MS111

Week 1: Evolution and Biodiversity

Key Words

marine biodiversity: the variety of life in our ocean

biodiversity hotspots: areas of high biodiversity that support processes such as nurseries, spawning, or feeding

functioning ecosystem: the natural processes are working effectively

Key Concepts

The earth formed 4.5 billion years ago.

Photosynthesis began more than 2.5 million years ago with the Great Oxidation Event.

Marine biodiversity allows our oceans to be productive, resilient, and adaptable.

Fishing has had the greatest impact on marine biodiversity in the last 50 years.

Major risks to biodiversity are bycatch, invasive species, pollution, overfishing, and climate change (BIPOC).

Week 2: Oceanography & Bathymetry

Key Words

oceanography: the study of the physical, biological, geological, and chemical properties of the sea

continental margin: stretches out as far as the eye can see and has 3 aspects; the shelf, slope, and rise

shelf: an underwater landmass that extends from a continent, resulting in an area of relatively shallow water known as shelf sea

slope: the area between the shelf and rise that has a steep grade and irregular erosion by currents, forming valleys and canyons

rise: found between the slope and the abyssal plain

volcanic islands: form when a volcanic eruption rises above the surface and forms an island

seamounts: undersea mountains formed by volcanic activity that do not reach the water’s surface

Deep sea trenches: deep, V-shaped trenches

mid-ocean ridges: mountain chains in the middle of the oceans

atolls: a ring-shaped coral reef including a coral rim that encircles a lagoon partially or completely formed when an extinct volcano or seamount has eroded partially beneath the water

abyssal plain: the ocean-basin floor, made up of abyssal hills

abyssal hills: a small hill that rises from the floor or an abyssal plain

Key Concepts

The continental margin is made up of the continental shelf, slope, and rise.

The continental rise can be shared between two countries: In the Timor Sea Oil and Gas Treaty, both Australia and Timor-Leste have legitimate sovereign rights over the gas fields in their continental rise. They share the benefits.

Abyssal hills are the most abundant geomorphic structure on earth

Week 2: Ocean Currents and Heat Distribution

Key Words

Coriolis effect: the deflection of moving objects (to the right in the northern hemisphere and left in the southern hemisphere) caused by the rotation of the earth tilted on its axis

convection currents: a cycle of movement in fluids (liquids or gases) caused by the uneven heating of the fluid

gyres: a large system of rotating ocean currents, driven by wind patterns and the earth's rotation, typically found in the major ocean basins

thermohaline circulation: a global ocean circulation pattern driven by differences in water temperature and salinity, which affects the density of seawater and influences deep ocean currents

flood current: tide coming in

ebb current: tide going out

spring tides: occur when the gravitational pull of the sun and the moon are combined and the tides are at their highest

neap tides: occur during a first quarter moon and again at a last quarter moon phase, the sun is at right angles to the moon

Antarctic circumpolar current: the powerhouse for global climate, connecting the Atlantic, Pacific, and Indian oceans in an eastward flow and features a region of high nutrient production south of Australia

Ekman transport: the net movement of water at an angle to the direction of the wind due to the Coriolis effect, resulting in a spiral pattern of water movement

Ekman spiral: the gradual change in direction and speed of ocean water layers with depth, where each successive layer moves at a greater angle to the wind, creating a spiral effect in the water column

upwelling: ekman transport moves surface waters away from the coast and they are replaced by the water that wells up from below

downwelling: ekman transport moves surface waters toward the coast where it piles up and sinks down

el nino: the trade winds’ push on the ocean surface falls and warm water that was once driven westward now runs back towards the central pacific, causing hot air to rise and split the trade wind circulation pattern. Stops upwelling in Peru

la nina: easterly trade winds push large amounts of warm water across the pacific causing upwellings in Peru and a monsoon in Australia

Key Concepts

Unequal heating of the earth happens because the sun’s rays hit the earth at a perpendicular angle at the equator, causing warmer temperatures as less heat is dispersed. The sun’s rays hit earth parallel to the poles, causing more heat to be dispersed making cooler temperatures.

Heat distribution: heat is distributed around the earth by currents pushing warmer waters from the equator toward the poles and back.

Heating at the equator causes air to rise which creates areas of low pressure. That hot air moves towards the poles where it cools and sinks, creating areas of high pressure.

Surface currents are driven by wind and deep water currents are driven by differences in density.

Gyres are located in the Indian Ocean, North Pacific, South Pacific, North Atlantic, and South Atlantic.

