Source: http://www.naturespeace.org/ed_ricketts1939sandybeach2.htm
Timestamp: 2019-04-24 16:29:18+00:00

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"Presumably because of their usually limited extent, the sandy beaches of the protected outer coast are the most barren of all intertidal areas. They occupy a strange position, biologically speaking. They are distinct, on the one hand, from the typical Pacific sandy beach, which is completely exposed and subjected to violent surf but nevertheless supports a highly specialized fauna, although it is neither abundant nor greatly varied. In closed bays, sounds, and sloughs, on the other hand, we find the completely protected sandy beaches supporting a fauna both rich and varied. No doubt the total area available for colonization is the chief factor in both the latter cases, for characteristic animals will not develop for a type of region that is representd by small and widely separated areas only, like the sandy beaches in question. Such beaches ordinarily occur in short stretches of a few hundred yards or a few miles, between outcroppings of rock and are almost destitute of life. It might reasonably be asked why such areas are not colonized by the animals of surf-swept beaches; the answer is, apparently, that the animals of surf-swept beaches will not tolerate the more sheltered conditions. The same answer, reversed, would apply to completely protected bay animals, for whom these areas would be too exposed. At any rate, barrenness is the rule, and we have three animals to record from the semi-sheltered sandy beaches, ignoring those forms which may occasionally be washed up from other habitats." [BPT, 1939, page 111].
§154. A giant beach hopper, Orchestoidea corniculata, is successful in this barren environment, possibly because it lives high up, avoiding the "old devil sea" to which it belongs. During the day it hides in burrows in the sand, coming out at night to feed on decaying seaweed and storm wrack. Occasionally, however, it may be found during the day under piles of seaweed. This beach flea is probably the chief scavenger of the semi-protected beaches. When the waves bring it nothing it must find the food supply rather scanty unless, as is suspected, it turns with equal gusto to detritus originating on land. In appearance, it is very similar to a still larger related hopper of surf-swept beaches (§185), but its antennae are not so long.
Smallwood, who has worked with an East-coast beach flea that is similar in form and habitat to our Orchestoidea, believes that the animals' reactions to light do not account for their nocturnal habits, but that keeping out of sight in the daytime is simply a protection against birds.
§155. A second and much smaller beach hopper, Orchestoidea benedicti, is the only animal from the surf-swept beaches that is at home here as well. Unlike the larger hoppers, it can be found at will during the day, which seems to upset the bird theory unless its size or flavor are protective factors.
"Whereas the animals living on surf-swept rocky shores have solved the problem of wave shock by developing powerful attachment devices, the inhabitants of surf-swept sandy beaches achieve the same end by burying themselves in the sand. Some, like the mole crab and the razor clam, are able to burrow with extraordinary rapidity. Others (Pismo clam) burrow more slowly, depending on the pressure-distributing strength of their hard, rounded shell. These have achieved the necessary great strenth and resistance to crushing, not through the development of such obvious structural reinforcements as ribbing, with the consequent economy of material, but by means of shells which are thick and heavy throughout. Ribbing would provide footholds for the surf-created currents which could whisk the animal out of its securely buried position in a hurry. Natural selection presumably has "bred out" a race of thick- and smooth-shelled clams over which the streaming and crushing surf can pour without effect. In addition the actively burrowing forms particularly, such as Emerita (§186), must be provided with a sense of orientation not dependent on sight.
That the problems faced by sand dwellers on an exposd coast are reasonably baffling is indicated by the fact that few animals are to hold their own under such conditions. While these beaches are not the barren wastes we found the smaller sandy beaches of the protected outer coast to be, they are still sparsely populated in comparison with similar rocky shores. Actually we know of only six or seven common forms that occur in any abundance on heavily surf-swept sand beaches, and two of them are already well along toward extinction as a result of human activities. This reflects a situation quite different from that assumed by most amateur collectors, who would have one but turn over a spadeful of beach sand to reveal a wealth of hidden life. [BPT, 1939, page 135].
§184. We have already cited several examples, notably the periwinkles, of animals with markedly landward tendencies. On the sand beaches of the open coast there is another, the little pill bug, Alloniscus preconvexus, about 5/8" long. This isopod is an air-breathing form which will drown in sea water. It will be found, therefore, in the highest zone, above the high-tide line, and because of the obvious nature of its burrows it is often one of the first animals to be noticed in this environment. The mole-like burrows are just beneath the surface, and making them the animal humps up the surface sand into ridges. Another air-breather, the isopod Tylos punctatus, a 1/4" to 1/2" oval form resembling Exosphaeroma (§198), is restricted to the southern California beaches.
