Coastal Ecosystems

Coastal Ecosystems

Rocky shores

Soft substratum

Marshes

Mangroves

Estuaries Sea

grass beds

Kelp forests

Rocky reefs

Coral reefs

Ice edge

Primary Producers

Photosynthetic organisms

• Cyanobacteria

• Diatoms and Coccolithophores

• Algae

– Haptophytes (Phaeophytes)

– Rhodophytes

• Plants

Primary Production

the lowest level of the food chain

utilize sunlight or chemical nutrients as a source of energy (autotrophy)

primary production = rate of photosynthesis or chemosynthesis

most occurs > 100 m (max = 268 m or 879 ft)

Primary producers serve as the basis

for nearly all life in the ocean

Factors Affecting Primary Productivity

• Light

– polar regions: a single pulse of phytoplankton abundance occurs in summer

– temperate latitudes: primary productivity is maximal in spring and autumn

– tropics: phytoplankton are nutrient-limited year round

• Nutrients

– oligotrophic

– eutrophic

– mesotrophic

• Hydrographic conditions

– Currents

– Upwelling

– Vertical mixing

Patterns of Productivity

Estimates of primary production

Total (marine plus terrestrial) global annual net

primary production (NPP) =

104.9 Gt C/yr

Terrestrial = 56.4 Gt or 53.8%

Oceanic = 48.5 Gt or 46.2%

(From Field et al. 1998. Science 281: 237-240)

Estimates of primary production

Pelagic zone = 50-600

Grasslands = 2,400

Tropical forests = 5,000

Mangroves = 2,700

Seagrass beds = 800-10,000

Coral reefs = 1200-8,000

(measured as g C/m2/yr )

Primary Production

1. Water column – Plankton

2. Seabed – Benthos

Most productivity occurs in plankton

Plankton Phytoplankton

Meroplankton part of lifecycle in plankton and benthos

Holoplankton entire lifecycle in plankton

Neuston plankton near surface

Ultraplankton <2 mm

Nannoplankton 2-20 mm

Microplankton 20-200 mm

Macroplankton 200-2,000 mm

Megaplankton >2,000 mm

Major Groups of Primary Producers-

Phytoplankton

• Cyanophytes

• Stramenopiles (Diatoms, Silicoflagellates)

• Haptophytes (Coccolithophores)

• Alveolates (Dinoflagellates)

• Chlorophytes

Cyanophyceae

Cyanobacteria

(blue-green algae)

• ultraplankton

• comprise ~25% of the total

primary production

• nitrogen fixation

• produced O2 in atmosphere

Stromatolites

Shark Bay, Western Australia

Oldest = 3.5 billion years old

Bacillariophytes: Bacillariophyceae

Diatoms

• Unicellular nanno – microplankton

• Dominate temperate-polar regions

• Silica valves (2) form pillbox frustule

• Centric diatoms – radially symmetrical

• Pennate diatoms – bilaterally symmetrical

Domoic acid

• Neurotoxin produced by Pseudo-nitzschia sp.

• Amnesic Shellfish Poisoning

Haptophytes - Coccolithophores •Unicellular

•Nannoplankton

•Calcium carbonate

coccoliths

•Can form large blooms

Emiliania huxleyi

Haptophytes - Silicoflagellates

• Internal skeleton of silica scales

• More abundant in Antarctica and open ocean

Dinoflagellates – Whirling flagella

Red Tides

Red Tides Many dinoflagellates produce neurotoxins

(saxitoxin, brevitoxin, polycyclic ethers)

• Paralytic shellfish poisoning (PSP)

Alexandrium sp.

• Ciguatera

Gambierdiscus toxicus

• Diarrhetic shellfish poisoning (DSP)

Dinophysis acuta and D. acuminata

• Neurotoxic shellfish poisoning (NSP)

Gymnodinium breve

Specialized dinoflagellates

• Zooxanthellae

• Noctiluca

Zooxanthellae

• Live as symbionts in

animal hosts

• Corals, clams, jellies

• Symbiodinium sp.

Zooxanthellae

• Live as symbionts in

animal hosts

• Corals, clams, jellies

• Symbiodinium sp.

Coral Bleaching

Noctiluca

Bioluminescence Chemiluminescent reaction in which a

substrate, luciferin, is oxidized,

releasing a large amount of energy in

the form of light

Pyrodinium bahamenese

Benthic primary producers

Major lineages of algae and plants:

• Chlorophyta (green algae/plants)

• Heterokonta (stramenopiles - brown algae)

• Rhodophyta (red algae)

General morphology

Life histories

Most have complex life histories:

• Alternation of generations (iso- or heteromorphic)

• Dispersing spore

• Rhodophytes have

tri-phasic life history

Chlorophyta

Sargasso Sea

• Location determined by the changing ocean

currents

• Supports a unique fauna associated with

drifting mats of Sargassum sp.

