Plankton An Introduction to the Drifters

Plankton An Introduction to the Drifters

What are plankton? Planktos – Greek meaning “to wander” Weakly swimming or drifting organisms Microscopic or macroscopic in size Plant (phytoplankton) or animal (zooplankton)

Why are plankton important? Food source (basis of the food web) Producer of oxygen (photosynthesis) Cause of toxic “blooms” (resulting in fish kills and shellfish poisoning) Means for dispersal of organisms by transport in currents Major players in the global carbon cycle

How are plankton studied? Collected with sampling bottles Special nets Microscopes Cultured in labs Photo by: Lisa Wu Students aboard the R/V Slover in the southern Chesapeake Bay

Collection Methods Fish and invertebrate larvae (net plankton) are collected during plankton tows Depth, distance towed, and the volume of water sampled must be calculated This plankton net is being deployed to collect nearsurface plankton in Maug caldera. The net is about 2 m (6.5 ft) long and has a mesh size of 236 microns (0.25 mm or 0.01 in). Mesh sizes of nets vary depending upon what is being researched The large aluminum frame of the neuston net is 1 meter high and 3 meters long. Here the net is being deployed off the starboard side of the R/V Seward Johnson

Collecting Plankton Bongo nets are towed over the side of the ship or carried by divers to collect drifting organisms Image ID: fish1014, NOAA's Fisheries Collection Photo Date: 1987 Photographer: Captain Robert A. Pawlowski, NOAA Corps Image ID: nur05536, Voyage To Inner Space - Exploring the Seas With NOAA Collect Photographer: J. Morin Credit: OAR/National Undersea Research Program (NURP) Deploying Bongo nets for sampling plankton

Can plankton be studied from space? Satellites equipped with color scanners measure the concentration of chlorophyll in the ocean Red high concentration of chlorophyll Chlorophyll is the major pigment for photosynthesis in phytoplankton Data provides information concerning biomass, productivity, and changes in plant populations Satellite Image of the Gulf of Maine

Phytoplankton blooms observed in the Atlantic Ocean off Africa Image ID: spac0361, NOAA In Space Collection 2003 May 2

Do organisms spend their entire lives as plankton? Holoplankton spend their entire life cycle as plankton. Examples include: dinoflagellates, diatoms and krill Meroplankton spend only a part of their life cycle drifting. As they mature they become nekton (free swimmers) or benthic (crawlers) Examples include: fish and crab larvae. Charleston Bump Expedition. Zooplankton, crab larva. Image ID: expl0172, Voyage To Inner Space - Exploring the Seas With NOAA Collect Location: Southeast of Charleston, South Carolina Photo Date: 2003 August 7 Photographer: Jerry Mclelland Credit: Charleston Bump Expedition 2003. NOAA Office of Ocean Exploration; Dr. George Sedberry, South Carolina DNR, Principal Investigator

How are phytoplankton different from zooplankton? Phytoplankton Producers Single cells or chains of cells Include the smallest plankton – picoplankton (0.2 -2 microns) Remain near the surface Zooplankton Consumers (including herbivores and carnivores) Include microscopic and macroscopic organisms May vertically migrate (to a depth of 200m) during the day for protection but resurface at night to feed

Investigating Plankton Scientists carefully observe characteristics and communicate these observations with sketches and photographs. Ten slides depict specimens you might find in plankton samples. Note: They are from different tows representing different oceans and different depths. Each slide will be visible for 2 minutes. As the slides are shown, observe and, using a pencil, sketch each sample on your worksheet. If there is more than one specimen on the slide, choose one to draw. Note body shape, projections, sensory organs, appendages, type of covering and degree of transparency.

Investigating and Observing Plankton continued Try to hypothesize as to whether the organism is phytoplankton or zooplankton, holoplankton or meroplankton. Following the drawing section, use your sketches and resources to identify the specimens.

Plankton Identification Resources The following sites have excellent resources for studying plankton. Information includes labs, instructions for making plankton nets, diagrams, photographs, and scientific research related to plankton. www.njmsc.org/Education/Lesson Plans/Plankton.pdf http://www.biosci.ohiou.edu/faculty/currie/ocean/ http://www.mos.org/sln/sem/mic life.html http://oceancolor.gsfc.nasa.gov/SeaWiFS/TEACHERS/ sanctuary 4.html http://www.indiana.edu/ diatom/diatom.html http://www.nmnh.si.edu/botany/projects/algae/ http://www.calacademy.org/research/diatoms/ http://earthobservatory.nasa.gov/Library/Phytoplankton/

Plankton Observation Worksheet Specimen # Characteristics: Description Body shape/Tail/flagella/appendages/eyes Transparency/gills/other features Circle one from each category: Phytoplankton or Zooplankton Holoplankton or Meroplankton sketch

Examples of Plankton Specimen #1

Specimen #2

Specimen #3

Specimen #4

Specimen #5

Specimen #6

Specimen # 7

Specimen #8

Specimen #9

Specimen #10

End of Drawing Section Now use your drawings to identify your specimens. Use any resources you have available or view the rest of the slides to discuss the specific organisms used. Sketch by T.A. Arsala

Plankton Identified Specimen #1 Mixed Diatoms Common in nutrient rich temperate, polar, coast and open ocean Important oxygen producer Occur as a single cell or in chains Covered in shells or frustules made of silica Siliceous shells used in industry as filters for breweries and swimming pools, as match heads, in car and jewelry polish, toothpaste whitener, and diatomaceous earth for gardens Beautiful marine diatoms as seen through a microscope. Image ID: corp2365, NOAA At The Ends of the Earth Collection Photographer: Dr. Neil Sullivan, University of Southern Calif.