§185. During the night, or most noticeably at dusk or at dawn, the foreshore seems to become alive with jumping hordes of the great beach hopper, Orchestoidea californiana (Pl. XXIX). They are pleasant and handsome animals, with white- or old-ivory-colored bodies, while the head region and long antennae are bright orange. The bodies of large specimens are considerably more than an inch long, so that, adding the antenna, an over-all length of 2 1/2" is not uncommon. Like the other beach hoppers, this form avoids being wetted by the waves, always retreating up the beach a little ahead of the tide. These hoppers seem always to keep their bodies damp, however, and to that end spend their daylight buried deep in the moist sand, where they are very difficult to find. Night is the time to see them. Observers with a trace of sympathy for bohemian life should walk with a flashlight along a familiar surfy beach at half-tide on a quiet evening. These huge hoppers will be holding high carnival-leaping about with vast enthusiasm, pausing to wiggle their antennae over likely looking bits of flotsam seaweed. They will rise up before the intruder in great windrows, for all the world like grasshoppers in a summer meadow. Too closely pursued, they dig rapidly into the sand, head first, and disappear very quickly. Ovigerous females have been taken in March in Monterey Bay.
When in the sand, the mole crab always stands on end, head end up. Characteristically the entire body is buried, while the eyes-tiny knobs on the ends of long stalks ... taken advantage of by hungry birds as well as curious collectors and bait-gatherers. The latter use the animals in their soft-shelled stag, that is just after they have moulted.
The spiny sand crab, Blepharipoda occidentalis (Fig.66), may occur with Emerita. It is larger, with a carapace up to 2" long, and is by no means as common. It has a recorded range of Monterey southward, and recent reports say that it is abundant outside Morro Bay.
§187. At about the mole-crab's level are minute, shrimp-like crustaceans, Archaeomysis maculata, called opossum shrimps because, like other mysids, they retain the young in a marsupial pouch under the thorax. Gills are attached to the legs and hang down in the water. There is a trick to finding these animals, for they are so transparent that they cannot be seen directly with the naked eye. On a sunshiny day, however, they cast shadows on the sand below the smooth runoff of waves dammed back momentarily by a shovel, and so can be located and captured. This form is related to the more visible mysids of the tide pools (§60).
§188. The bean clam, Donax gouldii (Fig. 67), is common from the San Luis Obispo region to Mexico. This small wedge-shaped clam, averaging an inch in length, is said to have been so common at one time that it was canned commercially at Long Beach. For many years it has not been available in commercial quantities, but the individual collector can still find enough for a delicious chowder by combing the sand just beneath the surface. The bean clam's hiding place is commonly revealed by tufts of a hydroid that grows on the shell and protrudes above the surface of the sand. This elongate hydroid, Clytia bakeri, related to Obelia, and occurring also on the Pismo clam, is the only hydroid found on exposed sandy shores.
Up to 80 per cent of these clams, according to canners, carry an internal commensal, .... MacGinitie, in a verbal communication, reported this or a related form from clams at Humboldt Bay. We have taken it also, but sparsely (only one was found ...), along the open sand beaches near Queets, central Washington.
§190. The Pismo clam, Tivela stultorum (Pl. XXIX), does not merely tolerate surf; it requires it. Clams removed from their surf-swept habitat to lagoons and sheltered bays to await shipment live but a few days, even though tidal exposure, temperature, and salinity are the same..... The Fish and Game Commission takes an annual census of the animals, based on test counts in strips of beach running from the upper limit of the intertidal zone out to the water line at extreme low water. The results indicate that, despite the present restrictions (fifteen 5-inch clams per person per day, certain areas are closed, and all shipments prohibited), the species is in danger of becoming extinct unless still more stringent restrictions are applied and enforced.
With the exception of man, the Pismo clam's natural enemies are few. .... There is reason for believing that when our own beaches are depleted the coast of Lower California can be called upon to supply large quantities of Pismos. It is to be hoped that the Mexican government, which has shown itself to be wide awake in the matter of conserving wild life, will enact and properly enforce legislation that will help Tivela to hold its own.
