‘Sea sawdust’ (Trichodesmium) and biogeochemical cycling Author: Greta Creed This resource was developed as a result of participation in CSIRO’s teacher professional learning program, Educator on Board. © ‘Sea sawdust’ (Trichodesmium) and biogeochemical cycling (created by Greta Creed) (2020). Copyright owned by the Department of Education, Queensland. Except as otherwise noted, this work is licenced under the Creative Commons Attribution 4.0 International Licence. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ cid:image005.png@01D4620F.F55F9320 cid:image005.png@01D4620F.F55F9320 Lesson Plan 1 - Marine Food Web - Tasmania Resources 1. Tasmania National Parks and Wildlife Service (Tas NPWS) - ‘Marine Food Web Species Info Sheets’ 2. Worksheet: ‘Ecology of Marine Organisms’ 3. Tas NPWS ‘Marine Food Web Diagram’ 4. Tas NPWS ‘Marine Food Web Answers’ Preparation Instructions: 1. Print four sets of pages 2 to 16 of ‘Marine Food Web Game Species Information Sheets’ (single-sided, 2 per page) or enough for the number of groups you wish to run. 2. Print enough copies of ‘Worksheet: Ecology of Marine Organisms’ for each student. 3. Print enough copies of ‘Tas NPWS Marine Food Web Diagram’ (A4 size) for students to work in pairs. Task 1 (group/shared work) 1. Divide class into desired number of groups. 2. Give one set of marine organism cards on the ‘Marine Food Web Game Species Information Sheets’ to each group. If not already cut up and folded as indicated, have students separate the cards. Cards are to be equally shared amongst the group members. 3. Each individual is to complete the Worksheet ‘Ecology of Marine Organisms’ for their cards. Task 2 (group work) Students are to lay out all cards in their trophic levels based on the information in the ‘Ecology of marine organisms’ worksheets for all group members. Producers are to be at the bottom, with apex predators at the appropriate trophic level/s at the top. Task 3 (pairs) When the trophic levels are organised, distribute the ‘Tas NPWS Marine Food Web Diagram’ for students to complete in pairs. Students are to show all feeding relationships on the food web, based on the group’s ‘Ecology of Marine Organisms’ worksheets (particularly the predator and prey columns). Answers can be checked using the Tas NPWS Marine Food Web Answers’ Task 4 (individual) Complete the Analysis Questions below. • Which species are only predators? Which species are only prey? Which are both? • Choose one organism in the food web. What would happen to the food web if this species were to become endangered or extinct? Which species would be affected, and how? • Why are phytoplankton species so important to the marine ecosystem? • What role do humans play in marine food webs? • How can human actions upset the balance of an ocean ecosystem? Task 5 (class) If time, view the following videos: BBC Earth: Humpback Whales Feeding on Krill https://www.youtube.com/watch?v=1_BqC9IIuKU (4:02) BBC Earth: Whales Bubble Net Fishing https://www.youtube.com/watch?v=Q8iDcLTD9wQ (4:14) BBC Earth: Whales and Orcas Feeding Together https://www.youtube.com/watch?v=XE49YW8NdJo (2:27) References BBC Earth. (2010, July 26). Humpback whales feeding on krill [Video]. YouTube. https://www.youtube.com/watch?v=1_BqC9IIuKU BBC Earth. (2015, January 2). Whales’ bubble net fishing [Video]. YouTube. https://www.youtube.com/watch?v=Q8iDcLTD9wQ BBC Earth. (2018, May 31). Whales and orcas feeding together [Video]. YouTube. https://www.youtube.com/watch?v=XE49YW8NdJo Tasmania Parks and Wildlife Service. n.d. Game: Marine Food Web. Tasmania Department of Primary Industries, Parks, Water and Environment Tasmania Parks and Wildlife Service. n.d. Marine Food Web Diagram. Tasmania Department of Primary Industries, Parks, Water and Environment Tasmania Parks and Wildlife Service. n.d. Marine Food Web Answers. Tasmania Department of Primary Industries, Parks, Water and Environment Humpback whale Photo: Humberto Braojos Worksheet: Ecology of Marine Organisms A whale at the surface of the water, eating krill. Use the Tasmania Marine Food Web organism cards to complete Table 1 below. Table 1 Tasmania Food Web – Ecology of Selected Organisms Species/ Organism type Size (microscopic/ up to 5cm/5cm – 1m/ >1m) Vertebrate/ invertebrate Preferred habitat (e.g. surface/ deep water/…) Type of feeder (producer/ herbivore/ carnivore/ omnivore/ decomposer) Prey (list what the species/ organism consumes) Predators (list what consumes the species/organism) Likely trophic level/s (producer/ first order consumer/ second order…/ decomposer) Lesson 2: Plankton Resources: 1. ‘Introduction to Plankton’ worksheet 2. Deep Look: From Drifter to Dynamo: The Story of Plankton https://www.youtube.com/watch?v=jUvJ5ANH86I (3:01) 3. Ted-Ed: The Secret Life of Plankton https://www.youtube.com/watch?v=xFQ_fO2D7f0 (6:01) 4. ‘What are Phytoplankton?’ worksheet (from Lindsey, R. & Scott, M.: What are phytoplankton?. https://earthobservatory.nasa.gov/features/Phytoplankton) 5. Plymouth University: Ocean Drifters – A secret world beneath the waves https://vimeo.com/84872751 (16:30) 6. Ted-Ed: How Life Begins in the Deep Ocean https://www.youtube.com/watch?v=i_R7ouD8-Eo (6:01) 7. ‘Plankton’ WordSearch (generated at Knowledge Share LLC: https://www.superkids.com/aweb/tools/words/search/) Preparation Instructions: Print individual copies of: (i) ‘Introduction to Plankton’ worksheet (ii) ‘What are Phytoplankton?’ worksheet (OR directly access the NASA Earth Observatory website) Task 1 (class) Complete the ‘Introduction to Plankton’ worksheet by viewing the following videos: (i) Deep Look: From Drifter to Dynamo: The Story of Plankton https://www.youtube.com/watch?v=jUvJ5ANH86I (3:01) (ii) Ted-Ed: The Secret Life of Plankton https://www.youtube.com/watch?v=xFQ_fO2D7f0 (6:01) Task 2 (individual) Read ‘What are phytoplankton?’ and answer the questions on the worksheet. Task 3 (class) View the video about plankton: Plymouth University: Ocean Drifters – A secret world beneath the waves https://vimeo.com/84872751 (16:30 minutes, narrated by David Attenborough) If time at end of lesson: 1. View Ted-Ed 2012 ‘How life begins in the deep ocean’ https://www.youtube.com/watch?v=i_R7ouD8-Eo (6:01) OR 2. Complete the Plankton WordSearch. References: Deep Look. (2015, March 3). From Drifter to Dynamo: The Story of Plankton [Video]. YouTube. https://www.youtube.com/watch?v=jUvJ5ANH86I Knowledge Share LLC. (1998-2016). SuperKids Wordsearch Puzzles. https://www.superkids.com/aweb/tools/words/search/ Lindsey, R. & Scott, M. (2010, July 13). What are phytoplankton? (Part 1 - Introduction, Part 2 – Importance of phytoplankton). NASA Earth Observatory. https://earthobservatory.nasa.gov/features/Phytoplankton Plymouth University. (2014, January 23). Ocean Drifters – A secret world beneath the waves [Video]. Vimeo. https://vimeo.com/84872751 Ted-Ed. (2012, April 2). The Secret Life of Plankton [Video]. YouTube. https://www.youtube.com/watch?v=xFQ_fO2D7f0 Ted-Ed. (2012, May 14). How Life Begins in the Deep Ocean [Video]. YouTube. https://www.youtube.com/watch?v=i_R7ouD8-Eo Introduction to Plankton Worksheet Task 1 View: (PBS) Learning 2019 ‘Deep Look: From drifter to dynamo – the story of plankton’ https://www.pbs.org/video/deep-look-drifter-dynamo-story-plankton/ (3:01) 1. Where does the word ‘plankton’ come from? 2. The two different types of plankton are ___________________ and zooplankton. 3. How do phytoplankton get their energy? 4. What gas is produced by phytoplankton? 5. Two types of phytoplankton are __________________ and _______________. They differ from each other because one has _________________ and the other doesn’t. 6. Zooplankton are much ________________ than phytoplankton. 7. In a food web, zooplankton are classified as _________________ because they ‘eat’ other organisms. 8. What role does upwelling have in determining plankton populations? 9. State a food chain that occurs as a result of upwelling. 10. What happens when the upwelling slows and the frenzy subsides? Task 2 View: Ted-Ed 2012 ‘The Secret Life of Plankton’ https://www.youtube.com/watch?v=xFQ_fO2D7f0 (6:01) 1. List some of the other planktonic organisms that the juvenile fish shared the ocean with. 2. What two inputs are required for phytoplankton to photosynthesise? 3. Of what are phytoplankton the base? 4. The fish states ‘I was part of the greatest daily migration on Earth’. What is this? 5. Describe three strategies used by zooplankton to capture their prey. Name the zooplankton organism. What are Phytoplankton? Source: Linsey, R. & Scott, M. (2010, July 13) What are phytoplankton? (Part 1 - Introduction, Part 2 – Importance of phytoplankton). NASA Earth Observatory. https://earthobservatory.nasa.gov/features/Phytoplankton Derived from the Greek words phyto (plant) and plankton (made to wander or drift), phytoplankton are microscopic organisms that live in watery environments, both salty and fresh. Some phytoplankton are bacteria, some are protists, and most are single-celled plants. Among the common kinds are cyanobacteria, silica-encased diatoms, dinoflagellates, green algae, and chalk-coated coccolithophores. Illustrations of types of phytoplankton. Illustrations of phytoplankton types (drawings not to scale). (Image: NASA) Like land plants, phytoplankton have chlorophyll to capture sunlight, and they use photosynthesis to turn it into chemical energy. They consume carbon dioxide, and release oxygen. All phytoplankton photosynthesize, but some get additional energy by consuming other organisms. Phytoplankton growth depends on the availability of carbon dioxide, sunlight, and nutrients. Phytoplankton, like land plants, require nutrients such as nitrate, phosphate, silicate, and calcium at various levels depending on the species. Some phytoplankton can fix nitrogen and can grow in areas where nitrate concentrations are low. They also require trace amounts of iron which limits phytoplankton growth in large areas of the ocean because iron concentrations are very low. Other factors influence phytoplankton growth rates, including water temperature and salinity, water depth, wind, and what kinds of predators are grazing on them. When conditions are right, phytoplankton populations can grow explosively, a phenomenon known as a bloom. Blooms in the ocean may cover hundreds of square kilometres and are easily visible in satellite images. A bloom may last several weeks, but the life span of any individual phytoplankton is rarely more than a few days. Satellite image of a phytoplankton bloom off the coast of New Zealand on October 25, 2009. This satellite image shows a bloom that formed east of New Zealand between October 11 and October 25, 2009. (Image: NASA) Importance of phytoplankton The food web Phytoplankton are the foundation of the aquatic food web, the primary producers, feeding everything from microscopic, animal-like zooplankton to multi-ton whales. Small fish and invertebrates also graze on the plant- like organisms, and then those smaller animals are eaten by bigger ones. Phytoplankton can also be the harbingers of death or disease. Certain species of phytoplankton produce powerful biotoxins, making them responsible for so-called “red tides,” or harmful algal blooms. These toxic blooms can kill marine life and people who eat contaminated seafood. Photograph of fish killed by a red tide on the shore of Padres Island, Texas. Phytoplankton cause mass mortality in other ways. In the aftermath of a massive bloom, dead phytoplankton sink to the ocean or lake floor. The bacteria that decompose the phytoplankton deplete the oxygen in the water, suffocating animal life; the result is a dead zone. Dead fish from harmful algal blooms on Padre Island, Texas, 2009 (Photograph: Terry Ross CC BY-SA 2.0) Questions 1. What are the five most common kinds of phytoplankton? 