How to replace Mangrove estuaries?

[DavidPT40]

Mangrove estuaries are said to be a pretty important place for young fish to mature. And in the last 100 years, a large percentage of the coastal mangrove trees have been removed for various reasons.

So my question is, how can mangrove estuaries be replaced? In many cases, the trees were destroyed to create physical structures on the coast. Is this just a case of existing habitat needing to be preserved, or can artificial structures or new mangrove swamps be created?

 

[archman]

Somebody's tried the fake mangrove stuff. Last I heard it was an expensive flop. But any coastal geologist could have told them that. Putting artifical erosion control features in low energy, soft sediment intertidal zones has always been iffy. Plants grow upwards to prevent burial; artificial structures can't do that.

Saltmarsh and seagrass restoration has been successfully achieved for decades now. I assume mangrove transplantation would fall under similar protocols. You'd need a nursery to grow the young plants up to a certain size. I'm sure somebody does this; I just haven't heard about it.

Repairing ecological damage is always far more expensive than buying up pristine lands. And the repairs are rarely very successful, unless they are minor and/or the habitat very small.

 

[DavidPT40]

I checked out a few websites, both Kenya and India have been replanting mangrove stands. The trees take forever to grow, but its a start at least.

 

[CBulla]

I have had to rewrite this before posting since it was basically not condusive for discussion..... the short of it being that despite knowing that this destruction is creating a lack of habitat and hurricane or tropical storm buffer, it continues to be sanctioned by the people we have chosen to elect (well, depending upon country).

I'm not sure what other countries motivations are, but down here in Southwest Florida the destruction is 100% materialistic regarding 'water front living'. This means restoration isn't going to happen unless we have a whopper of a hurricane totally wipe out costal communities. Places I've seen new habitat grow and take shape took years for smaller plants to be estalished well enough to be more than a few shells hanging out together.

 

[DavidPT40]

Thats a shame CBulla. However, I like the beach as much as the next person (probably more), so I see the conflict here.

Maybe coastal states should have some sort of legislation that decrees a certain % of shoreline has to be undeveloped (25% or so). Then maybe some sort of off-shore structure could be made to help with fish stocks. Japan is pretty good at this, they have several man-made islands for their airports.

 

[chip104]

I checked out a few websites, both Kenya and India have been replanting mangrove stands. The trees take forever to grow, but its a start at least.

They also do it here in the PI. You can actually see some of the work being done when taking the boat into Puerto Galera. To stop squatters from settling in mangrove areas, they put up bamboo fences to restrict access. This is especially by the town area where the mangroves are important to filter the water and keep it clear.

FWIW, one thing to worry about when replanting mangroves is that certain plants require to be replanted at a certain tidal heights. If not replanted properly, the restoration effort would be fruitless. The way they tested this here was to lay the same plant species at certain heights and see where they thrived.

Just my 2 centavos in the discussion (which is worth only 0.04 cents).

 

[marku]

Chip104, if you ever find yourself in Bohol, you might want to check out the mangrove forests in Banakon & Batasan. They're in the NorthWest side of Bohol, part of the Danajon double barrier reef system. Large parts of their mangrove forests were re-planted. The thing with re-planted mangrove forests is that they don't have the diversity of natural mangrove forests; though I'm not certain if that's a problem or not. If you get a chance, try diving the Batasan marine protected area. I've seen schooling barracudas, bumphead parrots, Napoleon wrasses, a whitetip reef shark, and monster giant clams while surveying the Batasan MPA 2 years ago.

-marku

 

[drbill]

Fortunately where my parents live in Sarasota FL, the developer chose to retain as much of the existing mangroves as possible. After some 30 years, it seems to have worked well. None of the units are directly on the water although some are close to the mangroves.

 

[archman]

Maybe coastal states should have some sort of legislation that decrees a certain % of shoreline has to be undeveloped (25% or so). Then maybe some sort of off-shore structure could be made to help with fish stocks. Japan is pretty good at this, they have several man-made islands for their airports.

Texas has a "backwards" regulation that prohibits private ownership of tidal or subtidal lands. Of course nowadays it's considered state of the art, and being modeled by other states. But our coastal lands are still fairly pristine, except for the beach areas that are compacted by vehicular traffic. About 50% of our coastal wetlands are pristine too, granted the only mangroves we have are stumpy little groves south of Copano Bay. They can't hack the occasional freezes.

The lack of beachfront development also means that in the case of hurricane, we won't gut FEMA nearly as much as most other states would. Hooray.

 

[chip104]

Chip104, if you ever find yourself in Bohol, you might want to check out the mangrove forests in Banakon & Batasan. They're in the NorthWest side of Bohol, part of the Danajon double barrier reef system. Large parts of their mangrove forests were re-planted. The thing with re-planted mangrove forests is that they don't have the diversity of natural mangrove forests; though I'm not certain if that's a problem or not. If you get a chance, try diving the Batasan marine protected area. I've seen schooling barracudas, bumphead parrots, Napoleon wrasses, a whitetip reef shark, and monster giant clams while surveying the Batasan MPA 2 years ago.

-marku

hey mark,

thanks for the tip, Bohol is definitely on the top of my list to dive. I've only been there for the non-diving activities (choco hills, tazier, river ride, snorkel/beach) but I can't wait to go back to check out the diving activities!

I've always been under the impression that a multispecies ecosystem thrives better than monospecies ecosystem. But still, Bohol is definitely a great example of ecotourism at work and I am impressed with their restoration efforts (ex mangroves & the manmade forest).