English subtitles

← Healthy Oceans: Solutions to Human Impacts | California Academy of Sciences

Get Embed Code
9 Languages

Showing Revision 20 created 05/19/2017 by Marilia_PM.

  1. ♪ (intro music) ♪
  2. We hear a lot about overfishing the ocean
  3. but occasionally fishing is the solution
    to the problems facing the seas.
  4. This is Academy scientist Luiz Rocha
  5. catching lionfish in the Caribbean.
  6. Lionfish are invasive in the region
    and are munching up the local fishes,
  7. endangering several species.
  8. Invasive species is a term
  9. that scientists use to describe species
  10. that are not where they are
    supposed to be.
  11. They were transported
    from one place to another, by humans,
  12. and introduced in a habitat
    where they didn't belong.
  13. Lionfish are a predator
    and they're not native to the Caribbean
  14. so species in the Caribbean
    don't recognize them as a predator
  15. so a lot of species
    in the Caribbean are suffering
  16. and many of the species
    that the lionfish are eating
  17. they do have critical roles
    in the ecosystem.
  18. What we can do, is control them.
    We can keep their numbers down
  19. and give the native fish of the Caribbean
    a chance to survive.
  20. The Caribbean fish,
    they will adapt to them
  21. they will learn that they are a predator.
    In a lot of places they are catching them
  22. just to try to keep their numbers down
    for awhile
  23. and this is having an impact
    because people are going out more and more
  24. trying to spear them
    and selling them to places
  25. where they get distributed
    to the whole country
  26. and sold in big numbers.
  27. I'll take an order
    of lionfish sushi, please.
  28. Pass the lionfish tacos, please.
  29. Lionfish aren't the only invasive species
    causing trouble in the ocean.
  30. Some species of fish, mollusks,
    plants and more
  31. wreak havoc
    throughout the world's marine ecosystems.
  32. Most of these organisms
    get to new locations by ship.
  33. Not in a comfy cabin,
    but in the ballast water ships
  34. carry in their hulls
    to keep the boats stable.
  35. Vessels take on this water
    bringing life forms onboard
  36. and discharge it in different ports
    with the liquid.
  37. In fact,
    many governmental organizations
  38. now have strict regulations
    about ballast water exchange.
  39. Some requirements mean
    that ships have to their exchange water
  40. in the middle of the ocean,
  41. where life
    would have a harder time taking hold.
  42. Some are working to treat ballast water
  43. to make sure invasives can't hitch a ride.
  44. Other regions are monitoring
    their waterways
  45. so that if non-native species do arrive
  46. they can't successfully
    take over an ecosystem.
  47. Here's another solution
    to invasive species
  48. and other threats facing the oceans:
    Marine Protected Areas.
  49. Marine Protected Areas
    or MPAs, as they're called
  50. can protect portions of the ocean
    for fish, birds, other animals
  51. and even humans.
  52. Some are established and run by countries.
  53. Others, by states.
  54. And some are even protected
    by local communities.
  55. Like this MPA in the Philippines,
  56. where local people
    are protecting their coastline
  57. from overfishing,
    including dynamite-fishing.
  58. Can I go to an MPA and swim?
    Or is it just for the fish?
  59. It differs by the location.
  60. In some places,
    you can't swim or fish at all.
  61. Others are more open to fishing,
    and even ecotourism.
  62. Marine Protected Areas
    are very diverse around the world.
  63. They can be a no-take area,
    or they can be an area
  64. that is a managed Marine Protected Area
    in which you can still fish
  65. but it's managed, so that
  66. there's as much
    sustainability incorporated as possible.
  67. So it can remain a healthy,
    functioning ecosystem.
  68. In the United States, 41% of US waters
  69. are under some type of protection.
  70. The one problem
    with Marine Protected Areas
  71. is that there's simply just not enough.
  72. They only protect around 4 percent
    of the world's oceans.
  73. And scientists estimate
    that to protect marine life
  74. we're going to need a lot more.
  75. Look at me!
    I'm saving the ocean right now.
  76. Well, you're certainly
    making your neighbors happy
  77. by picking that up (laughs)
  78. but I'm not really sure
    you're helping save the ocean.
  79. Actually, she's right.
  80. One of the biggest threats
    to ocean health is nutrient pollution
  81. caused by fertilizers, sewage treatment,
    and even pet waste.
  82. But nutrients sound like a good thing.
  83. They are up to a certain point.
  84. But too much runoff of nitrogen
    and phosphorous into the ocean
  85. can cause areas
    known as dead zones.
  86. When water carries these nutrients
    from farmlands or urban settings
  87. into waterways that run into the ocean
  88. the nitrogen and phosphorous
    may cause algae to bloom.
  89. Many small ocean animals eat this algae
  90. but when there's just too much of it,
    the animals can't keep up.
  91. As the algae die and sink to the seafloor,
    they decompose
  92. which uses up most
    or all of the oxygen in the water
  93. causing dead zones.
  94. At 7,000 square miles
    in area—about the size of New Jersey—
  95. one of the largest dead zones is
  96. where the Mississippi River
    feeds into the Gulf of Mexico.
  97. Overuse of fertilizers from farmlands
    all along the Mississippi River
  98. contribute to this dead zone.
  99. If farmers
    use fertilizers more efficiently
  100. it would go a long way
    to help solve this issue.
  101. I can't believe using something here
    affects the ocean over there.
  102. That's why, no matter where we live,
  103. we should make sure
    these things don't end up in the ocean.
  104. We can all do our part.
    Local actions have global impacts.