2. Why can some types of phytoplankton be classified as both producers and consumers? 3. Complete the diagram below to show twelve factors (e.g. nutrients, environmental conditions) that influence phytoplankton growth rates. phytoplankton Plankton WordSearch A K N J Z D S O R O L T I G O S V K E G G R E I D P L Y O H A O K J E N E E S S H N Q E E T P I C M O A E S T P H O T O S Y N T H E S I S A M O R R B I Z F W S P H E X A C V G N H C O C C O L I T H O P H O R E E T N Y D O A O A I N O E H A A O T M R I A U N R P G F E S R Y L E S E O Y J N C S B L E O I P U T G A C G O E S O E U O A L O R H T O A N O F L M P B R M N N L D T O A P E I P E B R I A E E Z K A W U R R L V T I M E O P C E R N T T E N U E A R R C Y E T V T A V N O E B X S P N K O O O F A S E L R X N Y E E J M K T G C T A D L R F I S E T A R B E T R E V N I E X I N D N N A R E S T O A N O R I R R A P M O T A I D N G N I L L E W P U Find the following hidden words: algae, bloom, carbon, coccolithophore, consumer, cyanobacteria, diatom, dinoflagellate, food web, invertebrate, iron, larvae, microscopic, nitrogen, nutrients, ocean, phosphorus, photosynthesis, phytoplankton, predator, prey, producer, temperature, toxin, upwelling, zooplankton Wordsearch generated using Knowledge Share LLC. (1998-2016). SuperKids WordSearch Puzzles. https://www.superkids.com/aweb/tools/words/search/ Plankton WordSearch A K N J Z D S O R O L T I G O S V K E G G R E I D P L Y O H A O K J E N E E S S H N Q E E T P I C M O A E S T P H O T O S Y N T H E S I S A M O R R B I Z F W S P H E X A C V G N H C O C C O L I T H O P H O R E E T N Y D O A O A I N O E H A A O T M R I A U N R P G F E S R Y L E S E O Y J N C S B L E O I P U T G A C G O E S O E U O A L O R H T O A N O F L M P B R M N N L D T O A P E I P E B R I A E E Z K A W U R R L V T I M E O P C E R N T T E N U E A R R C Y E T V T A V N O E B X S P N K O O O F A S E L R X N Y E E J M K T G C T A D L R F I S E T A R B E T R E V N I E X I N D N N A R E S T O A N O R I R R A P M O T A I D N G N I L L E W P U Find the following hidden words: algae, bloom, carbon, coccolithophore, consumer, cyanobacteria, diatom, dinoflagellate, food web, invertebrate, iron, larvae, microscopic, nitrogen, nutrients, ocean, phosphorus, photosynthesis, phytoplankton, predator, prey, producer, temperature, toxin, upwelling, zooplankton Wordsearch generated using Knowledge Share LLC. (1998-2016). SuperKids WordSearch Puzzles. https://www.superkids.com/aweb/tools/words/search/ Lesson 3: Types of Phytoplankton Resources: 1. BBC Earth. (2015, June 8). Why are plankton the most vital organisms on Earth? https://www.youtube.com/watch?v=UjnYJVKysfo 2. ‘Types of Phytoplankton’ PowerPoint 3. ‘Types of Phytoplankton’ worksheet Preparation Instructions: 1. Set up the BBC video as the starting point for the lesson 2. Print individual copies of ‘Types of Phytoplankton’ worksheet Task 1 (class) View the video BBC Earth: Why are plankton the most vital organisms on Earth? https://www.youtube.com/watch?v=UjnYJVKysfo (3:36) Task 2 (class and individual) 1. Go through the PowerPoint ‘Types of Phytoplankton’ – discuss video links, images and so on as you go through it. 2. The first part of the worksheet ‘Types of Phytoplankton’ is to be completed as you go through the slides. Task 3 (class/individual) 1. Visit the NASA Earth Observatory website (https://earthobservatory.nasa.gov/). Use the search terms ‘plankton’ and ‘phytoplankton’ to find images of the day showing phytoplankton blooms. 2. Three main types of phytoplankton are visible from space – students are to attempt to identify the three, and use the information provided with the image of the day to complete the ‘Types of Phytoplankton’ worksheet. If time at end of lesson: Allow students to further explore the NASA Earth Observatory website for images, feature articles, global maps and so on. References: BBC Earth. (2015, June 8). Why are plankton the most vital organisms on Earth? https://www.youtube.com/watch?v=UjnYJVKysfo NASA Earth Observatory website: https://earthobservatory.nasa.gov/ Types of Phytoplankton Phytoplankton Phytoplankton are microscopic organisms that live in both marine and fresh water environments. Phytoplankton have chlorophyll to capture the energy from sunlight through photosynthesis. These single-celled producers are an essential component of marine food webs, providing nourishment to many freshwater and marine species. Phytoplankton Photosynthetic Diatoms Source: R. Kirby, n.d. Phytoplankton Despite being one of the smallest organisms on Earth, phytoplankton are one of the few living things that can be viewed from space. Spiral of Plankton - selected image Source: NASA Earth Observatory, 2014 Phytoplankton The most common forms of phytoplankton are: •cyanobacteria (also