Practical 1

• Land reclamation/coastal development

• Aquaculture

• Mechanic damage due to fishng and boats/gear

• Logging

• Climate change

—> species with a disproportionate influence on an ecosystem (relative to mass)

e.g. Predatio of mussels (Mytilus) by sea starts (Pisaster) enables complex communities; sea star removal leads to mussel monoculture

—> species which define much of the structure of a community

e.g. kelp forests, allowing the existance of a group of “obligate understory” species

Other examples are mangroves, salt marshes and seagrass meadows

1. Corals: 4-9%/yr

2. Seagrass: 2-5%/yr

3. Mangrove: 1-3%/yr

4. Salt marsh: 1-2%/yr

5. Tropical forest: 0.5%/yr

Warming ocean waters are a stressor for kelp forests slowing down their growth. Another species affected by higher temperatures are seastars, a natural predator of sea urchins. The latter feed on the stalks of kelp and due to a lack of predators they wiped out over 90% of kelp forests between 2008 and 2017. Sea otters, another predator of sea urchins, was hunted nearly to extincion by the early 20th century.

• Beam trawl

• Van Veen grab

• Box corer

• Line intersect transects (LITs)

• Counting frames

• Hyperspectral imaging 400-900nm

• eDNA/metabarcoding (extract DNA from water samples, or use biological homogenates of individually sampled organisms, or mixtures of species - use PCR)

• Microbenthos (<100µm)

• Meiobenthos (100 - 500µm)

• Macrobenthos (>500µm)

• Megabenthos (>1cm/>5cm)

pragmatic classification - boundaries are fuzzy

• Macrozoobenthos is long-living (several seasons/years) and integrates environmental information over time

• MZB is locally stable and shows effects of adverse phases even if these cannot be observed directly

• MZB is thus a good indicator of environmental health

DNA released from an organism into the environment

Massive parallel sequences of a mix of DNA sequences

Simultaneous DNA-based identification of many taxa found in the same environmental sample

1. Collect an environmental sample

2. DNA extraction from environmental sample

3. Amplufy DNA markers

4. High-throughput sequencing

5. Bioinformatic processing

6. Species identification

7. Ecological analysis

Protists: All single celled eucaryotes

Cyanobacteria: Phototrophic bacteria

• Phytoplankton: plant-type (O2-producing), photosynthesis

• Zooplankton: animal nutrition - particulate organic substance <— Microzooplankton/Protozoa

• Bacterioplankton: usually heterotrophic - nutrition by DOC, at Redox-interfaces also chemoautotrophic bacteria (more often in sediements)

• Mixotrophs

• Bacteria (prokaryotes)

• usually with chlorophyll a or divinyl-chlorophyll a & b (Prochlorococcus)

• phycobilins (hydrophilic pigments): phycocyanin, phycoerythrin

Some species:

• gas vacuoles

• nitrogen fixation

• filamentous cyanobacteris: Trichodesmium

• only flagellates

• two flagella of slightly diifferent length, both hairy

• found almost everywhere. but rarely dominant in the ocean

• chlorophyll a and c2

• olive, brown, red, blue - also phycobilins

• no cell wall

~99% of all microorganisms cannot be cultivated in the laboratory

• Eutrophication

• Climate Change

• Introduction of Alien species

• 1150km

• predominantly soft:

  • glacial sediments (clay, sand , gravel, boulders)

• characterized by fjords, sand drifts, beaches, coastal lagoons (Bodden)

Higher salinity input from the North Sea during Autumn and Winter due to storms

• diversity of species/functional groups

• substrate coverage

• annual productivity

• changes is parameters along gradient e.g. salinity

• differences between sites

• express similarity/dissimilarity of ecologically relevant functions due to different traits

• e.g. Mythilus: Large in size, massive growth form, suspension feeder, sessile

• generally more species present mean more functional groups

• more functional groups and more species per functional group make a communty more resilient to disturbance

• alpha: species richnes on panel

• beta: differences among panels assessed by alpha and gamma

• gamma: cumulated species richness on one site

relative amount of autotrophs to heterotrophs to total productivity

—> tells a lot about community/food web structure

A group of organisms occurring in a particular environment, presumably interacting with each other and the environment and seperable by of ecological survey.

