By Toni Parras

he many and varied habitats of the ocean provide a home for a stunning array of marine creatures. From the nearshore seagrass beds to the deepest ocean floor, the variety and plenitude of marine life is mind-boggling, if not always easily perceptible. The seagrass environment is home to many fishes and other animals, such as seahorses, starfish, rays, shrimps, crabs, sea urchins, sea cucumbers and seashells, and provides a breeding and feeding ground for many others. In addition, many marine plants, algae and sponges are found in seagrass habitats.

Coral reef (Eduardo Cu-Unjieng)

Then we have the teeming coral reefs, the “rain forests of the sea”. Coral reefs cover approximately 27,000 square kilometers of Philippine waters and are home to thousands of species of marine creatures, one of the highest species diversity in the world. It has been estimated that healthy coral reefs can produce up to 20 tons of fish or other edible marine animals per square kilometer per year, and can generate up to USD72,000 in tourist revenues per square kilometer per year, making them economically important to Filipinos. Coral reefs also act as important physical buffers, protecting the coast from storm surge and subsequent shoreline erosion. Moreover, creatures found on coral reefs may one day provide valuable medicines to science.

Aside from these practical attributes, the intrinsic beauty of coral reefs lay within the creatures that inhabit them. Many of these animals have bizarre shapes, patterns, colors and habits, and many are rarely noticed, either because they are not of commercial value or they are not easily viewed. I write this essay to pay tribute to not only the grand but also the small critters of the ocean.

Featherstars on a coral head (Toni Parras, 1999)

As a scuba diver, I am entranced each time I enter the water and witness the multitude of colors and shapes waving in the current around me. Crinoids, or featherstars, which are loosely related to sea stars, come in every possible color combination: candy-striped pink and white, Halloween-banded orange and black, or solid mint green, bubble gum red, lemon yellow. Some are huddled up in big bunches on the tops of coral heads, others have their many arms fully extended, holding on to a sea fan to get the most reach into the current, from which they pick little bits of food.

Bubble coral(Toni Parras, 1999)

Corals also come in a vast array of shapes, hues and personalities. Some resemble big boulders, solid and round, others are spiky and branching, some bubby, some soft with flowing tentacles. There is a soft coral whose tentacles look like many flowery hands grabbing into the current as they search for food. Tube anemones, related to corals, resemble big flowers, but instead of petals, they have long elegant tentacles in subdued, glowing colors. Spiral and whip corals look like long lassos extending into the deep blue, and black corals appear like soft feathery ferns and actually come in a variety of colors, including yellow, orange, green and white.

Sea slugs (Toni Parras, 1999)

Some of my smaller favorites on the reef include the brightly hued nudibranchs. Although some are no bigger than the size of a bottle cap, they are a delight to see. Their soft snail-like bodies are often striped or polka-dotted in bright tones, which serve to warn away potential predators. A frock of frills extending from their body is actually their gills, supplying the animal with oxygen from the seawater. Their egg ribbons are also a sight to see. Thousands, perhaps millions, of nudibranch eggs are laid in a delicate pattern, which resembles a lace cuff from a child’s dress. Those also come in a variety of bright colors – red, pink or white

Many creatures of the reef are masters of camouflage. Frogfish, which literally hop across the seafloor, resemble a lumpy sponge when unmoving. The scorpionfish, so named because its dorsal fins are equipped with poisonous spines, are often barely visible because they blend in so well with the surrounding rocks and algae. A similar fish, the lionfish, has a long “mane” of these poisonous spines, but is otherwise a docile and beautiful animal.

Clown fish (Eduardo Cu-Unjieng)

Countless other creatures, from the intelligent octopus to the curious blenny to the wary clownfish darting to its host anemone for refuge, make every trip to the undersea world a fresh and treasured experience.

Manta ray (Eduardo Cu-Unjieng)

Further out in the sea are the pelagic, or open-ocean animals, including squid, sea turtles, sharks, whales and larger fishes like tuna and mackerel. These animals also play an important role in the biodiversity of marine life. Sharks, for example, when left to their natural habits, are effective at eliminating the weak and diseased fishes from the food chain by being the natural predators that they are. This is similar to the wolf’s role of reducing inferior and infirm cattle and thus keeping the stocks healthy.

And finally, many of these fishes, crustaceans, mollusks and other marine animals provide sustenance and livelihood for man, the ultimate predator.

Marine biodiversity is important for a variety of reasons. For one thing, the food web, which travels all the way up to man, as described above, is dependent on biodiversity. Removal of one character in the play changes the entire scenery. Take, for instance, what happens when the “grazers” are removed from a coral reef. Grazers include the sea urchins and fish, such as parrotfish (or mulmol), which eat the dying or dead coral and the algae that grows on it. Algae is a natural competitor of coral for space on the reef, and if the grazers are removed by, say, overfishing, the reef will proliferate with algae, which is normally kept in check by the grazers. This, over time, leads to death of the coral reef and loss of valuable habitat for the food fish and organisms on which man depends.

Another extreme example of this alteration of the delicately balanced marine ecosystem is the over-fishing of the Triton, a remarkably beautiful shell which is sought after for the souvenir trade, but which is the only natural predator of the insidious crown-of-thorn starfish. Virtual eradication of the Triton on coral reefs has led to a proliferation of the crown-of-thorn, which voraciously eats living corals. This, again in a relatively short period of time, ultimately leads to the death of the coral reef, the home of our food fish.

Similarly, the over-fishing of large predators like shark, leads to the natural balance of the seas being disturbed, and the proliferation of lower quality, sick and inferior fish for our consumption. Further, the elimination or depletion of one target species causes a displacement in the chain and another species may multiply to fill the niche as a result. Often, we cannot see the ultimate result of this; only time will tell how the ecosystem has been altered. It is the classic “butterfly effect”, in which the tiniest shift in the natural web of life leads to dire consequences.

Finally, preserving marine biodiversity is important to medical science, as yet undiscovered marine creatures may someday provide a cure for various diseases.

The quest to protect marine and all biodiversity on earth is a grand and necessary movement to pursue, not only for the sake of preserving beauty and variety in our world, but also in order to secure man’s own well-being and perpetuation.

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