commonly referred to as blue-green algae) •silica-encased diatoms •dinoflagellates •green algae •chalk-coated coccolithophores Illustrations of types of phytoplankton. Source: NASA, 2010 Cyanobacteria Cyanobacteria are also known as blue-green algae due to blue (phycocyanin) and green (chlorophyll) pigments in their cells. They are the oldest known life-form on Earth, and are still the most common. Trichodesmium Source: FWC, 2013 Diatoms Diatoms are one of the larger types of phytoplankton. They have a number of unique characteristics: •cell walls are made of silica box shape around the individual. •found singly or in chains. It is thought that there are as many as 100,000 species of diatoms in both fresh and salt water. https://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Diatoms_through_the_microscope.jpg/1280px-Diatoms_through_the_microscope.jpg Diatoms Source: NOAA, 1983 Dinoflagellates Dinoflagellates (approximately 2000 species) are the most common form of larger phytoplankton. They also have unique characteristics: •cells are protected by cellulose (not silica) •mobile as they have flagella •solitary as they do not form chains •some species can produce toxins, which results in‘red tides’ and death of other marine life •some have strong bioluminescence. https://miro.medium.com/max/720/0*QNAiTgn-FlKjlUdX.jpg Dinoflagellates Source: fickleandfreckled, 2012 Green algae There are about 6,000 species of green algae. Green algae are found in 3 forms: •unicellular •forming colonies or filaments •multicellular obvious macroscopic seaweeds. Filamentous algae Source: K. Peters, 2009 Coccolithophores Coccolithophoreslive in large numbers throughout the upper layers of the ocean. Their features include: •surrounding themselves with a plating of limestone (calcite)known as coccoliths •the coccolithsare about 3/1000ths of a millimetre in diameter •loose coccolithscan form dense clouds in bloom conditions, turning the water an opaque turquoise visible from space https://joidesresolution.org/wp-content/uploads/2016/12/coccolithophores-luc.png Coccolithophores Source: Luc Beaufort, 2016) References •Background/Slides 1 and 2: Photosynthetic diatoms, Kirby, R. (n.d.). in Martin, C. (2013, March 15). Vanishing marine algae can be monitored from a boat with your smartphone. https://www.smithsonianmag.com/science-nature/vanishing-marine- algae-can-be-monitored-from-a-boat-with-your-smartphone-2785190/ •Slide 3: Spiral of Plankton, NASA Earth Observatory, (2014, January 9), NASA, https://earthobservatory.nasa.gov/images/82761/spiral-of-plankton(Use of images permitted for schools) •Slide 4: Types of Phytoplankton, NASA, (2010, July 13). https://earthobservatory.nasa.gov/features/Phytoplankton(Use of images permitted for schools) •Slide 5: Trichodesmium thiebautii, FWC Fish and Wildlife Research Institute, (2013, April 24), Flickr, https://www.flickr.com/photos/myfwc/8678780050/in/photolist-mTV11H-btacQo-bsQrbb-bGnan6-btHMDN-mRTaMn- 4pfcWa-4pf7eX-py1fA5-mPsgqQ-9QYFn4-GLioE-GLrx1-Mj3mQk-2ftAEq3-qxiDhb-mRaVsd-mR96HZ-mVLP62-mTK6iC-mPmEtz- 286TJQh-edV1WN-9XWThV-mTUYsc-py1VHT-KTcChL-py44E3-py1fdb-pNmErL-mTHaWa-mPqrGM-oTDKsi-mRT9Ec-mPmCvB- mTWMVh-mPqtdx-mRE3tH-pAKcR7-mPmxZK-mR1hAM-pmgTLk-mR1yut-pCvAMD-mPquwK-mR95Pp-pAKiCY-mR38Gu- mRaSqw-mRDYg4, CC BY-NC-ND 2.0 •Slide 6: Diatoms through the microscope, NOAA Corps Collection, 1983, Wikimedia Commons, https://commons.wikimedia.org/w/index.php?curid=246319Public Domain •Slide 7: Dinoflagellates, fickleandfreckled, 2012, Flickr, https://www.flickr.com/photos/fickleandfreckled/6939384773/in/photolist-bzdak4-bAzECZ-bnEPpd-bAzECp-bnEPs1CC BY 2.0 •Slide 8: Stigeocloniumsp., Peters, K., 2009, Wikimedia Commons, https://commons.wikimedia.org/w/index.php?curid=9432615CC BY-SA 3.0 •Slide 9: Four coccolithophore images taken on a scanning electron microscope, Beaufort, L., 2016, JoidesResolution, https://joidesresolution.org/the-magical-world-of-coccolithophores/ Types of Phytoplankton This worksheet accompanies the PowerPoint ‘Types of Phytoplankton’. 1. What important pigment is possessed by phytoplankton that allows photosynthesis to occur? 2. List the five most common forms of phytoplankton and give at least two important distinguishing characteristics of each in the table below. Table 1 Five most common forms of phytoplankton and distinguishing characteristics Phytoplankton type Distinguishing characteristics 3. Visit the NASA Earth Observatory website . Use the search terms ‘plankton’ and ‘phytoplankton’ to find images of the day featuring plankton blooms. There are generally three types of phytoplankton that create the blooms visible from space. Complete the graphic below to identify: • the type of phytoplankton (e.g. diatom, dinoflagellate) • the main species or genus involved (include common name if given) • examples of locations in the world where the blooms occur Phytoplankton Type 1: Species/genus: Locations: Phytoplankton Type 2: Species/genus: Locations: Phytoplankton Type 3: Species/genus: Locations: Lesson 4: Studying Phytoplankton Resources: 1. ‘Studying Phytoplankton’ worksheet 2. ‘Studying Phytoplankton’ PowerPoint 3. ‘Atlas of Living Australia’ website: https://www.ala.org.au/ Preparation Instructions: Print individual copies of the ‘Studying Phytoplankton’ worksheet Task 1 (class and individual) 1. Go through the PowerPoint ‘Studying Phytoplankton’ – discuss video links, images etc. as you go through it. 2. Questions 1 and 2 on the worksheet ‘Studying Phytoplankton’ are to be completed as you go through/review the slides. Task 2 (class/individual) 1. Explore the ‘Atlas of Living Australia’ website: https://www.ala.org.au/ Students are to search for Trichodesmium and Noctiluca species initially to complete the distribution maps (Question 3 on the ‘Studying Phytoplankton’ worksheet). 