• fundamental concept of ecology

• controversy on: Scope, Boundaries, Regulation

• wide variety of definitions

Descriptive statistics

• graphical presentation of communty patterns

Explorative statistics

• explorative description

• reduction of data complexity

Analytical statistics

• test of hypothesis

• parametric vs. non-parametric approaches

• regresson analysis

• “search for cause of patterns”

True natural patterns go through a sampling filter that is defined by multiple diifferent factors (gear, selectivity, number of samples, replicates, randomness)

—> observed patterns are different from true patterns

• Surface currents: Baltic outflow

• Deep currents: North Sea inflow

Summer: warming surface water —> shallow thermal stratification

Winter: cooling —> deep mixing: new nutrients in surface

The pycnocline

Compensation depth: depth at which 1% of the light intensity is left

Critical depth: depth at which net photosynthesis is positive

• oxygen depletion of at depth during summer startification

• salinity drop due to outflow of Baltic Sea (influenced by rivers (in summer)

• Spring bloom after mixing, rise intemperatures and increased light availability and small autumn bloom after stratification decreases

C : N : P — 106 : 16 : 1

106CO2 + 122H2O + 16HNO3 + H3PO3

• consumption/remineralization of nutriients in fixed stoichiometry

• production/consumption of oxygen

• production/connsumption of CO2

1. water column physics

   • stratification (temperature salinity)

2. Light

   • compensation light intensity (below or above pycnocline)

   • comparing k-values (light meter vs. Secchi Disk)

   • potential for light limitation

3. Nutrients

   • which macronutriient would limit growth if uptake is according to Redfield

   • are changes in oxygen related to T or S

   • do we see hypoxia (sat. <30%)

Abundance decreases with increasing cell size

Carbon fixation increases with increasing cell size

extinction coefficient, empirical equation: k = 1.7/Secchi depth

Because of objects in the water e.g.

• particles

• phytoplanktondissolved OM

• phytoplankton

• even water has a certain attenuation coefficient

When the mixed layer depth is < compensation depth —> bloom

1. Decrease in cell division in autumn

2. overgrazing and dilution due to deepening of mixed layer depth

3. depletion of grazer populations

4. by early winter depletion grazers exceeds light-limitation of cell division

5. bloom is initiated

6. concentrations remain low due to convective mixing

7. mixed layer stops deepening by the end of winter

8. phytoplankton and grazer concentrations rise in parallel

9. ecosystem feedbacks and light driven increase in division rate trigger bloom during spring stratification period

The latter is taking grazers into account

1E = 1mol of photons

usually in µE//s*m2)

• anything that is not deissolved

• produced in situ: phytoplankton, fecal pallets

• added: dust, wood particles, microplastic

• generally: more small particles than bigger ones

• highest in the surface —> due to phytoplankton

• sinking particles decrease with depth -> do not increase in the deep

• increase at seafloor due to suspension

• produced in different concentrations at different times of the year

• higher production during blooms (spring and summer)

• less production during absence of phytoplankton (winter)

—> single nucleotide polymorphism (SNP) as genetic marker

• different stocks/populations of different species have multiple SNPs that allow to distinguish between them

• only 8 SNPs (point mutations) aliow to discrminate cod stocks

Homology:

• homology of characteristics evolving from one ancestor (e.g. mammal extremities)

• genomes evolve through mutations

Alignments

• same thing on a genetic scale —> sequences that show similarities

• Basic Local Alignment Search Tool

• can search for matching sequences in large databases

• Method for DNA sequencing

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Meroplankton:

planktonic larvae of benthic organisms

Holoplankton:

live their whole life in the water column

Microzooplankton:

<0.2mm

Foraminifera, Copepod nauplii, Ciliates

water bottles, nets

Mesozooplankton:

0.2-20mm

Copepods, Pteropods, Decapod larvae

multinet, bongos net

Makrozooplankton:

>20mm

Polychaetes, fishlarvae, chaetognaths

RMT, MOCNESS

Light zone (photic): 0-100m

Twighlight zone (dysphotic): 100-470m

Dark zone (aphotic): >470

Arctic: strong summer bloom in phyto- and zooplankton when sea ice melted

North Atlantic: Strong spring bloom and weak late summer bloom

Tropics: shifted oscillation between phyto- and zooplankton

Polar:

• low diversity -> low species in high abundances

• most species with large oil sac or droplets

• mainly calanoid copepod species

• Arctic: Calanus species

• Antarctic: calanoids euphausiids

(Sub)tropics:

• many species in low abundances -> high diversity

• most species: small, no oil sac or oil droplets

• mainly cyclopoid copepod species

Shelf:

• few species, low diversity

• mainly smaller speciies -> few large taxa

• e.g. cladocera, meroplanktonic larvae

Oceanic:

• more species, higher diversity

• no to very few meroplanktonic larvae

• e.g. siphonophora, pteropoda, ostracoda

• over 100.000 species

• 35-50% of oceanic primary production

• 20-50% of global oxygen production per year

• assimilate over 6.7 billion tons of silicon per year

• distribution: ubiquitous: plankton (centric) & benthos (pennate) -> oceanic, coastal and fresh water

• silica cell wall -> more stability (grazing, abiotic factors)

