Life Inside a Dead Whale

SciShow

30 Nov 201503:31

Summary

TLDRWhale falls, the natural occurrence when a whale dies and sinks to the ocean floor, create a unique ecosystem. Initially, scavengers consume the flesh. Then, invertebrates feed on remaining tissue and sediment. Finally, bacteria colonize bones, producing hydrogen sulfide gas that supports a sulfur-loving community. This process, lasting decades, parallels life found near hydrothermal vents and cold seeps, and is crucial for the deep-sea biodiversity.

Takeaways

🐳 **Whale Fall Phenomenon**: When a whale dies in the open ocean and sinks to the ocean floor, it creates a unique ecosystem known as a whale fall.
🌌 **Deep Sea Impact**: A whale fall occurs at depths of at least a thousand meters where food is scarce, providing a significant food source for deep-sea creatures.
🔬 **First Discovery**: The first whale fall was discovered in 1987 by scientists in a deep submergence vehicle, revealing bacteria similar to those found in hydrothermal vents.
🦐 **Scavenger Stage**: Stage one of a whale fall involves scavengers like sleeper sharks, hagfish, and amphipods consuming the whale's flesh.
🐚 **Invertebrate Stage**: Stage two sees invertebrates such as crustaceans, molluscs, and polychaete worms feeding on remaining tissue and sediment.
🦠 **Bacterial Stage**: In stage three, bacteria colonize the whale bones, consuming lipids and producing hydrogen sulfide gas, which supports a sulfur-loving community.
🕰️ **Longevity**: The bacterial stage can last for decades, similar to the ecosystems found around hydrothermal vents and cold seeps.
🌐 **Ecosystem Similarities**: Whale falls, hydrothermal vents, and cold seeps are all nutrient-rich environments that support diverse life forms in the otherwise barren deep sea.
🔍 **Ongoing Research**: Scientists continue to study whale falls to understand the species involved and their adaptations to extreme conditions.
🐋 **Impact of Whaling**: Whaling may have reduced the occurrence of whale falls, affecting deep-sea ecosystems, a subject of ongoing research.
🧬 **Adaptations**: Organisms that thrive in whale falls have evolved unique adaptations to survive in the absence of oxygen and sunlight and amidst toxic chemicals.

Q & A

What is a whale fall?
-A whale fall is a phenomenon that occurs when a whale dies in the open ocean and its carcass sinks to the ocean floor, typically at depths of at least a thousand meters.
How does a whale fall impact the deep sea ecosystem?
-A whale fall creates a complex, unique ecosystem by providing a rich food source in an otherwise food-scarce environment, leading to the development of a specialized community of organisms.
When was the first natural whale fall discovered?
-The first natural whale fall was discovered accidentally by a team of scientists in 1987 during an expedition using a deep submergence vehicle.
What types of bacteria were found on whale bones during the first whale fall study?
-The bacteria found on whale bones were similar to those found in hydrothermal vents, and some new species of clams were also discovered.
What are the stages of a whale fall ecosystem?
-The whale fall ecosystem goes through three stages: 1) the flesh-eating stage with scavengers like sleeper sharks and amphipods, 2) the invertebrate stage with crustaceans, molluscs, and worms, and 3) the bacterial stage where bacteria feed on whale bones.
How much tissue can scavengers consume during the first stage of a whale fall?
-Scavengers can consume 40 to 60 kilograms of tissue per day during the first stage of a whale fall.
What unique species were discovered during the study of the first whale fall?
-A species of snail was discovered on the first whale fall in 1987, leading to the identification of a new family of aquatic snails.
How long can the third stage of a whale fall last?
-The third stage of a whale fall, where bacteria colonize the bones, can last for decades, specifically between 50 to 100 years.
How are whale falls similar to hydrothermal vents and cold seeps?
-Whale falls, hydrothermal vents, and cold seeps are similar in that they all provide a rich food source in the otherwise barren seafloor, attracting and supporting various life forms.
What are the challenges in studying whale fall ecosystems?
-Studying whale fall ecosystems is challenging due to their remote and deep-sea locations, which are difficult to access and require specialized equipment.
How are biologists studying the effects of whaling on the seafloor ecosystem?
-Biologists are studying the effects of whaling on seafloor ecosystems by examining artificially-placed whale bones and other sunken biomass like wood and kelp to understand the organisms that colonize these environments.
What adaptations have organisms near whale falls evolved to survive?
-Organisms near whale falls have evolved adaptations to survive without oxygen or sunlight and to tolerate toxic chemicals, such as the hydrogen sulfide produced by bacteria.

Outlines

00:00

🐳 The Wonders of a Whale Fall

This paragraph introduces the phenomenon of a whale fall, which occurs when a whale dies and sinks to the ocean floor, creating a unique ecosystem. Despite the scarcity of food in the deep ocean, a whale carcass provides a rich food source that significantly alters the local environment. The first whale fall was studied in 1987, revealing bacteria similar to those found near hydrothermal vents and new species of clams. The paragraph outlines the stages of a whale fall ecosystem: initial scavenging by creatures like sleeper sharks and amphipods, followed by invertebrates feeding on leftover tissue and sediment, and finally, bacteria colonizing the bones and creating a sulfur-rich environment that supports a diverse community of sulfur-loving species. The comparison is made to hydrothermal vents and cold seeps, highlighting the rarity and importance of such nutrient-rich areas in the otherwise barren deep sea.

