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Goal 1: Goal 1: Study, understand, model & predict the impacts of land use & climate variability Subproject 1: Water quality dynamics in relation to land.

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Presentation on theme: "Goal 1: Goal 1: Study, understand, model & predict the impacts of land use & climate variability Subproject 1: Water quality dynamics in relation to land."— Presentation transcript:

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2 Goal 1: Goal 1: Study, understand, model & predict the impacts of land use & climate variability Subproject 1: Water quality dynamics in relation to land use and climate variability (Project Leaders: Eric May & Ali Ishaque) Subproject 2: Understand the dynamics of phytoplankton and macroalgae species including HABs in MCBs (Project Leaders: Madhumi Mitra & Chunlei Fan) Subproject 3: Dynamics of zooplankton community structure and the driving mechanisms (Project Leaders: Paulinus Chigbu & Kam Tang) Subproject 4: Physiological effects of hypoxia and environmental contaminants on Atlantic croaker (Project Leader: Andrea Johnson) Subproject 5: Effects of environmental factors on blue crab and its relation to infection by Hematodinium sp. (Project Leaders: Joseph Pitula & Sook Chung)

3 Interrelationships Among the Subprojects Zooplankton Community Structure & Dynamics Theme 3 HABs Occurrence & Dynamics Theme 2 Distributional & Physiological Effects of water quality on Fish Theme 4 Effects of water quality on Hamatodinium- Blue crab relationships Theme 5 Climate Variability Weather Land Use

4 What are Plankton? What are Zooplankton?

5 Plankton Aquatic organisms that have limited powers of locomotion & therefore can not swim independent of water movement Two sub-divisions of plankton: –Phytoplankton: Free-floating organisms capable of photosynthesis –Zooplankton: Free-floating animals & animal- like protists –Bacterioplankton (bacteria)

6 Phytoplankton

7 Zooplankton

8 Animal Phyla & Animal-like Protists Protozoan Groups Sponges: Phylum Porifera Radiate Animals: Phylum Cnidaria & Phylum Ctenophora Acoelomate Bilateral Animals: e.g. Flatworms (Phylum Platyhelminthes) Pseudocoelomate Animals (e.g. Phylum Rotifera) Molluscs (Phylum Mollusca) Segmented Worms (Phylum Annelida) Arthropods (Phylum Arthropoda) Echinoderms (Phylum Echinodermata) Chordates (Phylum Chordata)

9 Classification of Plankton by Size Net Plankton: –Megaplankton (> 20 cm) –Macroplankton (2 – 20 cm) –Mesoplankton (0.2 – 20 mm) –Microplankton (20 – 200 micron) Nanoplankton: (2 – 20 micron) Picoplankton: (0.2 – 2 micron)-> bacteria & cyanobacteria Femtoplankton: (0.02 – 0.2 micron)

10 Classification of Zooplankton based on Life History Characteristics Holoplankton: Spend their entire lives in the water column as plankton Meroplankton: Spend part of their lives in the water column

11 http://www.bluecrab.info/lifecycle.html Benthic as adult (live on the bottom) Planktonic as a larva (live in the water column)

12 Life cycle of a squid, a meroplankton

13 Diversity of Zooplankton Zooplankton consist of a host of larval & adult forms that represent most of the animal & many of the protistan phyla. In the marine environment, the dominant net zooplankton are the copepods (subclass: Copepoda; subphylum: Crustacea; Phylum: Arthropoda)

14 Copepods May be free-living, planktonic, benthic or parasitic Free-living planktonic forms swim weakly, using their jointed thoracic limbs & have a characteristic jerky movement Use their large antennae to slow their rate of sinking

15 Copepods

16 Reproduction in Copepods Sexes are separate Sperm packaged in spermatophores is transferred to the female Eggs are fertilized & enclosed in a sac attached to the female’s body Eggs hatch into nauplius larvae which pass through many naupliar stages, copepodid stages and finally adult stage

17 Cladocerans, Ostracods, Mysids, Amphipods, Euphausids *Most are small filter feeders straining algae out of water *Some (e.g.) mysids are also active predators

18 Other Zooplankton Kingdom: Protista Phylum: Sarcomastigophora Order: Foraminiferida (forams) Order: Radiolaria *Important grazers in the marine environments *Net plankton, Holoplankton *Radiolarians & foraminiferans are single-celled organisms that produce skeletons of CaCO 3 and SiO 2 (glass), respectively *Thick layers of their skeletal remains occur on the ocean floor as foraminiferan and radiolarian ooze

19 Radiolarians

20 Radiolarians contd.

21 Foraminifers

22 Other Zooplankton contd. Other important grazers include: ciliates (Phylum Ciliophora) and small flagellates (Phylum Sarcomastigophora) Are nanoplankton Are major grazers of the nanophytoplankton

23 Examples of some plankton members of the Kingdom Protista (a) Foraminiferan (b) Radiolarian (c) Ciliate (d) Flagellate (e) Flagellate

24 Holoplanktonic Members of the Phylum: Cnidaria Includes: (a) Jellyfishes of the classes Hydrozoa and Scyphozoa and (b) Complex hydrozoan colonies known as siphonophores *Scyphozoan jellyfishes are among the largest planktonic organisms and may occasionally be found in large numbers