2. Instruct students to click on ‘interactive map’ for each species and use the zoom tool. They can click on individual sightings (dots) to also obtain details about contributors to the data and the dates of sightings shown on the map. If time at end of lesson: Students can continue to explore the Atlas of Living Australia website for other species of interest – either other marine species (for example, humpback whales, crested terns) or species of personal interest to the student. References ‘Atlas of Living Australia’ website: https://www.ala.org.au/ Studying Phytoplankton Studying Phytoplankton There are a number of ways that phytoplankton can be studied, ranging from the global scale to genetic analysis. Techniques include: •satellite technology monitoring algal blooms or other indicators of the presence of algae •direct collection of phytoplankton samples from the water (at permanent observations stations or from ships) preservation of samples for laboratory analysis (microscopic and genetic) •citizen science apps and projects Satellite Technology –NASA View the following video to understand NASA’s role in monitoring phytoplankton. NASA Goddard. (2009, October 13). Earth Science Week: the Ocean’s Green Machines[Video]. YouTube. https://www.youtube.com/watch?v=H7sACT0Dx0Q Satellite Technology –Spectroradiometer Chlorophyll, associated with phytoplankton blooms in the ocean, can be detected using satellite technology. This is because there is a change in the way light reflects from the ocean surface as a result of higher concentrations of chlorophyll (more green is reflected). An animation of the global distribution of chlorophyll (and therefore phytoplankton) between July 2002 and October 2019 can be viewed at: NASA Earth Observatory. (2019, November). Global Map -Chlorophyll. https://earthobservatory.nasa.gov/global-maps/MY1DMM_CHLORA Satellite Technology –LIDAR LIDAR (light detection and ranging) uses laser light as a survey method. Scientists examined data from the day and night passes of the CALIPSO satellite. Areas coloured redor orangehad the greatest difference in light scattering, a signal that indicates significant numbers of vertically migrating marine creatures feeding on phytoplankton at night. Lidar –daily vertical migration Source: NASA Earth Observatory, 2019 Satellite Technology –natural colour images Technology on satellites also allow the capture of natural colour images, such as this image of a plankton swirl to the south of Australia in 2014. Swirl of plankton Source: NASA Earth Observatory, 2014 Spiral of Plankton Spiral of Plankton Direct Collection –CSIRO’s RV Investigator CSIRO’s Marine National Facility’s (MNF) Research Vessel (RV Investigator), like other research ships, has a number of techniques for the direct collection of phytoplankton samples. RV Investigator Source: Creed, 2019 Direct Collection -CTD The CTD (conductivity, temperature, depth) rosette is lowered overboard and water samples are collected at specified depths. The water can be analysed for chemical, physical and biological properties (including sampling for plankton). Collecting plankton samples from CTD -RV Investigator Source: CSIRO, 2019 Deployment of CTD rosette at night -RV Investigator Source: Creed, 2019 Direct Collection –CPR CPR is the acronym for the continuous plankton recorder. This technology hails from the 1930s but it is very effective in collecting plankton between two spools of silk as the CPR is towed behind the ship (like a large fishing lure). Useful long-term plankton data has been collected this way. Retrieval of silk cassette from CPR by Dr Robyn Schofield -RV Investigator Source: Creed, 2019 Direct Collection –CPR View a video of how a CPR works (with an alternative scientific focus in also collecting data about plastics in the ocean) at: Marine Biological Association. (2019, May 7). The Continuous Plankton Recorder (CPR) Survey and ocean plastics [Video]. YouTube. https://www.youtube.com/watch?v=lyZKV3p33QA(2:00) Direct Collection –Plankton nets Plankton nets involve the direct collection of water samples from near the ocean surface. The nets themselves vary in size, from small to very large, depending on the desired sample size. Collecting Trichodesmiumin plankton net -RV Investigator Source: CSIRO, 2019 Global Distribution –Phytoplankton Researchers from an international consortium have collected around700,000 water samples from around the world to create a plankton map. A video about this research can be viewed at: ETH Zürich. (2019, November 15). Diverse Plankton –unevenly active, unevenly distributed [Video]. YouTube. https://www.youtube.com/watch?v=HdIAAxySAvk View the animation showing the global distribution of phytoplankton: Phys.org. (2019, May 16). Mapping the global distribution of phytoplankton.https://phys.org/news/2019-05-global- phytoplankton.html Citizen Science A number of survey, monitoring and reporting techniques are available to seafarers and other interested people who can add data to government, non-government organisation (NGOs) and university projects involved in the collection of data about phytoplankton. A video explaining the work of citizen scientists in monitoring phytoplankton as part of the SecchiDisk Study can be viewed here: