27-Apr-99

Chapter 8

Coral Reefs

CaCO3 fixers (limestone)

Atmosphere .4%CO2 Because of photosynthetic and it is permanently sequestered as CaCO3.

CaCO3 fixers = animals 50% algae 50%

Corals live in top 25 meters of water low nutrient system low N&P. Cyanobacteria N-fixing

Very efficient nutrient recyclers etc.

Development of Coral Reefs

Darwin got the idea of evolution through watching the coral reefs- large new volcanic islands developed fringing reef attached to shoreline as shoreline erodes lagoon forms, as island disappears an atoll is formed.

Hawaiian islands furthest west Seamount new island forming no reef on Hawaii main island some fringing reef, Oahu fringing reef, Molokai barrier reef, Wake & midway atolls.

Structure of Coral reefs

Algal ridge that breaks water then a reef flat covered by shallow water about a mile from land (lagoon). Sometimes reef patches in lagoon that separate algal turfs on seaward side and sandy lagoon on the land side. Corals grow below algal ridge lagoon bottom make of rubble from algal ridge.

Turf algae – rapid growth, filaments or sheaths, crustose slow growing not palatable, Chemical defenses against grazing ex Calerpa = Calerpine –peppery taste used as spice.

Human activity impacts what grows on reef – silts cover and kill; pollutants algal blooms; fishing pressure – fleshy algal bloom.

Soft Bottom Communities

Atlantic=Spray zone at the top of high tide barnacle and blue green algae zone anfelchia red algae grows on rocks (fish cannot reach shallow areas – drawback- air exposure, surf damage) then tidal pools that remain full as low tide exposes surrounding areas, fucoid zone (fucus and padina) in surrounding area, floats s-a sargassum and reds in lower intertidal zone below low tide zone sub-tidal are kelps.

Pacific= follows same pattern but there is a faster drop off on the way to the subtidal zone because of younger shores results in a larger subtital zone (more kelps) Seal Palm life in surf zone postelsia

Laminaria (single blade) and kelp (20m deep) are main species.

Presentations

Algae blooms poison wildlife, livestock forms n from NO3 contaminates ground water. Causes liver to hemorrhage in wildlife, hepatitis and skin irritation in humans common in eutrophic lakes. People add nutrients to fresh water contaminating it so they can get more fish out of it etc. Wrong because the earth is only 3%fresh water.

RuBisCO - Cori

Ribulose 1-5 Biphosphate Carboxylase Oxygenase - enzyme used in photosynthesis where CO2 is converted to sugar. Red algae has a more efficient form of RuBisCO, experiments in gene splicing into terrestrial crops for more efficient growing grains.

Dinofyces - Alyssa

Shellfish poisoning. Annual cycle reaches peaks in fall and spring. Toxicity levels decrease with an increase in depth most dense at 1-5 Meters deep. Toxins diffused with fresh water influx.

Toxins: Okadaic acid; Dinophysis Toxin 1 (DTX-1)

Tested with Elisa (protiens) & mouse bioassay (mouse roulette)

Parasitic Red Algae - Andrea

Make up 15% of all red algae; 90% of which are adelphoparasites (closely related to hosts) 10% alloparasites (not related). Adelphoparasites possibly evolved from red algae (Setchell). Parasitic algae evolved from free living algae that became dependent upon Red algae hosts (Struch & Feldmans).

Glen Canyon Dam - Chris

Regulation of the Colorado river. 3 major characteristics changed in river because of dam:1. Depth - flow regulations expose algae to air or cover them up from light-changes dominance 2. Temperature- Creates cold water 3. Disturbed algae ripped off substrates Cladophera/ diatoms dying trout dye with them.

Biological controls of fresh water algae - Justin

Chemical, physical, biological

Biological: Pathogens; cyanophages- virus infects blue-green algae isolated in 1963 attacks photosynthetic function eutrophic water success. Bacteria fungi -close physiological algal growth inhibitor use haybales as substrate. Algae - Pandorina morun has growth inhibitors to other algae. Protozooans zooplankton - ameobas, rotophers. Fish- Tilapia pithofora eat algae; Carp root up increase turbidity prevents light penetration. Birds, tadpoles- eat filamentous algae. Bio-manipulation - small, expensive, needs to be well chosen, correctly timed ex. Chemical additions circulating water etc.

Lichens - Collette

Algae & fungus- fungus genera generally not found by itself. Algae genus = greens and Cyanobacteria. Cover 8% of earth's surface. Need hard substrates to grow. Used as bio-indicators not tolerant to pollution. Fungus incorporated into algae cell wall, inside cell wall, or attached to outside of cell wall. Algae sunlight + Carbon = Glucose fungus takes glucose to manitol.

Coral reefs - Abel

Coral polyps have zooxanthellii algae inside when bleached the zooxanthelli is expelled.

Virus eating algae - Absalom

Removal of enteric viruses by algae during waste water treatment. Algae not really destroyed but eaten and caused to settle. Use bacteriophages MS2 or PRD absorb viruses and combine algae with bacteria.

CLOD - Rayna

Salicornia - Justin

Edible seaweeds - Luiza

Bio-technical apps. for algae - Cory

Phytoplankton on sockeye Salmon -

Pfisteria - Amanda

Macrocystis pyrifera Giant Kelp - Randy

Biodiversity - Julie