PLANS

PLankton And Nutrient Studies

for the Chesapeake Bay

Plankton Manual

Morgan State University Estuarine Research Center

and

The Society for Ocean Sciences

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Plankton in Summer Bay Food Web

Striped Bass

(Menhaden)

Bay Anchovy

Mesozooplankton

(Acartia)

Phytoplankton & Bacteria

Ctenophores

Microzooplankton

Jellyfish

Bay anchovy larvae

?

baydriftercharters.com/

Oysters

Nutrients

System in Balance

Mesozooplankton

Microzooplankton

Phytoplankton

Mesozooplankton

Microzooplankton

Phytoplankton Bloom

Human Influence

Low or High Nutrients Low or High

Low or High *Chlorophyll Low or High

Good or Poor *Water Clarity Good or Poor

Low or High *Dissolved Oxygen Low or high

* The EPA has determined that the Bay is impaired. Chlorophyll, water clarity, and

dissolved oxygen levels are used to determine the amount of impairment.

System out of Balance

NutrientsNutrients

Circle which one is correct for each type of system

Characteristics of a Healthy versus Impaired System

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Important Plankton Definitions

Plankton- From the Greek word for “drifters”. Drifting organisms; some are motile (can move on their own) but are still largely under the influence of the movement caused by wind, tides, and currents. Phytoplankton- Plant plankton; mostly microscopic and unicellular, these organisms are grouped into 10 major taxonomic groups. The most common ones fall into 3 groups: Bacillariophyta (diatoms), Dinophyta (dinoflagellates) and Microphytoflagellates (small flagellated algae). They serve as the base of the pelagic (organisms living freely in the water column) aquatic food chain and produce over 50% of the planet’s oxygen. Some phytoplankton species, however, are considered undesirable: they are called nuisance or harmful algae. These usually are poor food for planktivorous herbivores (plankton eaters); some form blooms, some may be toxic or otherwise noxious. Zooplankton- Animal plankton; a wide variety of organisms of different shapes and sizes, including almost every major group of aquatic animals, either for their entire life cycle (holoplankton) or for short periods for part of their life cycle (meroplankton- such as early life stages of many invertebrates and even some vertebrates, e.g., fish eggs and larvae, the young of oysters, crabs, barnacles). Zooplankton play an important role in the aquatic food chain: many zooplankton feed on phytoplankton and they, in turn, are food for many other aquatic organisms. Chlorophyll- The photosynthetic pigment common to all plants. There are different chlorophyll molecules but the only one common to all groups of plants is chlorophyll a. This pigment is commonly measured as a surrogate measure of the total amount of plant material (biomass) in a water sample. Nutrients- The chemical elements, which along with light, are necessary in the process of photosynthesis. These are divided into macro-nutrients (carbon, hydrogen, oxygen, nitrogen, phosphorus, silicon, magnesium, potassium and calcium) which are needed in relatively large amounts and trace elements which are required in much smaller concentrations. Eutrophication- The process of excessive nutrient-loading giving rise to vast amounts of primary production. This process is driven by human influences, such as sewage, fertilizers, and burning fossil fuels. It has serious repercussions in the aquatic environment such as destruction of biota, habitat and depletion of oxygen (hypoxia or anoxia) from the water with the breakdown of algae by microbial action.

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Water Quality Monitoring

This broad term, in this case, refers to the measurement of physical and chemical parameters in the water to assess the condition of the water body. A large number of different parameters are measured in this assessment. Some of these parameters are described below:

Physical Parameters

Temperature – the temperature of the water is important because of its relationship to the organisms that inhabit the water, all of which have specific tolerances to temperature. In addition, temperature is important relative to water’s ability to retain dissolved oxygen. Colder water has a greater natural capacity for dissolved oxygen than does warmer water. Temperature is measured in degrees Celsius or Centigrade (this scale relates to Fahrenheit by the following equation: (1.8C) + 32 ). Finally, temperature is important for when combined with salinity, the density of the water is determined.

Salinity – the salinity of the water is once again important to the

organisms that inhabit the water for they all have a specific tolerance to the amount of salt that is dissolved in the water. Salinity is also important in giving water its density (mass per unit volume). Salinity is measured in grams of salt/kilogram of water parts or per thousand (ppt). The salinity of freshwater = 0, while that for seawater is ~ 35ppt. The primary salts which are dissolved in seawater are sodium, chloride, magnesium, calcium and potassium, with sodium chloride comprising ~ 75% of the total.

