Dangerous Marine Organisms

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Dangerous Marine Organisms

• Protistans and Invertebrates

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Outline

• Algae
• Sponges
• Cnidarians
• Mollusks

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Algae Red Tide

• Red Tides occur in and around the US as well as
  other areas of the world
• Occasionally, the algae grow very fast or "bloom"
  and accumulate into dense, visible patches near
  the surface of the water.
• These blooms often appear red in color
• The term is a misnomer nothing to do with tides

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Algae are Protist

• Simple plant like organisms - autotrophs
• Often single celled, but some are multi -
  cellular
• Marine, freshwater and terrestrial
• Dinoflagellates are often associated with blooms

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Dinoflagellates
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Algae Life Cycle
http//www.whoi.edu/redtide/whathabs/whathabs.html
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California Noctiluca Bloom
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HABs

• HAB refers to bloom phenomenon that contain
  toxins or that cause negative impacts (Harmful
  Algae Blooms)
• These toxins are neurotoxins and they may cause
  the death of fish, birds and even humans

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Organisms Affected
http//www.whoi.edu/redtide/foodweb/HABfoodweb.htm
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Shell We Do Lunch?
1990 six fisherman almost died after eating
steamed mussels (Georges Bank)
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Alexandrium

• This blooming algae produces a neurotoxin
• Clams, mussels and other filter feeders
  concentrate the toxin.
• Toxin causes the paralysis of the diaphragm
  muscles.asphyxiation may result
• Coast Guard air lifted the fisherman ashore
• They were hospitalized, but recovered in a few
  days. Soon back fishing.

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Fish Kills due to Harmful Algal Blooms
Florida Beach Covered with Red Tide Killed Fish
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Marine Mammals Die
1991 Cape Cod 14 Humpback Whales Die from
Saxitoxins in Mackeral
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Where Do They Occur in US?
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Why Do HABs Occur?

• No clear answer
• Some evidence that pollution may cause HABs
• Other studies indicate pollution not a major
  factor
• Some hypothesize that increased monitoring of
  marine waters turns up cases that would otherwise
  be missed.

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Ciguatera (CFP) - 1

• CFP produces gastrointestinal, neurological, and
  cardiovascular symptoms. Generally, diarrhea,
  vomiting, and abdominal pain occur initially,
  followed by neurological dysfunction including
  reversal of temperature sensation, muscular
  aches, dizziness, anxiety, sweating, and a
  numbness and tingling of the mouth and digits.

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Ciguatera and Reef Fish

• Ciguatera results from the eating of reef fish
  affected with ciguatoxin. Ciguatoxin originates
  from a dinoflagellate name Gambierdiscus toxicus
  which colonizes coral beds. The toxin first
  affects the coral-grazing fish and is then passed
  up and through the food chain to the piscivorous
  fish (i.e., snapper, grouper, amberjack,
  barracuda) and finally to man. The toxin is not
  affected by either cooking or freezing, and the
  affected fish, cooked or raw, is not tainted by
  bacteria in any way. Typically, the victim
  states, "It was the best fish I ever tasted."

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Some History

• Ciguatera symptoms were first described in the
  1500's by the Spanish explorers to Cuba and were
  attributed to the ingestion of a small snail
  which they called cigua.
• In the Pacific, the first Tahitian death on the
  ship Bounty (of the famous Mutiny on the Bounty)
  was the ship's surgeon after a fish feast "Old
  Bacchus died not of drink, as might have been
  supposed, but of eating a poisonous fish.
• http//www.rehablink.com/ciguatera/poison.htm

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Ciguatera (CFP) - 2

• causative organisms Gambierdiscus toxicus,
  Prorocentrum spp., Ostreopsis spp., Coolia
  monotis, Thecadinium sp. and Amphidinium carterae
• toxins produced Ciguatoxin/Maitotoxin
• Avoid eating tropical reef fish
• No cure
• http//www.whoi.edu/redtide/illness/illness.htmlC
  iguatera20Fish20Poisoning

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Fire Sponge
Body Smooth, soft, with wide irregular lobes,
few large pores bright red or orange. Colonial
encrusts on rocks, corals, mangrove roots.
Caution causes severe rashes and
blisters.Habitat Low-tide line to 50 deep
bays, lagoons.Range Throughout region
(Florida, Bahamas, and the Caribbean). .
http//www.enature.com/fieldguide/showRguide.asp?r
guideID711speciesID4738
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The Cnidaria