§191. Although we ourselves have never taken them, E. and C. Berkeley report (1932) from Long Bay, an exposed beach on the west coast of Vancouver Island (in addition to abundant specimens of a nephtys, N. caeca, similar to those treated in §265), an annelid worm which merits consideration. It is Ophelia mucronata, previously known only from southern California, and is said to occur "in vast numbers . . . . , whole stretches of sand being tunnelled by countless millions. Judging by the complex system of furrows on the sand beds they inhabit, they seem to emerge from their burrows and crawl on the surface of the sand, but none were found exposed. Large flocks of sandpipers are frequently seen at low tide, extracting these worms and feeding on them." This was described as a slender ophellid, 35 X 1 to 25 X 2 mm., with triangular head, and bearing gills on the lower middle two-thirds of the body.
§192. A good many favorably known food fish, notably striped bass, are found along sandy shores just outside, or even within, the line of breakers. The live-bearing surf perch occurs similarly, but is usually too small for food. Although these can scarcely be considered intertidal forms, one interesting southern fish (which has been reported in Monterey Bay also) actually comes high into the intertidal zone for egg deposition. This is the famous grunion, Leuresthes tenuis, a smelt about 6" long.
The egg-laying time of the grunion is holiday time for tremendous numbers of southern Californians. Along the coast highways cars are parked bumper to bumper for many miles, and the moon and thousands of beach fires light up the scene. The fish are caught with anything available, from hats to bare hands, and are roasted over the fires, making fine fare indeed.
The grunion's extraordinary spawning habits are as perfectly timed as those of the palolo worm of the South Seas, and the timing force is as mysterious. On the second, third, and fourth nights after the full moon - in other words on the highest spring tides - in the months of March, April, May, and June, and just after the tide has turned, the fish swim up the beach with the breaking waves to the highest point they can reach. They come in pairs, male and female. The female digs into the sand, tail foremost, and deposits her eggs some three inches below the surface. During the brief process the male lies arched around her and fertilizes the eggs. With the wash of the next wave the fish slip back into the sea. Normally the eggs remain there, high and dry, until the next high spring tides, some ten days later, come to wash them out of the sand. Immediately on being immersed the eggs hatch, and the larvae swim down to the sea.
The fish mature and spawn at the end of the first year, and they spawn on each set of tides during the season. During the spawning season their growth ceases, to be resumed afterward at a slower rate. Only 25 per cent of the fish spawn the second year, however, 7 percent the third, and none the fourth.
§193. The storm wrack and flotsam cast up on sandy beaches is sure to contain the usually incomplete remains of animals from other kingdoms-representatives of floating and drifting life and of bottom life below the range of the tides. Both of these great life zones lie outside the scope of this book, and the stray specimens thrown inshore can be given but scant mention.
Shells of deep-water scallops, snails, piddocks, and other clams are very commonly washed up. While perfect specimens of this sort are adequate for the conchologist, to the biologist they are merely evidence that the living animals probably occur offshore.
In the spring of 1927 the junior writer, aboard a sailing ship a few hundred miles off the coast of central California, sailed for several days through incalculable numbers of purple-sailed "floats"-siphonophores, ... A little later, storms drove tremendous numbers of the creatures, Velella lata (Fig. 68), ashore along the California coast-a performanc that is repeated once in every few years. ....Specimens picked up on the beach .... but occasionally a perfect one may be found, with purple zooids trailing below the disc and even with a purple goose barnacle attached.
"Gooseberries," the "cat's eyes" of the fishermen, are occasionally cast up on the beach, where succeeding waves roll them around until they are broken. These are comb jellies or ctenophores, usually Pleurobrachia bachei (Fig. 69).
Great blubber-like masses of the jellyfish Aurelia (§330) are often cast up in the fall, but usually so wave-torn as to be scarcely recognizable.
*Any number of other animals may be stranded at times, but those mentioned can be expected fairly regularly. Flotsam timbers, if they have been in the water any length of time, will almost surely have adherent goose barnacles, Lepas anatifera, etc., relatively similar to the Mitella of §160.
Finally, we can state simply that a continuation of marine biology research from the 1930s to 2006, involving Ed Ricketts, George MacGinitie, and John Clamp is linked together by connecting the dots and then, this writer sharing this story with you. We really do have a unique episode of California environmental history, serendipity, and California natural history bound together in the "life and times" of "sandy beaches" with its marine biology and "life history" of a marine clam put into an eclectic nature story, full of magic, mystery, and awe.

References: §154

§155

§184

§185

§187

§188

§190

§191
 §265

§192

§193
 §160