Dissolved Oxygen – all of the atmospheric gases are found

dissolved in water. Dissolved oxygen is extremely important to biological processes in the water. Dissolved oxygen is measured in mg-atoms/liter of water or mg/L. This values ranges from 0 - > 10 mg/L. The concentration of dissolved oxygen in water is determined by the temperature and salinity of the water, the biological activity in the water and factors which mix the water (currents and other mixing processes). The important biological activities which affect dissolved oxygen in water are photosynthesis by the microscopic plants (phytoplankton) which produces oxygen and respiration by bacteria which utilizes oxygen. A healthy concentration of dissolved oxygen is

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> 5 mg/L as it has been determined that below this level certain organisms become stressed.

Water Clarity - the transparency of water is related to light

entering the water being scattered by particles suspended in the water. These particles can either be organic (phytoplankton, zooplankton, detritus) or inorganic (sediments comprised mainly of silts and clays). The importance of water clarity is mainly biological as all plants (phytoplankton, seagrasses and macroalgae) require certain amounts of light and many animals can tolerate specific concentrations of particles in the water (Ex: Oysters shut down feeding when high loads of suspended particles are present in the water).

Chemical Parameters Nutrients – these chemicals fuel plant growth much as fertilizers do for land plants. The primary nutrients are nitrogen and phosphorus. The sources of nutrients to the water are from the land (sewage, fertilizers from farms and homes and animal waste), air (emissions from autos and industry) and groundwater. A healthy water body maintains a specific balance of nutrients which enables an appropriate amount of plant growth which serves as the base of the aquatic food chain. Chlorophyll - this is the primary photosynthetic pigment in all plants. The measure of chlorophyll is important because it enables one to assess the response of microscopic plants to the nutrient concentrations in a body of water. The amount of chlorophyll indicates the state of the balance between nutrients and the amount of plant material at the base of the food chain. Too little chlorophyll is bad because there is not sufficient food for organisms up the food chain and too much chlorophyll is bad because there is a surplus of food for other organisms. This surplus serves as the food for bacterial metabolism which consumes the oxygen dissolved in the water.

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Phytoplankton

Some terms and definitions: Prokaryotes- primitive cells with no cell wall or organized organelles, i.e. nucleus Eukaryotes- evolved from prokaryotes, have a cell wall, nucleus and chloroplasts

Major Types of Phytoplankton Found in the Patuxent River

Diatoms- free-floating, single celled or chain forming plants enclosed

by silicon (glass-like) case. A dominant group of phytoplankton in the Patuxent River. There are centric (round shaped) and pennate (elongated) diatoms. One common species is the centric, chain-forming diatom, Skeletonema costatum.

Dinoflagellate- mostly single celled organisms that have two whiplike threads (flagella) for locomotion. They are a sub-dominant group and are responsible for the phenomenon known as red or mahogany tides, which is an increase or “bloom” of usually one particular species. Almost every Spring there is a mahogany tide caused by the species Prorocentrum minimum. Microphytoflagellates- share a life-form characterised by small size and the possession of one or more flagella, but belong to several taxonomically distinct groups of algae. Most of these groups include species with photosynthetic ability--therefore called phytoflagellates; Ex: Cryptomonas sp., Pyramimonas sp., Euglena sp.. Cyanobacteria- also referred to as blue-green algae; predominantly fresh-water, single celled, colonial or filamentous plants. Can form massive blooms in tidal-fresh regions of some rivers. Ex: noxious blooms of Microcystis aeruginosa on the upper Potomac River during the 1970-80’s.

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Why Phytoplankton are Important

As photosynthetic plants, phytoplankton were responsible for the formation of our atmosphere. They naturally produce carbon dioxide and oxygen which were necessary components for the evolution of higher plants and animals. Phytoplankton are the first community within the biota to respond to changes in nutrient loads. This response at the base of the food web could ultimately affect the food availability to higher organisms such as larval fish and shellfish.

Distribution Most aquatic organisms, including the plankton, have limited temperature and salinity tolerances. That is, some species will do better in cool or cold temperatures, some do better in warm. Those same species may do better in high salinity waters, some in lower, some can’t tolerate any salt at all and are found only in fresh water. Thus, in a river like the Patuxent, plankton communities may differ up- and downstream and from one season to another.

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Diatoms• Single celled or chain forming enclosed by silicon (glass) case

•A dominant group of phytoplankton in all rivers and estuaries

•There are centric (round shaped) and pennate (elongated) diatoms

•Good food for lower trophic levels

Dinoflagellates•Mostly single celled organisms that have two whip like threads (flagella) for

locomotion

•Are responsible for the phenomenon known as red or mahogany tides, which

is an increase or “bloom” of usually one species

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Microphytoflagellates•Characterized by small size and the possession of one or more flagella

•Belong to several taxonomically distinct groups of phytoplankton

•Examples: Cryptomonas sp., Pyramimonas sp., Euglena sp., Chlorella sp.

