More Explorations: Cabezas de San Juan

The Para la Naturaleza (http://www.paralanaturaleza.org/en/category/news/?lang=en) is a nature conservancy in Puerto Rico that supports a dozen or so sites of historical and/or environmental significance.  We recently visited Las Cabezas de San Juan Nature Reserve in Fajardo, just over an hour east of San Juan.  This area is unique in that six separate ecosystems – a bioluminescent lagoon, coral reefs, dry forest, mangroves, and sandy and rocky beaches – all exist in the same 300 acre location. Our 2.5 hour guided tour provided us with tons of information on each system.

Our first stop was the Cabo San Juan Lighthouse. The lighthouse is still in use but no longer has staff who live onsite. 

 

As you can imagine, the view from the top is magnificent. Las Cabezas – ‘heads’ in Spanish – gets its name from the terrain which can be seen from the lighthouse. Three rounded prominences – heads  or headlands – are areas of land that extend into the water.

If you look carefully, you can see a rainbow reflecting on the water.

Spectacular cloud formations!

A fun fact: the spiral staircase going from the main floor to the roof curves in a counter-clockwise direction. It was built this way to facilitate defense against invaders, who were mostly right-handed. Interesting fact: Only 12% of the population are left-handed. The two lefties in our group – daughter Karen and grandson James – would be at a decided advantage if they were attacking the lighthouse!

There were a number of exhibits in the lighthouse including a tank with a sea cucumber in it. The guide had visitors wash their hands then he handed the creature to them. Karen and James each took a turn. They described the sensation like holding silly putty. The sea cucumber is an invertebrate that has a number of fascinating properties. One is that when hung over your hand, it lengthens. Another is its ability to dump its internal organs as defense. When it is safe again, it can regenerate the organs. Not only that, if it loses its front half, it can grow a new one. No such luck if it loses its back half. 

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Another exhibit took place in a darkened room where we got information on the bioluminescent organisms that live in a number of bays in Puerto Rico. Movement of the water in which they live – such as during an attack – results in a chemical reaction that produces light. We were each given a small packet of water containing zillions of these protozoans. When we shook the bag, sure enough, colorful light played across the packet. Our guide explained that the ability of the organisms to emit light decays over time and demonstrated that a fresh bag produced more light than those we had been shaking for a couple of minutes.

No photos were allowed in the darkened room so I got this photo from: http://www.abyss.com.au/diving/wp-content/uploads/2015/11/bioluminescence.jpg

After spending nearly an hour at the lighthouse, it was on to the rocky beach. Nearly all the beaches – ‘playas’ -  we have seen in Puerto Rico have consisted of amazingly soft sand. The beach at Las Cabezas was rocky – much more like beaches we see on the coast of Maine. The explanation for this has to do with the speed with which the waves hit the shore. The waves here hit with enough force that they remove all the sand and silt.

An example of brain coral.

This is a lovely specimen of fan coral.

Next, it was on to the mangrove forest. We walked onto a boardwalk that took us through several different areas of mangroves. We learned that black mangroves send up roots through shallow water and that red mangroves drop seeds into the water. We saw areas where the mangroves had died because of changing salinity and new areas of growth. Completely fascinating.

Black mangrove roots.

 Some examples of animals and fish that live amongst the mangroves.

Note the orange color of the water. This is because this area is populated by red mangroves.

Examples of a dead mangrove swamp - killed by changing salinity of the water.

Para la Naturaleza tours are a real bargain. Total cost for five of us – two seniors, one adult, and two kids – was $53. We plan to take advantage of more of their tours while we’re here.