Monday, June 13, 2011

Rio Chone Estuary


The Rio Chone estuary marked by San Vicente on the northern side of the 3 km wide mouth,  Bahia de Caraquez to the south, and San Antonio some 36 km east at the merging of several river sources.  The tributary source is 15 meters wide and fed from 21 different micro-basins.




A roadway flanks the entire estuary and the circular drive, or an open chivas bus crawling snakelike along this route is very scenic.


View Larger Map

Leaving Bahia you will cross the new 2 km bridge,



passing the airport ( often referred to as "new"  - however it has been open for several years but does not yet receive any commercial passenger traffic ) From San Vicente there are good views across the bay.


Ironically the other day San Vicente held a huge parade to celebrate  "Environment Day " it was several miles in length with most of the participants adorning recycled costumes handmade from recycled bottles, newspapers, lottery tickets, tin cans etc... I wish I would have had the camera. Bahia - the self proclaimed eco-city was very quiet without any event.




Over the length of many miles of Rio Chone shoreline the scenery is dominated by vast industrial shrimp farms, agricultural fields of maracuya,




cotton, rice, and yuka.  The shrimp breeding ponds are bordered by brown dams without vegetation.


About 85 % of the mangroves were deforested to make way for shrimp farming. In the Rio Chone estuary the shrimp ponds at the mouth have higher water circulation and enjoy higher growth rates of shrimp than the ponds in the upper regions.


In 90 day cycles just before the full moon the shrimp are  harvested as their new shields are particularly hard and the animals are more resistant for the harvest, and transport to market.

On the northern edge you  pass Puerto Portovelo which is the tour entrance for Isla Corazon.

The estuary has a long history of water quality problems resulting from the seasonal climate influences and mis-management of natural resources.


The estuary is primarily affected  by the influx of sediment from eroding hillsides and the construction of shrimp ponds.


Seasonal climate changes combined with decreased freshwater flow and shrimp aquaculture development  which replaced mangroves and directly discharge wastes into the estuary. Ammonia in shrimp ponds causes high mortality rates and can also cause low growth rates in shrimp. Monocultures in agriculture are susceptible to viruses and bacteria and about a dozen years ago the shrimp farms were devastated with Mancha Blanca. Ecuador, once the second largest exporter in the world,  shrimp production  plummeted by over 60 %.


Mangrove Forests form the transition between sea and land, where their interwoven root systems offer living space, and provide food to a number of animals and plants.


The mangroves biological "waste" (leaves, blossoms and fruits),  supply the first components of the food chain. The daily tide action washes this mud away to the sea to supply new organic substances for the sea life.


Seaweed, snails, shells, fish, birds, crabs, insects and other tiny animals find protection from predators, food and a suitable place for reproduction in these tidal forests.



Many fish species use the mangroves for reproduction. They provide protection, from the open sea, from large predatory fish, and a rich variety of food.  The Snapper spends its entire youth in the tropical coastal mangroves. About two thirds of all fish species living in the sea grow up under the protection of mangroves.


Without the mangroves our marine ecosystem breaks down ultimately affecting you at the top of the food chain. Shrimp in nature, contrasted to industrial breeding, grow up in this complex ecosystem where a large variety of fish, birds and mammals make up a diverse food chain together with the mangroves.















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