Shallow shore cenote Jardín del Edén, Quintana Roo, Yucatán, Mexico

59th place in Biotope Aquarium Design Contest 2017

Costa_Rica Costa Rica. Nelson Alonso

Volume: 120L
Dimensions: 100x40x30h  cm
List of fishes: Poecilia Velifera(2 males,  6 females, 1 juvenile male, X fry), Daphnia Magna (not appreciable in the video or pictures)
List of plants: No plants (Macro algae)
Description of decorations: I used natural limestone to recreate the limestone rock present in the Cenote Jardín del Edén, The sand is bahamas oolite, that not only is very similar to the one in the Yucatan Cenotes, beaches, but its almoust the same as the Playa del Carmen, and of course, the Bahamas itself Which are very near. I pour some almond leaves remains to give it a bit of a “dirty” look, even tho in the Cenote is almoust unnoticeable, same as dritwood and else.
Description of equipment: DIY 78 Watts LED light, with a personal mix of 6500k and 10000 k, and a few 15000-20000k royal blue, and full spectrum LED. It has a 150 watt internal glass heater. One canister EXTernal pump (210 gph) and a internal 200lph filter for surface movement.
Water parameters: Temperature is 29-30°C, PH of 8.4, GH 280 PPM, KH 200 PPM, NO2 0.0, NO3 0.5, Ammonia 0.0

Description of the area surrounding the biotope: Cenote Jardín del Edén is a small anchialine column located at the Northeast Yucatan Peninsula, México, in the state of Quintana Roo , bordered by the states of Campeche to the west. At just 2.5 kilometers from the Caribbean sea coast, Cenote Jardín del Edén is surrounded by many other Cenotes like Cenote Ponderosa, which is just a few meters away or Cenote Azul, 100 Kilometers to the North near Playa del Carmen and many more. This are interconnected by the flow of the underground stream of water system which is a mix of different waters. At just 2 meters above the sea level, the Cenote Jardín del Edén is framed by many trees, plants and rock structures in the shore, being deep and hollow at the bottom, home of  many different animal species endemic of this place.

Description of the underwater landscape of the biotope: From the deep, beautiful shaded turqouise color to a clear, pristine crystaline water in the shore, the Cenote is mainly shaped by white limestone structures and a sandy bottom. Being slightly sedimmented, you can find a few remains of the leaves and branches which decompose quick due to the highly alcaline reaction, making Yucatan Cenote´s one of the most clear water bodies in the world. The Limestone rocks are covered in green algae which some fish and crustacean graze on and due to the natural rock erosion many fish fry and crustacean larvae hide between the cracks in the shallow water. Poecilia Velifera swims thru the open water in search for algae to graze on between the rocks, males also fight for dominance over the females and dance to the females as they swim in groups of 6 to 15 individuals. Their outgoing nature makes them easy to appreciate since they are not shy at all.

Description of the parameters of the habitat: Many factors have influence in the water chemistry, the closeness to the sea, rain water, underground flow, rock/vegetable matter and oxigen dissolution makes the halocline water fluctuates from fresh to brakish water, being the shore where the fresh water acmulates most of the time. The temp can vary form 25° to 32° on Summer. Sometimes the thermocline effect can have different temperatures in the same area. Ph from 7.6 to 8.5  STD 1400.0  Na+ (mg/L)  330.0  K+  (mg/L) 15.0  Mg2+ (mg/L)  41.5  Ca2+ (mg/L) 270.0 NO3 (mg/L) 0.5  NO2 (mg/L) 0.5

List of fishes: Poecilia Velifera, Daphnia pulex

List of plants: Macro algae

Threats to the ecology: Cenote´s are one of the most endangered places in the whole Yucatán area. The delicate water systems are being attacked by the excesive and uncontroled tourism, the human polution, water contaminants like pesticide, sewage waters, toxic waste and many more. Even after proben studies of dedicated scientifics, the place has almoust no control over the excesive treatment of the land. Things like trimming a plant field or poluting the water, may result in the destruction of the whole cenote structure, which is hold by roots and ground formations and destroying this beautiful, unique and strange place which is unique in the world , taking into consideration the process of years, evolution, almoust no human touch and even a rare cosmic event like an asteroid crash in this place, there is a very high chance of ruin what nature, beautifully create for us, the world, to appreciate.

Sources of information: Wikipedia, Facebook groups, some books and lots of internet articles and videos, also the colaboration of naturalist, students, photographers and people of the area, trhu the internet which I didn´t have the concent to mention, even tho I did have the concent of  Rhett Butler, from MongaBay to use some of his pictures as references.
I also studied other biotopes and water bodies like Cenote azul, and so, which are very similiar!