ALGAE & SEAWEEDS An Overview

Phycology The study of Algae Also called Algology Not a plant - lack the structural complexity of higher plants They DO photosynthesize

Characteristics Range in size from microscopic to single celled organisms to large seaweed Autotrophic – make own food from the sun Live in Epipelagic Zone Aquatic and have flagella at some point in life Often contain pyrenoids, organelles that synthesis and store starch

Algae Classification Major groupings are called divisions: Based on the following: Light-harvesting pigments for photosynthesis Polysaccharide reserve Cellular organization Morphology –form, shape, structure Ecology –interactions among organisms and environment

General Structure

The complete body is called the thallus. Usually, all regions of the thallus can photosynthesize.

Most seaweeds have gas-filled bladders or floats that will help them maximize sunlight exposure. Sometime these floats contain carbon monoxide.

This structure does not aid in gathering nutrients. A holdfast is a root-like structure that holds the seaweed to the bottom. This structure does not aid in gathering nutrients.

The holdfast does not penetrate through sand or mud, so like this Sea Palm, most macroalgae are only found on hard sediments.

Some seaweeds have a stem-like structure called the stipe. The stipe provides support and can be long and tough, as in the Giant Kelp Not found in all seaweeds.

The stipe also allows a place for the attachment of the blades. Blades are like leaves of a plant. Photosynthesize

Types of Algae Chlorophyta = Green Phaeophyta = Brown Rhodophyta = Red

Phylum Chlorophyta Green algae 4000 diverse species Biologist reason that green algae give rise to land plants. Both green algae and land plants have chlorophyll A and B as well as carotenoids and store food as starch Bright Green because of the chlorophyll. Both have walls made of cellulose.

Caulerpa floridana

Caulerpa racemosa

Chaetomorpha

Udotea spp

Ulva lactuca

Phylum Phaeophyta 1500 species of Brown algae Mostly marine and include seaweed and kelp and sargasso Color varies from olive green to dark brown because there are many yellow-brown pigments that mask the color of chlorophyll. All are multicellular and large (often reaching lengths of 147 feet) can grow to over 100m (300Ft) Primary producers in temperate and polar regions Used in cosmetics and most ice creams

Biology of Seaweeds – Brown Algae some kelp have the capacity to grow as much as two to three feet per day!!

Kelp

Biology of Seaweeds – The Kelp Forest

Dictyota

Fucus

Padina

When Columbus reached the deep blue waters of the central North Atlantic, he thought he was very close to shore. After all, there was suddenly an abundance of plant life in the form of a floating algae, which he called, simply, "weed." His sailors, meanwhile, feared that their ships would become irretrievably entangled in the stuff. Their fears were misplaced — as were Columbus' hopes. The weed — which scientists ultimately dubbed sargassum, after a Portuguese word for it — is neither sturdy nor abundant enough to ensnare a ship of any size. And even the westernmost boundaries of the Sargasso Sea — a two-million-square-mile ellipse of deep-blue water adrift in the North Atlantic — lie many hundreds of miles from the North American shore

Sargassum

Phylum Rhodophyta 6000 species of RED Algae More species of red than green or brown Most are marine found at a depth of 200 meters. Contain chlorophyll A and C as well as phycobilins which are important in absorbing light that can penetrate deep into the water Some have calcium carbonate within their cell walls that help form coral reefs. Have cells coated in carageenan which is used in cosmetics, gelatin capsules and some cheeses

Halimenia spp

Halimenia spp

Sebdenia spp

Peyssonellia spp

Importance of Seaweed/Algae

1. Seaweeds are important to tropical ecosystems Seaweeds are eaten by many animals. These include sea slugs, fishes and turtles. Seaweed provide shelter for many small animals that hide among their fronds. Lay eggs on the blades

2. Seaweeds make beach sand when die Many tropical seaweeds have a hard skeleton made of calcium carbonate. When the seaweed dies or the fronds fall off, the skeleton breaks down. This can make as much as 44% of the components of reef sediments or sand on some beaches.

3. People eat seaweed Seaweed salads and soups are popular in Asian food In Japan edible seaweed crops have an annual value of over half a billion dollars and seaweeds are the world’s 6th largest aquatic crop.

as thickeners 4. Byproducts used in everyday products Seaweeds are in a lot of products in a typical US grocery store; They are included in things you use everyday, like toothpaste as well as treats like, gum, ice cream and yogurt.

5. Used as fertilizer and fodder for livestock Seaweed has been used as a soil improver for centuries, particularly in coastal areas Seaweed was also used as fodder for livestock and as natural fertilizer for crops owing to their high potassium content.

6. Seaweeds are vital for biotechnology – agar plates Agar comes from some species of red algae and is used in deserts as vegetable gelatin …. Without agar biomedical researchers could not grow bacteria or do genetic analysis. Bacteria grown on agar plates are vital for research in many disease as well as tests for antimicrobial drugs. Agarose gel

We are training Seaweed biologists There are 231 species of seaweed recorded in Bocas del Toro, Panama With the help of the US National Science Foundation and Panama’s SENACYT, STRI’s Bocas del Toro Research Station held a workshop to train 20 seaweed scientists from 16 countries.

Other seaweed facts Toyota wants to make a car out of seaweed Using Kelp-based Bioplastics for Future Hybrid Cars http://www.toyota.com.au/HybridSynergyDrive/news/160209.html