Thermohaline circulation: The sun heats water north of the equator in the Atlantic and drives it from the Gulf Stream towards northern latitudes, distributing heat into the atmosphere in the poles. This loss of heat to the atmosphere causes the water to cool and sink as it is more dense. More warm water is transported north and pushes this cooler water down along the ocean floor to Antarctica. Eventually, the cold bottom waters return to the surface through mixing and wind-driven upwelling, continuing the conveyor belt around the globe.

Tutorial Questions

Discuss the factors that affect ocean currents:

• Heat from the sun on the ocean alters the density of the surface water by changing its temperature

• Coriolis effect modifies the course of ocean currents by deflection to the right in the northern hemisphere and to the left in the southern hemisphere

• Wind drives surface currents

• Density drives deep currents

Why are ocean currents important?

• Nutrient distribution through upwelling and downwelling

• Currents help regulate the earth’s temperature by distributing heat to the poles

• Water turbines get energy generation from the currents

Characteristics of gyres:

• large, circular ocean currents formed by the Coriolis effect and global wind patterns

Week 3: Marine Geology

*different setup because this unit was not focused on by Prasad*

Tutorial Questions

Describe, with the aid of diagrams, the basic characteristics of a wave

• crest: the highest point of a wave

• trough: the lowest point of a wave

• wave height (H): the vertical distance between the crest and the trough

• wavelength (L): the distance between two successive crests

• 
  

  

Explain longshore drift:

Longshore drift is when the currents hit the beach at an angle and carry sand and sediments down the beach, creating things like sandbars.

Briefly explain the difference between an eroding beach and an accreting beach:

eroding beach: during storms, the sandbar from the longshore drift moves further out to sea fed by sand from the dunes

accreting beach: when calm weather moves sand onto the beach by wave bores and they deposit layers in micro ridges

Describe the different types of plate boundaries:

Divergent plate boundaries are when plates move away from each other, causing earthquakes and mid-ocean ridges. Convergent plate boundaries are when plates come together, causing mountain ranges or seafloor trenches. Transform plate boundaries are when the plates slide past each other and create fault zones.

Provide evidence for plate movements:

• most earthquakes originate in areas where plates collide

• the ocean floor near ocean ridges has very little sediment buildup because this is where the ocean floor is spreading and the new crust is being formed

• continents have been measured to be moving apart at 3 cm/year

• volcanic island chains in the Pacific show movement of the ocean floor

Why are biogeochemical cycles important?

Biogeochemical cycles such as the water or carbon cycle are crucial for maintaining the balance of ecosystems, supporting life by recycling nutrients, and regulating climate. They help ensure that living organisms have access to the necessary resources for growth, reproduction, and survival.

Give an example of a biogeochemical cycle and describe how it works:

The water cycle is the continuous process through which water moves between the Earth's surface and the atmosphere. It begins with evaporation, where water from oceans, rivers, and lakes turns into vapor and rises into the air. As the vapor cools, it condenses to form clouds through condensation. Eventually, the water falls back to the surface as precipitation, such as rain or snow. This water then flows into bodies of water, infiltrates the ground, or is taken up by plants, and the cycle repeats.

List the major plates of the world:

• African

• Antarctic

• Eurasian

• Indo-Australian

• Pacific

• South American

Provide examples of the three plate boundary interactions:

• Divergent: mid-Atlantic ridge

• Convergent: Pacific Ring of Fire

• Transform: San Andreas Fault Line

Week 4: Classification & Marine Biodiversity

Key Words

taxonomic key: uses a choice of characteristics to differentiate a species or other taxonomic ranks (present or absent, round or square)

pelagic habitat: water column

benthic habitat: reefs, seagrass beds, mangroves, sediment

primary production: organisms, such as phytoplankton and seaweed, that convert sunlight or inorganic compounds into organic matter through photosynthesis or chemosynthesis, forming the base of the marine food web

Key Concepts

The order of the taxonomic ranks is: Kingdom, Phylum, Class, Order, Family, Genus, Species.

Defining biodiversity is important for ocean understanding, utilization (e.g. fisheries), conservation (e.g. of endangered species), and management (e.g. human influences and assets).

Tutorial Questions

What is classification and why is classifying organisms important?

Classification is grouping organisms according to their likeness and special traits and it is important for keeping track of organisms that have been discovered and identifying possible new species that are discovered.

Why does each organism need to have an acceptable scientific name?

Each organism needs an acceptable scientific name so it can be recognized worldwide, no matter what language is being spoken in that area. The scientific names are worldwide standardization.

Describe the binomial nomenclature:

Binomial nomenclature is identifying organisms by their genus and species. Genus comes first and has a capitalized first letter. Species come second and is all lowercase. Both words are italicized.

