compiled by
Robert Roy Jan van de Hoek
March, 2003
P.O. Box 1145
Malibu, California 90265
The following web page on George MacGinitie is excerpted reproduction of an article about Newport Bay written in 1939, but based on field observations made during March 1938. The article was published in American Midland Naturalist in 1939. The web page was created and compiled to guide the curious individual into the realm of "knowledge is power" and "breaking through." The information presented here pertains to Newport Bay but is useful to undertanding estuaries around the world, but particularly those in California. Such California estuaries as Morro Bay, Elkhorn Slough, Mugu Lagoon, Carpenteria Marsh, Goleta Slough, Malibu Lagoon, Ballona Wetlands, Ballona Creek Estuary, Ballona Lagoon, Cerritos Wetland, Bolsa Chica Lagoon, Bolsa Chica Wetlands, and many other coastal wetlands with a remnant of California wild nature still found in them. There is something to be said for just plain pure education, knowledge, and curiosity to know
about natural landscapes from the perspective of WILD NATURE. That kind of knowledge in all of the writing of George MacGinitie. It is also hoped that this web page will help educate us all about the inter-relationships of the land and the sea, through the eyes of a gifted marine naturalist, marine biologist, and marine ecologist.
The American Midland Naturalist
Volume 21 ....... September, 1939 .......... Number 5
Pag 681 to 686
Some Effects of Fresh Water on the Fauna of a
Marine Harbor
G.E. MacGinitie
During the first week in March, 1938, Southern California was visited by an unusually severe storm. The rainfall accompanying this storm was of sufficient magnitude to cause floods over th greater part of Southern California, with an attendant loss of life and property. Although at present the Santa Ana River empties directly into the ocean, it did in times past use the entrance of Newport Bay as an outlet; and March 3, 1938, the Santa Ana River broke through one of its levees and a portion of the discharge again found its way through the bay and out the entrance. The stream running into the bay from the break in the levee at the river was 1,000 feet or more wide, had an average depth of a little over on foot, and a velocity of about 2 feet per second, or considerably over 1 mile per hour. This break in the levee occurred at about 3 o'clock in the morning, and it ran about 4 hours before it was finally brought under control.
This amount of water, in conjunction with the run-off from the surrounding hills, supplied a quantity of fresh water which markedly affected the animal life of the bay, and it is the purpos of this paper to summarize some of the effects noted.
It is a well-known fact that fresh water floats on top of salt water for a considerable tim if surface disturbance is at a minimum...................
...... In the yacht anchorage near Bay Island, which is approximately 2 miles from the entrance of the bay, the animals were killed to a depth of 6 feet 9 inches, and .....................
At the tim of writing this paper (December, 1938) all animal life has re-established itself, and those animals which wre above the dividing line between the fresh and salt water have been repopulated from members which were below this line, a fact which in itself supplies data as to their vertical distribution. Some forms may have re-established themselves from larvae from outside, or from the jetties, though I deem this rather unlikely, except, perhaps, with the hydroids.
Since the intake for the salt water system of the laboratory is below low water mark, we were able, by pumping at the height of the incoming tid, to keep the water supply sufficiently pure that animals in the laboratory managed to surviv nicely. Even the most suseptible animals, such as Ciona intestinalis, were unharmed in the laboratory.
SUMMARY
1. Practically all marine animals of bays and estuaries are killed by fresh water.
2. Those which have no method of closing out the freshwater, or which do not live in tubes or burrows are quickly killed by it.
3. Those which do not have a method of closing out the fresh water or which live in tubs or burrows may more successfully endure a period of dilution by freshwater.
4. Occasional exceptions, such as the oysters and mussels, are able physiologically to adjust themselves to fresh water dilutions, though each to a different degree.
KERCKHOFF MARINE LABORATORY,
CALIFORNIA INSTITUTE OF TECHNOLOGY,
CORONA DEL MAR, CALIFORNIA.
