Title: PHYCOLOGY Kelp Forest Ecology and Deep Water Algal Assemblages By Heather Spalding Moss Landing Mari
1PHYCOLOGYKelp Forest Ecology and Deep Water
Algal AssemblagesBy Heather SpaldingMoss
Landing Marine Laboratories
Developed for the Marine Science Research summer
institute 2000 Dr. Simona Bartl, program
director
2- I know of few things more surprising than to
see this plant growing and flourishing amidst
those breakers of the western ocean, which no
mass of rock, let it be ever so hard, can long
resist. - -Darwin (1860)
3Terminology
- Phycology- study of algae
- Algae
- pond scum, frog spittle, water mosses, seaweed
- convenient term for most nonvascular aquatic
plants - capable of photosynthesis with oxygen evolution
- distinguishing characteristic is their sexual
reproduction
4Morphological Terminology
- Coralline ( G. korallion, coral) term frequently
used to refer to calcareous (impregnated with
calcium carbonate) Rhodophyta of the
Corallinaceae which resemble coral - Geniculate (L. geniculum, a little knee) bent in
the manner of a knee geniculum is an uncalcified
joint between segments of coralline algae - Nongeniculate encrusting coralline algae, does
not bend - Foliose (L. folium, leaf) leaf-like a flat or
curled, expanded thallus - Stipitate (L. stipes, stalk) stalked
53 Main Phyla
- Phaeophyta brown algae, i.e. kelps
- kelps large brown algae in the Order
Laminariales - Giant Kelp Macrocystis pyrifera, a type of
large brown algae that can grow up to 60m and
form canopy-like forests in the water column - Rhodophyta red algae, i.e. foliose reds and
coralline algae - Chlorophyta green algae, i.e. sea lettuce
6Chlorophyta Codium sp.
Phaeophyta Macrocystis pyrifera
Rhodophyta Chondrus crispus
7Overview of talk
- Human interest in algae
- history
- biodiversity
- invasive and nuisance species
- human uses
- scientific research
- Local research
- kelp forest ecology
- deep water algal assemblages
8Human interest in algae
- Seaweed collected for food
- China 2500 years ago
- Europe 1500 years ago
- Ireland over 800 years ago
- Seaweed mariculture
- Japan and China for over 300 years
9Porphyra (Nori) Mariculture
10Human interest in algae
- 1600s European mariners used Macrocystis as a
navigational aid - floating canopy of attached plants indicated
shallow reefs - floating bundles of drift plants indicated that
the coast was not far off
11First ecological research
- 1860 (Darwin) published some of the first
insights made the first analogy between this
giant kelp and terrestrial forests
12Research continued
- 1945 Andrew pioneered research on the fauna of
giant kelp holdfasts - included some underwater observations, but
hampered by the lack of simple diving equipment
13Research continued
- 1950s
- With the advent of SCUBA, direct observations of
kelp forests became relatively simple
14- Also in the 1950s
- A large tract of Macrocystis disappeared off the
Palos Verde Peninsula (Los Angelos County) and
from other areas of southern California - Lead to the idea that stands of Macrocystis may
be ephemeral - May be disturbed by pollution associated with
large centers of population - This spawned a number of research programs to
study life history features of giant kelp and its
associated organisms - These found that many factors were responsible
for the variation in kelp abundance
15For example
- 1967, 1969 Dayton estimated the size of
Macrocystis beds by assessing the percent cover
of surface canopy at several locations - found variation over time
- To present.these studies continue, with hundreds
to thousands of published papers on Macrocystis - Seaweed research in the U.S. has been ongoing for
about 60 years
16Algae researchWhy do we care?
- Positive effects in nature
- Important primary producers (base of the food
chain) - Oxygenate the water during the day by
photosynthesis - Some algae form symbiotic relationships with
other organisms - Coral, certain protozoa, sponges, and marine worms
17Symbiotic relationship Algae living the gut
tissues of this anemone (Anthopleura
xanthogrammica) give it a green hue. The anemone
gets extra nourishment from the by-products of
the algal photosynthesis, and the algae are
protected from grazers.
