INVESTIGATING PLANKTON IN AQUATIC ECOSYSTEMS BY Nancy Biegel. INVESTIGATING PLANKTON IN AQUATIC ECOSYSTEMS. 2013 CMARS Teachers. Photo by Kathy Richardson. www.owrb.ok.gov . academics.smcvt.edu. INTRODUCTION. COMMON ZOOPLANKTON. COMMON PHYTOPLANKTON. IMPORTANCE OF PLANKTON.
IN AQUATIC ECOSYSTEMS
IN AQUATIC ECOSYSTEMS
2013 CMARS Teachers. Photo by Kathy Richardson.
IMPORTANCE OF PLANKTON
“Plankton are among the most important organisms on Earth, without which most life would die.”
~Life on an Ocean Planet
An important consumer of phytoplankton, copepods are tiny crustaceans and are the most numerous multicellular animal on Earth. They are a critical link between the autotrophs and the larger organisms in aquatic food webs.
The largest species in the ocean depend on the smallest for their survival. The base of any aquatic food web begins with those microscopic drifters, the plankton. Made up of free-floating organisms and weak swimmers, plankton move with the ocean currents and tides.
The phytoplankton, or microscopic plants, harvest the Sun’s energy to make food and oxygen. The microscopic animals, or zooplankton, feast on the phytoplankton and are in turn, eaten by larger and larger organisms. Without plankton, there would be no life in aquatic ecosystems.
Plankton are critical to the health of the complex food webs of all aquatic ecosystems. From oxygen production to carbon fixation, and production of food, plankton, the smallest of organisms, is the organism we can’t live without, even on land.
Examine a sample of freshwater or saltwater and chances are, you’ll see diatoms. They are the most dominant and efficient phytoplankton in any aquatic environment. They have cell walls called frustules which are made of silica. This allows light to pass through which is ideal for photosynthesis.
FISH & SHELLFISH LARVAE
Many larger organisms, such as crabs, oysters, and finfish, begin their lives as plankton. In the plankton stage, they may look nothing like their adult forms.
WHAT IS PLANKTON?
The miniature world of plankton can be divided into three groups, phytoplankton, zooplankton and bacteria. Each has a niche in aquatic ecosystems.
CREST-CISCEP (Center for the Integrated Study of Coastal Ecosystem Processes) is a NSF grant funded program at UMES aimed at exposing students, especially those from under represented populations, to the marine sciences through summer internships, paid undergraduate and graduate level assistantships and K-12 outreach activities. CREST-CISCEP creates an educational and financial pipeline through which scientifically inclined students can travel as far as a Ph.D.!
Phytoplankton, single-celled plants, are primary producers, or autotrophs. They make their own food using light energy and produce 50% of the world’s oxygen, more than any other organisms. One drop of water may contain thousands of phytoplankton.
Callinectes sapida - Blue crab zoae.
Another common phytoplankton are the dinoflagellates. Most have two flagella to help them move up and down in the water column. They can be photosynthetic or parasitic, and a few can even produce their own light, called bioluminescence. These unicellular organisms are responsible for large algae blooms that happen during warm summers in coastal areas.
The primary consumers of phytoplankton, and a vital link for larger organisms, are zooplankton. Most are microscopic, but some, like jellyfish, can be much larger. Zooplankton includes single-celled organisms, as well as fish & shellfish larvae, copepods, jellyfish and comb jellies. Some are herbivores, while others are predators.
Dr. Andrea Johnson, CISCEP Associate Director
Dr. Paulinus Chigbu, CISCEP Director
Kerrie Bunting Program Coordinators
Christopher Daniels, CISCEP Boat Captain
Ciliates, radiolarians, foraminiferans, and other species come in different sizes and shapes with special adaptations that help them stay afloat. Some have skeletons of silica while others are made of calcium carbonate .
CTENOPHORA & CNIDARIA
Comb jellies, the ctenophores lack the stinging cells of the cnidarians. Their cilia show a rainbow effect when they move, caused by diffraction. The jellyfish, or cnidarians, catch their prey with stinging cells called nematocysts. Both phyla are weak swimmers which puts them with the plankton.
Dr. Eric May
Dr. Joseph Pitula
Dr. Madhumi Mitra
Dr. Patricia Goslee
Dr. Yan Waguespack
These are an important source of food for aquatic ecosystems. Plates of calcium carbonate make up their outer covering. When the organism dies, the plates contribute to ocean sediments such as limestone.
And all of the students who assisted with the program.
In aquatic ecosystems bacteria have the important job of decomposition. They feed on the remains of dead organisms, breaking them down and returning the nutrients back into a form plants can use. Zooplankton and filter-feeders also feed on the bacteria.