Chapter 4

LIFE AT THE EDGE OF THE SEA

Everyone likes to be a beachcomber! And each passing tide exposes the secrets of the sea to those interested enough to take a closer look. Suppose that we examine this world which is revealed to us twice daily.

“WEEDS” OF THE SEA

The sea holds many strange plants that have taken on fantastic sizes and shapes because of their underwater environment. In spite of their size, these plants are usually among the most primitive—a simple sheet of cells. Such plants are called _algae_ and are subdivided according to their colors.

_The Brown Algae_

Common Rockweed (_Fucus_, several species)

Brown, flattened body Central midrib Stem has air bladders

The bladders are filled with air, and children like to squeeze them to hear their pop. These bladders cause the plant to float upright, thus keeping all its sides in contact with water.

Nodose Rockweed (_Ascophyllum nodosum_)

Thin, round stem No central midrib

When dried by the sun, this plant makes an interesting and lasting souvenir, for it turns a lustrous black.

Common Kelp (_Laminaria agardhii_)

Broad, flat blade Several feet in length

The kelps of the Pacific grow several hundred feet in length, making them the largest of the algae and among the very largest plants.

Fingered Kelp (_Laminaria digitata_)

Many blades, extending like fingers on a hand

All kelps have a rootlike structure called a “holdfast” to serve as an anchor. Often tiny sea creatures dwell in among the holdfast. Why not take a look?

Perforated Kelp (_Agarum cribrosum_)

Central midrib Broad blade punctured with hundreds of holes

In Asia this kelp is farmed for food called agar. An extract of the plant, agar-agar, is used in the laboratory as a culture medium for bacteria and other disease-producing organisms.

_The Green Algae_

Sea Lettuce (_Ulva species_)

A sheet of green

This is a very simple seaweed that reproduces itself by fragmentation, each fragment growing into a new plant. Two common kinds are found at Crane’s Beach:

_Ulva lactuca_, which is the broad green “leaf”; _Ulva lanceolata_, which is in thinner, more ribbon-like strips.

_The Red Algae_

Irish Moss (_Chondrus crispus_)

Flattened, branching fronds Purple in life, white when sun-bleached

Here is a very common tidal plant that has commercial value. It is called “Dulse” on the Boston markets, and a very delicious pudding is prepared from it (seamoss farine). Why not take some home and try it?

Polysiphonia (_Polysiphonia_, several species)

Pink or red color Branching, lace-like appearance

Sometimes called “Mermaid’s Hair,” these tiny plants are very common on the beach. There are many kinds of Polysiphonias, but a microscopic study is usually necessary to tell them apart.

Coralline Algae (_Coralline_, several species)

White or pink limy covering Appear jointed

These plants have the amazing ability of concentrating lime from the sea water and depositing it on their fronds, thus acquiring a stony, coral-like appearance.

ANIMALS OF THE SEA

Animals, in a kaleidoscope of unbelievable sizes, shapes, and colors, abound here at the margin of the sea. Specializations range from the single-celled body of the zooplankton to the multicellular body of the Seals and the occasional Porpoise.

_The Sponges_

Finger Sponge (_Chalina oculata_)

Brown or tan color In colonies of fingerlike projections

The most common sponge on Crane’s Beach is the Finger Sponge. Even a small piece may be identified by the holes on its surface, through which the animal filtered water. The strange appearance of this sponge has given it the repulsive name of “Dead Men’s Fingers.”

Crumb-of-Bread Sponge (_Halichondria panicea_)

Pale green in life Light tan or white when dried on beach Crumbles easily

Only the most searching eye will discover this sponge, because it so closely resembles a dull uninteresting rock or pile of bread crumbs. When it has been freshly broken, it has a vile odor—a good clue to identification.

_The Jelly-like Animals_

White Jellyfish (_Aurelia aurita_)

Flattened body Under 10″ in diameter

The tentacles dangling down from the underside of this jellyfish are covered with tiny stinging cells, which in this species do not penetrate human skin.

Pink or Red Jellyfish (_Cyanea capillata_)

More than 10″ in diameter Reddish center, yellowish sides

This jellyfish occasionally grows up to eight feet in diameter, with tentacles a hundred or more feet long. The stinging cells can painfully wound a swimmer, but you may examine a small jellyfish safely by placing your hand on the smooth dorsal surface and turning it over.

Sea Anemone (_Metridium dianthus_)

Cylindrical, soft body Tentacles at top give flower-like appearance Generally very colorful

The “petals” of the Sea Anemone’s flower-like head are actually tentacles covered with stinging cells and used to stun its food. Generally found in the water at tide level, the Sea Anemone moves by walking on its single, base-like foot.

