At their roots, these unique ecosystems are fuelled by chemical energy, which enters the ocean from sources like seafloor hydrothermal vents. There are other deep-ocean ecosystems that are entirely independent of the sunlight energy that kick-starts the main marine ecosystem. The primary marine food web, which is based on plant productivity, includes many of the sea's species-but not all of them. Surgeonfish vary greatly in size from one species to another, though most stay within the 6 to 16 inch range, making them a small- to medium-sized fish. This is the same family that contains tangs, unicornfish, and doctorfish so these names are somewhat interchangeable. When top predator species are depleted, their numbers are often slow to rebound, and their loss can send shock waves through the entire food web. The species known as surgeonfish belong to the Acanthuridae family. They are also long-lived and usually reproduce slowly.īut the marine food chain's top predators are common prey for the most deadly hunters of all-humans. These apex predators tend to be large, fast, and very good at catching prey. The large predators that sit atop the marine food chain are a diverse group that includes finned (sharks, tuna, dolphins), feathered (pelicans, penguins), and flippered (seals, walruses) animals. Though these animals are very successful hunters, they often fall prey to a simple fact of ocean life: big fish eat smaller fish. This level of the food chain also includes larger animals, such as octopuses (which feed on crabs and lobsters) and many fish (which feed on small invertebrates that live near shore). The zooplankton of level two sustain a large and diverse group of small carnivores, such as sardines, herring, and menhaden. Many of them also share the same fate-which is to become food for the carnivorous animals of the food chain's top two levels. Larger herbivores include surgeonfish, parrotfish, green turtles, and manatees.ĭespite their differences in size, herbivores share a voracious appetite for ocean vegetation. On the ocean's surface waters, microscopic animals-zooplankton, which include jellyfish and the larval stages of some fish, barnacles, and mollusks-drift across the sea, grazing opportunistically. The next level of the marine food chain is made up of animals that feast on the sea's abundant plant life. They also produce more than half of the oxygen that we breathe on Earth. Together, these humble plants play a large role: They are the primary producers of the organic carbon that all animals in the ocean food web need to survive. On the coast, seaweed and seagrasses do the same thing.
These tiny plants and bacteria capture the sun's energy and, through photosynthesis, convert nutrients and carbon dioxide into organic compounds. Countless billions of one-celled organisms, called phytoplankton, saturate sunlit upper-ocean waters worldwide. The foundation of the sea's food chain is largely invisible. Most of these aquatic species are tied together through the food web. But the sea is so vast that a million or more as yet unknown species may live in its waters. Some 300,000 marine species are known to science-about 15 percent of all the species identified on the planet.
0 kommentar(er)
