Marine Plants Producers Chapter 14

Marine “Plants” Most photosynthetic marine organisms are members of kingdom Protista – not kingdom Plantae. Protists do not have specialized tissues and organs. Plants do have specialized tissues (ex: vascular and dermal tissues)

http://www.algaeindustrymagazine.com/part-six-algal-classification/

Plant cell specialization and tissues

Features Plants Share with Green Algae Pigments: Chlorophyll a & b; carotenoids Food Reserve: Starch Cell Walls: Cellulose Cell Division: Cell Plate Body Structure: Multicellular Life Cycle: Heteromorphic Alternation of Generation Sexual Reproduction: Oogamy

Phytoplankton Plant-like protists Usually single celled (unicellular algae) Perform nearly all of the photosynthesis in the oceans (more than seaweeds, algae, etc.) Produce half the O2 in the atmosphere Examples: diatoms and dinoflagellates

Diatoms Unicellular phytoplankton, enclosed in a shell made of silica (SiO2) Glassy shell is called a frustule Frustule is made of two halves that fit tightly together like a box Frustule is clear so light can penetrate for photosynthesis

http://www.bhikku.net/archives/03/img/diatoms.JPG

Dinoflagellates Unicellular autotrophs, have two flagella One flagella acts as a tail, the other wraps around the body for steering Cell is surrounded by a cell wall made of plates of cellulose (theca plates) Plates may have spines or other ornaments

http://www. scottcamazine http://www.scottcamazine.com/personal/selforganization/haeckel/images/dinoflagellates_jpg.jpg

Harmful Algal Bloom (HAB) Rapid growth and bloom of dinoflagellates or diatoms Often referred to as a red tide This is incorrect May not be red or any color at all; has nothing to do with tides Can be toxic and cause fish kills Shellfish store the toxin and can then pass it on to humans Red tides may be caused by increased nutrient input Can lead to Eutrophication Bacteria feed on dead algae Bacteria consume all the Oxygen, making the water hypoxic/anoxic Anoxic/hypoxic conditions kills all other animal life

Primary Production

10-2 Primary production is the total amount of carbon (C) in grams converted into organic material per square meter of sea surface per year (gm C/m2/yr). Productivity varies greatly in different parts of the ocean in response to the availability of nutrients and sunlight.

10-3 Primary productivity varies from 25 to 1250 gm C/m2/yr in the marine environment and is highest in estuaries and lowest in the open ocean. In the open ocean productivity distribution resembles a “bull’s eye “ pattern with lowest productivity in the center and highest at the edge of the basin. Continental shelves display moderate productivity between 50 and 200 gm C/m2/yr because nutrients wash in from the land and tide- and wave- generated turbulence recycle nutrients from the bottom water.

In the tropics and subtropics sunlight is abundant, but it generates a strong thermocline that restricts upwelling of nutrients and results in lower productivity. High productivity locally can occur in areas of coastal upwelling, in the tropical waters between the gyres and at coral reefs. In temperate regions productivity is distinctly seasonal. Polar waters are nutrient-rich all year but productivity is only high in the summer when light is abundant. 10-2

Seaweeds Multicellular algae Parts: Blade – absorbs nutrients, does photosynthesis Stipe – provides support Air bladders – keep blades afloat Holdfast – anchors seaweed to surface

Types of Seaweed Three major groups: Chlorophytes – green algae Phaeophytes – brown algae Rhodophytes – red algae

Chlorophytes –green algae May be unicellular or multicellular Thought to be direct ancestors of higher plants Ulva make use of sewage outfalls Phaeophytes-brown algae Multicellular Include kelp – largest algae Can grow 50cm a day, reach lengths of 60m Rhodophytes-red algae High commercial value Can thrive in dim light http://marinelife.about.com/od/plants/tp/typesofalgae.htm

All true plants are autotrophic and photosynthetic Plants In Aquatic Habitat All Cells Surrounded or Close to Water Dissolved Minerals Dissolved CO2 and O2 Water Supports Weight of the Plant Unicellular Reproductive Structures Motile Gametes All Cells Photosynthetic What had to happen for plants to colonize land?

Evolutionary steps for the colonization of land: How to disperse gametes in drier environment pollen or spores How to protect embryos from drying out seeds geo.arizona.edu

Evolutionary steps for the colonization of land: How to take up water and nutrients from below ground roots How to take up CO2 from the air stoma How to transport water and nutrients long distances Zylem and phloem school.net.th

terra.dadeschools.net

Recolonization of aquatic environments by plants Terrestrial plants evolved from aquatic green algae. Some terrestrial plants have returned to the water. True aquatic plants retain many of those terrestrial plant characteristics. What challenges might there be in recolonizing saltwater environments? Dehydration from high salinities Gas exchange Current resistance Reproduction

Kingdom Plantae: Angiosperms “flowering plants” Halophytes : Plants that grow in saline environments Halophytes generally: Have roots that extract nutrients High salt tolerance Actively excretes salt through salt glands on epidermis Grow along estuaries and salt marshes, shallow marine environments, or desert soils with high salt content

Juncus roemerianus “Black needlerush” Marsh Plants – tolerant to fluctuations in salinity and water availability due to tides. http://www.flickr.com/photos/94388891@N00/89371084/ Spartina alterniflora “Smooth Cordgrass”

Marsh plants Salicornia fruiticosa “pickle weed” Limonium carolinianum “Sea lavender” badgerbushcraft.com

Sea Grasses Grow totally submerged in saltwater Reproduce asexually and sexually with flowers and current dispersed pollen Require shallow, clear water conservationmagazine.org

Turtle grass (Thalassia testudinum) Shoal grass (Halodule wrightii) Manatee grass (Syringodium filiforme) http://www.floridadep.org/coastal/habitats/seagrass/

Mangroves Mangrove Tree Saltwater swamps inhabited by large flowering trees Grow in tropical regions in bays and lagoons Thick roots that prop the trees up http://www.jpbutler.com/thailand/ images/mangrove-2.jpg

http://marinebio.org/oceans/estuaries-salt-marshes-mangroves.asp

Economic Importance Extracts from Seaweeds are used in many products Algin As a stabilizer and emulsifier in dairy products As a thickener in shampoo, shaving cream, pesticides, plastics

Carrageenan As an emulsifier in dairy products and processed foods Agar Forms a jelly Used to protect canned meats Used in laxatives Medium for growing bacteria

Biodiesel Diesel fuel made from natural, renewable sources. As part of the photosynthesis process algae produce oil and can generate 15 times more oil per acre than other plants used for biofuels, such as corn and switchgrass. Algae can grow in salt water, freshwater or even contaminated water, at sea or in ponds, and on land not suitable for food production. http://www.biodiesel.org/ http://www.virginia.edu/uvatoday/newsRelease.php?id=5985