_The Worms_

Clam Worm (_Nereis virens_)

Jointed One pair of paddle-like feet per segment Two “tails” Pinchers on the head (watch out!)

This is the best-known worm on the beach because of its desirability as fish bait. During the day it lives in its burrow in the sand, wandering forth at night and swimming about in the water, where it becomes easy prey for gulls and fishes. The skin is brilliantly iridescent in the sunlight.

_The Crustaceans_

Common Barnacle (_Balanus balanolides_)

Common on rocks and shellfish White, volcano-shaped shell Two “barn doors” at top

This animal goes through life standing on its head and kicking food into its mouth with its feet! When it is submerged in sea water you can see its shell doors open and its feather-like feet sweep the water for microscopic food organisms. The limy shell first suggests a relationship with the clam, but body structure shows it to be a closer relative of the crab.

Shrimps (_Crago septemspinosus_, the Sand Shrimp, and _Palaemonetes vulgaris_, the Prawn)

Hard, transparent shell Long antennae Paddle-like tail

These tiny tide-pool creatures look for all the world like the larger edible shrimp served in local restaurants. Actually, these miniature two-inch-long shrimps are edible also, and quite enjoyable if you have the time and patience to collect enough for a meal.

American Lobster (_Homarus americanus_)

Bits and pieces of Lobster are frequently found on the beach, but seldom the entire animal. The Lobster inhabits deeper water and finds its way to shore only after losing a battle with one of its enemies. A favorable dining size is one or two pounds; however, Lobsters do attain weights up to forty pounds.

True Crabs (Cancridae and Portunidae)

Football-shaped in cross section Two large claws Eyes mounted on stalks

The three very common True Crabs of Crane’s Beach may be found in one search of the tidal pools. They are:

Rock Crab (_Cancer irroratus_): A brick-red shell, somewhat granulated, with a black and yellowish undersurface.

Jonah Crab (_Cancer borealis_): Similar in color to the above, but its shell has a more sculptured surface.

Green Crab (_Carcinides maenas_): A greenish-colored shell. The last pair of legs end in sharp points, rather than being flattened like paddles.

Horseshoe Crab (_Limulus polyphemus_)

Shell with horseshoe-shaped outline Long, sharply pointed tail Two immovable compound eyes

The Horseshoe is not a Crab at all, but is more closely related to the spiders, mites, and scorpions. In spite of its relations, the Horseshoe is a harmless creature whose only protection is its hard shell. Therefore it may be examined freely—a strange “living fossil” that has survived 400,000,000 years of evolution with very little change.

_The Mollusks_

Oyster (_Ostrea virginica_)

Mottled, unattractive shell Gray splotches on inside surface

Even without pearls, our Oyster is worth many thousands of dollars a year to shellfish dealers because of its delicious flesh. Its tropical relatives are the pearl producers.

Mussels (_Mytilidae_)

Blue-colored shells Shells covered with black, horny skin

Living mussels are always found attached to rocks or pieces of wood by tiny threads of their own making. Two common mussels are:

Edible Mussel (_Mytilus edulis_): Smooth, velvety-blue shell identifies it. The animal within is edible and quite delicious. It is commonly utilized as food in Europe but less so here, where we have, and seem to prefer, the Oyster.

Ribbed Mussel (_Modiolus demissus plicatulus_): Similar to the above but with many distinct ribs radiating on the surface. The Ribbed Mussel is not considered edible. While not poisonous, it is most unpalatable.

Hardshell Clam (_Venus mercenaria_)

Thick, round shell Purple blotches on inside surface

Also called “Quahog,” “Little Neck,” “Round Clam,” or “Cherrystone,” the Hardshell Clam is another highly prized seafood.

Edible Clam (_Mya arenaria_)

Fragile shell with egg-shaped outline Wing extending out from inside top of left half of shell

These clams are found just a foot or so under the sand, and their empty shells are common on the beaches. This is the Softshell Clam, which we enjoy steamed, baked, or fried, as well as in New England’s famous clambakes and clam chowders.

Surf Clam (_Spisula solidissima_)

Very large shell Spoon-shaped trough at inside top of shell

This is the largest clam on the Atlantic seaboard, growing up to about seven inches in length. It is edible, and just one or two make a large chowder. The shell makes a fine ashtray and an unusual and useful souvenir.

Razor Clam (_Ensis directus_)

Elongated brown shell

The Razor has a very large foot, with which it can often dig faster than the hand trying to discover it. Although delicious, the Razor Clam is seldom seen on the markets because it is so difficult to capture.

Snails (Littorinidae, Thiasidae, and Naticidae)

Clams in a coiled shell

Several species are found at Crane’s Beach:

Periwinkles (_Littorina_): These have a wrinkled shell about the size of a thumbnail. Because they are able to withstand long periods without water, Periwinkles are often found high on a beach.

