The Stages of Whale Decomposition

[Music] surviving in the deep sea is no easy task with fierce competition no sunlight and scarce food and nutrients organisms at these depths have developed a number of peculiar lifestyles in response to such an extreme environment nearly all nutrients in the depths are supplied by debris that fall down from the surface waters the food webs are sustained only by a slow drizzle of organic particles and detritus known as marine snow it isn't much but it's enough to sustain scattered communities of detritivores who rely on this organic matter for [Music] food however on some rare occasions the nutrient poor depths are treated to a feast every now and then a citation carcass will sink to the sea floor and draw scavengers from miles around to feed on the nutrient-rich carrion this is a whale fall an event that creates complex localized ecosystems on the sea floor which can support life for decades [Music] [Music] as a whale dies and sinks the carcass provides a sudden concentrated food source in the otherwise food poor abyss in fact when whale full ecosystems were studied in 1988 by a team of researchers at the university of hawaii it was estimated that the sedimentation of a decomposing 40-ton whale carcass provides nutrients equivalent to 2 000 years worth of material that falls as marine snow for an area of 50 square meters in a region of the ocean where food is often just a slow trickle from above these events are significant the body can last for decades in that time it creates an island of life on the sea floor supporting an ever-changing ecosystem that blooms out of the benthos and as it decomposes it provides a miniaturized model of ecological succession [Music] in much the same way as life on oceanic islands sees a change in its communities over time the stages of whale decomposition support a number of different scavenger communities and just like islands whale falls are hot spots of adaptive radiation the process in which organisms rapidly diversify from an ancestral species into a multitude of new forms this is because the new resources provided by whale falls alter the way in which deep sea creatures interact with one another and open up new niches for organisms to occupy as a result many new species that appear to be specialized to living exclusively at whale falls have been discovered during recent studies these findings suggest that whale fools may help to generate biodiversity on the sea floor let's take a closer look at the complex fascinating communities that gather at whale falls [Music] it begins at the surface soon after death the insides of the whale begin to decompose as decay sets in gases cause the body to expand and float up to the ocean surface where it's scavenged by sharks and seabirds [Music] but once these gases escape the whale's body begins to sink into the sunless void of the deep sea [Music] once it settles on the ocean floor at depths of a kilometer or more it can be classified as a whale full and now begin the four key stages of ecological succession which each support their own distinct communities of life [Music] first is the mobile scavenger stage after the carcass comes to rest on the ocean floor life arrives at the scene in a matter of hours mobile scavengers such as hackfish and sharks allured by the scent of death and swim from afar to consume the flesh and blubber hagfish use their dental plates to burrow deep into the carcass or bite off chunks of food while they eat they twist their bodies into a knot then pass the knot along their body and force it against the carcass to increase the power of their bite this allows them to tear flesh from even the toughest of meals [Music] the mobile scavenger stage of whale fall ecosystems is characterized by larger organisms visiting the carcass like this sleeper shark which can grow to nearly seven meters in length in a matter of months the carcass is stripped clean down to the bone however in an ecosystem so nutrient deficient as the deep sea when something so large falls to the depths nothing goes to waste [Music] now begins the second phase known as the enrichment opportunist stage many of the larger scavengers have moved on and it's now the turn of smaller organisms to comb the surrounding sediment for decomposing tissue organic fragments or detritus may enrich the sediments nearby for over a year [Music] the carcass you're seeing now was filmed in 2019 by the eevee nautilus team at the davidson seamount 3240 meters beneath the surface of the ocean [Music] here invertebrates have begun to colonize the bones [Music] worms crustaceans and mollusks like these moose octopus octopuses feed on leftover blubber or burrow down into the nutrient-enriched sediment beneath the whale eel pouts pick the bones of any flesh left behind by the mobile scavengers over time as the organic material is slowly depleted the scavenger populations begin to decline [Music] one year later in 2020 the ev nautilus team returned to the davidson seamount whale fall what they found was a dramatically different scene for it had entered the third stage called the sulfophyllic stage this is by far the longest stage of a whale fall for it may last for 50 years or more many of the bones appear to have disintegrated and there's a much lower density of scavengers but although the carcass may appear devoid of life the remaining skeleton supports a remarkable community of chemosynthetic bacteria that begin to break down lipids trapped in the bones this process forms sulfites as a byproduct which are released up to eight feet into the surrounding sediment and supports a rich mix of dense bacterial mats muscles clams and worms feeding not on flesh but on the microbes polychaete worms like the bone-eating ozodax worms carpet the whale's bones in a fuzzy red fringe these have neither eyes nor mouth but they present reddish plumes that act as gills and green roots that burrow down into the skeleton from the marrow the worms roots extract fats and oils which microbes living inside the roots break down [Music] a fourth stage of whale full ecological succession has also been postulated known as the reef stage it involves the solid mineral remains of the whale bones providing a hard substrate for suspension and filter feeders to inhabit out on the abyssal plain the soft sediments prevent many sessile organisms from finding a solid surface to attach to as a result hundreds of years after death a whale's corpse may still be able to provide islands of abundance at the bottom of the ocean [Music] the successive communities that thrive around these whale carcasses show just how important whaleful events are to the deep sea ecosystem the immense biomass of whales and especially high bone lipid content allows their carcasses to support diverse and complex ecosystems that would otherwise not exist in the energy poor deep sea [Music] but they're not only important for the survival of existing species for the niches they create may play an important part in allowing new species to develop for example an abundance of new bristle worm species have been discovered at these sites which may be uniquely adapted to survive at whale falls for species such as these whale falls may provide evolutionary stepping stones to allow new lineages to adapt to new extreme habitats like hydrothermal vents and brine pools

Channel: Natural World Facts

Views: 2,057,132

Keywords: ocean exploration, deep sea creatures, marine biology, deep sea, whale fall, dead whale, sunken whale, whale, whale fall ecosystem, whale fall natural world facts, whalefall ecosystem, mariana trench

Id: QxSUsn8H2zs

Length: 12min 20sec (740 seconds)

Published: Tue Mar 22 2022

Reddit Comments

[u/spilltheteasis_]

I’ve watched this video 3 times already and I’ll continue watching it, because it’s so interesting and beautiful

[u/CaptainThaddeus]

Billy Football never talks about cool stuff like this r/pardonmytake