Wharf Piling

Edward F. Ricketts


Environmental Factors

While work on this division was in progress, it was discovered that piling animals show variations apparently closely corrlelated with the degree of exposure to the surf. Whether these differences are due actually to the presence or absence of wave shock, as is thought to be the case with rocky-shore animals, or to the different make-up of bay waters and open waters, cannot be stated. It is known that the waters of bays and harbors differ from oceanic waters materially in oxygen content, salinity, degree of acidity-alkalinity, and even temperature. It may be that we must look to these factors for the explanation of the faunal differences, but until more definite information is available the degree of protection from surf will serve as a convenient method of classification.

For obvious reasons no wharves or piers are built in fully exposd positions. Nevertheless, the outer piles of long piers, such as those at Santa Cruz and Santa Barbara, get pretty well pounded during the storms, and it is noticeable that the animals most frequent on such piles are barnacles and California mussels, both referable to surf-swept rocky headlands and perfectly able to take care of themselves in rough weather. The piling fauna, therefore, will be considered under the two headings (A) exposed (using the term relatively) and (b) protected.

Piling offers a conspicuous means of observing depth zonation, although for some reason such zonation is not as obvious and clearcut on the Pacific as it si on the Atlantic. Dr. Allee speaks of the piles at Vineland Haven, Massachusetts, as having four distinct bands, recognizable by their color. Apparently very few West-coast workers have been interested in the ecology of wharf pilings, and much of the data reported below is more or less tentative. It would take several more years of work to establish the dividing line between the fauna of protected and eposed piling - or even to determine if there is such a thing, strictly speaking, or if we must look elsewhere for the explanation of the faunal differences. All that can be said is that the following information seems to be correct for the limited areas we have collected over.

A. Exposed Piles

Zones 1 and 2. Spray- and storm-wetted area and high-tide horizon.
315. Very few Littorina are to be found on piling, and the highest animals encountered are very small barnacles, often under 1/4" in diameter. They occur sparsely, and almost flush with the wood. Typical individuals taken from the Monterey wharf and sent to the National Musuem were identified as Balanus balanoides, a species name by Linnaeus in the eighteenth century and probably known on the coasts of Europe for many hundreds of years. So far as we know, this small circumpolar barnacle has not been recorded previously south of Sitka. It is strange to find it the commonest small barnacle on piling as far south as Monterey.

Intermingled with these barnacles, and a little below them, are a few preliminary and unhappy-looking clusters of California mussels. With the mussels, and bit below them, some of smallest examples of the rather prettily colored warty anemones (the aggregated phase of Cribneria) are likely to occur. A few of the rock crabs Pachygrapsus) may be seen walking about here, retreating, when danger threatens, into the larger mussel clusters below.

Zone 3. Mid-tide horizon
316. This zone (and the upper part of the lower) is characaterized by lush growths of an almost white hydroid, Obelia; by large clusters of big California mussels; and by the great barnacle Balanus nubilis. [compilation to be completed later].

317. Balanus nubilis is the largest barnacle on our coast and probably one of the largest in the world. It ranges around the world in the North Temperate zone - on this coast from Alaska at least as far south as Monterey.... We have such clusters from the Santa Cruz wharf that are more than a foot high. The animal's great size and accretionary habits are not entirely helpful to it, since clusters get so large and heavy that they often carry away the bark or part of the disintegrating wood and sink to the bottom, where it is likely that the barnacles cannot live. The shell of nubilis is frequently covered with the bryozoan Barentsia, and may provide attachment base for anemones and tube worms also. . . B. nubilis is another of the long series of barnacles originally described by Darwin. His description still stands correct - a tribute to the carefulness of the work put on this difficult group by a thoroughly competent mind.

A smaller but even more striking barnacle that is characteristic of boat bottoms and is occasonal on wharf piling and even on rocks is Balanus tintinnabulum (Fig. 104). The nearly cylindrical shell is a pinkish red with white lines, and the "lips" of the mantle, as with nubilis, are vividly colored.