SecchiDisk Foundation. (2016, December 5). The SecchiDisk Foundation[Video]. Vimeo. https://vimeo.com/194397011(04:06) SecchiDisk App Source: SecchiDisk Foundation, 2012 Citizen Science The Atlas of Living Australia (ALA) encourages citizen scientists to contribute to an extensive biodiversity database for Australia and Australian waters. And yes, phytoplankton sightings have been recorded. Explore the Atlas of Living Australia website at https://www.ala.org.au/. Try searching for two common phytoplankton in Australian waters: •Trichodesmium •Noctiluca (Hint: Click on ‘Interactive Map’ to identify data contributors by clicking on the dots.) References •Slide 1/Background of all slides: Bioluminescence, Ligon, G., 2014, Flickr, https://www.flickr.com/photos/gerryligon/14851802820/in/photolist- oCpnxS-7MUmNc-24wtkwV-2epHa9Y-wuJuaN-ppD7Tw-KWPkBW-ir7VAx-298RAfk-JeSzrh-5oEw54-8Eqdz-9M8akd-Uf6PZk-bj87PB-Pic2Fv-XaKd1i- 25amhC4-27usXK5-j3X3Lv-nHZbTm-aqprAq-24uHEtM-jeGfT-3aNg5x-PpA8Ju-dtiFvZ-MGp2cC-2d664WD-25WVMWZ-td6hCg-YSuGFb-pLhULb- JPDDML-34UJA9-dB8D6W-TiKWoK-ir7jnY-5WQRrj-bwsU7v-pSbgC1-7mHfjL-7mDk72-7mDiNg-7mDm9D-afKjY7-tixsqv-qdYYe5-bjtCWt-jYGmMKCC BY-NC 2.0 •Slide 3: NASA Goddard. (2009, October 13). Earth Science Week: the Ocean’s Green Machines[Video]. YouTube. https://www.youtube.com/watch?v=H7sACT0Dx0Q •Slide 4: NASA Earth Observatory. (2019, November). Global Map -Chlorophyll. https://earthobservatory.nasa.gov/global-maps/MY1DMM_CHLORAUse of images permitted for schools •Slide 5: Satellite Observes Massive OceanMigration,NASA EarthObservatory, (2019, December4). NASA, https://earthobservatory.nasa.gov/images/145941/satellite-observes-massive-ocean-migrationUse of images permitted for schools •Slide 6: Spiral of Plankton, NASA Earth Observatory, (2014, January 9), NASA, https://earthobservatory.nasa.gov/images/82761/spiral-of-planktonUse of images permitted for schools •Slide 7: Creed, G. 2019 ‘On the deck of RV investigator’ •Slide 8: Creed, G. 2019 ‘CTD rosette –RV Investigator’; CSIRO 2019 ‘Collecting plankton samples from CTD’ •Slide 9: Creed, G. 2019 ‘Retrieving CPR cassette following towing behind RV Investigator’ •Slide 10: Marine Biological Association. (2019, May 7). The Continuous Plankton Recorder (CPR) Survey and ocean plastics [Video]. YouTube. https://www.youtube.com/watch?v=lyZKV3p33QA •Slide 11: CSIRO 2019, Chris La Rosa (Educator on Board) collecting plankton samples in plankton net •Slide 12: ETH Zürich. (2019, November 15). Diverse Plankton –unevenly active, unevenly distributed [Video]. YouTube. https://www.youtube.com/watch?v=HdIAAxySAvk; Phys.org. (2019, May 16). Mapping the global distribution of phytoplankton. https://phys.org/news/2019-05-global-phytoplankton.html •Slide 13: The SecchiDisk Foundation. (n.d.) SecchiDisk Study. http://www.secchidisk.org/; SecchiDisk Foundation. (2016, December 5). The SecchiDisk Foundation[Video]. Vimeo. https://vimeo.com/194397011 •Slide 14: Atlas of Living Australia website: www.ala.org.au satellite technology • • • • • • • • Organisations: Organisations: Organisations: Studying Phytoplankton This worksheet accompanies the PowerPoint ‘Studying Phytoplankton’. 1. A range of techniques can be used to study phytoplankton. Complete the diagram below to: • outline these techniques. • identify organisations utilising the data collection methods outlined 2. What is the RV Investigator? 3. Refer to the Atlas of Living Australia website (www.ala.org.au). Search for the two phytoplankton species Trichodesmium and Noctiluca. Use the interactive map to view the distribution of both species. Show the distribution of Trichodesmium and Noctiluca on the maps of Australia below. Figure 1: Distribution of Trichodesmium Figure 2: Distribution of Noctiluca Lesson 5: Trichodesmium and CSIRO Data Resources: 1. ‘Trichodesmium Fact Sheet’ 2. ‘RV Investigator and Trichodesmium’ worksheet 3. Spare graph paper 4. Catalyst: Iron Whales https://www.abc.net.au/catalyst/iron-whales/11012780 (8:09) 5. Sustainable Human: How Whales Change Climate https://www.youtube.com/watch?v=M18HxXve3CM (4:27) Preparation Instructions: 1. Print individual copies of: (i) ‘Trichodesmium Factsheet’ (can be printed 2-up) (ii) ‘RV Investigator and Trichodesmium’ worksheet Task 1 (class/individual) 1. Read through the ‘Trichodesmium Fact Sheet’ and discuss the ecology of this type of phytoplankton (e.g. preferred conditions, limiting factors) Task 2 (individual) 1. Read through ‘RV Investigator and Trichodesmium’ worksheet, completing all tasks in order. If time at end of lesson: 1. View the Videos: (i) Catalyst: Iron Whales https://www.abc.net.au/catalyst/iron-whales/11012780 (8:09) (ii) Sustainable Human: How Whales Change Climate https://www.youtube.com/watch?v=M18HxXve3CM (4:27) References: Catalyst. (2011, April 14). Iron Whales [Video]. Australian Broadcasting Corporation. https://www.abc.net.au/catalyst/iron-whales/11012780 Sustainable Human. (2014, November 30). How Whales Change Climate [Video]. YouTube. https://www.youtube.com/watch?v=M18HxXve3CM Trichodesmium Source: FWC, 2013 Trichodesmium blooms – Sunshine Coast, Queensland and Wessel Marine Park, Northern Territory Photos: Greta Creed, 2019 Trichodesmium Fact Sheet Trichodesmium was described by Joseph Banks on board the Endeavor with Captain Cook, and despite attempts at further research, there are still many gaps in our knowledge of this form of phytoplankton. There are a number of Trichodesmium species. Trichodesmium, also known as sea sawdust, sea straw and sea scum, are a type of