PLANS Discussion of the key words in this project- plankton, nutrients, and Chesapeake Bay PLankton and Nutrient Studies for the Chesapeake Bay

The Chesapeake Bay Is the largest estuary (body of water where freshwater and saltwater mix) in the US Is 200 miles long & 35 miles wide in its widest area Holds 16 trillion gallons of water The average depth is 21 feet Freshwater from rivers in the north flows down and meets saltier water that is coming up from the ocean Has more than 100,000 rivers and streams in its drainage basin from 6 states Supports more than 3600 species of wildlife

Let’s Define Plankton and Nutrients since that is what PLANS is all about!!!!! Plankton Plankton are the small (often microscopic) plants and animals that drift in the water. Phytoplankton (algae) are small plants that are part of the plankton. Zooplankton are the animals, often small, that are part of the plankton. The most well known of the zooplankton is ® PLANS will change change your mind about this!!!!

Nutrients Nutrients are chemicals needed by plants (including phytoplankton) for energy and that fuel their growth The 2 major nutrients that we will be discussing are nitrogen and phosphorus Remember - excess nutrients in the water often lead to too much phytoplankton in the water!! What the Potomac River used to look like in the summer Photo by W. Bennett, USGS

What’s wrong with nutrient levels being too high and having too much phytoplankton in the Bay? Nitrogen and phosphorus can cause the growth of excessive amounts of phytoplankton, leading to phytoplankton blooms (huge amounts of phytoplankton cells in the water) Some of the phytoplankton is eaten by filter feeders like oysters and menhaden Unconsumed or “leftover” phytoplankton die and sink to the bottom, where they are decomposed by bacteria During this process, bacteria use up oxygen until there is little or no oxygen left in these bottom waters This is bad for whatever lives there! Bloom of the phytoplankton Karlodinium which turned the water dark brown in Mackall Cove, summer 2003.

Dissolved oxygen (DO), needed by all organisms in respiration, is measured in mg/L. More is better for the organisms that live in the Bay. Levels can get up to 12 mg/L. This chart shows the minimum amounts of dissolved oxygen that various organisms need to survive in the Bay. Think about this - if crabs or fish get into an area of low DO, they can try to move away but oysters and clams can’t. How would you like to be a poor oyster that can’t get away from low DO? Dissolved oxygen information and chart taken from

pagebuilder/39421.gif Bad News! What is this graph showing about changes over time in the amount of low oxygen (hypoxia) or no oxygen (anoxia) in the Bay? No oxygen Low oxygen Volume of low dissolved oxygen water 10 9 m 3 Don’t forget about that poor oyster!!!!

Where do nutrients come from? People, animals, and industries contribute nutrients to the Bay and its tributaries In general, excess nutrients reach the Bay from three major sources: specific point sources; run off from the land; and air pollution Wastewater treatment plants contribute the majority of nutrients that enter the Bay through point sources. They release treated water, often still containing large amounts of nutrients, into local streams and rivers, which eventually flow to the Bay. Blue Plains Advanced Wastewater Treatment Plant on the Potomac River Image taken from

The dominant nutrient load to the Bay is from the land runoff, including farmland and urban and suburban areas. There are a number of sources, including fertilizers, septic systems, boat discharges, and farm animal manure (non-point sources). Air pollution from vehicles, industries, gas-powered lawn tools, and other emitting sources contribute nearly one-third of the total nitrogen load to the Chesapeake's waterways. Airborne nitrogen enters the Bay region from a large area around it. Image taken from

But wait, there’s more! Nutrients also come from a number of natural sources - soil, plant material, wild animal waste, and the atmosphere Have always been a part of the Bay ecosystem, but not at the excessive levels found today Prior to significant human activity in the region, most were absorbed or held in place by natural forest and wetland vegetation As forests and wetlands have been replaced by farms, cities, and suburbs to accommodate a growing population, nutrient loads to the Bay have increased