318. The big-clawed porcelain crab, . . . [compilation to be completed later].

319. Crawling about on these same empty barnacle shells are specimens of Pcynogonum stearnsi (Fig. 106), the largest and ungainliest of all local sea spiders. A border design of these grotesque yet picturesque animals might surround the pen-and-ink representation of a nightmare.... J.W. Hedgpeth, in a personal communication, reports finding this form also on the hydroid Abietinaria (83), and even on the rockweed Fucus in tide pools. . . . [compilation to be completed later].

320. There are a few clusters of goose barnacles on the outer piles, and some large solitary specimens of the great green anemone Cribneria. . . . [compilation to be completed later].

Zone 4. Low-tide horizon
321. The anemone Metridium dianthus [compilation to be completed later].

322. Where it occurs at all, the stalked simple tunicate Styela montereyensis (Fig. 107) may be present in such numbers as to be a feature of the tidale "pile-scape." [compilation to be completed later].

323. The kelp that grows on piling in this zone has teh usual concomitants of life in a crowded environment. Most it is plastered and encrusted with unbidden guests: Aglaophenia, Obelia, and sertularians among the hydroids; the omnipresent Membranipora and tiny colonies of the tubed Tubulipora among bryozoa. [compilation to be completed later].

324. The infrequent bare spots on piling are furred and plumed with the usual hydroids - the same that occur on kelp and the hard tests of tunicates. Bugula neritina (Pl. XLV), a red or yellow-purple bryozoan in sparse palmate clusters, seems to be characteristic of bare spots on piling or boat bottoms. We have often found it on submerged wood, never on rock. . . [compilation to be completed later].

325. The starfish found on piling all attain their maximum abundance elsewhere. Considerable numbers of the common starfish (Pisaster ochraceous) are attracted by the easy picking in the way of mussels, and in the lower levels a few of the quiet-water Pisaster brevispinus will be found. The brilliantly colored sea bat Patiria occurs also, and the little six-rayed Leptasterias may be abundant. [compilation to be completed later].

326. The chunky little shrimp Betaeus harfordi, some 3/4" long, may often be found piling. Like its relative of the southern tide pools (fig.18), this form has carapace that extends over its eyes. No doubt this device affords protection to the eyes, but it must also be a considerable handicap in greatly limiting the animal's field of vision. B. harfordi has been reported from Point Arena to Laguna Beach.

327. The kelp crab, Pugettia producta (107), is quite as characteristic of piling as it is of rocky tide pools. At low tide it will usually be found at least a few inches below the surface, and even when the tides rises it seems to prefer this low zone. This fairly large member of the spider crab group is also one of the most active, but it is the most likely, of all crabs on this coast, to be infected with the strange parasite . .

328. To many well-informed persons the biological connotations of wharf piling all center around the word "teredo." These wood-borers have been the bane of shipping for at least two thousand years, for they were known, unfavorably, by the ancient Greeks and Romans. It seems quite possibl that the early Mediterranean custom of hauling boats ashoree when they were not in use was motivated, in part at least, by an understanding of the fact that frequent drying would protect them from attack by the shipworms. The species of Teredo and their near relatives are still, after many years of scientific research as t preventives, the cause of tremendous destruction to marine timbers - destruction that often runs into millions of dollars a year in a single seaport.

The term "shipworm," which popularly applied to the whole group, is a misnomer, for the animal is acutally a clam, although its small calcareous shell - its boring tool - covers only the head end of its long, worm-like body. The are highly efficient wood-workers.

329. Dampier, the Enlgish buccaneer, who was something of a naturalist also, is said to have written that his wormy ship was being attacked also by small white animals resembling sheep lice. Undoubtedly he was referring to a wood-boring isopod, the gribble, the most numerous and active species of which, on this coast, is Limnoria lignorum (Pl. XLVI). Shipworms perform their work on the inside of wood; . . . . .

330.Whoever frequents wharves, piers, and floats, especially at not-quite-respectable hours, will be certain to see some of the more obvious free-swimming invertebrate animals that haunt the harbors. While such pelagic animals are not within the scope of this work, it would be a pity not to mention the bell-shaped jellyfish. . . [compilation to be completed later].