Describe the three levels of biodiversity:

• Genetic diversity: the variety of genes within a species

• Species diversity: the number of different species and the abundance of each species within a given area

• Ecosystem diversity: the variety of ecosystems in a particular region, including the different habitats, communities, and ecological processes that support various forms of life

Describe one ecosystem function of any ecosystem (asking how an ecosystem can benefit humans):

Mangroves root themselves in coastlines and are the first line of defense when it comes to tsunamis. They protect the inland land and help prevent erosion.

Week 4: Plankton

Key Words

plankton: a diverse collection of organisms that live in the water column and are unable to actively propel themselves against currents

phytoplankton: plant-like plankton

zooplankton: animal-like plankton

diatoms: unicellular phytoplankton encased in a siliceous cell wall, often live in aggregations

dinoflagellates: unicellular phytoplankton with flagella that help them move

meroplankton: organisms that spend only part of their lives in the plankton

holoplankton: organisms that spend all their lives as planktonic

Key Concepts

Phytoplankton are primary producers and directly influence the trophic levels above them, known as bottom-up control.

Factors contributing to phytoplankton success:

• Photosynthesis: efficient conversion of light energy into chemical energy

• Growth: rapid reproduction rates that enhance population dynamics

• Resource acquisition: effective strategies for obtaining nutrients and light

• Grazer avoidance: adaptations to minimize predation and infection

Organisms like copepods and most shrimps are holoplankton, whereas barnacles, lobsters, and crabs are meroplankton.

Copepods are the most abundant animal in the ocean.

Diurnal vertical migration of copepods is when copepods spend daytime in colder, deeper waters to avoid predators and conserve energy…and they spend nighttime at the surface where they are less likely to be eaten.

Week 5: Seawater, Seawater Chemistry & Seawater Conditions

Key Words

solute: the salt dissolved in water

concentration: grams per liter of the solute

conductivity: how well electricity travels through water

refractometer: a handheld device that measures the change of direction or bending of light as it passes from air to water

isohaline: lines on a figure that join places of the same salinity

thermocline: changes in temperature with depth

pycnocline: changes in density with depth

halocline: changes in salinity with depth

pH: potential of hydrogen is a measure of the acidity of a substance

ocean acidification: worldwide reduction in the pH of seawater as a consequence of the absorption of large amounts of carbon dioxide by the oceans

polar covalent water molecule: two electrons shared but not shared equally in the asymmetrical molecule

hydrogen bond: bond between hydrogen and some electronegative atom

surface tension: when air meets upper layers of liquid water the hydrogen bonds are strong and make a type of tense skin on the water

viscosity: the resistance of a liquid flowing through or passing an object

density: the number of grams of a substance found in a given volume

heat capacity: the ability of water to resist temperature change

salinity: how much of dissolved salts are present in a body of water

diffusion: the process where particles move from an area of higher concentration to an area of lower concentration until they are evenly distributed

latent heat of vaporization: the amount of heat needed to convert liquid to gas at a constant temperature

latent heat of melting: energy needed to turn solid to liquid

ionization: process of breaking apart ions (electrical charges)

Key Concepts

Seawater’s unique characteristics are that it is an excellent solvent, has a high heat capacity, has variable density, and can absorb light.

Dissolved gases enter the ocean from the atmosphere by a process called diffusion, or are released from animals and plants that live in the ocean.

Concentrations of oxygen and carbon dioxide vary according to the biological processes such as photosynthesis and respiration. Nitrogen values remain fairly constant.

Aerobic organisms need oxygen to extract energy from organic molecules and dissolved carbon dioxide is necessary for autotrophic nutrition.

Temperature gradients within the ocean determine where most animals and plants will live. The temperature controls the metabolic rate of all cold-blooded animals and controls distributions of warm-blooded animals who are poorly adapted to change in temperature.

Light entering the ocean is absorbed and converted to heat.

Red light is absorbed by the ocean first with blue and violet light penetrating the furthest.

Marine plants that photosynthesize are limited to live only in the photic zone.

A covalent bond in a water molecule links one H to the O.

A hydrogen bond in water molecules links one H from one water molecule to an O in a separate water molecule.

A water molecule is polar because the negatively charged electrons are not shared equally in the asymmetrical molecule.

Water that has dissolved salt in it will conduct electricity better than water with no dissolved salt.

The more salt in the water, the slower light moves.

