What biotic factors affect kelp?

The factors influencing kelp forest stability are diverse: kelp harvesting; grazing by fishes, sea urchins, and crustaceans; plant competition; storms; El Niño events; sedimentation; and pollution.

What biotic factors affect the kelp?

The factors influencing kelp forest stability are diverse: kelp harvesting; grazing by fishes, sea urchins, and crustaceans; plant competition; storms; El Niño events; sedimentation; and pollution.

What do sea urchins eat in kelp forests?

Sea urchins are voracious herbivores. They climb up the holdfast and graze on the stipe, as well as eat drift algae that accumulate on the ocean bottom. Studies have found urchins responsible for completely removing kelp from an area, leaving it an urchin barren.

What does the kelp eat?

In kelp forests, the most commonly found invertebrates are bristle worms, scud, prawn, snails, and brittle stars. These animals feed on the holdfasts that keep kelp anchored to the bottom of the ocean and algae that are abundant in kelp forests.

What eats sea urchins in a kelp forest?

New research shows otters focus on hunting urchins in healthy kelp forests instead, leaving the areas outside alone.

What effect do sea otters have on sea urchin numbers?

Sea otters are a “keystone species” which means that they can exert top-down pressure via predation on sea urchins, which are grazers upon kelp. As urchin density decreases from sea otter predation, so does the grazing pressure on kelp and as a result kelp forests flourish in the presence of sea otters.

What factors affect kelp?

Numerous natural impacts as well as human activities, affect kelp forest environments. The factors influencing kelp forest stability are diverse: kelp harvesting; grazing by fishes, sea urchins, and crustaceans; plant competition; storms; El Niño events; sedimentation; and pollution.

What happens when kelp forests disappear?

But when the predators that keep their numbers in check disappear, the population booms and can quickly consume a kelp forest, creating what is called an urchin barren. Once their food is gone, the urchins, which can live for more than 50 years, lower their metabolism and essentially hibernate.

What happens when sea urchins eat the kelp forests?

Sea urchins will often completely remove kelp plants by eating through their holdfasts. Other invertebrates found in kelp forests are sea stars, anemones, crabs, and jellyfish. A wide range of fish can be found in kelp forests, many of which are important to commercial fishermen.

What is the relationship between co2 and o2 for kelp?

Despite their short lives by plant standards, kelps siphon huge amounts of carbon from the atmosphere—what scientists call “primary productivity.” They take carbon dioxide from the air and turn it into sugar fuel with the help of sunlight and water, releasing oxygen back into the air.

What is the relationship between kelp sea urchins sea otters and small fish?

relationship because both species benefit from the interaction. The sea otters help the kelp by eating the sea urchins because if there is too big of a population of sea urchins the kelp is endangered. The kelp in return provides and anchors for the sea otters while they are sleeping and doing daily activities.

What is the role of sea urchins in the disappearance of kelp forests?

Sea urchins feed on kelp, and this has ultimately led to a decrease in kelp forests. Areas which used to have forests of kelp and many other species have turned into beds of sea urchins.

What is the zombie urchin phenomenon?

From the New York Times Today, more than 95 percent of California’s coastal kelp are gone, devoured by a population explosion of purple sea urchins in the past seven years. This proliferation has led to dead zones known as “urchin barrens,” where carpets of urchins can be seen for miles.

What sea urchins live in kelp forest?

Purple sea urchins have boomed off Northern California, destroying kelp forests that provide a crucial ecosystem. They’re purple, spiky and voracious, and just off the West Coast, there are more of them than you can count.

What threats do kelp forests face?

Unfortunately, kelp forests today face a variety of threats, such as commercial kelp harvesting, pollution, and climate change, which exacerbates El Niño southern oscillation (ENSO) events and negatively impacts kelp reproduction and survival.

What type of relationship does the kelp and sea urchin have?

Sea urchins are herbivores and feed on seaweeds like kelp. When urchins are uncontrolled by predators they become larger and more abundant, feeding on kelp until little remains. In contrast, Dr. Estes noticed that places with healthy sea otter populations often had healthy kelp forest habitat as well.

Why are kelp forests disappearing?

Northern California’s kelp forests are declining due to two stressors. First, there has been unusual and drastic ocean warming in the area. Second, sea star wasting disease is killing the main predator of sea urchins, the sunflower sea star.

Why are kelp forests threatened?

The 2016 paper, coauthored by 37 scientists, concluded that “kelp forests are increasingly threatened by a variety of human impacts, including climate change, overfishing, and direct harvest.”

Why are sea urchins bad for kelp forests?

Having overgrazed the coastal kelp and devastated the red urchin population, the purple urchins are now starving. Worse still, they can exist in this state of starvation for decades, lying in wait to gobble up any kelp spores that appear, which prevents kelp forests from growing back.

Why are sea urchins population increasing?

The explosion of purple sea urchins is the latest symptom of a Pacific north-west marine ecosystem that’s out of whack. Kelp has been struggling because of warmer-than-usual waters in the Pacific Ocean. … “You can imagine all of these small urchins growing up, each one of them looking for food, desperate for food.

Why is sea kelp so important?

Shelter sea life Kelp forests provide food, nursery areas, and shelter—including protection from predators and storms—for hundreds of commercially and recreationally important fish species as well as West Coast marine wildlife.

Are purple sea urchins invasive?

Red sea urchins, a cousin of the purple variety, are already harvested and eaten on the West Coast, but the purple ones were once considered too small.

Are pacific purple sea urchins venomous?

Razor-sharp spines can easily pierce even a thick wetsuit and lodge deep in a diver’s skin. Many urchin species, such as the purple sea urchin, have an additional defense mechanism called the pedicellarines. The pedicellarines are tiny, jaw-like structures that can clasp onto a diver’s skin and inject a painful poison.

Are sea urchins a plant or animal?

sea urchin, any of about 950 living species of spiny marine invertebrate animals (class Echinoidea, phylum Echinodermata) with a globular body and a radial arrangement of organs, shown by five bands of pores running from mouth to anus over the test (internal skeleton).

Are sea urchins poky?

Sea urchins are primitive animals, but they boast a powerful defense mechanism. Their stings can be extremely painful and may cause extensive damage to the skin, tissue, and even bone.

Are tiger sharks protected in hawaii?

Tiger sharks are one of the many shark species that inhabit Hawaiian waters. Its companion bill, HB808, would establish administrative fines for any person who knowingly captures, takes, possesses, abuses, entangles, or kills any shark within state marine waters. …

Can sea urchins be invasive?

They are devastating kelp forests, which serve as an important habitat and food source for many organisms in the ocean ecosystem. But there is another natural predator of the sea urchin — humans. … Now, purple urchins are being captured and raised in tanks to mature, turning an invasive species into a delicacy.

Can urchins flip themselves?

If flipped upside down, urchins can right themselves through specialized movements of these spines.