• advanced photo system

• large central vacuole

• efficient nutrient uptake and recycling system

• resting stages

• efficient CO2 uptake system

• biochemcal defense system

• forms foam at the shore

• adaptive response to predation pressure due to size

• may experince lower nutrient uptake

• skin like structure: virus protection

• mucus: Mn & Fe storage

• single cells:

  • over-wintering strategy

  • mixotrophy (ingesting bacteria or other small particles)

  • inefficient food source for mesozooplankton

Phaeocystis

• have coccoliths (calcified plates that form coccosphere/exoskeleton) -> not all species calcify at all stages

• 5-100µm

• mostly sperical

• ecological success due to increased defense, buoyancy control, protection from UV damage

• involved in the BCP and CCP

• asexual through meiosis and mitosis

• 2 distinct phases:

  • haploid/holococcolith stage (thin)

  • diploid/heterococcolith stage (thick)

Protists: unicellular, eucaryotic organisms

Metazoa: all multicellular organisms

—> heterotrophic and mixotrophic organisms between 20-200µm

• links samller phytoplankton and larger Mezozooplankton

• key composer of microbial loop

• consumption: 75% of particulate primary production -> 50% of plankton biomass/day

• control pico- and nano sized flagellate abundances

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• species identification

• individual examinations (stomach content, diseases, parasites)

• gain better understanding of interrelationships of structure and function, evolutionary pathways

• Mouth

• Eyes

• Nares (Nostrils)

• Operculum

• Spiny dorsal fin

• Soft dorsal fin

• Caudal (tail) fin

• Pectoral fins

• Pelvic fins

• Scales

• Vent

• Anal fin

• Lateral line

• Peduncle

Red muscle:

• steady constant-effort swimminng

• well supplied with oxygen

• londitudinal arrangement

White muscle:

• anaerobe

• quick bursts of movement (escape/hunt)

• helically arranged

pink muscle:

• intermediate form

• series of muscle blocks -> myotomes

• myotomes -> seperated by connective tissue -> myosepta

• horizontal septum seperates myotomes -> dorsal and ventral

Esophagus:

short and expandable -> walls are layered with muscle

Stomach:

in most bony fishes (not all) -> usually bent musculat tube (U or V shape)

gastric galnds -> release substances: break down food, preparation for digestion

pyloric caecae -> blind sacs at posterior part

Intestine:

nutrient absorption -> length varies greatly

herbivorous -> long, coiled intestines -> food is harder to break down

carnivorous -> short intestine

pancreas -> secretes anzymes into intestine for digestion

• gas filled bladder

• in most bony fishes

• originally developed as respiratory organ (from lung of lung fishes)

• neutral buoyancy

• some fish: can function as sound amplifier

• developes in later live stages and is filles with oxygen by gas gland

  • O2 diffusion from venous to arterial capillaries

  • pO2 (blood) > pO2 (bladder)

  • production and release of lactate and CO2 inside gland cells

  • root effect: lower O2 binding capacity of fish hemoglobin/O2 transport agains gradient

two chambers -> atrium (bulbus arteriosus) and ventricle (sinus venosus)

Hearing

connected to ear via slim air ducts -> 360 species of clupeiformes

• bone reduction

• squalene enriched liver oil

• fine tuning lipid content

• active swimming

• fin positioning

• extracellular enrichment of lipids

Red: pelagic

white: benthic

• 4 gills on each side

• protected by operculum

  • held by bony arches (have gill rakers wiith hooks)

  • act like sieve (dense when plankton feeders)

• high amounnt of lamella

• large surface area for respiratory exchange (diffusion)

• endothermic: maintain temperature higher than surroundng water

• net of arteries and veins -> counter current exchange system

• heat of venous blood -> allows more efficient muscle use

• heat conservation from normal metabolism

Osmolytes:

• maintain integrity of cells

• amino acids and derivates, urea, etc.

• TMAO -> trimethylaminooxid

• Osmocomformer and Osmoregulators

Euryhaline:

• tolerate wide range of salinity

• need osmosensors

Salt water:

Gills are primary site of net sodium and chloride transport

Fresh water:

Gills, kidneys and digestive tract = maintenance of body fluid balance

• Lateral line

  • current detection

  • somatotopic maps

• ampullae of lorenzini

  • detect (or create) electric fields

  • modified hair cells

Bony fish:

• External fertilization -> Ovipary

  • large number of eggs

  • larval stage

  • dispersion

  • some exceptions known: seahorses, eelpout

Cartilagenous fish:

• internat fertilization -> Ovovivipary

  • embryo develops within a layed egg

  • large yolk

  • fewer eggs needed

• Internal fertilization ->

  • embryo develops within uterus

  • more protection

  • direct nutrient supply from parent

—> mor parental care -> higher aurvival rate -> less offspring needed