cyanobacteria. Cyanobacteria are commonly but inaccurately known as blue-green algae (based on the blue and green pigments in their cells – blue phycocyanin and green chlorophyll). Trichodesmium appear as trichomes (hairy bundles) but will form extensive blooms in the right conditions. Trichodesmium occur naturally throughout the world, including in Australia’s tropical and sub- tropical waters. They can occur at a depth of up to 200m. Up to 60% of chlorophyll-a in the top 50m of the water column can be produced by Trichodesmium. Blooms, that can produce a strong ‘fishy’ odour, occur mostly in Spring and early Summer (when temperature, hours of sunlight and other environmental factors favour growth). Trichodesmium are nitrogen fixers – they are able to convert atmospheric nitrogen into ammonium, which is then made available to other organisms in the marine food web. Therefore they are a critical producer within the marine ecosystem. However, phytoplankton are dependent on a range of essential nutrients for growth, including phosphates and iron. If these nutrients are in limited supply, Trichodesmium will not thrive. Temperature is also a limiting factor, with an optimal range of 26°C—27°C (minimum 20°C—22°C, maximum 32°C—35°C). Trichodesmium generally do not present problems (unlike dinoflagellates that can form toxic ‘red tides’). However, sometimes Trichodesmium blooms may deplete the oxygen content of water (due to increased rates of nocturnal respiration and decomposition) which can result in the death of other marine organisms. They can also absorb other plankton types that are toxic; these toxins can be released into the environment when Trichodesmium individuals decompose. References FWC Fish and Wildlife Research Institute Trichodesmium 2013, ‘Trichodesmium thiebautii’ CC BY-NC-ND 2.0 005/006 Source: CSIRO, 2019 CSIRO - MNF RV Investigator and Trichodesmium A marine phytoplankton of great importance IN2019_T02 Voyage and projects In October 2019, the CSIRO Research Vessel (RV Investigator) undertook a voyage (IN2019_T02) from Brisbane, Queensland to Darwin, Northern Territory. Several projects were conducted on the voyage. One project undertaken was the collection of data to investigate the hydrochemistry of the ocean water at a number of sites, with a focus on the upwelling of nitrate rich waters from deep below the surface. Data for this project was collected using a CTD (conductivity, temperature, depth) rosette at six locations on the voyage (see Figure 1). Figure 1 Locations of CTD rosette deployments Another research project involved the collection of plankton using near surface water samples from the CTD rosette, a plankton net and a CPR (continuous plankton recorder). The phytoplankton Trichodesmium was the particular focus of the project (see Trichodesmium Fact Sheet). CTD Rosette Deployments and Hydrochemistry The CTD rosette, with 24 Niskin bottles, was deployed at a number of sites on the voyage. A range of data was collected including dissolved oxygen, temperature, fluorescence (an indicator of the quantity of chlorophyll-a in photosynthetic organisms such as phytoplankton), phosphate concentration and concentration of nitrates (NOx). The data from two sites have been selected for comparison – Deployment 1 and Deployment 5. These sites had the following characteristics: • Both deployments occurred at night. • Deployment 1 occurred in deeper waters at some distance from the coast off Fraser Island, Queensland. Deployment 5 occurred in shallower waters very close to the Wessel Archipelago in the Northern Territory (see Figure 1). • There was no obvious population of Trichodesmium on the water’s surface at the first location; however, at the second, extensive Trichodesmium slicks were observed. • Data has been included from approximately 5m below the surface to a depth of approximately 90m. Recordings from 5m are regarded as ‘surface’. Photos: Greta Creed 2019 Task 1 Use the data in Table 1 (next page) to draw a line graph showing the temperature for two CTD deployment locations from RV Investigator Voyage IN2019_T02. Remember to comply with all graphing conventions (i.e. SALTS: scale – evenly spaced; axes – labelled including relevant units of measurement; legend/key – if required; title; source of data – if required). Table 1 Temperature at Depth for Two CTD Deployment Locations Depth (m) Temperature (°C) Deployment 1 Deployment 5 5 23.2 26.4 10 23.2 26.4 15 23.1 26.4 20 23.1 25.3 25 23.1 24.8 30 23.1 24.6 35 23.0 24.6 40 23.0 24.5 45 22.6 24.4 50 22.3 24.3 55 22.2 23.7 60 22.1 23.5 65 21.9 23.5 70 21.9 23.4 75 21.7 23.3 80 21.6 23.2 85 21.5 23.2 90 21.2 23.2 Source: Marine National Facility, 2019 Graph 1 Task 2 Refer to the graph you have drawn (Graph 1), Graphs 2 and 3 (next page), and the ‘Trichodesmium Fact Sheet’ to respond to the following questions. 1. Refer to the temperature graph (Graph 1) you have created to answer the following questions. a) Describe the trend in temperature as water depth increases. b) At which location is temperature higher? c) What is the temperature range at the location of Deployment 5 (i.e. difference between minimum and maximum temperatures)? How does this compare to Deployment 1? d) Is there a correlation between water temperature and the occurrence of Trichodesmium? Suggest reasons for this. 2. Refer to Graph 2 showing fluorescence as an indicator of chlorophyll-a to respond to the following questions. a) At which depth was fluorescence most equivalent for both deployments. b) Calculate the difference between the fluorescence levels at 40 metres for the two locations. c) Identify the location and depth at which fluorescence was greatest. d) Discern at which location you would expect higher concentrations of phytoplankton to occur? What evidence supports your decision? 