Comprehensive Marine Biology and Oceanography Course Overview

Why is the ocean considered a global life-support system?

The ocean supports life by providing carbon fixation, a food source, and medicinal compounds.

What role do phytoplankton play in carbon and climate?

Phytoplankton fix as much carbon through photosynthesis as all land plants combined.

What percentage of global protein for humans comes from marine fisheries?

5% to 25%.

What unique substances are found in sponges, corals, and microbes?

Chemical compounds used to develop new drugs.

What does the term 'plankton' mean?

It is derived from Greek, meaning 'drifter'.

What are the two main types of plankton?

Phytoplankton (plant-like) and zooplankton (animal-like).

What is the primary function of phytoplankton?

They perform photosynthesis, provide food, produce oxygen, and remove CO2.

What is the euphotic zone?

The top layer of the ocean where there is enough light for photosynthesis, usually ~70m to 100m deep.

What is the dysphotic zone?

A layer where light is present but too weak for photosynthesis.

What is the aphotic zone?

The vast majority of the ocean that is in permanent darkness.

What are limiting factors for phytoplankton growth?

Nutrients like Nitrogen and Phosphorus.

What is the 10% rule in the trophic pyramid?

Only about 10% of energy from one trophic level is passed to the next.

What is the Biological Pump?

A process where phytoplankton take CO2 from the atmosphere, die, and sink, moving carbon to the deep ocean.

What was the Great Oxidation Event (GOE)?

A period about 2.4 billion years ago when Cyanobacteria began producing oxygen through photosynthesis.

What is Prochlorococcus?

The most abundant photosynthetic organism on Earth, discovered in 1988.

What are diatoms known for?

They have silica shells and are efficient at exporting carbon to the deep sea.

What is diatomaceous earth?

A sediment formed from the accumulated shells of dead diatoms.

What happens to carbon when phytoplankton die?

They sink as 'marine snow', moving carbon into the deep ocean.

Why is coastal upwelling important for fisheries?

It brings nutrients from the deep ocean back to the photic zone, supporting marine life.

What would happen if primary producers like phytoplankton disappeared?

The entire food web would collapse due to the loss of the base energy source.

Which process occurs only in the light?

Photosynthesis.

Why is the biomass of top predators smaller than that of plankton?

Energy transfer is inefficient, leading to less biomass at higher trophic levels.

What are Coccolithophores?

Single-celled organisms with shells made of Calcium Carbonate ($CaCO_3$) that bloom and turn the ocean a milky turquoise color.

What role do Coccolithophores play in the ocean?

They play a significant role in the ocean's alkalinity and the 'Carbonate Pump.'

What are Dinoflagellates known for?

They have two whip-like tails (flagella) for movement and can cause bioluminescence and Harmful Algal Blooms (HABs).

What is 'Marine Snow'?

Organic material, including dead plankton and poop, falling to the deep sea.

Why are Diatoms better at carbon sequestration?

Their heavy silica shells make them sink faster.

Who 'invented' oxygen?

Cyanobacteria.

What is the difference between the shells of Diatoms and Coccolithophores?

Diatoms have silica/glass shells, while Coccolithophores have Calcium Carbonate/chalk shells.

What is the 'Hard Requirement' for animal life?

Oxygen is essential for the survival of multicellular animals.

What is the significance of the Burgess Shale?

It is a fossil formation that preserved soft-bodied animals from around 500-560 million years ago.

What are Trilobites?

Segmented arthropods that were one of the most successful early animal groups and dominated the seafloor for millions of years.

What are the two main strategies for temperature regulation in marine animals?

Ectothermic (cold-blooded) and Endothermic (warm-blooded).

What are the advantages of being Ectothermic?

Saves energy but can be sluggish in cold water.

What are the advantages of being Endothermic?

Can stay active in freezing water but requires a large amount of food to maintain body heat.

What is streamlining in marine animals?

A shape adaptation to reduce drag and improve swimming efficiency.

What is the evolution of Cetaceans?

Cetaceans evolved from four-legged land mammals, adapting over 50 million years to become fully aquatic.

What evidence supports the land ancestry of whales?