• Jellyfish, corals and their relatives
• Almost all species are marine
• All contain stinging cells (nematocysts)
• Very few species are" dangerous
• Two basic body forms polyp and medusa

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Australia's box jellyfish
http//www.ucmp.berkeley.edu/cnidaria/cubozoa.html
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Chironex fleckeri
About 100 deaths during the past century Native
to the marine system of Northern Australia
Many have survived encounters with Chironex
Death may result when stung by 6-8 meters
of tentacles.
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Portuguese Man-o-war

• Fatal Portuguese man-o'-war (Physalia physalis)
  envenomation.Stein MR, Marraccini JV,
  Rothschild NE, Burnett JW.Office of the Medical
  Examiner, West Palm Beach, Florida.A fatal case
  of Physalia physalis (Portuguese man-o'-war)
  envenomation occurred on the Florida Atlantic
  coast in 1987. Despite appropriate beachside
  first aid, the patient was conscious only several
  minutes before having primary respiratory arrest
  and, later, cardiovascular collapse that resulted
  in death. Discharged nematocysts were still
  visible on the injured stratum corneum five days
  after envenomation. Additional treatment
  maneuvers suggested by this case include testing
  the tentacle fragments found on the victim's skin
  before their removal to ensure that nematocyst
  firing has been counteracted. We document the
  first human fatality caused by P physalis
  envenomation.

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Physalia
Physalia in composed of a colony of polyps
http//www.ibss.iuf.net/people/skryabin/neuston.ht
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Swimming Medusa Video

• http//www.pbrc.hawaii.edu/bekesy/angel/video/alat
  a.html

Stinging Cell
(nematocyst)
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Mollusks

• Clams, mussels, snails, octopi and their
  relatives
• Marine, freshwater, and terrestrial species
• Shelled, have foot for locomotion
• Clams and mussels are filter feeders
• Many snails are predacious
• All octopi are predators

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Cone Shell

• Marine reef dwelling snails
• Predators (fish, snails, and worms)
• Toxic harpoons
• Toxin has medicinal properties
• The active components of the venom are small
  peptides toxins, typically 12-30 amino acid
  residues

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Cone Shells
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Cone Shell
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Cone Shell Radular Apparatus
Radula
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Distribution

• In the US Cone shells are indigenous to US
  waters, but travelers are not likely to encounter
  them (Gulf of Mexico and Florida Keys)
• Internationally Thirty cases of human
  envenomation have been recorded from the
  Indo-Pacific region and Australia.

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Envenomations

• When envenomations occur in humans, usually
  to the hands or feet, the result is somewhat
  unpredictable. Minor envenomations cause pain,
  swelling, and localized numbness that often
  subsides within hours of onset. Serious
  envenomations are associated with a rapid
  progression of symptoms, including paralysis,
  respiratory arrest, cardiac failure, and death.
• http//www.emedicine.com/med/topic1636.htm

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Xenome (Pharmaceutical Company)

• About Xen2174
• Xen2174 is a synthetic drug modeled on a peptide
  isolated from the venom of a cone shell found on
  Australia's Great Barrier Reef.
• Xen2174 is currently under preclinical
  development for the management of chronic pain.

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Blue Ringed Octopus
http//www.earlham.edu/sheedjo/blue-ringedoctopus
.htm
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Blue Ringed Octopus

• Distributed from Japan to Australia
• Common in tide pools and reefs
• Small 200mm across
• Very toxic (bite)
• Tetrodotoxin (same as found in pufferfish and
  poison arrow frogs)
• Neurotoxindumbness, paralysis, difficulty in
  breathingmay require ventilation

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The Mystery of TTX

• It was a mystery why such a diversity of
  unrelated organisms would all evolve the same
  toxin, until it was recently discovered that
  bacteria associated with many of these animals
  actually produce TTX. This is the case in
  blue-ringed octopuses. Their salivary glands
  harbor dense colonies of TTX-producing bacteria.
  The blue-rings have evolved a symbiotic
  relationship with the bacteria.
  http//www.nhm.ac.uk/hosted_sites/tcp/bluering2.ht
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