18Create environment for biodiversity
- North(1971) listed 130 species of plants almost
800 species of animals associated with giant kelp
in So. CA and Baja, Mexico - Defined 5 zonal associations occurring along a
depth gradient in a giant kelp community
19Inhabitants of a generalized kelp forest
Association 1 On surface of algae
Bryozoan on kelp blade
Association 2 Plankton
Crab larvae
Sea star larvae
Copepod
20Inhabitants of a generalized kelp forest
Association 3 Fauna in giant kelp holdfast
Association 4 Flora and fauna on horizontal
surfaces
21Inhabitants of a generalized kelp forest
Association 5 Organisms on Vertical Faces
22Create environment for Biodiversity cont.
- A variety of birds and mammals forage in the kelp
forest community - Cormorants, harbor seals, sea otters
23Create environment for Biodiversity cont.
- Drift kelp is an important source of energy to
other communities, from the deep sea to the beach
24Negative effects in nature
- Some algae form macroalgal blooms
- Create an unpleasant smell and taste to water
- Create an anoxic environment in the water
- Nuisance algae and introduced species
- Can foul boats and smother a native marine
environment (Example Caulerpa taxifolia in the
Mediterranean) - Some algae (dinophlagellates) secrete toxins
- red tides and the fish-killing algae
Pfiesteria
25Invasive species Caulerpa taxifolia
Caulerpa taxifolia completely covering a coral
reef system in the Mediterranean. Photo credit
Alexander Meinesz, Univ. Nice-Sophia Antipolis
26Nuisance algae Pfiesteria
27Human Uses
- Pharmaceuticals
- Some algae (Cryptosiphonia) secrete compounds
that are used to treat herpes virus infections - In China,
- Laminaria and Sargassum species have been used in
China to treat cancer (anti-tumor activity
documented in animals and thought to be due to
long-chained polysaccharides) - Dry Laminaria stipes, which slowly take up water
and expand, have long been used in obstetrics to
dilate the cervix prior to the insertion of
intrauterine devices
28Human Uses Food!
Yum !!!
29Human Uses Food
- Over 493 species eaten in Asian countries
- Seaweeds account for 10 of the Japanese diet
- Examples
- Nori (Porphyra sp.) wrapped in sushi
- Kombu (Laminaria sp.) cut into strips or
powdered - Wakame (Undaria sp.) additive to soups
- Kelps, such as Kombu and Wakame, are often used
as a source of iodine as well as flavor
30Human Uses Food
- -In Ireland and Scotland
- Dulse (Palmaria palmata) used as a sea
vegetable sliced, diced, dried, etc. also in CA - Irish Moss (Chondrus crispus) used in soups,
puddings, etc. also on the East Coast of USA
Palmaria palmata
Chondrus crispus
31Human Uses Food
- Native Americans have been harvesting seaweed on
the Northern California Coast for many thousands
of years
The Kashaya call the seaweed they harvest mei
bil, sea leaf (Porphyra sp.)
32Additives for Human Consumption
- Industrial Gums products used to achieve
various levels of viscosity - Carrageenan (red algae, Chondrus crispus)
- For thickening and stabilizing ice cream and
other prepared foods - Agar (red algae, Gelidium sp.)
