Aice Marine Chapter 5

Bioluminescence

the biochemical release of light by living organisms.

World Ocean

the combination of all major oceans into one large, interconnected body of water that encircles the world's continents.

Epipelagic zone

the zone of the ocean between 0 and 200 m deep which receives enough light for photosynthesis.

Mesopelagic zone

the zone of the ocean between 200m and 1000m deep which receives very little light

Bathypelagic zone

the zone of the ocean between 1000m and 4000m deep which receives no sunlight.

Abyssopelagic zone

the zone of the ocean between 4000 and 6000m deep with near freezing water temperatures and intense pressure.

Benthic zone

the lowest depth region in any body of water including the surface of the substrate.

Benthos

the community of organisms found in the benthic zone.

Ecosystem services

benefits people obtain from ecosystems, including food, flood regulation, climate control and water purification.

Carbon sink

a natural environment that absorbs carbon dioxide from the atmosphere faster than it releases it.

Pacific

Largest (33%)

Atlantic =

2nd largest (20%)

Indian

3rd largest

Southern

4th largest

Arctic

Smallest/Shallowest

3 regions of the ocean and their locations

Tropical: 60-90 deg.

Temperate: 30-60 deg.

Polar: 0-30 deg.

Zones of our ocean depths and details of each

epipelagic zone

0-200m - Light intense enough for photosynthesis

mesopelagic zone

200-1000m (twilight) - Deepest penetration of light

bathypelagic zone

1000-4000m - Organisms feed on detritus & marine snow

from above; some are transparent & some

are bioluminescent

abyssopelagic zone

>4000m - Some species are blind & colorless; very

cold & high pressure

Importance of Oceans and interactions with atmosphere (x1)

- Regulate Temperature

- Carbon Storage

- Oxygen Production

Cnidarians

marine animals that capture food using cells.

Cnidocytes

stinging fellas that cover the tentacles of cnidarians.

Polyp

non-moving; cup-like life stage of cnidarians.

Nematocyst

the harpoon-like organelle inside of cnidocyte that contains toxin to be delivered to the prey.

Basal plate

lower part of the coral calyx that separates the polyp from the substrate.

Calyx

the stony cup in which a coral polyp lives its life.

Theca

the walls of the calyx

Hard corals

stony corals capable of reef-building that have a relationship with zooxanthellae.

Soft corals

corals that do not build reefs and lack calcification.

Zooxanthellae

symbiotic; photosynthetic dinoflagellates living within the tissues of many invertebrates.

Fringing reef

a reed close to and surrounding newer volcanic islands or that borders continental landmarks.

Barrier reef

a reef separated by a lagoon from the landmass with which it is associated.

Atoll

a coral reef somewhat circular in shape with a central lagoon.

Patch reef

small, isolated reef usually located within the lagoon of a barrier reef.

Lagoon

a shallow, sheltered body of water with a soft sediment bottom.

Reef erosion

when a coral loses more of its calcium carbonate skeleton per year than it gains.

Bioerosion

reef erosion caused by living organisms.

Ocean acidification

a process where the pH of the ocean is reduced over an extended period of time; generally attributed to a rise in atmospheric carbon dioxide.

Climate change

changes in global or regional climate patterns since the late twentieth century.

Coral bleaching

whitening of coral that results from the loss of coral's symbiotic zooxanthellae.

Desiccation

the removal of moisture or drying out of an organism.

Artificial reef

an underwater structure built by humans to mimic the characteristics of a natural reef.

6 Conditions required for coral reef growth AND where they are typically found

- Tropical (0-30O ish N & S latitude)

- Shallow (optimal: less than 30 m; max 120m)

- Warm (optimal: 23-25 O C)

- Clear (no silt-blocks light & is abrasive)

- Hard, rocky substrate (for attachment)

- Saline water (32 - 38O/OO) ppt (parts per thousand)

- pH between 8.1-8.3

Fringing

closest to coast

Barrier

separated from coast by a lagoon

Atoll

circular shape with central lagoon

Path Reef

small, isolated, often grow in the lagoon

Formation of an Atoll (DDD Theory)

(Charles) Darwin-(Reginald) Dana-(James) Daly

1. Volcanic island forms

2. Coral grows around it in shallow water → forming a fringing reef

3. Island begins to sink & is slowly eroded, coral continues to grow, leaving a lagoon between the reef and island → forming a barrier reef

4. Island fully submerges & is eroded, leaving a central lagoon → forming ring-shaped atoll

Detailed relationship between Coral and Zooxanthellae

mutualistic symbiotic relationship (both species benefit)

- Coral receives food/glucose & O2

- Zooxanthellae receives shallow-water habitat & CO2

Characteristics of different types of coral reefs

Hard coral

reef building; hard coral has zooxanthellae

Characteristics of different types of coral reefs

Soft Coral

DO NOT build reefs; soft coral does not have zooxanthellae.