B. Protected Piles

As previosuly stated, we can draw only a vague line between relatively exposed and fully protected piling. Between the obvious extremes there is probably great overlapping, and we have to remind the reader that this classification is offered tentatively. Further work may justify it as a working hypothesis or may show that other factors than exposure are the primary ones.

Depth zonation is apparent here as on more exposed piling, but the distinctive animals are so few in number that they will be treated without formal zonal classification.

331. We were surprised to learn, from the identification of specimens sent to the National Museum, that the common small barnacles of protected piling in two test spots, Berkeley and Newport Bay, are the omnipresent Balanus glandula (4). For some reason the small barnacles of this coast have been almost entirely overlooked by collectors, so that until someone works them over carefully it is impossible to make any general remarks that further investigation may not refute.

332. The California mussels of the more exposed piling are replaced in these quiet waters by the smaller and cosmopolitan bay mussels, Mytilus edulis (197). In favorable environments they often form great bunches that double the diameter of the piles on which they grow, and they may be found in probably every suitable port between the Bering Sea and northern Mexico. They attain their maximum development in the middle zone, so they are very obvious, even at half tide. . .

A pycnogonid (sea spider) occurs in hydroid clusters of this sort: Achelia nudiuscula. In a personal communication, J.W. Hedgpeth says of it: "abundant on Obelia on pilings and junk along the east shore of San Francisco Bay - in very filthy water." It is known only from this, the type locality. There is a good illustration in Hall (1913).

In cleaner stretches of quiet water, particularly up north, the tenuous . . . [to be compiled later].

333. In the extreme low-tide zone enormous bushy clusters of the naked hydroid, Tubularia crocea (Pl. XLVI), will be found banding the piles or floating landings with delicate pinks or reds. It's nearest relative is the small solitary ... We have found T. crocea in Newport Bay, Elkhorn Slough, and San Francisco Bay, and it is known from many regions to the northward and from both sides of the Atlantic.

Hilton found the . . . .

334. Crawling about on the piling throughout the intertidal zone, but keeping fairly weel under water whateve the height of the tide, any of several crabs may be seen. Practically all of the rock-shore forms have been reported, and two spider crabs seem to be characteristic. In Montery Bay southward to Panama a thoroughly attenuated, gangly form, . . . Sponges and seaweeds mask this sluggish little crab so that it will seldom be noticed until what appears to be a bit of the fixed piling growth moves slowly away from the observer.

Oregonia gracilis is very similar, but twice the size of the Pyromaia. It may be seen occasionally on wharf piling in Puget Sound and in eelgrass beds, whence it ranges northward to the Bering Sea and southward, but in deeper water, to Monterey. The masking habit of this group of crabs is discussed in 131.

Several cucumbers occur, in the Puget Sound area especially. Huge Stichopus californcus (77) crawl about on the pilings frequently enough to be considered characteristic here, but keep pretty well below the low-tide line.

335. On these fully protected piles we find a good many of the animals already mentioned as occurring on more exposed piling: The omnipresent Pisaster, both the common (157) and the brevispinus (209) forms, and the usually white anemone, Metridium (321). There are the usual tunicates,

336. Boring forms are as common here, and as destructive as on less-sheltered piling. The boring isopods, Limnoria (329), operate quite indiscriminately in these quiet waters, assisting the shipworms to make life miserable for harbor engineers. Another isopod of ill fame is the large . . .