- For packing canned food, treating constipation,
and microbiological culture substrate - Alginates (brown algae, Macrocystis)
- As emulsifiers and binding agents in food and
pharmaceuticals - For medical dressings on burns and extensive
wounds
33Other Human Uses
Fucus used for fertilizer and fodder
- Waste Management
- Some algae are used as biological scrubbers to
remove excess nutrients and oxygen from effluents - Manufacture
- Macrocystis harvested for potash for making
gunpowder in World War I - Some intertidal algae used as fertilizer in soil
- Feed
- Some intertidal algae used as fodder (food) for
cattle and sheep Macrocystis harvested for
abalone farming
34Macrocystis Harvesting in CA
Kelco Kelp Harvesting Boat
Giant Kelp (Macrocystis pyrifera) Forest
35Other Human Uses
- Tourism
- Recreational SCUBA diving
- Sport Fishing
- abalone, lobsters, crabs, scallops, fish
- North (1971) lists over 40 species of fish
associated with kelp forests that occur in the
commercial and party boat catch in California - Maintenance of Fisheries
- Kelp Forests serve as refuges for early life
stages of commercially valuable fish
36Whats known from research
- Algal life history
- Large variation in number of life stages across
taxa - Simplest
- Fucus sp. animal-like life history
- Possibly most complex
- Pfiesteria over 23 life stages documented thus
far - In contrast to terrestrial plants
37Typical terrestrial plant life history
- Pollen transported to Pistil
- Pollen fertilizes Ova (N) to produce a seed (2N)
- Seed which grows into the sporophyte (plant2N)
Sporophyte
Pistil Ovary enclosed
Stamen pollen -bearing
38Macrocystis Life History
- Macrocystis pyrifera
- Sori on sporophylls produce microscopic haploid
(1N) spores - Spores settle and become male and female
gametophytes (tiny stages we dont see) - Male gametes (sperm) fertilize eggs on female
gametophyte - Resulting zygote develops into the macroscopic
diploid sporophyte (2N the big plant we see)
Sporophyte (2N) with sporophylls at base of plant
39Macrocystis Life History
Gametophytes (N)
Spores (N)
Male- releases sperm
Female
Sori
Developing Sporophyte (2N)
Sporophyte (2N)
Juvenile Sporophyte (2N)
40Geographic Distribution
- Subtidal forests of Macrocystis occur in many
areas of the world, but are most widely
distributed in the southern hemisphere
41What makes central CA so ideal for kelp and other
seaweeds?
- The primary requirement for seaweed is hard
substrate (rock) for attachment, but many other
factors affect its probability for survival
42Factors affecting algae in CA
- Substrate
- Need rock for attachment, hardness of rock
affects mortality due to water motion - Sedimentation and Sand movement
- Can bury, scour, or prevent attachment of plants
(especially microscopic stages) - Light
- Need certain quality (kelp gametophytes need blue
light to reproduce) and quantity (at least 1 of
surface levels)
43Factors affecting algae cont.
- Water Motion
- Can cause plant and animal loss in surge and
current - Distributes nutrients and increases nutrient
uptake - Temperature
- Needs water lt16º C (related to nutrients)
- Nutrients
- Needs certain quantities of Nitrates, Phosphates
and trace minerals and metals
44Factors affecting seaweed cont.
- Toxic Substances (heavy metals, pesticides)
- Copper reduced algal growth and fertility at 30
ppb - DDT possible alternation of community
- Grazing (fish, sea urchins, snails, isopods,
etc.) - Can destroy Macrocystis if plants at low density
- Create small areas nearly devoid of foliose red
algae - May destroy canopy and sub-canopy
- May consume small life stages
45Grazing Urchins
Urchin
Urchins grazing kelp holdfast
Giant kelp forest
Urchin barrens All vegetation grazed
46Factors affecting seaweed cont.
- Predation on grazers
- Sea stars, sheephead, sea otters, and other
predators (including humans) may affect the
distribution and abundance of grazers - Competition
- Canopy shading inhibits understory algal
recruitment and growth within and among species - Pre-emption of space
- Whiplash effects of algal fronds
47Predation on Grazers
Sunflower Star
California Sheephead
Pycnopodia (Sunflower star)
Sea otter preying on urchin
48Kelp forest ecology
- The complex interaction of all these factors
makes modeling and prediction very difficult - For example
- Is an El Nino event beneficial or detrimental for
kelp forests?
49Overview of an El Nino
50El Nino-Southern Oscillation Event
- Causes
- higher water temperatures
- a lapse in upwelling
- strong storms with large swell
- increased terrestrial water run-off from rivers,
streams, etc.
51El Nino effects on a giant kelp
forest(Bluenegative Whitepositive)
- Higher Water Temp
- increased algal growth
- less nutrients
- increased growth of bacteria and epiphytes
- Lapse in Upwelling
- Higher water temp (see above)
- Less nutrients upwelled from deep water
52El Nino effects on a giant kelp forest
(Bluenegative Whitepositive)
- Strong Storms with Swell
- Increased water motion tears out vegetation
- Increased sand scour abrades vegetation
- More space and light made available!
