Marine BiologyPlankton

General Info:Plankton comes from the Greek word planktos which means drifter.

MovementMost organisms move with the current. Some have the ability to move on their own. For example, copepods are the fastest animal for their size- they move more than 500 body lengths per second.

Two Types of PlanktonPhytoplankton- which are autotrophs (plank-like)Zooplankton- which are heterotrohs (animal-like)

Location- Epipelagic region of the ocean:This location is near the surface where the water is warmer and lighter.The depth is from the surface to 200m or 650 ft.It often corresponds with the photic zone, the is the region where light penetrates.

Location: Epipelagic region of the ocean (cont)Shallowest part of the pelagic realmThe pelagic realm is the vast open ocean away from the bottom and the shore

Location: Epipelagic region of the ocean (cont)Coastal/neritic: are waters that lie over the continental shelf (small portion of the epipelagic)Oceanic: are surface waters beyond the continental shelf.

Location: Epipelagic region of the ocean (cont)This area lacks deposit feeders since there is NO bottomSuspended feeders are therefore ABUNDANT

None of these deposit feeders!

All energy comes from the sun:Nearly all primary producers (photosynthesis) from the ocean occurs in the epipelagic zoneFood produced sinks or is carried by the currents to other parts of the ocean.Autotrophs carry out photosynthesis by taking in carbon dioxide and converting it to organic food (glucose)

Plankton have trouble remaining afloat:Organisms and their shells are more dense than water and therefore should sinkCoping strategies:Increase water resistance- the greater the surface area the more resistanceBeing small is helpfulFlat shape also increases surface area, as do projections and spines

Plankton have trouble remaining afloat (cont):Coping strategies (cont)Increase buoyancySome store lipids as vacuoles of oil (less dense than water)Some use pockets of gas which is less dense than waterRegulating the amount of gas can move the organism up and down the water column Exchange heavy ions for lighter ones

Vertical MigrationPredators abound the epipelagic. Therefore, some zooplankton sink where there is little light during the day and rise to feed at night

Recent ResearchNew methods to count and identify phytoplankton biodiversityFlow cytometry is optical technique that can process hundreds of thousands per minuteMIT researchers discovered tiny but abundant new species called prophlorophytesDNA research to understand evolution and relationships among plankton

PhytoplanktonPhotosynthetic AutotrophsGreater than 95% of photosynthesis in the oceanProduce nearly 50% of the oxygen in our atmospherePrimary producer in the epipelagic- WHY?Gouped by sizePicoplankton- too small to be caught in netsNet plankton- (micro, meso, macro, nano), large enough to be caught in nets

Phytoplankton (cont)2 Main TypesDiatomsKingdom ProtistaHave characteristics of both plants and animalsPrefer temperate, polar, and nutrient-rich waterThey are unicellular, although some gather in chains or clustersEnclosed in a cell wall that is made out of silicon dioxide

Phytoplankton (cont)Diatoms (cont)They have a glasslike frustules which is a shell with tight-fitting halves. There is a wide variety of beautiful frustules!Some frustules have perforations and spines that allow light to pass through and gasses and nutrients to enter and leaveFrustules from dead diatoms accumulate on the ocean bottom and are called diatomaceous oozeFossilized sediments of the ooze found inland are mined as diatomaceous earth which is used for polishing (toothpaste), insulating, and filtering (swimming pools)

Phytoplankton (cont)Diatoms (cont)Reproduce rapidly when conditions are good. Other species are depend on this and it influences the success of some fish species.

Phytoplankton (cont)Second typeDinoflagellatesKingdom ProtistaMost abundant phytoplankton in warm, tropical watersUnicellular with a cell wall made of cellulose platesMost outstanding characteristic: 2 unequal flagellaOne wraps around the groove in the middle of the cellOne trails freeThey both direct movement in practically any direction

Phytoplankton (cont)Dinoflagellates (cont)Unique DNA remains coiled in chromosomes throughout lifeAlthough autotrophic they also feed on other food particlesReproduce by cell divisionHuge surges of reproduction are called bloomsThey produced the Red Tides which actually turned the water red to red-brown

Phytoplankton (cont)Dinoflagellates (cont)2 Problems with Red TidesProduce toxins which may cause fish to die or accumulate in the tissues of resistant organisms which can result in paralytic shellfish poisoning which can be fatal to humansAs the bloom dies and decomposes, the bacteria deplete the dissolved oxygen form the water causing fish to die

Phytoplankton (cont)Dinoflagellates (cont)Some species produce light by Bioluminescence which can be seen at night in the open oceanSome species celled zooanthellae live in symbiotic relationships with other marine organisms such as coral. They release organic matter used by the coral and help in the formation of the coral skeleton.

Phytoplankton (cont)NanoplanktonVery small and hard to catchStill important in ocean primary productionTwo typesCyanobacteriaCoccolithophorids

Phytoplankton (cont)Nanoplankton (cont)CyanobacteriaKingdom Monera, therefore prokaryoticContain chlorophyll (green pigment) and phycocyanin (blue pigment)Most are microscopic, but can form long visible strands or matsLikely the first photosynthetic organisms on Earth and contributed to the accumulation of oxygen in the atmosphereCan also carry out nitrogen fixation- converting atmospheric nitrogen gas to usable from alike ammonia

Phytoplankton (cont)Nanoplankton (cont)CoccolithophoridsCovered with rounds calcium carbonate paltes

ZooplanktonTiny planktonic animalsA few species are a critical link in the food web- they are herbivores, meaning they eat autotrophsMost are carnivorous and feed on the herbivorous zooplankton

Zooplankton (cont)They are divided into two groups: Holoplankton and MeroplanktonHoloplankton: spend their entire lives a planktonCopepodsMost abundant zooplankton (70% or more) and may be the most abundant animal on EarthThe are crustaceansMost eat phytoplankton and zooplankton (use bristled antennae)Move fast to escape predators

Zooplankton (cont)Holoplankton (cont)KrillShrimp-like crustaceansPrefer colder watersFilter feeders, eat diatoms, detritus, and zooplankton

Zooplankton (cont)Holoplankton (cont)Other holoplanktonSalps- related to sea squirtsLarvaceans- also related to sea squirts and secrete a house of mucusPteropods- small snail-like creatures with modified foot to make wing-like projectionsArrow worms (chaetognaths)- feed on copepods

Zooplankton (cont)Meroplankton: Only a portion of the lives are spent as plankton (larva of fish and invertebrates)Veligers- mollusksOphiopluterus- brittle starsBipinnaria- sea starsTrpchophore- polychaete worms and some mollusksNauplius- crustaceans

*For a person 5ft tall, this is 2500 ft per second (a little under a half mile per second)*Uses a beam of light to focus on a single cell for counting, sorting, and examining