Marine Biology: Ecosystems and Coral Reefs Overview

Ecology

The study of the relationships between organisms and their environment.

Abiotic factors

Non-living components of an ecosystem, such as temperature, water, sunlight, soil, etc.

Ecosystems

Interconnected communities of living organisms and their physical environment.

Competition

Interaction between organisms where both compete for limited resources.

Predators/Prey

Predators hunt and consume other organisms (prey) for sustenance.

Symbiosis

Close and long-term interaction between different species, often benefiting one or both.

Benthic organisms

Organisms that live on or near the bottom of a body of water.

Pelagic organisms

Organisms that live in the open ocean away from the bottom.

Plankton

Microscopic organisms that float or drift in water and are unable to swim against currents.

Heterotrophs

Organisms that cannot produce their own food and must consume other organisms for energy.

Logistic growth

A type of population growth characterized by a carrying capacity.

Food web

Illustrates the complex, interconnected relationships between organisms in an ecosystem, including multiple feeding interactions and alternative pathways for energy flow.

Energy flow in food web

Energy is lost as you move from the primary producers at the base of a food web to the top predators.

Calcium carbonate

Limestone, deposited by organisms, which creates coral reefs.

Hermatypic corals

Corals that build reefs; their polyps produce calcium carbonate skeletons.

Coral polyps

The actual organisms that create coral reefs, resembling sea anemones.

Coralline algae

Grow in rock-hard sheets on the reef, deposit large amounts of calcium carbonate.

Warmest temperature range coral can tolerate

86°F-95°F.

Effects of sediments on coral

Sediment clouds the water, cutting down on light for zooxanthellae and can smother the coral or cause disease.

Barrier reefs

Lie along the coast but occur much further offshore, separated from shore by a relatively deep lagoon.

Reef flat

The widest part of the reef, shallow, and drops gently toward the sea.

Zooxanthellae

Cells that use carbon dioxide and water to carry out photosynthesis, providing nutrients to the host coral.

Epipelagic zone

The uppermost layer of the ocean, ranging from the surface to about 200 meters deep, where most marine life is found.

Phytoplankton

Microscopic, photosynthetic organisms that form the base of the ocean food chain.

Zooplankton

Small, often microscopic animals that drift in the water, feeding on phytoplankton and other small organisms.

Meroplankton

Organisms that spend only part of their life cycle as plankton, usually as larvae or juvenile stages.

Planktivores

Animals that feed primarily on plankton, such as certain fish, whales, and jellyfish.

Sense organs

Specialized structures that allow organisms to detect and respond to stimuli from their environment, such as eyes, ears, or antennae.

Echolocation

A process used by certain animals (like bats and dolphins) to locate objects by emitting sound waves and interpreting the returning echoes.

Vertical migration

This migration occurs when organisms move up to the uppermost layer of the water at night and return to the bottom of the daylight zone of the oceans or to the dense, bottom layer of lakes during the day.

Cephalopods in the mesopelagic

Especially squids, photophores, membranes that connect their tentacles like the webbing between the duck's toes.

Most common fish in the mesopelagic

lanternfish

Amount of primary production reaching the mesopelagic

About 20 percent of primary production from the surface falls down to the mesopelagic zone.

Amount of primary production reaching the deep sea

5 %

Why deep sea animals do not vertically migrate

The surface is too far and the change in pressure is too great.

Bioluminescent lures

Glowing fishing lures occasionally work because they mimic a natural phenomenon called bioluminescence. Various organisms, including fireflies and prey of fish, glow naturally. This ability comes from an internal chemical reaction.

Hermaphrodites

produce both eggs and sperm.

Base of benthic food web

dead fish and animal feces.

Polychaete worms

are usually the most abundant large animals found on the deep seafloor.

Deep sea gigantism

the phenomenon where some deep sea animals are giant compared to their shallow-water relatives.

Hydrothermal vents

created when seawater trickles down through cracks in the earth's crust and is heated to very high temperatures.

