1. What Charles Darwin said…
“I can only compare these great aquatic forests…with the terrestrial ones in the intertropical region. Yet if in any country a forest was destroyed, I do not believe nearly so many species of animals would perish as would here, from the destruction of the kelp. Amidst the leaves of this plant numerous species of fish live, which nowhere else could find food or shelter…”
Charles Darwin, 1 June 1834, Tierra del Fuego, Chile

2. Past, Present and Future
KELP FORESTS
Past, Present and Future

3. MAJOR OBJECTIVES Kelp structure and function
Kelp ecosystem biodiversity
Change of kelp through time
Human destruction of kelp
Kelp forests in the future
3 different kelp forest study sites will be focused upon

4. Kelp knowledge
We know so much about kelp because of its location – right next to the shoreline
Gives us a chance to understand the complexity of marine ecosystems
Kelp forest details and changes tend to be much more observable in scientific study than, for example, coral reefs

5. The Order Laminariales!
Diverse and productive!
Kelp growth controlled by 3 factors:
Recruitment
Growth
Competition
*Oceanographic conditions determine these 3 factors
Next to coral reefs, considered largest biological structure in the oceans
Useful species, common names, some of their uses?
SpeciesCommon nameUses acanthopeltis agar Ahnfeltia plicata in USSR agar Anaebaena-Azolla symbiosis "green manure" Inoculation of 0.2 kg of Azolla per hectare is equivalent to 30 kg/hectare of commercial nitrogen fertilizer. Not as popular now because we have found that Azolla growth is limited by phosphate, which is non-renewable. Next break is low-phosphorus requiring Azolla Ascophyllum nodosum (bladder wrack) alginates thickening agents (fruit drinks and salad dressing), colloid stabilizers in food (ice creams, sherbets and cheeses), textile, cosmetic, pharmaceutical, paper and welding industries. Calcareous algae to reduce soil acidity. Caulerpa racemosa (Nama) in Fiji food Chlamydomonas and other soil algae soil amendment by making mucilage that loosen compacted soil. Chlorella only microscopic green used commercially Chondrus crispus (Irish Moss) agar, carrageenan Codium geppii (Sagati) in Fiji food Diatom fossils (diatomaceous earth, diatomite) flea killers, embalming compounds, enamel polishes, diatomaceous bricks, to filter sewage in UK from 1976, to filter sugar cane liquors from 1914; Nobel stabilized nitroglycerine. Durvillaea (Australia & Chile) alginates thickening agents (fruit drinks and salad dressing), colloid stabilizers in food (ice creams, sherbets and cheeses), textile, cosmetic, pharmaceutical, paper and welding industries. Ecklonia alginates thickening agents (fruit drinks and salad dressing), colloid stabilizers in food (ice creams, sherbets and cheeses), textile, cosmetic, pharmaceutical, paper and welding industries. Eucheuma in Philippines carrageenan Furcillaria fastigiata in Denmark agar Gelidium amansii in Japan agar Gelidium arborescens in USA agar Gelidium cartillagineum in USA agar Gelidium latifolium in Ireland. agar Gelidium nudifrons in USA. agar Gelidium pulchellum Ireland agar Gigartina clavifera in New Zealand carrageenan Gigartina mamillosa (very similar and known as Irish Moss). carrageenan Gigartina undulata in New Zealand carrageenan Gracilaria (Lumicevata) in Fiji food Hypnea (Lumiwawa) in Fiji food Kelp and mixed seaweeds liquid fertilizers, soil amendment Wayne and Wanda! rich in potassium and nitrogen but low in phosphate. Free of terrestrial weeds and fungi. Kelps (Kombu) vegetables in Japan and China Laminaria (kelp - English; kombu - Japan and China) Food. Maybe 75% of their dry bulk is indigestible Laminaria digitata in UK and Norway alginates thickening agents (fruit drinks and salad dressing), colloid stabilizers in food (ice creams, sherbets and cheeses), textile, cosmetic, pharmaceutical, paper and welding industries. Laminaria cloustoni (oar weed) alginates thickening agents (fruit drinks and salad dressing) colloid stabilizers in food (ice creams, sherbets and cheeses), textile, cosmetic, pharmaceutical, paper and welding industries. Macrocystis pyrifera (kelp - USA) alginates thickening agents (fruit drinks and salad dressing) colloid stabilizers in food (ice creams, sherbets and cheeses), textile, cosmetic, pharmaceutical, paper and welding industries. Mastocarpus stellata in British Isles. agar Phyllophora nervosa in USSR. agar Porphyra (laver - England and USA; luche - Chile; karengo - Maori; nori - Japan; slack - Scotland; sloke - Ireland) Food - Maybe 75% of their dry bulk is indigestible. Toasted and used to wrap sushi North Pacific. Cultivated for centuries in Japan, Korea and China Pterocladia agar Spirulina food protein - blue-green used for protein food in old (Lake Chad) and new world (Aztecs before conquistadores) Ulva food - eaten as a green vegetable Undaria pinnatifida (wakame) food - Maybe 75% of their dry bulk is indigestible