Cyanobacteria•Also referred to as blue-green algae; are prokaryotes (do not have an

organized nucleus or other organelles)

•Single celled, colonial, or filamentous plants

•Can form massive blooms in tidal-fresh regions of some rivers and as floating

amsses over 100s of km’s in the open ocean

•Example - blooms of Microcystis aeruginosa in upper Potomac R. during the

1970-80’s.

Foam can form when the bloom

breaks downMicrocystis colonies in water

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Prorocentrum minimum- “Mahogany tide” Karlodinium veneficum- can be “toxic”

Scrippsiella trochoidea-common dinoflagellate in Pax River

Diatom bloom

Typical Chesapeake Bay Phytoplankton

Karlodinium bloom, Mackall Cove, 2003

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Zooplankton

Zooplankton- the small animals that are part of the plankton. Because of large taxonomic and size differences in the kinds of animal plankton, zooplankton are commonly grouped by size:

Gelatinous Zooplankton- These organisms are usually larger than the mesozooplankton (centimeters to meters in diameter). They are transparent, soft-bodied and delicate, with the consistency of jello. Mesozooplankton- The larger zooplankton. They are >200µm in size and are hard-bodied. Microzooplankton- The zooplankton which are very small. They are <200µm in size.

Major Types of Zooplankton Found in the Patuxent River

Gelatinous zooplankton Jellyfish- The stinging sea nettle with the long tentacles found during the summer is Chrysaora quinquecirrha and the one often seen during the colder months is the moon jelly Aurelia aurita. Comb Jellies- The 2 found in the Patuxent River have no tentacles and do not sting. The sea walnut, Mnemiopsis leidyi, is found in great numbers from May to September while Beroe ovata shows up towards the end of the summer and can be seen throughout the winter.

Mesozooplankton

Copepods- Small crustaceans which feed on algae and smaller microzooplankton. They are important food for some fish and fish larvae. During the summer, the main copepod in the higher salinity areas of the river is Acartia tonsa. Polychaete Larvae- The very young stage of worms that will eventually live in the sediment.

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Barnacle Nauplii and Barnacle Cypris Larvae- The two young stages of a barnacle. Before a barnacle settles and attaches to a hard surface, it has two swimming stages. Cladocerans- Small aquatic crustaceans, whose bodies are covered by a bivalve (2 part) shell from which the head and antennae extend. There are many types that are fresh-water but only a few are found in higher salinities.

Microzooplankton Rotifers- Small multicellular animals that have a crown of cilia (fine hairs) around their mouths. They can be food for very small fish larvae and copepods. Copepod Nauplii- Early stages of copepods. Ciliates- One celled organisms that often have rows of cilia on their bodies. Tintinnids are ciliates that live in houses or loricas that they build, often out of particles that are in the water. Some have clear loricas. Some ciliates do not have loricas and have soft bodies. Pelecypod Larvae- The very young stage of animals that live in shells that have 2 distinct sides (bivalves) such as oysters, clams and mussels. Gastropod Larvae- The young stage of certain snails.

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Why Zooplankton are Important

It is important to note that harmful algal species are often believed to be undesirable food for zooplankton, leading to lower zooplankton production (lower reproduction resulting in lower abundance).

Gelatinous zooplankton are important predators or consumers of zooplankton and fish eggs and larvae. They also compete with other organisms that eat zooplankton. Jellyfish are the primary consumers of ctenophores (comb jellies).

Mesozooplankton are important consumers of phytoplankton, microzooplankton, and other mesozooplankton, and are food for other mesozooplankton, gelatinous zooplankton, larval fish, and adult stages of some fish as the Bay anchovy.

Microzooplankton eat or graze bacteria and or phytoplankton. They are important food for mesozooplankton and the first feeding stages of certain kinds of fish as white perch and striped bass.

Zooplankton are important links between phytoplankton and the higher levels in the food web (such as fish). Changes in their populations (increases or decreases) or shifts in the types found in the river can be signals that something is happening in the ecosystem.

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Gelatinous Zooplankton

Jellyfish -

Chrysaora

Taken from

www.ucmp.berkeley.edu

Comb jelly-

Mnemiopsis

Comb jelly- Beroe

Copyright: Richard Harbison, WHOI

Taken from

jellieszone.com/beroe.htm

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Copepod Acartia

Polychaete larva

MesozooplanktonPhotos by Center for Aquatic Research 2006 and PLANS students

Barnacle nauplius

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Microzooplankton

Photos by F. Ogunjinmi and PLANS students

Acartia nauplius Rotifer- Brachionus

Pelecypod larva Rotifer- Synchaeta

Tintinnids- Tintinnopsis

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PROTOCOL FOR PHYTOPLANKTON SAMPLE COLLECTION

Materials: bucket, sample bottles (1-1L, 1-500ml), lugols, tape, sharpie Procedure-

1. Label sample bottle with tape and record sampling site, date and time. 2. Rinse bucket 3X before using to grab a sample. Then after rinsing 500ml

sample bottle 3X--fill by dipping the bottle just below the surface. 3. Add ~5mls Lugols (iodine)fixative. (Your sample should have a weak tea

color.) 1. 4 Invert a couple of times after capping for mixing. **Keep sample out of

direct sunlight.