Structure of typical coral polyp including function for the structures

- Tentacle - captures food & clears debris

- Nematocyst - stings food with toxins

- Mouth - takes in food & expels waste

- Calyx - the "cup" in which the coral lives (made up of theca & basal plate)

- Theca - the walls surrounding the "cup"

- Basal plate - floor of the "cup;" attaches to a rocky substrate

Description of the 2 ways coral gets nutrition

Zooxanthellae

Most of their nutrition comes from the glucose produced by zooxanthellae (photosynthesis)

Description of the 2 ways coral gets nutrition

Nematocysts

Sting zooplankton with the nematocysts in their tentacles & bring it into their mouth

Enzymes are released in the gastrovascular cavity

Diffusion across their tissues

Causes of Coral Reefs Erosion

- Acidic water / lower pH = dissolves coral skeletons & coral cannot absorb calcium to make its skeleton

- Warmer water = coral bleaching

- Blast/dynamite fishing = self explanatory

- Suspended sediment (from rivers, dredging, etc) = is abrasive & blocks light to zooxanthellae

- Trash/pollution = entangles around & suffocates coral & refuse contains toxic chemicals

- Large, rough wave action = break coral

- Boat anchors & benthic trawling = break coral

- Predators = feed on coral

- Exposure to air = coral dries out

Importance of Coral Reefs

- Coastal protection - by absorbing (97% of the energy)/ slowing / dissipating waves (84% wave height reduced), they prevent erosion; protect coastal properties & inland ecosystems

- Food - for millions of people globally: fishes, mollusks, crustaceans

- Medicine - for cancer, arthritis, Alzheimer's, etc. from sessile (immobile) coral with chemical methods of preventing predation

- Recreation & tourism - fishing, diving, hotels, restaurants, etc. (estimated $35 billion from tourism)

- Maintaining biodiversity - high biodiversity b/c of high productivity

Importance of Artificial Reefs

Additional place for coral reefs to grow.

Zonation

distribution of plants or animals into specific zones within an ecosystem based on a specific abiotic factor, like desiccation.

Intertidal zone

area known as the seashore which is exposed at low tide and under water at high tides.

Splash zone

area of a rocky shore that is just above the high tide mark and receives water through the splashing of waves.

4 zones on an exposed rocky shore and characteristics of each

Splash Zone

- only receives water during abnormally high high tides & when waves crash during high tide

- periwinkles are common - they remain in their shells & keep water in their gills for gas exchange

- limpets grip tightly to the rock to hold water in for gas exchange & to keep cool

- both have strong muscular foot for attachment on the rock

4 zones on an exposed rocky shore and characteristics of each

Upper Shore

- submerged during high tide

- long periods of time exposed to air without food or water &

temperature increases drastically

- chitons & limpets grip tightly to the rock

- channeled wrack prevents desiccation by curling their

fronds to reduce water loss by evaporation

4 zones on an exposed rocky shore and characteristics of each

Middle Shore

- immersed & emersed for equal amounts of time

- barnacles come out of their shell to feed when the tide is in & close shells while exposed to air to prevent desiccation &

predation

- mussels use byssal threads to attach to the rock to help hold on to the rock when waves are crashing & can close their 2 shells

to prevent water loss/desiccation

4 zones on an exposed rocky shore and characteristics of each

Lower Shore

- only exposed to air during extreme low tides

- few adaptations for living outside of the water & therefore can overheat and dry out easily

- higher biodiversity other organisms: seaweed, algae, sea stars, sea urchins, sea anemones & oysters

4 zones on an exposed rocky shore and characteristics of each

Tide Pool

- when tide is out, water remains;

- found in all zones

- keep organisms cool

- allow for gas exchange and feed.

- Longer the tide is out, the more saline the water becomes and the less oxygenated due to shallowness, evaporation, and respiration.

Porous

substrate with holes that allow for the passage of air and water.

Permeability

how well water flows through a substrate.

Porosity

how much water a substance can hold based on the empty space within it.

Characteristics of sandy shores

Unstable, shifting, porous,

Adaptations for organisms living in sandy shores

- Burrow

- Feed on detritus

- Filter-feed when the tide is in

Abiotic and Biotic factors that affect sandy shores

Abiotic:

- Temperature changes

- Shifting substrate (animals burrow / infauna)

- Salinity changes

- Light intensity

- Constant change / movement of tides / water height

- Waves & currents

Biotic:

- Terrestrial & marine predators

- Not many species present because not many have adapted

Propagule

a reproductive structure that detaches from the parent plant and is able to grow into a new individual.

Lenticel

a raised pore in the roots of a mangrove that allows gas exchanged between the atmosphere and the internal tissues.

Viviparous Reproduction

[plants] a reproductive strategy where the seed develops into a young plant while still attached to the parent plant.