The biological significance of temperature:

• animal migrations occur due to temperature

• whales migrate to warmer waters to calf

• corals spawn at certain temperatures and the composition and texture of marine animals and plants are governed by temperature

• animals that live on the rocky shores also develop protective coverings to compensate for temperature changes

Basics of ocean acidification:

• the worldwide reduction in the pH of seawater as a consequence of the absorption of large amounts of carbon dioxide by the oceans

• largely the result of vehicles, industries, and agricultural practices loading the atmosphere with CO2

• the pH declines, making the ocean more acidic

• increased acidity reduces the concentration of carbonate ions and the availability of aragonite (a significant source of calcium carbonate). Organisms that use carbonates (coral, shellfish, and other marine calcifiers) will have less available materials to maintain their skeletons and shells

Tutorial Questions

What special properties does polar covalent bonding give water?

• enormous ability to dissolve substances

• high heat capacity

• multiple physical states (gas, liquid, solid)

• high latent heat of vaporization

• viscosity

• surface tension

State the salts in seawater and their origin:

NaCl, MgCl2, (NaSO2)4, KCl, and CaCl2 come from runoff from land rocks or coming up through cracks in the seafloor.

Explain why icebergs float in seawater:

Ice is less dense than water because salt is excluded when ice forms. Less salt equals lesser density. Less dense water will float while more dense water will sink.

State what an Oxygen Minimum Zone is and explain how it is formed:

Persistent layers in the water column that have low oxygen concentration due to biological, chemical, and physical processes. Stratification allows these layers to persist over large stretches of geological time. This zone forms where the oxygen is consumed by the decomposition of sinking organic matter faster than it can be replenished due to limited mixing. Also called dead zones.

Week 6: Marine Plants

Key Words

infauna: species that spend most or all of their adult life within the substrate, boring into hard substrates or burrowing in soft sediments

epifauna: animals that may move over, or are attached to, hard or soft substrates

primary production: rate of photosynthesis or chemosynthesis

seagrass roots: anchor the seagrass and absorb nutrients

seagrass rhizomes: part of seagrass that spreads beneath the sediment to store nutrients and help the seagrass propogate

epiphytes: organisms like algae, bacteria, and small invertebrates that grow on seagrass leaves, competing for light and nutrients

epifauna: animals such as crustaceans, molluscs, and worms that live on seagrass leaves and sediments, grazing on epiphytes to prevent overgrowth and promote nutrient cycling

mariculture: the farming of seaweeds

phycocolloids: gelatinous chemicals produced by seaweeds that are used in food production and product manufacturing

Key Concepts

Mangrove distribution is controlled by climate, salinity, tidal fluctuation, sedimentation, wave energy.

Mangrove ecological functions:

• transitional zones: mangroves thrive in areas that are neither terrestrial or aquatic

• provide shelter

• serve as nursery spots

• sink many contaminants before reaching the ocean

• highly productive area

• sites for accumulation of carbon, nutrients, and sediments

Mangrove anthropogenic services:

• provide wood

• protect inland areas from tides and hurricanes

• host many species of fish

• provide food and medicine resources

Mangroves trap contaminants (including heavy metals) from land before they reach the marine environment. This is why they are called “sinks”.

Challenges that mangroves face include:

• construction

• deforestation

• overfishing

• sea level rise

• temperature rise

• salinity rise

Seagrasses are primary producers. They utilize sunlight or chemical nutrients as a source of energy to produce organic matter from CO2 usually by photosynthesis.

Factors affecting primary productivity:

• light: essential for photosynthesis (aka productivity)

• nutrients: essential for the growth of seagrass, which makes them stronger and able to do more photosynthesis

• hydrographic conditions: conditions like temperature and salinity can promote or hinder growth

• currents: transport producers to different areas

• upwelling: increase in nutrients increases productivity

• vertical mixing: distribution of oxygen and nutrients throughout the water column supports growth and overall productivity

Week 7: Phylums Protozoa and Porifera

Key Words

open circulatory blood system: moving blood flows from the vessels and into the sinuses, bathing the internal organs and eventually seeping back to the heart

closed circulatory blood system: the blood remains in the vessels following a specific path- heart to arteries to capillaries to veins to heart (hacvh- heart apple cider vinegar heart)

radial symmetry: can be divided into similar halves by multiple planes that pass through a central axis (a starfish looks the same when cut in any direction)

bilateral symmetry: can be divided into two mirror-image halves along a single plane, usually with a distinct left and right side (like a crab)

Key Concepts for Protozoa

Domain: Eukarya. Kingdom: Protista. Phylum: Protozoa

- Class Rhizopoda (Amoeba):

• Amoeboids are characterized by pseudopodia or cytoplasmic extensions

• They have holes called foramina

• Amoeboids are constantly moving so pseudopodia are not fixed, they can recede back into the main body and then extend when needed