Phytoplankton Counting Procedure

1. Gently invert sample bottle a few times. 2. Using macropipette with clean tip, draw out appropriate volume. 3. Fill settling chamber and slide cover glass on. 4. Wait ~20 minutes to allow cells to settle. 5. Using the inverted scope, identify and enumerate individual cells by

randomly moving around the chamber. 6. Count at least 10 fields and a minimum of 100 cells. 7. Calculate # per liter (abundance) using equation:

#cells counted * #fields in chamber * 1000 = #cells/liter # mls settled # fields counted

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PROTOCOL FOR MICROZOOPLANKTON SAMPLE COLLECTION Note- for any containers to be used, rinse 3 times before using

Using a Pump

Materials- pump, in hose and out hose, carboy, stop watch, 44µm mesh plankton net, container to put sample in, sharpie, tape Procedure-

1. Set up pump so the long hose is connected to the in port and the short hose to the out port

2. Put long hose just under surface of the water and turn on pump 3. Time how long it takes to fill carboy with water to 10 liters 4. Multiply this time by 3- this will tell you how long it takes to pump 30 liters of

water through the net 5. Set the net up in the bucket- make sure clamp at the end of the net is

secure 6. Pump 30 liters of water into the net 7. Open the clamp and let the water drain into the labeled sample container 8. Secure clamp, rinse down net, and drain into container 9. Repeat 2 more times

Using a Bucket

Materials- 2 buckets, 44 um mesh plankton net, squirt bottles, container to put sample in, sharpie, tape Procedure-

1. Hold net over one bucket 2. Fill second bucket with 5 liters of water (try to keep jellyfish out) 3. Pour into net 4. Repeat 5 times 5. Rinse net with squirt bottle and empty into container 6. Repeat 2 more times

Microzooplankton Counting Procedure

1. Sample into jar with foramalin. 2. Let sample sit overnight and draw down to concentrate. 3. Using Hensen-Stempel pipet, remove 1ml of sample. 4. Put into Sedgewick-Rafter cell (can stain with Rose Bengal stain). 5. Identify and count microzooplankton in chamber. 6. Count by rows, going across chamber. 7. Calculate # per liter using equation: #/L for an organism = organism count X total # of mls in jar #mls counted # liter filtered

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PROTOCOL FOR MESOZOOPLANKTON SAMPLE COLLECTION

Collection protocol: 1. Pre-label the sample bottles, including project, date, station, replicate number

and/or other uniquely identifying information about the sample. 2. Samples are collected by towing the plankton net in a stepped oblique fashion,

beginning just above the bottom, raising the net in timed progressive steps, and ending just below the surface. The number of 'steps' depends on station depth. Measure the station depth and determine at what depth- and time-intervals to tow the net. The total towing time is usually 5 minutes. In the Cove, a typical tow is at 3 m, 2 m, 1 m and surface depths, towing for 1 min 15 sec at each depth.

3. Before deploying the net, note the starting number on the flow meter. Record the new number after the tow when the net is brought back on board.

4. After the first tow, assess the towing time: if the plankton net is clogged and zooplankton are numerous then consider a shorter tow. If zooplankton are sparse, consider a longer tow.

5. After the tow, rinse down the net thoroughly with a pump in order to collect all the organisms into the cod end. Remove the collection cup over a bucket and the rinse the net end and cup contents into the bucket.

6. Mesozooplankton: Pour the contents through the large-mesh sieve into the finer-mesh sieve over a bucket. Jellyfish and ctenophores should be retained on the large-mesh sieve; the smaller mesozooplankton will be retained on the smaller mesh sieve.

7. Rinse the fine-mesh sieve with the squirt bottles to concentrate the organisms to one small area of the sieve and wash the material through a funnel into the sample bottle. Rinse the sieve 3 times.

8. Add formalin and close lid tightly. 9. Gelatinous zooplankton: Pour the contents of the large-mesh sieve into a

beaker or graduated cylinder, measure and record the volume. Measure jellyfish and ctenophores separately if possible. Pour the sample (or subsample, if the number is very large) into a counting tray, count and record the number of individuals.

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PLANS Programsponsored by a grant from the

NOAA B-WET Program