6. Where kelp is found
Shallow rocky shores where light & oceanographic conditions are suitable for long-lasting growth -- cold temp. & high nutrient concentration upwelling
Kelp forests rarely occur above or below degree latitude band
at these limits, kelp forests are usually less diverse & productive, while suffering from competition with other algae
(found within certain areas of the Tropics of Cancer and Capricorn)
depends upon strong upwelling anomalies of cold, nutrient-rich water

7. Figure 13.21

8. KELP MORPHOLOGY 3 different groups of kelp: CANOPY STIPITATE PROSTRATE
3 different groups or guilds – defined by canopy height
CANOPY KELPS: largest, produces floating canopies – Macrocystis, up to 45 meters long
Holdfast
Pneumatocysts
Found on North and South America, South Africa, southern Australia, New Zealand coasts
Most species reach height of about 10 meters

9. FUNCTION AND FORM

10. STIPITATE KELPS – second largest group
held to the sea floor with rigid ‘stipes’
5-10 meters long
Example: Laminaria,
dominant kelp across North Pacific Rim
– most species are less than 5 meters long
(Japan, Alaska, northern California – sea otters aplenty) Stipitate kelp sp. also found in Europe, Australia, New Zealand
PROSTRATE KELPS – smallest of kelp species, covering the sea floor w/ fronds
Example: smaller sp. of Laminaria – same locations as larger sp. but also found in North Atlantic (Gulf of Maine to Greenland), Iceland, Norway, and Africa

11. Kelp diversity Low taxonomic diversity
High structural and functional diversity
Low taxonomic diversity
High structural and functional diversity
Morphological differences occur within and among genera
All three kelp guilds coexist on a seafloor covered with turf algae and encrusting coralline algae

12. Kelp forest ex.

13. Similarities and differences to terrestrial forests
Kelp forest structure similar to terrestrial forests – different canopy levels, varied understory
Kelp forests more productive, more diverse (phylogenetically)
Shorter life spans, shorter heights
Kelp forests reach meters within 1-3 years, few sp. lasting more than 25 years
Terr. forests reach meters within years, living thousands of years
Recruitment and growth of new kelp depends upon canopy breaks for available light
Terrestrial forests are habitat for roughly 3 phyla
Kelp forests are habitat for 10 or more phyla

14. The purpose of kelp
Kelp forests alter and shape local environments and ecologies
-- dampen wave movement, influencing water flow, coastal erosion, sedimentation, benthic productivity (primary & secondary), & recruitment of species
-- canopy coverage reduces light, creating conditions for low light intensity species of algae and animal
Sessile algae and animals use kelp as substrate
Mobile animals live and feed off of kelp – some cannot live without kelp
Predatory fishes use kelp forests as primary habitat
Canopy litter acts as food for detritivores
Predatory fishes use kelp forests as primary habitat – canopy loss can result in trophic cascades
Canopy litter acts as food for detritivores on sea floor – direct contribution to secondary productivity

