Phytoplankton, Macroalgae, and Eutrophication Problems in the Bays

1. 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 E-mail: mmitra@umes.edu

2. ALGAEStudy of Algae--Phycology How are algae similar to higher plants? How are algae different from higher plants?

3. 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.

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

5. 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.

6. 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: http://www.botany.hawaii.edu/faculty/webb/BOT311/Cyanobacteria/Cyanobacteria.htm

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

8. DIVERSITY IN ALGAE BODY OF AN ALGA=THALLUS DIVERSITY IN MORPHOLOGY ----MICROSCOPIC Unicellular, Colonial, and Filamentous forms. Source: http://images.google.com/images

9. 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

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

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

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

13. 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 10 15 g). CYANOPHYTA, CHLOROPHYTA, PYRRHOPHYTA, CRYPTOPHYTA, CHRYSOPHYTA, BACILLARIOPHYCEAE

14. 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.

15. 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.

16. Limiting Nutrients for Growth Nitrogen---N2, NH4+, NO3-, NO2-, and urea. Phosphorus---Inorganic phosphate can occur in a number of forms (HPO42-,PO43-;and H2PO4- Sulfur—SO42-,H2S

17. NITROGEN FIXATION IN CYANOBACTERIA Reference: Biology of Algae By Sze

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

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

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

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

22. 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.

23. 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

24. 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.

25. 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.

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

27. 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.

28. 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 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.

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

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

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

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

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

34. JOINTED-CALCAREOUS TYPE Calcareous, upright Calcified segments, flexible joints Texture-stony Photosynthetic rate-very low Toughness-very high Corallina, Halimeda Corallina officinalis Reference: http://seaweed.ucg.ie/descriptions/Coroff.html

35. CRUSTOSE GROUP Encrusting Calcified, some uncalcified Texture-stony, tough Photosynthetic activity-low Toughness-very high Encrusting corallines, Ralfsia,Hildenbrandia Hildenbrandia Reference: http://www.guiamarina.com/chile/02%20plants/Rhodophyceae/Hildenbrandia%20sp..htm

36. 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? Sheet like Filamentous group Coarsely branched group Thick-leathery group Jointed calcareous group Crustose group

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

38. Assignment/Group Activity • How will you incorporate Algae in your curriculum? • How will you incorporate Eutrophication in your curriculum?