STARVED ABALONES: Clean Freshwater as a Toxin & Poison

compiled by
Robert 'Roy' J. van de Hoek
Spring Equinox, 2001
Malibu, California

The following web page on George MacGinitie and Nettie MacGinitie is an example of the wide interest of MacGinities in marine biology. Although this is a short article by MacGinities, it is relevant today, 25 years after its publication, since Abalones are now rare in southern California. In many areas of southern California, the abalone is locally extinct!!!!!! In this brief article, we learn that the MacGinities had moved from Kerckhoff Marine Lab in southern California to Friday Harbor in Washington between 1958 and 1966.

In this brief article, we note that "FRESHWATER" is a toxin and poison to the Abalone. Ricketts (1939) in Between Pacific Tidesnoted that it was proper to refer to "FRESHWATER" as a poison and toxin to abalones and other marine invertebrates. It is well to remember that "FRESHWATER" is a poison and toxin to many animals and plants in estuaries, sloughs, tidal creeks, lagoons, bays, and coastal wetlands. It doesn't mean that a little "damping" of salinity will immediately kill many estuarine animals, but the "poison" and "toxin" cannot be persistent, frequent, and repetitive. The California Horn Snail, I have observed cannot live much more than 10 days in poisonous freshwater.

The web page was created and compiled to guide the curious individual into the realm of "knowledge is power" and "breaking through." There is something to be said for just plain pure education, knowledge, and curiosity to know about animlas and their natural landscapes from the perspective of WILD NATURE. That kind of knowledge is in all of the writing of George MacGinitie. It also hoped that these web pages will help educate us all about the inter-relationships of the land and the sea, through the eyes of a gifted marine naturalist and marine biologist.

NOTES & NEWS

Volume 8; Number 4 .............. THE VELIGER .................. Page 313

STARVED ABALONES
by
Nettie MacGinitie
and
George MacGinitie
Friday Harbor, Washington 98250

That Abalones stay pretty much in one place and do not wander extensively is no doubt a matter of fairly common knowledge among divers interested in our subtidal fauna. Evidence for a "home" instinct is found in the abalones that not infrequently are taken with shells abraded on the top because the animals were living between rock ledges that provided too shallow a space. This abrasion is sometimes so extensive that the shell is entirely worn away between two or more of the apertures. It is improbable that a wanderer would have stayed in a place that permitted so little freedom of movement.

It would seem that if anything would induce an abalone to move, it would be lack of food, but apparently not even starvation can induce this mollusk to move far from "home." On 28 April, 1958, an abalone diver, Mr. Dale Seeman, brought to the Kerckhoff Marine Laboratory some abalone that had been collected near the Laguna Beach outfall. In this area the seaweeds had been killed off, no doubt largely by the fresh water from the outfall. The abalones that Mr. Seeman brought to us were obviously in a starved condition. The animals appeared shrunken within their shells and the flesh was not firm. Mr. Seeman said that all the abalones in the area denuded of seaweeds were in the same emaciated condition. Typical of such abalones was a Haliotis corrugataGray with a shell measuring 6 1/4 inches in length, 5 1/16 inches in width, and 1 7/8inches in height at its highest point. The foot of the animal measured 3 1/2inches in length, 2 1/4inches in width, and was 9/16inch below the level of the margin of the shell. The mantle did not extend to the margins of the shell. Along the sides it lacked 3/4inch and at the ends 15/16inch of reaching the margin of the shell.


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