15. Animals of the kelp forest

16. Kelp forests come and go…
Kelp forests can disappear quickly
-- temperature changes
-- severe storms
-- outbreaks of herbivorous invertebrates
-- disease
However, the kelp forest community can regrow just as quickly

17. Isoyake! “Rock burning”, 1902
Oldest known term for algal deforestation, means “rock-burning”
-- Japanese coast, reason: salinity anomalies
-- lower latitude deaths caused by environmental changes
-- destruction is short-lived, reversible
Reasons for death are different depending on latitude placement
LOWER LATITUDE DEATH (less than 40 degrees): deforestations result from temperature, salinity and nutrient anomalies which directly kill or trigger diseases
MID-LATITUDE DEATH (40-60 degrees): kelp deforestation caused by intense herbivory by sea urchins

18. Death by Sea Urchin! Primary cause for mid-lat. Death
“Urchin barrens” – 1960s
Urchin-caused deforestation most often seen in Northern Hemisphere (particularly Alaska)
In Southerm Hem., widespread urchin death prevented by increased competition, oceanographic limitations, increased predation

19. Controlling urchin populations
Kelp forest habitat determined by urchin abundance
Urchin abundance determined by various factors:
Predation (ex. Otters, fish -- most important factor), interspecific competition (other herbivores, i.e. abalone), disease, turbulence, storms, etc.

20. Rise of urchins through time
Urchin death a recent phenomenon
First seen in 1930’s, Japan
More seen 1950s-1960s
Mid-1970s, urchin barrens a major problem, resulting in vast losses of kelp
Conferences met in 1980s to propose ways to eradicate sea urchins
Damage to kelp suggested to be irreversible

21. NORTH PACIFIC/ALASKA Sea otters, sea cows, sea urchins and humans
Kelp forest ecosystems arose mya along w/ strongylocentrotid urchins, otters, and Steller’s sea cow – animals which played major roles in forests
First major change: sea cows hunted to extinction by effect on forests undetermined

22. Human growth in N. Pacific
Colonization by 30,000 ya, boats used by ya off Japan coast
Shellfish, finfish, marine birds & mammals abundant food
Easy hunting of giant sea cow & eventual depletion led to evolution of whaling
Rich plant/animal life may have been determining factor of colonization by modern humans est. 30,000 ya, boats used by ya off Japan coast
Suggested that easy hunting of giant sea cow & eventual depletion led to evolution of whaling

23. Colonization of Alaska
Human occupation in Alaska est ya
At time, relationship between otter/urchin/kelp forest firmly established
Indigenous tribes begin to hunt otters 2500 ya
More death soon to come – European invasion for otter pelts begins mid 1700s
Ecosystem begins to change, urchins let loose

24. Otters and urchins

25. NORTH ATLANTIC
Sea urchins, no sea otters, but very large predatory fish!
Kelp and urchins migrate w/out otters from Pacific
Urchins encounter new controlling predators – big fish
Predatory fish documented for at least 5000 years in area
Via transarctic interchange

26. Humans like to eat cod
Indigenous peoples’ fish for fish & other life for 1000s of years
Europeans like cod, arrive in 1500’s
“land of the codfish”!
Kelp forests seen to exist in conjunction with predatory fish
Europeans are pleased and excited by extraordinary abundance of cod & other sp. at arrival in early 1600s
Western N. Atlantic coast called “Bacallaos”, Portugese for “land of the codfish”
Kelp forests seen in conjunction with pop. of predatory fish

27. Urchins rise again Fishing technology decreases cod pop. by 1930s
Sea urchin populations rise, kelp forests fall
Urchin barrens present in N. Atlantic, increase until kelp forest all time low reached by 1980s
Abundance of cod & others continue to vex Europeans until mechanized fishing technology & ship refrigeration allow abundance to drop into insignificance and disaster beginning in 1930s