Sargasso Sea

Brown Algae • Their cells contain different pigments, such as

chlorophyll c and fucoxanthin

• Almost all phaeophytes are marine

Kelp forests

Kelp forests

Kelp forest distribution

Rhodophyta

• Highly variable morphologies

• Some members heavily calcified (coralline

algae) by calcium carbonate in cell walls

• Contain chlorophylls a, d

• Cell wall made of agar or carrageenan

• Store sugars in the form of Floridian starch

Rhodophyta

Angiosperms

• Seagrasses

• Mangroves

Seagrasses

• 59 species worldwide in 12 genera

• Abundant in Australia, Alaska, S. Europe,

India, E. Africa, SE Asia, Caribbean, Gulf

of Mexico

• 7 species found in Caribbean:

Thalassia, Syringodium, Halodule, Ruppia, Halophila

engelmanni, H. decipiens, and H. baillonii

Seagrasses

Jobos Bay, PR

Functions of seagrass –

An ecosystem perspective

• Primary production

• Canopy structure

• Epiphyte and epifaunal substratum

• Nutrient, contaminant and sediment filtration and

trapping

• Below-ground structure

• Nutrient regeneration and recycling

• Wave and current energy damping

Seagrass ecosystem

Mangroves • Over 60 species worldwide

• Mainly limited to tropics in the intertidal

• Indo-West Pacific has highest diversity

• Important in island formation

• 4 species found in Caribbean:

Rhizophora mangle (Red mangroves),

Avicennia germinant (Black mangroves),

Laguncularia racemosa (White mangroves), and

Conocarpus erectus (Buttonwood mangroves)

Mangroves

Mangroves

Mangrove dispersal

•Red mangrove dispersal

period = 40 days

•Black mangrove = minimum

14 days

•White mangrove = 5 days

Germination occurs on parent

Ice shelf • Resource-poor and inhabited

by only the hardiest of

creatures (similar to deep sea)

• The transition to a fully

mature community may take

hundreds to thousands of

years

• In the water column, change

occurs more quickly

(opportunistic when ice

opens)

• Krill extremely abundant

Adaptations

• Good swimmers

• Adapted to life in extreme cold

– Layer of blubber

– Thick layer of feathers

– Behavior modification (huddling)

– Live near ice-free zone

Penguin species:

1. Emperor

2. King

3. Yellow-eyed

4. Chinestrap

5. Adelie

6. Gentoo

7. Royal

8. Rockhopper

9. Snares Crested

10. Macaroni

11. Fiordland Crested

12. Erect-Crested

13. African Black-footed

14. Magellanic

15. Peruvian

16. Galapagos

17. White-Flippered

18. Blue (Fairy)

Emperor Penguins

Aptenodytes forsteri • Colonies of 200,000 individuals in the Ross

Sea, Antarctica

• Large birds (30-40 kg)

• Only organism to breed during the Antarctic

winter

Emperor Penguins

Aptenodytes forsteri

Emperor Penguins

Aptenodytes forsteri

Order

Procellariformes

• Large wing span

• “Pelagic” birds

• Most of the world's albatross nest in subantarctic waters in the southern hemisphere

• Albatross are the “tuna” of the avian world with the most efficient flight and one of the largest wingspans – 12 ft

• Oldest seabird reaching 60-70 years old

• Lay only one egg per year

• Frigates sleep on the wing!

Order Pelecaniformes

Frigate Bird

Tern

Cormorant

Order

Charadriiformes

• Most diverse group (112 sp.)

• Many species very abundant

(i.e.,Auks)

Order Charadriiformes

Skimmers

Bird migrations

• Arctic tern has longest migration (25,000

miles every year)

Transients

Marine Mammals

• Order Carnivora

– Suborder Fissipedia (dogs, cats, weasels, sea otters,

polar bears)

– Suborder Pinnipedia (seals and sea lions)

• Order Cetacea (whales and dolphins)

• Order Sirenia

Suborder Fissipedia - Sea otters

Enhydra lutris

Suborder Fissipedia - Sea otters

Enhydra lutris

Ursus maritimus

Ursus maritimus

Order Cetacea Suborder Mysticeti (baleen whales)

Suborder Odontoceti (toothed whales)

Family Delphinidae (marine dolphins)

Family Phocoenidae (porpoises)

Family Physeteridae (sperm whales)

Family Monodontidae (beluga and narwal)

Family Ziphiidae (beaked whales)

Suborder Mysticeti (baleen whales)

Suborder Odontoceti (toothed whales)

Suborder Pinnipedia

Sea lion

Seal

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Diving Physiology

• Deepest dive by mammal (unaided): 2,250 m, Sperm Whale

• Elephant seals spend most of their time submerged and can dive to over 1,500 m depth

• Provides access to prey living at great depths (ie, Giant Squid)

• Animal must have mechanisms to deal with oxygen consumption and build-up of carbon dioxide and lactic acid

Diving Physiology

Major adaptations:

1. Larger volume of blood transport

2. Storage of oxygen in hemoglobin of muscles

3. High red blood cell concentration

4. Low heart and oxygen consumption rate

5. Restriction of peripheral circulation

Sirenia