- Increased terrestrial water run-off
- Increased turbidity, so less light
- Increased nutrients, so more algal growth, but
may stimulate phytoplankton blooms, so less light - Increased sedimentation with possible burial
- Increased pollutants
53El Nino effects on a giant kelp forest
(Bluenegative Whitepositive)
- Also, an El Nino is usually followed by a La Nina
(cold water, lots of upwelling), which greatly
stimulates algal growth!
54Local research
- Two preliminary studies on human effects on kelp
forests - One comprehensive study of deep water algal
assemblages
55Local Research on Kelp Forest Ecology
- Diver Disturbance in Kelp Forests (Schaeffer and
Foster, 1998) - The Effects of Small-scale Kelp Harvesting of
Giant Kelp Surface Canopy Dynamics in the Ed
Ricketts Underwater Park Region (Donnellan and
Foster, 1999)
56Diver Disturbance in Kelp Forests
- Recreational SCUBA diving activity has greatly
increased in the past 20 years, with the
potential for causing important disturbance to
subtidal reefs. - While diver disturbance on coral reefs has been
assessed and negative impacts have been
documented, effects on temperate kelp forests
have not been previously examined.
57Diver Disturbance in Kelp Forests Hypotheses
- Ho Divers are having no effect on giant kelp
forest communities - Ha Divers are causing permanent disturbance in
giant kelp forest communities - Ha Divers are having an effect, but no permanent
disturbances
58Diver Disturbance in Kelp Forests Methods
- 42 divers followed underwater
- first group divers making a shore entry
concurrently with investigators - divers told investigators were observing
environments that divers like to explore, so
normal diving behavior would not be altered - Disturbances documented
- Observations started when divers were completely
submerged, recorded for 20-30 min., and
standardized to 30 min.
59Diver Disturbance in Kelp Forests Results
- During a 0.5 hr dive, the average diver
- contacted the bottom 43 times
- touched 4 animals
- detached 2 algal blades
- An estimated 60,000 divers use the studied kelp
forests every year
60Diver Disturbance in Kelp Forests Conclusions
- Investigators concluded that the large
concentration divers in local, usually
wave-protected kelp forests could lead to
permanent alterations in community structure - Diver impacts might be mitigated through
- More environmentally aware diving programs
- Designation of ecologically resilient shore
entry, exit points, and underwater training areas
61Diver Disturbance in Kelp Forests Future
Directions
- A more comprehensive analysis, would
- compare different locations
- assess diver experience
- compare heavily utilized diving locations to
areas not used by divers - monitor the long-term impacts or ecological
effects
62The Effects of Small-scale Kelp Harvesting
- This study assessed the effects of
hand-harvesting of giant kelp on the surface
canopy of local kelp forests
- These harvesting activities are concentrated
within a small local area during the winter - Hand-harvesting may negatively impact the giant
kelp, rockfish, and sea otter populations
63Methods
- Data from two sources was compared
- aerial photographs dating to 1976
- kelp forest harvest records
- Kelp harvesting intensity divided into 3 periods
- Moderate 1972-1985 (n8)
- Low 1986-1995 (n8)
- High 1996-1998 (n2)
- Assessed kelp canopy surface area, kelp forest
spatial extent, and kelp canopy blade intensity - Used a BACI (Before-After-Control-Impact) study
design and ANOVA (Analysis of Variance) to
compare above variables between 3 harvested areas
and one non-harvested control area.
64Results Conclusions
- No statistically significant differences were
found, but statistical power to detect an effect
was low given the small sample size of the
high-intensity period (n 2) and inherent
natural variability of kelp canopies - Conclusion Continued yearly aerial surveys
during the period of fall maximum kelp canopy are
needed to substantiate results
65What lies beyond the giant kelp forest?