Mindmap

Keywords

💡Whale fall

A 'whale fall' refers to the phenomenon where a dead whale sinks to the ocean floor, providing a unique ecosystem for various marine organisms. It is central to the video's theme as it illustrates how the carcass of a whale can create a complex and rich ecosystem in the deep sea where food is scarce. The script describes how the whale's body becomes a food source for scavengers and eventually supports a community of bacteria and other organisms that thrive on the nutrients released from the decomposing bones.

💡Ecosystem

An 'ecosystem' is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. In the context of the video, the whale fall creates a localized ecosystem on the ocean floor. The script explains how different stages of decomposition support a variety of life forms, from scavengers to bacteria, each playing a role in this临时的 yet complex ecosystem.

💡Scavengers

Scavengers are organisms that feed on dead or decaying organisms. In relation to the video, the first scavengers to arrive at a whale fall are creatures like sleeper sharks, hagfish, and amphipods. They consume the whale's flesh, which is crucial for the establishment of the whale fall ecosystem. The script mentions that these scavengers can eat up to 40 to 60 kilograms of tissue per day.

💡Invertebrates

Invertebrates are animals without a backbone or spinal column. The script discusses how a swarm of invertebrates, including crustaceans, molluscs, and polychaete worms, move in after the initial scavengers have stripped the whale's flesh. These invertebrates feed on the leftover tissues and the sediment surrounding the whale, highlighting the diverse life forms that can thrive in such an environment.

💡Bacteria

Bacteria are single-celled microorganisms that play a vital role in nutrient cycling and decomposition. In the video's narrative, bacteria colonize the whale bones, feeding on lipids and producing hydrogen sulfide gas, which is toxic to most life forms but essential for the sulfur-loving community in a whale fall. The script describes this as the start of the third stage of the whale fall ecosystem.

💡Hydrogen sulfide

Hydrogen sulfide is a colorless gas with the characteristic foul smell of rotten eggs. In the context of the video, bacteria break down the fats and oils in whale bones, producing hydrogen sulfide. This gas is a key component of the sulfur-loving community that develops in the later stages of a whale fall, as described in the script.

💡Sulfophilic community

A 'sulfophilic community' refers to a group of organisms that thrive in environments rich in sulfur compounds. The script explains that hydrogen sulfide produced by bacteria creates such a community around the whale bones, consisting of the bacteria themselves and other organisms that feed on them. This community can persist for decades, similar to those found around hydrothermal vents.

💡Hydrothermal vents

Hydrothermal vents are fissures in the Earth's surface from which geothermally heated water issues. The video script compares whale falls to hydrothermal vents as both provide a rich source of nutrients in an otherwise barren deep-sea environment. These vents spew mineral-rich water, supporting unique life forms that have adapted to extreme conditions.

💡Cold seeps

Cold seeps are areas on the seafloor where hydrocarbon-rich fluids leak from the seabed, often containing high levels of sulfide and methane. The script mentions cold seeps as another example of environments, like whale falls, that support unique ecosystems. These seeps are briny pools that, despite their toxicity, foster life due to the availability of chemicals that can serve as energy sources for certain organisms.

💡Adaptations

Adaptations are traits that enable organisms to better survive in their environment. The video discusses how life forms colonizing whale falls have evolved various adaptations to survive without oxygen or sunlight and in the presence of toxic chemicals. This highlights the resilience and diversity of life and its ability to thrive in extreme conditions.

💡Whaling

Whaling is the hunting of whales for meat, oil, and other products. The script touches on how whaling might have impacted the seafloor ecosystem by reducing the number of whale falls. This is significant as it suggests that human activities can have indirect effects on marine ecosystems, altering the availability of these nutrient-rich environments for deep-sea life.

Highlights

Whale falls create a unique ecosystem even without direct observation.

A whale fall occurs when a whale dies and sinks to the ocean floor, at least a thousand meters down.

The ocean floor is typically food scarce, making whale carcasses a significant food source.

The first natural whale fall was discovered by scientists in 1987 using a deep submergence vehicle.

Bacteria found on whale bones are similar to those found in hydrothermal vents.

New species of clams were discovered as part of the whale fall ecosystem.

Whale fall ecosystems consist of multiple stages, starting with scavengers consuming the flesh.

Sleeper sharks, hagfish, and amphipods are among the first to feed on a whale carcass.

The process of flesh consumption can take several years for a large whale.

Stage two involves invertebrates feeding on leftover tissue and sediment.

Unique species, like a new family of aquatic snails, are found in these ecosystems.

Stage three begins with bacteria colonizing the bones and feeding on lipids.

Hydrogen sulfide gas, toxic to most life, is a key component of the whale fall ecosystem.

Sulfur-loving communities form around the hydrogen sulfide, supporting a variety of species.

This stage can last for decades, similar to hydrothermal vents and cold seeps.

Whale falls, vents, and seeps are rare food sources on an otherwise barren ocean floor.

Studying these environments is challenging due to their depth and remoteness.

Artificial whale bones and sunken biomass are used to study these deep-sea organisms.

The life forms have evolved unique adaptations to survive in extreme conditions.

Whaling may have impacted the seafloor ecosystem by reducing the number of whale falls.

SciShow is a resource for learning about unusual life forms, including those found in whale falls.