished when silt runs into the estuary and harbour.  The additional silt makes it easier for the Mangroves to take hold.  

Whangamata Harbour is an example of this with the forestry surrounding it.  

We an encouraging Mangroves with our use (misuse) of land.  

Agreed. Mangroves are a symptom , not the cause.

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at little shoal bay

 

they seem to have come up with a reasonable solution

 

ie not all or nothing

 

the locals have been allowed to carve out mangroves from a nicely slopped sandy bit to make a beach for the kids to play in

 

but leaving the other 90%? on the mud for small fish to hide behind, oxygenate the water? and consume? some of the nitrate run-off

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The results of that effort really needs a photo but I reckon it was a complete waste of time . I'll get a pic when Im there over the weekend. 

It has left the "beach" as unusable as it ever was and a bald patch of mud with the vertical root-sprouts bits still poking out of the mud and hardly appealing. 

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Yes there is a species of mangrove exclusive to NZ,mangroves grow north of Tauranga from memory.They provide a habitat for fish to hide,unlike the tropics etc where fish actually come in to the shallows to breed,They do not do this in NZ.

 

The thought was fresh water killed them when cut and rots the roots but how do explain the ones growing by the old Kopu bridge in Thames in a paddock??they have clear most from Pahurehure lagoon but some greenie claims to of found a foot print in the mud from an endangered bird, Most of the mangroves have gone and the silicone sand beach is returning.But the mud needs to sucked up and removed,someone in council said remove the mangroves and the tide will flush out the silt.Hmm yes that will work on the out going tide and when tide changes will come back in I would of thought. 

Bayswater marina was suppose to of gone ahead mid 70s but didnt due to greenies saying it will effect the ecology,whats the results of the ecology now the marina in in??bet the crabs still in ngataranga bay along with flounder,bet the old devonport tip is still leaching out toxins.

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Have a read up re mangroves. There is a NZ native species that have been here for thousands of years. They offer a habitat to breading fish, where the eggs are laid and then the little fellows live in relative safety till they are big enough to roam out into deeper less protected waters. They also stabilize the silt within esturies to stop it being washed away.

The fact that they are spreading may well be due to other factors perhaps.

 

This is correct. I think there may even be two species if my memory serves me correctly. Mangroves also hep prevent against storm surges, and a number of other important things. Shallow harbours without mangrove buffers suffer higher levels of algal bloom. I.e. sea lettuce

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