Let’s sum it up Phytoplankton, like all plants, use 2 major nutrients as chemical sources of energy during photosynthesis – nitrogen and phosphorus Many aquatic systems have become overloaded with nutrients, resulting in high algal biomass, a condition called eutrophication Eutrophication indicates that the balance between nutrient loading and plant production has gone haywire - too much nutrients and too many phytoplankton The end result is too much phytoplankton, low or no DO in summer waters, and destruction of sea grass (submerged aquatic vegetation) beds because they are shaded out by the phytoplankton - ALL BAD!!! /03/Menace-of-Eutrophication.jpg

Going back to the cast of characters Plankton Microscopic plants and animals that drift in the water Bacteria Phytoplankton or algae - microscopic plants Zooplankton - microscopic animals (divided into micro-, meso-, and gelatinous) Macroscopic (visible by eye) plants and animals Fish larvae Gelatinous zooplankton - ctenophores & jellyfish Fish These two groups interact with larger organisms eating smaller organisms in a FOOD WEB

Why do phytoplankton play the lead role? They serve as the base of the food chain Naturally produce oxygen which is a necessary for all organisms Is the first community within the ecosystem to respond to changes in nutrients loads This response at the base of the food web could ultimately affect food availability to higher organisms such as larval fish and shellfish Who are they and what roles do they play?

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

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 masses over 100s of km’s in the open ocean Example - blooms of Microcystis aeruginosa in upper Potomac R. during the ’s. Foam can form when the bloom breaks down Microcystis colonies in water

Prorocentrum minimum- “Mahogany tide” Karlodinium veneficum- can be “toxic” Scrippsiella trochoidea- common dinoflagellate in Pax River Diatom bloom Typical Chesapeake Bay Phytoplankton

Zooplankton usually do not have lead roles 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 Jellyfish - The stinging sea nettle with the long tentacles found during the summer is Chrysaora quinquecirrha 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 Jellyfish - Chrysaora Comb jelly- Mnemiopsis Copyright: Richard Harbison, Woods Hole Oceanographic Inst Comb jelly- Beroe Taken from jellieszone.com/beroe.htmjellieszone.com/beroe.htm

Mesozooplankton Larger zooplankton are >200µm in size and are hard-bodied Copepods - Small crustaceans (as crabs) 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 Barnacle Nauplii - The young stages of a barnacle. Before a barnacle settles and attaches to a hard surface, it has swimming stages Copepod Acartia Barnacle nauplius Polychaete larvae Photos by Center for Aquatic Research 2006

Microzooplankton Zooplankton which are very small, <200µm in size Rotifers - Small multicellular animals that have a crown of cilia (fine hairs) around their mouths. Can be food for very small fish larvae and copepods Copepod Nauplii - Early stages of copepods (Baby Plankton) Ciliates - One celled organisms that often have rows of cilia (hairs) on their bodies. Tintinnids are ciliates that live in houses or loricas that they build, often out of particles in the water. Some have clear loricas. Some soft bodied Pelecypod Larvae - Very young stage of animals that live in shells that have 2 distinct sides such as oysters, clams, and mussels Acartia nauplius Rotifer- Brachionus Pelecypod larvaeRotifer- Synchaeta Tintinnid- Tintinnopsis Photos by F. Ogunjinmi

Put them all together- How do the plankton and nutrients interact in the Chesapeake Bay?

The Food Web in the Bay As one organism eats another, a food web is formed - each step in the web is known as a trophic level The lowest level of the web (phytoplankton) – producers Those organisms that eat producers or other animals – consumers Organisms that digest the bodies of dead plants and animals and the waste products of both – decomposers The complex network of feeding continuously cycles organic matter and nutrients N and P back into the ecosystem-remember that the phytoplankton take up N and P Image taken from

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

Why do we want to study all this? Why do we care? The results of too much phytoplankton in the water can be harmful algal blooms!!! Can lead to fish kills or crabs fleeing the water as well as slowed oyster growth Can happen because of toxins or bacteria removal of all oxygen when the algae die and decompose - this suffocates the animals Some bloom species can also impact oysters and other organisms, such as microzooplankton, domestic animals, and humans, with toxins or poisons they produce

What can we do? We/you can prevent algal blooms by being good stewards in your homes and schools Don’t over-fertilize Don’t have bare ground Don’t cut down trees, plant them! Reduce nutrients coming into the system!

How we think of the Bay in 1608 Knowing what you have just learned- How did we get from these conditions

Today to these?