- Because of its size and commercial importance,
most research on seaweed ecology has focused on
Macrocystis communities - Other communities are less studied
- Even fewer studies have gone beyond 30m (100ft)
due to the time and depth limitations of
conventional SCUBA diving
66New technologies allow for deep water studies
- Recent technological advances
- SCUBA with enriched air Nitrox diving
- access to submersibles and Remotely Operated
Vehicles (ROVs) - Scientists can now study deep water (gt30m) algal
communities
67Deep Water Algae
- Have same requirements as other algae
- rock substrate
- nutrients
- temp. lt16 C
- light
- the limiting factor controlling the lower depth
limits
Maripelta rotata
68Why study Deep Water Algal Assemblages (DWAAS)?
- To understand a new ecosystem
- To assess algal biogeography
- knowing what is found where allows us to
monitor long-term changes in the ocean - A gradual warming of the water over a long period
of time would affect an algas distribution - DWAAS may form habitat for commercially important
fish
69Why study DWAAS cont.
- Water quality bio-indicators
- As water quality decreases, turbidity increases,
and so the lower depth limits and possibly
species composition changes.. - It has been suggested that the deep water
environment is less variable over time - .But first we have to know how variable the
algae are at different locations and in bodies of
water with different water clarities!
70In order to test the variability of deep water
algal communities, we have to find out.
- What are the species composition and abundances
of deep water algae? - What are the lower depth limits of deep water
algae? What are the light levels? - What is the temporal (year to year) and spatial
(among and within locations) variation? - How does the zonation of DWAAS in central CA
compare with worldwide zonation observations and
lower depth limits?
71- Methods
- SCUBA sampling (30m)
- Counts of algae in 5x1m area
- cover based on 20 random point contacts in a
5x2m area - Qualitative collections made for algae
identification
72Methods The ROV Ventana
- Video surveys of algae from 100m-30m depth
- At each 5m depth increment, 5 1m2 areas were
sampled - Representative species were collected for
verification
73Method of determining cover from ROV Ventana
digital video with Optimas imaging software
74Beers Law
75DWAAS Preliminary Results
- The lower limits of different algal groups are
78m Nongeniculate (encrusting)
59m Foliose reds
50m Unknown green algal film
42m Kelps
76Nongeniculate coralline
Foliose red algae
Brown algae
Depth (m)
cover
77Pleurophycus gardneri
Desmarestia tabacoides
Maripelta rotata
10 SE
4 SE
Depth (m)
Individuals
78Results
- Profiles (K)
- Offshore of East Pinnacle
- 10/5/99 ------------0.1101
- 10/17/99 -----------0.117
- 1/27/00 ------------0.113
- 3/11/00 ------------0.123
- 5/4/00 --------------0.1246
- 5/18/00-------------0.0921
- Other sites
- 9/29/99 Diablo Pinnacle ------0.1077
- 9/29/99 Yankee Point ---------0.085
- Average K (SE) 0.109 (0.005)
79Comparison of K values
from Kirk (1994)
80Comparison of SI
81Conclusions
- Deep water kelps are abundant to 40m in central
CA, forming previously undescribed kelp beds
below the giant kelp forests - Pleurophycus gardneri, a kelp previously
described as rare in California, is the most
abundant alga at 30m with up to 10/m2. - The SI at the extinction depths of different
algal groups is similar to that described by
Hiscock (1986) - Central California water is exceptionally clear
with an average K value of 0.109
82Summary
- Algae have a number of human uses
- Algae create an environment for biodiversity
- Kelp forests are the most studied algal system in
the US - Complex system with inherent natural variability
- Local preliminary studies have addressed impacts
of divers and hand harvesters
83Summary
- Deep water algae in central CA are present to at
least 78 m - Form previously undescribed algal assemblages
84Acknowledgements
- Local Research Studies by Tim Schaeffer, Mike
Donnellan, and Mike Foster - Deep Water Algal Assemblage work by Heather
Spalding, Mike Foster, and John Heine through
NOAAs National Undersea Research Program,
Monterey Bay Initiative - Monterey Bay Aquarium Research Institute provided
video lab time - Website images by Monterey Bay Aquarium, National
Univ. Ireland, Catalina Island website by Dr.
Bushing, UCSC Biology Dept. Macrocystis homepage,
Sonoma State Univ. Dept. Biology, Maine Coast Sea
Vegetables, Berkeley Dept. Biology