28. CALIFORNIA
CA kelp forests considered most diverse in world…until humans arrive
CA kelp forests considered most diverse in world
First major colonization occurred ya, strong exploitation of marine life followed
Aboroginal middens reveal decrease in animal size as hunting increases
Numerous sp. of kelp & urchins, crustaceans, abalone, snails, otters, lobsters, sheephead fish

29. ANIMALS DISAPPAEAR
Europeans arrive and happily contribute and quadruple fishing efforts, resulting in loss of indigenous people and marine life
Otters functionally gone by early 1800s
Kelp forest ecosystem still survives!
Why?

30. White sea bass landings

31. CA kelp begins to change
CA kelp forest so diverse, other predators keep urchin pop. down
Continues to persevere for another 150 years
Now on edge of disaster
CA kelp forest so diverse, alternate predators (sheephead, lobsters), herbivorous competitors (abalone) keep urchin colonies at bay
Continues to persevere for another 150 years
Big new fisheries develop for abalone, lobster, and sheephead – one sp. of abalone now possibly extinct, all other animals vastly reduced in abundance and individ. size
CA kelp forest now on brink of possible disaster

32. Kelp forest changes

33. THE FUTURE OF KELP
Climate change (global temp. increase), human pop. growth, coastal development, oil spills, overfishing impacts, non-native sp. invasions all predicted to increase over next 25 years
Currently, in some areas fisheries for urchins coincide with fisheries for urchin predators – a delicate balance achieved
Market demand for urchin could change
Not all areas will be affected in future by temperature changes, but devastation could occur – mean annual temp. expected to increase by degrees Celcius by 2025

34. A sign of things to come

35. FINAL CONCLUSION
Kelp forests are home and nurseries for much marine life
If human trends continue (greed, population growth, mass destruction of wild life, habitat degradation) as they have for majority of written human history, kelp forests could possibly disappear or become functionally extinct within the next several decades

36. References Steneck RS, Graham MH, Bourque BJ, et al.
Kelp forest ecosystems: biodiversity, stability, resilience and future ENVIRON CONSERV 29 (4): DEC 2002
ESTES JA, DUGGINS DO, RATHBUN GB
THE ECOLOGY OF EXTINCTIONS IN KELP FOREST COMMUNITIES CONSERV BIOL 3 (3): SEP 1989
SIMENSTAD CA, ESTES JA, KENYON KW
ALEUTS, SEA OTTERS, AND ALTERNATE STABLE-STATE COMMUNITIES SCIENCE 200 (4340):
JOHNSON CR
STABILITY OF ATLANTIC KELP FORESTS TRENDS ECOL EVOL 4 (3): MAR 1989

37. References cont. WITMAN JD Dayton PK, Tegner MJ, Edwards PB, et al
STABILITY OF ATLANTIC KELP FORESTS TRENDS ECOL EVOL 3 (11): NOV 1988
Dayton PK, Tegner MJ, Edwards PB, et al
Sliding baselines, ghosts, and reduced expectations in kelp forest communities ECOL APPL 8 (2): MAY 1998
TEGNER MJ, DAYTON PK
SEA-URCHINS, EL-NINOS, AND THE LONG-TERM STABILITY OF SOUTHERN CALIFORNIA KELP FOREST COMMUNITIES MAR ECOL-PROG SER 77 (1): OCT 1991

38. Selected Readings Jackson JBC, Sala E
Unnatural oceans SCI MAR 65: Suppl. 2 SEP 2001
Jackson JBC, Kirby MX, Berger WH, et al.
Historical overfishing and the recent collapse of coastal ecosystems SCIENCE 293 (5530): JUL
Jackson JBC
What was natural in the coastal oceans? P NATL ACAD SCI USA 98 (10): MAY