Marine Ecology - Exam 3

Where are Coral Reefs Located?

Near mangroves, due to tropicalization. Coral reefs are located globally.

Are coral animals

Yes

Polyps

Individual Corals

Coral Colony

Thousands of coral polyps

Symbiodinium

Microscopic algae that has a symbiotic relationship with coral.

• Algae photosynthesizes providing nutrients to corals.

• Coral provides habitats for algae.

Hard Coral

• Reef builders

• Branched

• Mounding

Soft Coral

More resilient

Not a reef builder

Obligate Mutualism

Can not survive without one another in their symbiotic relationship.

Facultative Mutualism

• Can survive without a species; can survive independently without a species.

Coral Reproduction can be…

• Sexual reproduction

• Asexual reproduction

Asexual Reproduction in Coral

Budding: grows through fragmentation.

Sexual Reproduction in Coral

• Sperm + egg

Broadcasting

• Sperm is released, egg is fertilized, zygote is formed in the water.

Brooding

Species that fertilize eggs internally and release fully developed larvae (planulae), rather than releasing gametes into the open water.

What do Coral Need to Survive?

• Light (0-10 m)

• Stable Temperature

• Salinity

• Right amount of Turbulence (water movement)

Goldilocks!

Fringing Reefs

Develops on shelving shores. Almost exposed at high tide (vulnerable). Extreme drop off.

Patch Reef

Develops in shallow lagoon areas surrounded by sand. Diversity → Patch Form → High Biodiversity

Barrier Reef

Forms a barrier, that surrounds tropical islands.

Varies in size.

Ex. Great Barrier Reef (AUS)

Atoll

Forms from volacanc eruptions where an island is formed that erodes into a ring of reefs.

Biodiversity is high

Isolated

Why are reefs declining?

• Increases in sea level changes

• Bioerosion

• Overfishing

• Marine Heatwaves

• Climate Change

• Disease

• Pollution

Bioerosion

The removal of carbonate by grazers and borers.

Mesophotic Reefs

Light dependent reefs at subtropical regions.

• 30-40 meters, up to 150 m.

Coral-Algal Competitions

Corals and algae compete for space on a reef.

• Algae chemically inhibits the coral → bleaches the coral.

  • BUT not all aglae is bad.

Trade-off

If you produce more chemicals → more likely to be eaten.

Allelopathy

The chemical inhibition of a species by another.

Chlorodesmis

“Turtle Weed”

Leads to coral death.

Crustose Coralline Algae

Algae that is beneficial to corals → helps aid in coral larval development.

Ocean Acidification

• Acidification and warming of the ocean can be stressors to corals — independently and sim.

• Warming can lead to bleaching

• Carbonate can affect the skeleton of corals.

Disease on Corals

Disease can lead to tissue loss — Stony Coral Tissue Loss Disease

Snails are a vector for bacteria

White Band Disease causes by corallivores.

Corallivores

Something that eats corals

Pollution

• Light Pollution

• Heavy Metals

• Nutrients: nitrogen can increase algal production

  • Sunscreen: chemical sunscreen can pollute the ocean.

Phase Shift

The transition from one state to another stable state.

Fisheries Provides…

• Jobs

• Business and Economic Gain

• Food Source

Problems with Fisheries

• Contribution to population loss (Northwestern Atlantic Cod)

  • Tipping Point → Quick population loss

  • Maturity age decreased → mature fish were caught → fish mature more quickly.

Overfishing

Fish is caught more than they can be replaced.

Causes of Overfishing

• Illegal Fishing

• Fishing in Closed Areas

• Fishing with prohibited gear (ex. dynamite)

• Fishing over quotas

  • Fishing of prohibited species.

Problems with Overfishing

• Human Rights Violations

• Local and global economic loss

• Increased chances of fishery collapse

• Damages the ecosystem.

Fishing down the food web

• Exploits organisms at the top of the food web, we eat organisms at the bottom

Sustainable Yield (Maximum Sustainable Yield)

The number of organisms that can be harvested without population collapse.

Issues with Sustainable Yield

• Does not account for birth and death rates

• Not accurate

• Variability within the environment.

Species Specific Overfishing

Fishing a specific species of fish.

Causes the food web dynamic to be thrown off.

Bottom Trawling

Big net dragging against the sea floor

• Not selective

• Can damage corals

• Can danger animals

By-catch

Unwanted catch that is dumped.

Can cause pollution

Longline Fishing

Longline of fishing bait and hook (miles long)

Used in tuna fishing

Longline Fishing Sharks

• When sharks are caught → cortisol increases → can die from too much stress.

Gill Net

Nets are used to catch fish by their gills

• Fish can die and can not breathe

Functional Redundancy

Does not rely on a singular organism, can rely on numerous other organisms to keep stable.

Sustainable Fishing Methods

• Rotating closed areas

• Changing out hooks → opt for J and circle hooks

• Fish across sizes

• Use technology

• Use hatcheries

Aquaculture

Farming aquatic creatures

Billion dollar industry

Examples of Aquaculture

• Shrimp

• Shellfish

• Seaweed

Cage Cultivation

Can take place miles offshore or next to land

Suspended in water.

Nutrient Pollution

Bacterial mats in aquaculture cages → reduces organism survival

Escaping Organisms

Lead to invasive species → from genetically modified organism

Animal Welfare

Disease runs rampant in the small enclosures.

Antibiotic Resistance

Can create resistance in native organism

Fish Meal

Food that is trawled from the bottom of the ocean to feed fish in aquaculture.

Pros of Aquaculture

• More sustainability than fisheries.

• More controlled environments than fisheries

Shore Pods

Can be natural or artifical

Cons of Shore Ponds

• Nutrient Pollution

• Animal Welfare

• Diseasse

• Antibiotic Resitance

• Destroys mangroves

Shellfish Farms

• Shellfish farming

• Shrimps filter feed → can help environment

Aquariums

• Caught not bred

• Can damage wildlife populations and ecosystems

• Some fish are now able to be bred

Rotating Cages

Allows for ecosystem recovery

Aquaponics

Closed recirculation system that requires no food.

What determines who is at risk for climate impacts?

• Exposure

• Sensitivity

• Ability to adapt or recover.

Effects of Pollution

• Biomagnification of heavy metals

• Nutrient Pollution → Eutrophication

• Plastic Pollution

• Oil Spills

PCB’s

• Polychlorinated biphenyls

• Carcinogen

Dredging

Removing silt and other materials from the bottom of the ocean to remove pollutants.

Can remove PCB’s

Ocean Benefits for Humans

• Mental health and wellbeing

• Drug discovery — opportunity for disease cure

• Food Security

PFAs

• per- and polyfluoroalkyl substances

• “Forever Chemicals”

• Could cause human health issues

• Do not break down easily.

Citizen Science

The public participates in scientific research to address real world issues.

• Data collection, data analysis, research design, scientific publications

Opportunity Cost

The value of what you lose when you choose from 2 or more opportunities.

Regulation Implentation

Interpol and sea shepards

IUCN Redist (Individual Species Protection)

Determines the endangerment of a species
Protects species.

Marine Protected Areas

Marine Protected Areas (MPAs)

Protective management of natural areas.