Opening the Mouth of the Mangrove--Playing with Mother Nature

Posted by Dave Collins on February 25, 2015, 10:07 pm
187.210.230.11

The recent opening of the mouth of La Manzanilla mangrove is a theme that interests me... mainly in terms of the ecological ramifications. Like most things there are two sides of the coin. And you can bet coin has to do with the opening of it! It was not open simply in order to augment the ecology of the mangrove and our beautiful Tenacatita bay. Of that we can be sure. I would bet that the decision has to do with two main factors: 1. There is a pending project to build a bridge over the mouth of the mangrove. I don´t know when the start date for the project is, but the high water levels due to the significant late rains are a potential hindrance to the project´s commencement . 2. The coconut plantations that border the mangrove have been flooded for quite some time due to the high water. But on to those ecological ramifications... In purely ecological terms (I´m going to stay away from the socio-political) I view the potential pros as the following: 1. The mangrove exports nutrients to the bay. Tropical waters like the ones that surround us, are known to be nutrient poor environments. Coral reefs, mollusks, crustaceans and a number of other marine organisms benefit from this export of nutrients as they are able to filter them up and grow from that infiltration. 2. There has been an exchange of fish and other marine organisms: those that mainly inhabit the mangrove and those that mainly inhabit the bay. This is a potential boon to the fisheries of Tenacatita Bay and beyond. Some fish like snook, mullet and pargo can only exist if there are in tact mangroves nearby because that´s where they reproduce. Now more of these "mangrove fish" are swimming around in the bay. The potential cons: 1. If there is sewage effluent that has seeped into the mangrove I would prefer to see it stay in there instead of polluting the bay because over time it gets filtered through the mangrove plants. Red mangrove in particular are know to be some of the best biological filters around—they thrive on the nutrients found in effluent. And though the majority of the La Manzanilla mangrove contains white mangrove, it does contain red as well. 2. A lot of that contained food supply of fish, shrimp, etc. just went into the ocean where it is no longer easily available as food for the abundant crocodile population. Now, perhaps, they will have to go into the ocean sooner than they normally would have had to in order to find food. 3. The dry season is upon us and the shallower parts of the mangrove toward the highway are the parts that dry up soonest forcing all aquatic life into the deeper parts of the mangrove. In 2002, the driest year of the 2000-07 drought cycle, about 75% of the mangrove dried up and many crocs died. Probably little chance of that happening again, but what if we´re entering another drought cycle…? Then a lot of valuable stored water was just lost to the ecosystem at a critical time. What is irrefutable at the end of the day: we humans have had an effect on the ecosystem, and it on us...

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