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

Past, Present and Future KELP FORESTS Past, Present and Future

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

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

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

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 60-40 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

Figure 13.21

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

FUNCTION AND FORM

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

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

Kelp forest ex.

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 10-30 meters within 1-3 years, few sp. lasting more than 25 years Terr. forests reach 10-30 meters within 20-30 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

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

Animals of the kelp forest

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

Isoyake! “Rock burning”, 1902 Oldest known term for algal deforestation, means “rock-burning” -- 1902 -- 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

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

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.

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

NORTH PACIFIC/ALASKA Sea otters, sea cows, sea urchins and humans Kelp forest ecosystems arose 20-40 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 1768 -- effect on forests undetermined

Human growth in N. Pacific Colonization by 30,000 ya, boats used by 25000 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 25000 ya off Japan coast Suggested that easy hunting of giant sea cow & eventual depletion led to evolution of whaling

Colonization of Alaska Human occupation in Alaska est. 9-1000 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

Otters and urchins

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

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

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

CALIFORNIA CA kelp forests considered most diverse in world…until humans arrive CA kelp forests considered most diverse in world First major colonization occurred 12-13000 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

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?

White sea bass landings

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

Kelp forest changes

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 0.28-0.58 degrees Celcius by 2025

A sign of things to come

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

References Steneck RS, Graham MH, Bourque BJ, et al. Kelp forest ecosystems: biodiversity, stability, resilience and future ENVIRON CONSERV 29 (4): 436-459 DEC 2002 ESTES JA, DUGGINS DO, RATHBUN GB THE ECOLOGY OF EXTINCTIONS IN KELP FOREST COMMUNITIES CONSERV BIOL 3 (3): 252-264 SEP 1989 SIMENSTAD CA, ESTES JA, KENYON KW ALEUTS, SEA OTTERS, AND ALTERNATE STABLE-STATE COMMUNITIES SCIENCE 200 (4340): 403-411 1978 JOHNSON CR STABILITY OF ATLANTIC KELP FORESTS TRENDS ECOL EVOL 4 (3): 79-80 MAR 1989

References cont. WITMAN JD Dayton PK, Tegner MJ, Edwards PB, et al STABILITY OF ATLANTIC KELP FORESTS TRENDS ECOL EVOL 3 (11): 285-286 NOV 1988 Dayton PK, Tegner MJ, Edwards PB, et al Sliding baselines, ghosts, and reduced expectations in kelp forest communities ECOL APPL 8 (2): 309-322 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): 49-63 OCT 1991

Selected Readings Jackson JBC, Sala E Unnatural oceans SCI MAR 65: 273-281 Suppl. 2 SEP 2001 Jackson JBC, Kirby MX, Berger WH, et al. Historical overfishing and the recent collapse of coastal ecosystems SCIENCE 293 (5530): 629-638 JUL 27 2001 Jackson JBC What was natural in the coastal oceans? P NATL ACAD SCI USA 98 (10): 5411-5418 MAY 8 2001