The Art of Science Did you know that in Victorian times the geometry of diatom frustules was appreciated by hobbyists as well as scientists? On microscope slides, diatom skeletons were arranged in artistic designs. In these arranged slides, the microscopic pictures are only a mm or two across and demonstrate the intricate structure and beauty of diatom anatomy. Slides from the collection of the Academy of Natural Sciences of Philadelphia - photo by Jan Rines

Specimen #2 Copepod Simple crustacean with jointed exoskeleton Use enlarged first antenna to swim Among the most common animals on Earth (most abundant of the net zooplankton) Zooplankton. Copepod. Image ID: fish3229, NOAA's Fisheries Collection Photographer: Matt Wilson/Jay Clark, NOAA NMFS AFSC

Specimen #3 – Copepod with Eggs Bristly appendages act as paddles and create water currents that draw individual phytoplankton cells close to feed on Many feed on zooplankton using claw like appendages to grab prey Eggs are attached to the tail Zooplankton. Copepod with eggs. Image ID: fish3261, NOAA's Fisheries Collection Photographer: Matt Wilson/Jay Clark, NOAA NMFS AFSC

Specimen #4 – Fish Larvae Coastal waters are rich in meroplankton (temporary members of the plankton) Nearly all marine fish have planktonic larvae Fish larvae may change from herbivores to carnivores as they grow Zooplankton. Fish larvae. Image ID: fish3363, NOAA's Fisheries Collection Photographer: Matt Wilson/Jay Clark, NOAA NMFS AFSC

Specimen #5 Copepods Although usually found near the surface plankton may also be collected at all depths even over hydrothermal vents in the deep sea Pacific Ring of Fire Expedition. Some common zooplankton (mostly copepods) collected near the surface over East Diamante volcano. Image ID: expl0102, Voyage To Inner Space - Exploring the Seas With NOAA Collect Location: Mariana Arc region, Western Pacific Ocean Photo Date: 2004 April Credit: Pacific Ring of Fire 2004 Expedition. NOAA Office of Ocean Exploration; Dr. Bob Embley, NOAA PMEL, Chief Scientist

Specimen #6 Crab Larva Some invertebrates have a whole series of different larval stages Charleston Bump Expedition. Zooplankton. Crab larva. Image ID: expl0215, Voyage To Inner Space - Exploring the Seas With NOAA Collect Location: Southeast of Charleston, South Carolina Photo Date: 2003 August 10 Photographer: Jerry Mclelland Credit: Charleston Bump Expedition 2003. NOAA Office of Ocean Exploration; Dr. George Sedberry, South Carolina DNR, Principal Investigator

Specimen # 7 Dinoflagellates Unicellular, mostly autotrophic protists with two flagella Most have a cell wall (theca) with plates of cellulose with spines and pores May form blooms that color the water “Red Tides” or Harmful Algal Blooms (HABs) Produce bioluminescence (light) often seen on the sea surface at night Some dinoflagellates live in symbiotic relationships with corals, giant clams, sea anemones. Some are parasitic – Pfiesteria – living as a cyst in sediments until triggered to bloom. Causes fish and invertebrate disease and even memory loss in humans Photo by: Karen Bullen and F. Lampazzi in the Ocean ography Lab at The Thomas Jefferson High School for Science and Technology

Specimen #8 Krill Not as abundant as copepods they aggregate into huge, dense schools Prefer colder polar waters Filter feeders (on diatoms) and detritivores feeding on fecal pellets and solid wastes of other zooplankton Small zooplankton are also eaten Important food for whales Tread water to stay afloat Have been researched as food for humans Krill Image ID: sanc0126, NOAA's Sanctuaries Collection Location: Gulf of the Farallones National Marine Sanctuary Photographer: Jamie Hall

Specimen #9 Moon Jelly One of 200 species of jellyfish (gelatinous zooplankton) Common in temperate and tropical waters Transparent umbrella shaped bodies may grow up to 1 foot wide Stinging cells are not toxic and don’t sting like other jellyfish 95% water but serve as food for many animals including turtles (NOTE: many animals die each year swallowing plastic that looks like the jellies) Feed by producing a sticky mucus on the bell. Planktonic organisms get stuck in the mucus and slide into the jelly’s mouth Reproduce sexually and asexually Reproductive organs are the 4 horseshoe shaped structures in the center Image ID: reef2547, NOAA's Coral Kingdom Collection Photographer: Florida Keys National Marine Sanctuary Staff Credit: Florida Keys National Marine Sanctuary (moon jelly)

Specimen #10 Octopus Larva Temporary members of the plankton, octopus and squid become nektonic (free swimming) and benthic (crawling) Giant squid are the largest invertebrates in the ocean Zooplankton. Octopus larva. Image ID: fish3612, NOAA's Fisheries Collection Photographer: Matt Wilson/Jay Clark, NOAA NMFS AFSC