Rock Purple (_Thais lapillus_): Has a rough, white shell coming to a point at the top. This snail secretes a purplish dye that was used by the American Indians and the ancient Phoenicians to produce their “royal purple” dyes.

Moon Snail (_Polinices heros_): Large white shell with almost round shape. The Moon Snail lays its eggs in a sand “collar,” which is frequently discovered on the beach in its dry state.

Slipper Shell (_Crepidula fornicata_)

Shell is boat-shaped Tiny “seat” inside shell

This animal protects its bare underside by attaching itself to a handy rock with its suction-cup foot. Often there are enough of them to give the rock a warted appearance.

_The Spiny-skinned Animals_ (_Echinoderms_)

Starfishes (_Asterias vulgaris_, and others)

Five-armed body

The Starfish seems to like Oysters as well as we do, and it opens them by sheer strength. Oystermen used to tear Starfish apart to destroy them, until they discovered that each arm has the ability to regenerate and become a whole starfish!

Sea Urchin (_Strongylocentrotus droehbachiensis_)

Round body Covered with spines

Here is a creature with a scientific name much too long for its size. Indeed, the name is said to be the longest in animal nomenclature. The Sea Urchin is a living fossil with four times as many extinct cousins as living ones.

Sand Dollar (_Echinarachnius parma_)

Silver-dollar size and shape Raised, star-shaped pattern on back

This is an animal of deeper water and so the bather seldom sees a live, heavily spined specimen. We find the dry, spineless shells on the beach. Wrap them carefully if you wish to take them home, because they are most fragile.

_The Fishes_

The waters off Crane’s Beach abound with many dramatic fishes such as Cod, Mackerel, Flounder, and Sand Sharks; but we are concerned only with the common tidal fishes that are regularly washed onto the shore.

Pipefish (_Syngnathus fuscus_)

Lead-pencil size and shape Hard, bony plates cover body

One look at a Pipefish will convince you that it must be related to the Seahorse. It spawns late in the spring, the female laying her eggs in the pouch on the stomach of the male. The male carries these eggs kangaroo-fashion, until they hatch during the summer.

Silverside (_Menidia menidia_)

Silver stripe running down a light side

These fish are also an important food item for the Gulls and Terns. Silversides run in schools of a hundred or more, which can be located by the flocks of birds gathered round overhead.

Skates (_Raja_, several species)

Strange bat shape Long ratlike tail

These are harmless fish resembling the dangerous Rays of the tropics, except for their habits. The egg cases of the Skate are rectangular, black, horny envelopes. They are commonly found on the beach, where they are called “mermaids’ purses.” If you find a fresh one and open it, you may discover a miniature Skate inside.

Killifish (_Fundulus heteroclitus_)

Stout, olive-green fish Rounded tail

The “Chub,” well known to fishermen, can live for a day covered only with a layer of damp seaweed. It does us a real service by feeding on the mosquito larvae in brackish water.

Sticklebacks (_Gasterosteus_ and _Apeltes_ species)

Spines on the back Very narrow base to tail

During the early summer months, the Stickleback builds a barrel-shaped nest, held together with gelatinous threads. After the eggs have been deposited, the male guards the nest with amazing vigor, considering his size.

Sand Lance (_Ammodytes americanus_)

Knife-shaped body Long dorsal fin (fin on back) Protruding lower jaw

Thriving abundantly off the beach, the Sand Lance is an important item in the diet of shore birds.

FOR MORE INFORMED BEACHCOMBING

Thus begins our day of beachcombing. Every animal and plant of the sea has a tale to tell and some of the most exciting of all are found in this ribbon-like strip of water in the tidal wash.

For your further investigation, here is a list of reference books:

Charles M. Breder, Jr., _Field Book of Marine Fishes of the Atlantic Coast_. Rev. ed. New York: Putnam’s, 1948. $5.00 Ralph M. Buchsbaum, _Animals without Backbones_. Rev. ed. Chicago: University of Chicago Press, 1948. $8.00, text ed. $6.00 Rachel L. Carson, _The Edge of the Sea_. Boston: Houghton Mifflin, 1955. $3.95 Roy Waldo Miner, _Field Book of Seashore Life_. New York: Putnam’s, 1950. $7.00 Percy A. Morris, _A Field Guide to the Shells of Our Atlantic and Gulf Coasts_. Rev. ed. Boston: Houghton Mifflin, 1951. $3.95 Herbert S. Zim and Lester Ingle, _Seashores: A Guide to Animals and Plants along the Beaches_. New York: Golden Press, 1955. Cloth $2.50, paper $1.00