A whale fall occurs when the carcass of a whale has fallen onto the ocean floor at a depth greater than 1,000 m, in the bathyal or abyssal zones. On the sea floor, these carcasses can create complex localized ecosystems that supply sustenance to deep-sea organisms for decades.

1. Whale fall ecosystem
and
Important

2. What is a whale fall?
When whales die and sink, their carcasses —
known as whale falls — provide a bounty of
nutrients for deepwater creatures.

3. Whale-fall ecosystems were first studied in 1988
by a team of researchers at the University of
Hawaiʻ i, led by Craig Smith.
In short, a whale fall is a food boon in this typically nutrient-poor region
of the ocean.
What Happens After A Whale Dies?

4. • When whales die and sink, the
whale carcasses, or whale falls,
provide a sudden, concentrated
food source and a bonanza for
organisms in the deep sea.
• Different stages in the
decomposition of a whale
carcass support a succession of
marine biological communities.
Scavengers consume the soft
tissue in a matter of months.
Organic fragments, or detritus,
enrich the sediments nearby for
over a year.
• The ocean's depths are supplied by nutrients falling down from the surface
waters.

5.  The whale skeleton can support rich communities for years to
decades, both as a hard substrate (or surface) for invertebrate
colonization and as a source of sulfides from the decay of organic
compounds of whale bones.
 Microbes live off of the energy released from these chemical
reactions and form the basis of ecosystems for as long as the food
source lasts.
 At deep sea levels this forms a new food web and provides energy
to support single- and multi-cell organisms and sponges, thus
adding to the ocean's food chain.

6. Fallen whale carcasses, abundant in the deep-sea

7. Whale falls are places of evolutionary novelty, sheltering species first discovered on
the bones of dead whales.
These species have adapted to live in the extreme environment of the deep sea: a
cold region of immense pressure and intense darkness.

8. Dead and decaying material that falls from the surface, forming
"marine snow" — dead plankton, dead animals shells, fecal
matter, and other inorganic material. But every so often,
something larger reaches the sea floor.
Understanding the importance of many of these habitats in the
deep sea, such as whale falls, is still new and emerging.

15. Four stages of ecological succession in a whale-fall
ecosystem
With each stage bringing new organisms to
the dinner table.
1. Mobile-scavenger stage.
2. Enrichment-opportunist stage
3. Self-fulfilling stage
4. Reef stage

16. 1. Mobile-scavenger stage
 Organisms in this first wave clean the carcass to the bone.
 "Big fish, like sharks and rattails and hagfish, and big
crustaceans like Isopods, which are kind of like rolly pollies,
and Anthropods, like lobsters.
 Active scavengers consume the soft tissues;
 They come from far and wide to feed on the flesh of the whale,"

21. 2. Enrichment-opportunist
stage
 Where smaller organisms comb the surrounding sediment
for decomposing tissue.
 Much smaller in size, like little crustaceans or little
worms.
 A lot of things that live in the sediment,"

26. 3. Self-fulfilling stage
 By far the longest stage in a whale fall community.
 Bacteria break down fat trapped in the bones, producing
hydrogen sulfide as a byproduct of that reaction.
 Through the process of chemosynthesis, the hydrogen sulfide
powers a variety of other bacteria and microbes.
 completely different set of organism
 thick bacterial mats, that grow all over the bones, and are white and yellow
and orange and sort of can glow.“

27.  During this stage, you'll also find organisms that rely on sulfur-
oxidizing bacteria, like chemosynthetic clams, known
as Vesicomyids.
 Bone-eating worms, known as Osedax.
 The genus Osedax were first discovered living on the bones of a
gray whale in 2002.

28. 4. Reef stage
 The mineral remains are colonized by suspension feeders, living
on the fat-depleted bones.

29. These “whale-falls” attract a diverse array of creatures from sleeper sharks to
‘snow-boarding’ worms and are considered important habitats for generating
species diversity in the deep sea. Over 120 new species have been discovered
living at whale falls including, the bizarre Osedax bone-eating worms.

30. A 30-ton whale in the Santa Cruz Basin covered with chemosynthetic
organisms.

32. Life After Whale
(On Whale Falls)
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