Ocean HabitatsChapter 12

Animals of the Benthos

98% of marine species are benthic Hydrothermal vents Rocky shore Coral reefs

Coral Reefs of the World(Figure 12-16)

Coral Reefs: Tops in Marine Biodiversity

Coral Reef Morphology(Figure 12-17)

Coral Reef Zone Tourcurrents, wave surge, sunlight, water depth

1 - Beach

2 - Reef Flat

3 - Algal Ridge

4 - Sub-Terrace

5 - Terrace

6 - Reef Slope

7 - Drop-off

Beach Zone:sands derived from erosion of reef limestone

Boxer crab doesn’t eat anemones but uses them as weapons

Coral Reef Zone Tourcurrents, wave surge, sunlight, water depth

1 - Beach

2 - Reef Flat

3 - Algal Ridge

4 - Sub-Terrace

5 - Terrace

6 - Reef Slope

7 - Drop-off

Reef Flat:RIGOROUS environment

wave action, intense UV radiation, high salinities, warm temps

corals are hermatypic (depend on zooxanthellae algae that live in coral poly tissues)

Coral & Zooxanthellae(Figure 12-14)

Reef Flat:Sharks & mantas frequent visitors

Coral Reef Zones currents, wave surge, sunlight, water depth

1 - Beach

2 - Reef Flat

3 - Algal Ridge

4 - Sub-Terrace

5 - Terrace

6 - Reef Slope

7 - Drop-off

Algal Ridge:

Coral Reef Zones currents, wave surge, sunlight, water depth

1 - Beach

2 - Reef Flat

3 - Algal Ridge

4 - Sub-Terrace

5 - Terrace

6 - Reef Slope

7 - Drop-off

Submarine Terrace

Submarine Terrace:Increasing coral cover attract fishes

that prefer rich coral growthBasslett fish (haremic, capable of sex reversal)

Coral Reef Zones currents, wave surge, sunlight, water depth

1 - Beach

2 - Reef Flat

3 - Algal Ridge

4 - Sub-Terrace

5 - Terrace

6 - Reef Slope

7 - Drop-off

Terrace

Coral Reef Zones currents, wave surge, sunlight, water depth

1 - Beach

2 - Reef Flat

3 - Algal Ridge

4 - Sub-Terrace

5 - Terrace

6 - Reef Slope

7 - Drop-off

Slope

Coral Reef Zones 1 - Beach

2 - Reef Flat

3 - Algal Ridge

4 - Sub-Terrace

5 - Terrace

6 - Reef Slope

7 - Drop-offlowest light levels, few sunlight-dependent coralssome feed on zooplankton and can descend as low as 1000 m

Drop Off:Soft corals are non-reef building (no zooxanthellae), no limestone skeleton, secrete toxins to discourage

competitors

Deepsea Coralslive off of the dead

Desmophyllum cristagalli

www.divediscover.whoi.edu

National Marine Sanctuaries

Map courtesy of NOAA National Marine Sanctuary System

The World Ocean Floor

Maps courtesy of National Park of American Samoa

Artwork by Jayne Doucette, Woods Hole Oceanographic Institution

By OrSt grad student Emily Larkin

FBNMS: Some Major Issues Natural & human impacts

– Crown-of-thorns invasion, hurricanes, bleaching– Illegal fishing, sewage outfall

Photos courtesy of NOAA National Marine Sanctuary System

FBNMS: Some Major Issues Prior to 2001…

– Sanctuary largely unexplored below depths of ~30-60 m

– no comprehensive documentation of the plants, animals, and submarine topography.

Little is known of tropical “twilight zone” – shelf-edge (50-120 m deep) of coral reef

habitats throughout the world

Fagatele Bay National Marine Sanctuary, 2001 bathy

Images courtesy of Kip Evans, Nat. Geographic and Rich Pyle, Bishop Museum

SCUBA / Rebreather Technology

Rebreather Dive Mission, FBNMS, 2001

BPI Zone and

Structure

Classification

Flowchart

Emily Lundblad, OrSt M.S. Thesis

Emily Lundblad, OrSt M.S. Thesis

Extra Credit #5 - Finding Nemo

5 copies will be on reserve by this weekend at Valley Library or rent it from a video store – 1-page reaction paper, typed, SINGLE-spaced– Discuss what in the movie is related to the

class Currents? Habitats? Fisheries? Conservation?

Due by 5:00 Friday, May 27th

– Hand in to your TA please !!!– Worth up to 20 pts. on final exam