Hydrogen sulfide

toxic to most organisms but is an energy rich molecule.

Chemosynthetic bacteria

the primary producers and base of the food web in hydrothermal vents.

Mesopelagic zone

found immediately below the epipelagic zone.

Pheromones

Chemicals used to attract mates.

Deep sea

the area below the mesopelagic.

Small size of mesopelagic animals

The small size of fishes means they don't require a large amount of food and large mouths because food is scarce meaning they cannot be picky and the large jaws allow them to eat a wide range of prey.

Anglerfishes reproduction

Tiny dwarfed males become permanently attached to relatively gigantic females, fuse their tissues and then establish a common blood circulation.

Earth's largest producer of organic matter

carbon

Percentage of total catch from the sea

40%

Why coastal fisheries are productive

Physical, chemical and biological processes take place along relatively short distances, which increases the intensity of the gradients.

Upwelling

A process in which deep, cold water rises toward the surface.

Largest catches in the world

Tuna

Most common non-animal harvested from the ocean

Seaweed

Overfishing

Catching too many fish at once, so the breeding population becomes too depleted to recover.

Sustainable yield

The harvest of a specific (self-renewing) natural resource.

Formation of fossil fuels

Dead organisms (like plankton and plants) settle on the seafloor and get buried under layers of sediment. Over time, more sediment builds up, increasing pressure and temperature. After millions of years, heat and pressure transform the organic material into fossil fuels such as oil, coal, or natural gas.

Increase in ocean mining

Problems associated with ocean mining impact ocean carbon.

Types of renewable energy using the ocean

Wind energy, wave energy, tidal energy.

Desalination

The process of removing salts and other minerals from water.

Best fish population size for harvesting

Medium.

What has kept the number of wild fish caught from increasing since 1985

The fish were farmed.

Anthropogenic impacts

The effects of human activities on the marine environment.

Direct effects on marine habitats

Dredging, landfilling, and even the use of explosives destroy habitats.

Percent of world's reefs lost or at high risk

More than a quarter of the world's reefs.

Ocean acidification

Caused by an increase in atmospheric carbon dioxide.

Cause of depletion of oxygen in the marine environment

Ocean acidification.

Stressors for corals

Temperature changes.

Types of pollutants in the ocean

Direct and indirect.

Eutrophication

Excessive amounts of nutrients that encourage too much algal growth.

Disease caused by shellfish from sewage infested waters

Intestinal infections.

Source of most polluting oil in North America

Stormwater and river runoff, fuel from small boats and jet skis, and fuel jettisoned by planes.

Impact of oil spills on marine mammals and birds

Oil spills affect their feathers or hair which affects their ability to maintain the thin layer of warm air needed for insulation.

How oil from oil spills can be broken down

Two types of substances commonly used are (1) dispersing agents and (2) biological agents.

Biological magnification

Animals absorb and accumulate the pesticides and other toxins in the organisms they eat, making their internal concentration of toxins higher than in their food supply.

What makes most solid waste in the ocean

Plastics.

Definition of endangered organism

When in immediate danger of disappearing.

Effectiveness of preventing habitat loss vs restoring destroyed habitats

It is more effective to prevent habitat loss.

Artificial reefs

Everything from concrete blocks, discarded tires, toilets, scuttled ships, and a jet has been used to build artificial reefs around the world.

Coral bleaching

Signals stress in corals, usually from high temperatures, pollution, or salinity changes. It occurs when corals expel their algae (zooxanthellae), turning white. Corals can recover if conditions improve, but prolonged stress may lead to coral death.

Parts of a reef diagram

Dead organisms (Like plankton and plants) settle on the seafloor and get buried under layers of sediment

Over time, more sediment builds up, increasing pressure and temperature

After millions of years, heat and pressure transform the organic material into fossil fuels such as oil, coal, or natural gas

In the photo on the back of the card, what has kept the number of wild fish caught from increasing substantially since around 1985?

fish were farmed