Phytoplankton, Macroalgae, and Eutrophication Problems in the Bays Subproject # 2—Phytoplankton and Macroalgal Studies in MD Coastal Bays Dr. Madhumi Mitra Associate Professor of Biological and Environmental Sciences Coordinator of Biology and Chemistry Education 7/18/12

ALGAE Study of Algae--Phycology  How are algae similar to higher plants?  How are algae different from higher plants?

FOSSIL HISTORY OF ALGAE  3.5 billion yrs ago  Cyanobacteria—first algae  Prokaryotes—lack membrane bound organelles  Later eukaryotes evolved— mitochondria, chloroplasts, and chromosomes containing DNA.

Similarities  Presence of cell wall—mostly cellulosic.  Autotrophs/Primary producers— carry out photosynthesis  Presence of chlorophyll a

Differences  Algae lack the roots, stems, leaves, and other structures typical of true plants.  Algae do not have vascular tissues—non vascular plants  Algae do not form embryos within protective coverings.  Variations in pigments.  Variations in cell structure—unicellular, colonial and multicellular forms.

PROKARYOTIC VS EUKARYOTIC ALGAE Prokaryotes ---No nuclear region and complex organelles— chloroplasts, mitochondria, golgi bodies, and endoplasmic reticula. -- Cyanobacteria. Chlorophylls are on internal membranes of flattened vesicles called thylakoids-contain photosynthetic pigments. Phycobiliproteins occur in granular structures called phycobilisomes.  Prokaryote algal cell Source:

Prokaryotic and Eukaryotic Algae  Eukaryotes ---Distinct chloroplast, nuclear region and complex organelles. --- Thylakoids are grouped into grana granum with a Stack of thylakoids pyrenoid

DIVERSITY IN ALGAE  BODY OF AN ALGA=THALLUS  DIVERSITY IN MORPHOLOGY ----MICROSCOPIC Unicellular, Colonial, and Filamentous forms. Source:

CELLULAR ORGANIZATION  Flagella=organs of locomotion.  Chloroplast=site of photosynthesis. Thylakoids are present in the chloroplast. The pigments are present in the thylakoids.  Pyrenoid-structure associated with chloroplast. Contains RUBP Carboxylase, proteins, and carbohydrates.  Eye-spot=part of chloroplast. Directs the cell towards light. Source: A Biology of the Algae By Philip Sze, third edition, WCB MCGraw-Hill

Variations in the pigment constitution  Chlorophylls (green)  Carotenoids (brown, yellow or red)  Phycobilins (red pigment-phycoerythrin blue pigment –phycocyanin)

ECOLOGICAL DIVERSITY  LAND---WATER  FRESH WATER---MARINE HABITATS  FLOATING (PLANKTONIC)—BENTHIC (BOTTOM DWELLERS)  EPIPHYTES

PHYTOPLANKTON  Autotrophic  Free-floaters  Microscopic  Mostly unicellular although some are colonial and filamentous

CLASSIFICATION  Phytoplankton ----Picoplankton-0.2 to 2µm ----Nanoplankton-2.0 to 20µm ----Microplankton-20 to 200µm Picoplankton are important contributors to primary productivity of plankton. Biomass in surface waters range from 40-50Pg C/year (P=peta, and 1 Pg is equivalent to g). CYANOPHYTA, CHLOROPHYTA, PYRRHOPHYTA, CRYPTOPHYTA, CHRYSOPHYTA, BACILLARIOPHYCEAE

LIGHT Irradiance is inversely proportional to water depth. COMPENSATION DEPTH --- Different species have different compensation depths. Rate of photosynthesis equals rate of respiration. No production of biomass takes place. Cells below the compensation depth are unable to grow and deplete their resources.

NUTRIENTS Nutrient concentrations vary in different bodies of water. EUTROPHY-Nutrient enrichment OLIGOTROPHY-Low nutrient level Macroelements-C, H, O, S, K, Ca, Mg, P, and N. Microelements-cofactors-Fe, Mn, Cu, Zn, Mb. Si is required by all diatoms.

Limiting Nutrients for Growth  Nitrogen---N 2, NH 4 +, NO 3 -, NO 2 -, and urea.  Phosphorus---Inorganic phosphate can occur in a number of forms (HPO 4 2-,PO 4 3- ;and H 2 PO 4 -  Sulfur—SO 4 2-,H 2 S

NITROGEN FIXATION IN CYANOBACTERIA Reference: Biology of Algae By Sze

NITROGEN  Nitrate is the primary source of nitrogen utilized by algae  Nitrate----(nitrate reductase)  Nitrite--- (nitrite reductase)--  Ammonium.  Ammonium is utilized in cell metabolism.

PHOSPHORUS  Phosphate in different forms  Organic phosphates---broken down by phosphatases in the membrane of algae.

FLOATING AND SINKING Photosynthesis goes up Accumulation of polysaccharides Gas vesicles collapse Buoyancy decreases Cells sink Photosynthesis decreases Increased vacuolation Buoyancy increases Cells rise

DIVERSITY IN ALGAE Photos are by Dr. Mitra’s Research Group. These pictures are not to be used for any purpose without Dr. Mitra’s approval. MACROALGAE

WHAT ARE SEAWEEDS?  Macroalgae found in estuarine and marine environments.  Non-vascular, multicellular, and photosynthetic plants.  Chlorophyta, Rhodophyta, and Phaeophyceae ---wall chemistry, chloroplast structures and pigmentation, arrangement of flagella in motile cells, and life cycles.  Found in polar, tropical, and temperate waters around the globe.