337. Twenty years ago the European shipworm, Teredo navalis, was altogether unknown on this coast. Just when or how it gained a foothold is not known, but in 1914 it was discovered that piling at Mare Island, in the northern part of San Francisco Bay, had been extensively damaged. The attack was repeated in 1917, and within three years the damage reached unprecedented and catastrophic proportions. Ferry slips collapsed, and warehouses and loaded freight cars were pitched into the Bay. All piling was attacked and most of it destroyed. Since then Teredo navalis has spread to all parts of the Bay. The animals can stand much lower salinity than other shipworms, which accoutns for their devasatating attacks in the northern parts of Bay, where piling was largely untreated because it had been supposed that the influx of fresh water from the Sacramento and San Joaquin rivers afforded immunity from borers. The freshwater does kill them off during the seasons of heavy rainfall, but when conditions improve they come back in force. [to completed later]

338. In Los Angeles and San Diego harbors, and in Hawaii also, the havoc-working shipworm is the small Teredo diegensis. Reaching a length of 5" but averaging near 2", it is the smallest shipworm occurring on the Pacific coast. Breeding apparently takes place throughout the year . . . Even if it survives it is unlikely ever to become an important destructive factor in San Francisco Bay's relatively cold waters.

Analysis by
Robert 'Roy' J. van de Hoek
Field Biologist & Geographer
Wetlands Action Network

Ed Ricketts refers to the title of this chapter as "Wharf Piling" which is also meant to indicate piers, such as Malibu Pier. Ed Ricketts was perceptive to realize that piers, wharves, and pilings were excellent places to study marine life of the shore. Here the rate of settlement of animals as well as the pattern of animal life in zones or bands on the pilings could be measured. Some animals require longer amounts of time to be covered with water while others require less. He also compared piers pilings on coasts where more wave energy occurred versus pier piling in protected harbors and estuaries. The theme of his observations follows his introduction of his 1939 book Between Pacific Tides. The preface of that book is worthy of note to recall in thinking of his writing about wharves and pier pilings.

The enormous wealth of life that occurs between the upper and the lower limits of the tide is a phenomenon of intense interest to the biologist and to the layman alike. Here strange plants and bizarre, brilliantly colored animals grow in such abundance that the most casual visitor to the seashore cannot fail to notice some of them. Almost invariable his curiosity is aroused: Is that gorgeous flower-like thing in the tide pool a plant or an animal? What is it called? What does it eat? How does it defend itself and reproduce its kind? Will it hurt me if I touch it?

And while the visitor is puzzling over his first sea anemone, a score of crabs may scurry away at his footfall or may rear up and offer battle in defense of life and liberty. When he turns to watch the crabs he may see a bed of urchins, their bristling spines half concealed by bits of seaweed and shell. He may stoop to pick up a snail, only to have the creature roll from the rock at the approach of his hand, tumble into a pool, and scramble awayat a very unsnail-like pace. He hears scraping sounds and clicks and bubbling, perhaps sharp cracks like pistol shots. Jets of water shoot up. Everywhere there is color, life, movement.

In shore, our visitor to a rocky shore at low tide has entered possibly the most prolific life zone in the world - a belt so thickly populated that often not only is every square inch of the area utilized by some plant or animal but the competition for attachment sites is so keen that animals settle upon each other - plants grow upon animals, and animals upon plants.

To supply such a person with as much as possible of the information . . . [to be continued]

In the Introduction, Ed Ricketts justifies his study of pier pilings and wharf pilings as follows:
"IV. Wharf Piling. In addition to many animals which will be found elsewhere, wooden pilings support numerous species, such as the infamous Teredo, which will seldom or never be found in any other environment. The nature of piling fauna justifies its division (for convenience, and probably in point of fact) into: A. Exposed. B. Proteced." It is abundantly clear to this writer that Ed Ricketts was fascinated with piers and wharves. In other writings and essay, he has certain special ways of using nostalgia, myths, poetry analysis, and other methods to tell us of his interest in piers and wharves. It seems to be paralleled in John Steinbeck as well. When John Steinbeck left California, and established a new home and bioregion for himself in New York on Long Island, in the small town of Sag Harbor, Steinbeck made sure that he had a small pier/wharf at his home, for his contemplation and his boat to be moored. Perhaps Ricketts and Steinbeck' nostalgia has to do with piers and wharves as being the starting and ending point of potential journeys to faraway places? Perhaps it is the boundary of human society and beginning of wilderness, wildness, and wild nature?