Post on 11-May-2015
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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
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