Sunday, March 11, 2007

Mouth Opening Controversial or not.


The Zululand Observer has a balanced article regarding the pro's and con's of the Estuary Mouth that naturally opened recently. Improvement in fishing conditions was almost immediately. With the high seas expected in the week of the 20th March 2007 it is likely that the opening will be more permanent. Park Authorities, whom have adopted a hands off approach, are relentless to say what is the future of the mouth.



During the prolonged closure of the Estuary feeding habits of crocodiles has changed dramatically and the public contributed to these prehistoric animals loosing their fear for man kind. A unexpected fisherman where taken one evening from behind a huge dead tree that he used as a shelter between him and the water. He had a small fire going from driftwood logs. None of this was detergent enough to protect him from the crocodile attacking.


It is clear that if the drought continues the mouth will quickly close up again. Good preparation during the drought has lead to positive salinity readings upwards from Brodies Crossing and well established sediment traps prevented disaster from striking. With the ocean being higher than the Lake Levels water flooded into the system, carrying vast deposits of sediment.



Water Levels at Catalina Bay are on the rise. It seems to be a pain staking slow process. With Charters Creeck that opened a little earlier this year to the public, day visitors only, after it was closed down due to low water levels after the mouth
was closed mechanically during the Jolly Rubino disaster.


With a low energy system, like the St. Lucia Estuary during drought conditions, the system cannot flush it self and sediment deposits carried in from the ocean settles higher up in the Lake. Only large floods like Demonia from 1984 and floods like the 1987 can make a real difference flushing this sediment back to the ocean. With all the soil erosion in the catchments
areas of the rivers flowing into the sea, a continues built up of sand is experienced on the Tugela Shelve. This sand migrates, through wave action and tidal currents, from South to North and end up in front of low energy Estuary
systems. One of these rivers carrying tons of sediment down with it's flood waters is the iMfolozi River.

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