They breathe air, have hair, nurse their young with milk, and possess vestigial hip bones.

What are Odontocetes?

Toothed whales, including Orcas and Dolphins, that use echolocation to hunt.

What are Mysticetes?

Baleen whales, including Blue Whales and Humpbacks, that filter-feed using baleen plates.

What is a Vestigial Structure?

A leftover body part that no longer serves a purpose, such as the whale's hip bone.

What is a Population in marine biology?

A group of organisms of the same species occupying a specific area.

What defines a Community in marine biology?

Many different populations of organisms that interact at a particular location.

What is a Habitat?

An organism's physical 'address' or location within a community.

What is a Niche?

An organism's role within its habitat, including what it eats and how it avoids predators.

What is an Ecosystem?

The most inclusive term, including the biological community plus the physical environment.

What is the 10% Rule in marine food webs?

Only 10% of energy is transferred to the next trophic level; 90% is lost as respiration, heat, or waste.

What is bioaccumulation?

The buildup of a toxin in the tissues of one individual organism over its lifetime.

What is the difference between top-down and bottom-up control in ecosystems?

Bottom-up control is driven by nutrient availability, while top-down control is influenced by predators controlling the abundance of species below them.

What challenges do organisms face in intertidal communities?

Organisms are subjected to wave action, desiccation from the sun, and predation from both land and sea.

What is zonation in the intertidal zone?

Different species live in distinct bands or zones based on their ability to survive out of water.

What occurs during a whale fall?

When a whale dies and sinks, it creates a food source that supports various scavengers and decomposers.

How do hydrothermal vent communities obtain energy?

Through chemosynthesis, where bacteria convert chemicals from the vents into food.

What is the 'whale pump' and its significance?

Whales feed at depth and release nutrient-rich waste at the surface, fertilizing phytoplankton and aiding in CO2 removal from the atmosphere.

What is marine pollution?

The introduction of substances or energy into the ocean by humans that change the environment and harm organisms or ecosystems.

What is the largest source of marine pollution?

Sewage, accounting for 30% of marine pollution.

What are microplastics?

Plastic pieces smaller than 5mm that can be mistaken for food by marine organisms.

What is eutrophication?

A process where excess nutrients lead to algal blooms, which can create dead zones due to oxygen depletion.

What is the 'tragedy of the commons'?

An economic theory where individuals deplete a shared resource, like the ocean, despite it not being in their long-term interest.

What is biomagnification?

The increase in concentration of a toxin as it moves up the food chain.

What is the impact of oil spills on marine environments?

Oil spills can cause extensive damage to marine ecosystems, affecting wildlife and habitats.

What is the Great Pacific Garbage Patch?

A massive area in the North Pacific Gyre where plastic accumulates due to converging currents.

What role do bacteria play in whale falls?

Bacteria break down fats in whale bones, releasing sulfur that supports a chemosynthetic community.

What is the process of decomposition in dead zones?

Bacteria decompose dead algae, consuming dissolved oxygen and leading to hypoxic conditions.

What are the stages of a whale fall?

Scavenger stage, opportunist stage, and sulfophilic stage.

How do phytoplankton contribute to climate regulation?

Phytoplankton absorb CO2, helping to mitigate climate change.

What is the significance of marine protected areas (MPAs)?

MPAs restrict fishing and drilling to allow ecosystems to recover and thrive.

What is the difference between biodegradable and photodegradable?

Biodegradable materials decompose naturally, while photodegradable materials break down through exposure to sunlight.

What happens during an algal bloom?

Excess nutrients cause a rapid increase in phytoplankton, which can lead to oxygen depletion when they die.

Why are sharks more likely to have high mercury levels than sardines?

Due to biomagnification, where toxins increase in concentration as they move up the food chain.

What is the impact of plastic pollution on marine life?

Plastics can cause entanglement, intestinal blockage, and act as carriers for toxic chemicals in the food web.

What is the role of giant tube worms in hydrothermal vent communities?

They host bacteria that convert vent chemicals into food, relying on symbiosis for survival.

What is the significance of nutrient loading in marine ecosystems?

It can lead to eutrophication and the creation of dead zones, harming marine life.