Kelp Forests

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Kelp Forests

• Oceans 11
• Ms. Bowie

2
Kelp Forests

• Kelp is a type of algae.
• Algae do NOT have roots.
• Algae has holdfasts that anchor it to the
  substrate such as rocks.
• Kelp absorbs nutrients directly from the water.

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Anatomy of Kelp

• Holdfast anchors the kelp to the sea floor
• Stipe stem-like structures that extend the
  blades toward the surface (sun)
• Blade leaf-like structures that carry out
  photosynthesis
• Bladder bouyant structures that float the kelp
  toward the surface.

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Anatomy of Kelp

• The frond is what we call the body of the kelp
  that is capable of carrying out photosynthesis
• Kelp can range from 2m to 30 m tall.
• Kelp grows quickly, sometimes as much as 3060
  cm/day

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Location of Kelp Forests

• Kelp grows in cool (5-20oC), nutrient-rich water
  generally in areas with a rocky bottom

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Animals of the Kelp Forests

• Common invertebrates
• bristle worms
• scud
• prawn
• snails
• brittle stars
• sea stars
• Anemones
• crabs and jellyfish.

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How Overfishing Damages Kelp

• Trawlers offshore are removing too many fish,
  such as herring.

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How Overfishing Damages Kelp

• Herring and other fish are staple diets of seals.

• As fish stocks decline, seal populations decline.

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How Overfishing Damages Kelp

• Seals are a fat and nutritious food source for
  Orcas.

• As seal populations decline, orcas turn to less
  nutritious food sources, such as sea otters

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How Overfishing Damages Kelp

• As more sea otters are taken by hungry orcas...

• Sea otter populations start to decline

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Sea Otters Kelp Forests

• The sea otter is a keystone species in the kelp
  forest.
• One of the sea otter's favorite foods is the sea
  urchin.

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Sea urchins Kelp Destroyers

• Sea urchins love to eat the holdfasts of kelp.
• Without their holdfasts, the kelp fronds simply
  float away on the tides.

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Kelp Sea Otters
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Recap Overfishing Leads to Kelp Forest Collapse
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Importance of Kelp

• Kelp forests provide food and shelter for many
  species of fish and invertebrates (like
  shellfish, crabs, snails, sea star, anemones,
  worms, etc.)

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Importance of Kelp

• Kelp forests also provide food for many birds,
  mammals and other large predators.

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Importance of Kelp

• Kelp also protects coastlines from damaging wave
  action by creating drag disrupting wave energy.

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Kelp A place to hide

• On rare occasions gray whales have been spotted
  seeking refuge in kelp forests from predatory
  killer whales.

19
Human Uses of Algin from Kelp

• Kelp is used to make many products
• toothpastes,
• shampoos,
• Cosmetics
• salad dressings,
• puddings, cakes,
• dairy products,
• frozen foods,
• Latex paint,
• pharmaceuticals.

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What Destroys Kelp

• Kelp harvesting by humans
• Grazing by fishes, sea urchins, and crustaceans
• Storms that rip the kelp from its attachment
  site
• El Niño events that heat the water
• Sedimentation from land run-off and
• Pollution by toxic chemicals sewage.

21
Kelp Recovery

• Kelp grows very quickly so most kelp forests
  recover from damage as long as the destructive
  force is removed or minimized.