3. Refer to Graph 3 showing phosphate concentration at selected depths at the two locations. a) Draw a line of best fit for each deployment. b) Calculate the difference in phosphate concentration at 90 m for the two deployment locations. 4. A Trichodesmium bloom was clearly observed at the location of Deployment 5 during the day and at night at the time of deployment of the CTD. Write a paragraph to outline the evidence from Graphs 1-3 that explains why the bloom was apparent at this location and not at the location of Deployment 1. Photo: Greta Creed 2019 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Fluorescence (indicator of chlorophyll-a) Depth (m) Fluorescence as an Indicator of Chlorophyll-a at Depth for Two CTD Deployment Locations Deployment 1 (no visibleTrichodesmium) Deployment 5 (visible Trichodesmiumblooms) Source: CSIRO 2019 Graph 2 3.50 5.96 Graph 3 Source: CSIRO 2019 0.06 0.07 0.36 0.13 0.15 0.51 0.62 0.86 0.95 0.95 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Phosphates (μM) Depth (m) Phosphate Concentration at Depth for Two CTD Deployment Locations Deployment 1 (no visible Trichodesmium) Deployment 5 (visible Trichodesmiumbloom) References CSIRO 2019, ‘RV Investigator Hydrochemistry Data Processing Report (IN2019_T02)’ http://www.cmar.csiro.au/datacentre/process/data_files/Investigator_NF/in2019_t02/doc/in2019_t02_HYD_ProcessingReport.pdf Marine National Facility 2019, Table 1: Temperature at Depth for Two CTD Deployment Locations (shared with permission). Suggested Answers Task 1 – Graph 1 Source: Marine National Facility, 2019 0 5 10 15 20 25 30 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Temperature (°C) Depth (m) Temperature at depth for two CTD deployment locations Deployment 1 Deployment 5 Task 2 Question 1 a) As water depth increases, the temperature slowly decreases. The greatest rate of decline in temperature was between 15m and 20m for Deployment 5. The rate of decrease of temperature at both locations is very similar. b) Temperature is higher at the location where Deployment 5 occurred (i.e. off the north-east coast of Northern Territory). c) Temperature range for Deployment 5 (shallower waters close to Wessel Archipelago, Northern Territory): Maximum – 26.4°C, minimum – 23.2°C, range – 26.4°C – 23.2°C = 3.2°C Temperature range for Deployment 1 (deeper waters off Fraser Island, Queensland): Maximum – 23.2°C, minimum – 21.2°C, range – 23.2°C – 21.2°C = 2.0°C The temperature range for Deployment 5 (3.2°C) is 1.2°C greater than that for Deployment 1 (2.0°C). d) The warmer waters at Deployment 5 had extensive Trichodesmium slicks, while the cooler waters at Deployment 1 had no obvious population of Trichodesmium. Trichodesmium has an optimum temperature range of 26°C to 27°C, temperatures that were observed in the upper 15m of the Deployment 5 sample site. Question 2 a) 75 metres b) Deployment 1 – fluorescence level at 40m: 3.50 Deployment 5 – fluorescence level at 40m: 5.96 Difference in fluorescence: 5.96 – 3.50 = 2.46 c) Fluorescence was greatest at 85m depth in Deployment 5 (off Wessel Archipelago, NT). d) Fluorescence is an indicator of the presence of chlorophyll-a, a pigment found in photosynthetic organisms. The higher levels of fluorescence recorded during Deployment 5 therefore indicated the possibility of higher concentrations of phytoplankton. This is supported by the higher concentrations of Trichodesmium observed at this location. Question 3 a) The line of best fit for the two deployment locations should closely resemble the lines indicated on the graph below. Source: CSIRO 2019 0.06 0.07 0.36 0.13 0.15 0.51 0.62 0.86 0.95 0.95 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Phosphates (μM) Depth (m) Phosphate Concentration at Depth for Two CTD Deployment Locations Deployment 1 (no visibleTrichodesmium) Deployment 5 (visible Trichodesmiumbloom) Linear (Deployment 1 (no visibleTrichodesmium)) Linear (Deployment 5 (visibleTrichodesmium bloom)) b) Deployment 1 – phosphate concentration at 90m: 0.36 μm Deployment 5 – phosphate concentration at 90m: 0.95 μm Difference in phosphate concentration: 0.95 – 0.36 = 0.59 μm Question 4 Student responses will vary, but they should address: • optimum temperature levels • phosphorus concentration • fluorescence as an indicator of photosynthetic pigment (chlorophyll-a) • visual observations of Trichodesmium at the two locations. An example response: For Trichodesmium to thrive, optimal water temperatures of 26°C-27°C are required. Nutrients, including phosphates are also required. Near the Wessel Archipelago in the Northern Territory, water temperatures from the surface to a depth of 15m are within the preferred temperature range. Phosphate levels are also higher than at Deployment 1. Visual observations at Deployment 5 showed the presence of Trichodesmium. Further evidence of its presence is the higher fluorescence levels indicating the presence of chlorophyll-a. Deployment 1 (off Fraser Island) had no visual evidence of Trichodesmium. The apparent lack of Trichodesmium is supported by the much lower fluorescence levels (therefore evidence of less chlorophyll-a). The temperature range and phosphate levels are more limiting so it could be expected that there would be less Trichodesmium.