25 A Hydrozoan Jellyfish (Crassota alba)

26 The large Scyphozoan Jellyfish (Pelagia colorata) with juvenile cancer crabs

27 Jellyfish (scyphozoan) & Siphonophore (Colonial hydrozoan; Physalia)

28 Ctenophore

29 Tomopteris (A holopelagic polychaete)

30 Nekton active swimmers

31 Benthos bottom dwellers Epifauna Infauna Nektobenthos

32 Meroplankton Larvae of meroplankton are derieved from virtually all animal phyla and from all different marine habitats Larvae of Decapod crustaceans, Bryozoa, Phoronida, Echinodermata, Porifera, Nemertea, Mollusca and Annelida

33 Meroplankton. Examples from several phyla

34 Role of Zooplankton in Aquatic Ecosystems and Significance to Humans Role in food webs Role in disease transmission Transmission of guinea worm in the tropics Transmission of pathogenic bacteria Importance in aquaculture

35 Microbial Loop & Relationship to the “Classical” Plankton Food Web

36 Guinea Worm (Dracunculus medinensis) Transmission in the Tropics http://upload.wikimedia.org/wikipedia/commons/2/27/Drac_life_cycle.gif

37 Transmission of Pathogenic Bacteria Harbor various types of pathogenic bacteria Vibrio species Vibrio cholerae Vibrio vulnificus Vibrio parahaemolyticus Vibrio alginolyticus

38 Importance in Aquaculture

39 Brachionus plicatilis (Marine) B. rotundiformis (Marine) B. calyciflorus (freshwater) Main Species of Rotifer Used for Rearing Larval Fish

40 Rotifers Fast growing and relatively easy to culture Still, too big for some marine fish larvae Pictures: vivo.library.cornell.edu/ servlet/entity?home=... Commonly used species: Brachionus plicatilis (~239  m) and B. rotundiformis (~160  m) Used in the rearing of over 100 spp. of fish and crustaceans

41 Are too Big to be Consumed by Larvae of Some Marine Fish (e.g. Red Snapper). –Large Strain (L)= 200 - 360 micron –Small Strain (S)= 150 - 220 micron –Super Small Strain (SS)= 94 - 163 micron Problem in the Use of B. plicatilis to Rear Larval Fish

42 Isolation and Culture of a Small Marine Rotifer, Colurella dicentra (Chigbu & Suchar 2006)

43 Copepods Harpacticoid Cyclopoid Calanoid Common in marine environments Principal diet of many marine fish larvae in nature High content in nutrients Size: 0.5 – 50 mm Difficult to mass culture (unpredictable yields) Only few sp. (Tigriopus japonicus) successfully mass cultured Pictures: www.woodbridge.tased.edu.au / mdc/Species%20Reg...

44 Zooplankton of the MCBs MCBs serve as nurseries for larvae and juveniles of many economically and ecologically important fish species Zooplankton are important components of the aquatic food webs Dynamics of zooplankton community in coastal aquatic ecosystems depend on many factors including climate variability, water quality & biotic interactions

45 Some environmental factors that regulate the abundance of zooplankton Mesozooplankton Community Structure & Dynamics Phytoplankton including HABs Occurrence & Dynamics Climate Variability Weather Land Use Planktivorous fish, Mysids & Ctenophores Microzooplankton Community Structure & Dynamics

46 Maryland Coastal Lagoons

47 Examples of Negative Effects of HABs (A. anophagefferens) on zooplankton Negative effect on growth of hard clam larvae (Padilla et al. 2006) Inhibit growth of some ciliates, e.g. Strombidium sp. (Caron et al. 2004, Lonsdale et al. 1996) Delay in copepod nauplii development; deterrence to grazing by copepod nauplii (Smith et al. 2008) Poor survival of copepodites of Acartia hudsonica and nauplii of Coullana canadensis fed unialgal diet (Lonsdale et al. 1996). Toxicity to copepod nauplii (Buskey & Hyatt 1995, Buskey et al. 2003) --- Aureoumbra lagunensis. Decrease in copepod egg viability (Felipe et al. 2006) ---- Karlodinium sp.

48 Need for Zooplankton Studies in MCBs As changes occur in the trophic state of the Coastal Bays, it is important to study and understand the impacts of such changes on zooplankton community. Information on the dynamics of zooplankton in the MCBs is very limited Monitoring of the mesozooplankton community

49 Objectives  Determine the assemblage/community structure of micro- and mesozooplankton in relation to water quality  Examine mesozooplankton mortality in situ, using a novel staining technique (Elliott & Tang 2009), under HAB and non-HAB conditions  Examine mesozooplankton feeding, growth rates and reproduction under HAB and non-HAB conditions

50 Objectives contd.  Quantify the size distribution, density and biomass of ctenophores Mnemiopsis leidyi relative to environmental factors  Examine using field studies and laboratory experiments whether ctenophores are having any significant effects on zooplankton community structure.

51 Methods of Collecting Zooplankton Samples Plankton Nets (Horizontal vs Vertical/Oblique Tows) Bongo Nets (Horizontal vs Vertical/Oblique Tows) Pumps Traps (e.g. Schindler-Patalas Trap)

52 Methods of Preserving Zooplankton Formalin (10% buffered) 70% Ethanol

53 Estimating Zooplankton Densities in Water Flow meter Record flow meter counts at the beginning & end of the tow, and find the difference Tow for about 3 minutes Estimate distance (m) covered during the tow Distance (m) = Diff. in counts X Rotor Constant 999999  Rotor Constant for flow meter (2030R) = 26,873  Vol. (m 3 ) = Distance (m) X area of the mouth opening of the net

54 Thank You!


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