WHY DO WE CARE ABOUT SEAWEEDS?  Primary producers-important role in the marine trophic structure  Calcareous seaweeds –major contributors to the structure of coral reefs (they can make up 30% of the reef). Porolithon and Lithophyllum  Mangroves and seagrass beds—seaweeds can provide a rich source of food for detritus feeders such as fiddler crabs. These seaweeds can also be important food sources for amphipods and isopods. Gracilaria-epiphyte of Zostera marina Photo: Dr. Mitra

WHY DO WE CARE ABOUT SEAWEEDS?  Seaweeds that are edible are called “seavegetables”  Health-promoting/medicinal properties (treatment of cancers, heart diseases, rheumatism, blood sugar, and flu)  Effective fertilizers, soil conditioners, and are a source of livestock feed  Used in wide range of products from ice cream to fabric dyes.

WHY DO WE CARE ABOUT SEAWEEDS?  Used as “biological scrubbers”—Ulva  Gels from seaweeds—Agar is derived from red seaweeds (Gelidium, Gracilaria, Hypnea, and Pterocladia). It is used in microbiological growth medium and food industry. Carrageenans are obtained from Chondrus and Gigartina. Alginates are found in the cell walls of many brown seaweeds. Primary sources are Macrocystis, Ascophyllum, and Laminaria.

ECOLOGICAL PROBLEM Nutrient and sediment loads Eutrophication Development of opportunistic and tolerant micro and macroalgae Environmental conditions become unfavorable and algae die and decompose Large biomass Recycling of nutrients and pollutants in the ecosystem Increase in herbivore population toxicity rises Water quality deteriorates Anoxia Death of organisms Photosynthesis declines Courtesy: Dr. Mitra Water acidification

IMPACTS OF SEAWEED BLOOMS  Benthic macroalgae have a low C/N content (rich in nitrogen and low in structural carbohydrates). Their decomposition can stimulate bacterial activity. This can result in sediment resuspension and high turbidity.

IMPACTS OF SEAWEED BLOOMS  Light availability—incident irradiation was attenuated. PRIMARY EFFECT  SECONDARY EFFECTS ---- Increase in ammonium concentrations within macroalgal mats. These levels may be toxic to eelgrass (van Katwijk et al. 1997) Increase in ammonium concentrations within macroalgal mats. These levels may be toxic to eelgrass (van Katwijk et al. 1997) Increase in sediment sulfide concentrations resulting from decaying macroalgal layer. Sediment sulfide can reduce photosynthesis. ----Anoxia. High sulfide and low oxygen concentrations can reduce growth and production of seagrasses by decreasing nutrient uptake and plant energy status.

TYPES OF SEAWEEDS (MORPHOLOGICAL TYPES)  Sheet like  Filamentous group  Coarsely branched group  Thick-leathery group  Jointed calcareous group  Crustose group

SHEET GROUP  Thin, tubular or sheetlike.  Soft  Photosynthetic activity-high  Toughness-low  Examples: Ulva, Enteromorpha, Porphyra. Photos: Dr. Mitra’s Lab Ulva lactuca Enteromorpha intestinalis

FILAMENTOUS GROUP  Delicate branches  Texture-Soft  Photosynthetic activity-moderate  Toughness-low  Chaetomorpha, Cladophora, Ceramium Photo: Dr. Mitra’s Lab Ceramium rubrum

COARSELY BRANCHED GROUP  Coarsely branched  Pseudoparenchymatous to parenchymatous  Texture—fleshy to wiry  Toughness-low  Gigartina, Chondrus, Agardhiella Agardhiella tenera Photos: Dr. Mitra’s lab Gracilaria tikvahiae

THICK LEATHERY GROUP  Thick blades and branches  Texture-leathery  Photosynthetic rate – low  Toughness-high  Fucus, Laminaria, Sargassum, Padina Photo: Dr. Mitra’s Lab Fucus vesiculosus

JOINTED-CALCAREOUS TYPE  Calcareous, upright  Calcified segments, flexible joints  Texture-stony  Photosynthetic rate- very low  Toughness-very high  Corallina, Halimeda Reference: Corallina officinalis

CRUSTOSE GROUP  Encrusting  Calcified, some uncalcified  Texture-stony, tough  Photosynthetic activity-low  Toughness-very high  Encrusting corallines, Ralfsia,Hildenbrandia Hildenbrandia Reference :

BENTHIC MARINE ALGAE- MORPHOLOGICAL TYPES  Which forms have the least resistance to herbivores?  Which forms have the highest resistance to herbivores?  Which ones are late successional forms? 1.Sheet like 2.Filamentous group 3.Coarsely branched group 4.Thick-leathery group 5.Jointed calcareous group 6.Crustose group

NUISANCE MACROALGAL SPECIES OF THE COASTAL BAYS Photos: Dr. Mitra’s Lab

Assignment/Group Activity  How will you incorporate Algae in your curriculum?  How will you incorporate Eutrophication in your curriculum?