• Consume prey by phagocytizing: pseudopodia take in prey and then direct it to the cell’s food vacuoles

• Consume algae, bacteria, or other protozoans

• Marine amoebas include foraminiferans and radiolarians

• They have pores in their outer membrane through which the pseudopodia passes through to extract food

• They have a chalky carbonate shell (or test) that sinks to the bottom after the animal dies forming a fine sediment known as “ooze”. Ooze forms chalk and silicon beds. Fossilized ooze can be used to measure climate from long ago because the shell changes with water temperature

-Class Ciliate and Flagella

• CILIATE

• cilia: special hairs used for movement and feeding

• gullet: specialized opening that is a channel/funnel for feeding

• digestion occurs in vacuoles

• nutrients absorbed into cells and residue goes out through the anal pore

• FLAGELLATA

• flagellum: whip-like hairs called flagella used for locomotion

• lifestyles include autotrophic, heterotrophic, parasitic, and symbiotic

• may be solitary, colonial, free-living, or parasitic (parasites live in the bloodstream of the host, and many others live as plankton)

• a comparison of a ciliate and a flagellate:

Key Concepts for Porifera

Domain: Eukarya. Kingdom: Protista. Phylum: Porifera

Phylum Porifera only has sponges

-Sponges:

• have many pores and cells but no organs

• filter food particles from water

• skeletal structure consists of limestone or silica spines

• attached to seafloor on rocks, sea plants, shells of animals, and artificial structures

• found at all depths

• brightly colored

Tutorial Questions

Differences in structural characteristics between Porifera and Protozoa:

Week 7: Cnidaria

Key Words

medusa: basic cnidaria body form that is umbrella-shaped with the mouth/anus opening pointing down

polyp: basic cnidaria body form that is cylindrical and has the mouth/anus opening at the top

nematocysts: stinging cells

fission: intratentacular reproduction; the mouth forms new polyp within the original ring of the parent tentacles, division of existing polyps

budding: extratentacular reproduction; new polyp is formed outside the original ring or parental tentacles from tissue between existing polyps

brooding: asexual production of planula larvae genetically identical to parent colony

fragmentation: breakage of smaller sections of a coral colony, new polyps can grow over the substrate they land on creating a new colony

mass spawning: when many coral colonies release their eggs and sperm into the water at the same time, usually synchronized with environmental cues like lunar phases or water temperature

Key Concepts

Phylum Cnidaria includes corals, jellyfish, gorgonians, soft corals, anemones, and sea pens.

Cnidaria are sac-like animals with body plans arranged in a circle and a sac at one end with two cell layers and stinging cells.

Cnidarians are radially symmetrical. They may be attached by means of a basal disc to form a polyp like corals or may drift in the water as a free-swimming medusa, like a jelly.

Three tissue types are outer epidermis, middle mesoglea, and inner gastrodermis.

Corals reproduce asexually by budding and sexually by mass spawning events.

-Class Anthozoa (sea anemones)

• the tentacles are connected to a mouth which leads down to a hollow gut which is where food is digested

• wastes are ejected out of the mouth

• sea anemones can move by sliding on their basal disc or by somersaulting from place

• reproduce by growing small buds on their sides or by producing eggs and sperm from inside their gut

• anemones can retract during low tide or to eat their prey using strong retractor muscles located in the body wall

-Class Anthozoa (corals)

• corals secrete a calcium carbonate base when they grow, leaving it behind when they die for new coral polyps to grow on. so, reefs are made of dead coral with a thin layer of living corals and animals on the outside

• four main requirements for corals:

  • clear water to get light

  • low nutrients

  • stable salinity

  • a hard surface to grow on

• soft corals lack a hard skeleton and protect themselves by secreting chemicals called terpenes. soft corals have eight fringing tentacles with each tentacle having side branches giving it a feathery appearance.

• sea fans are like soft corals but the polyps are supported by a substance called gorgonium. They often protrude out from coral mounds

• hard corals are classified by their appearance (boulder, branching, table, etc)

• polyps extend from coral to feed at night when zooplankton are most active. they use their tentacles armed with nematocysts to catch prey. nutrients are passed between polyps after feeding and the limestone base is added slowly as a result of the polyp absorbing calcium carbonate from seawater

• algae (zooxanthellae) help coral promote calcium materials and growth while the corals provide them a place to live and some nutrition from polyp waste.

• planula larvae are ciliated larvae which are fertilized during mass spawning and then drift for days or weeks until settling down to root and grow

-Subclass Octocorallia, Order Pennatulacea (sea pens)

• sessile plankton feeders

• colonial organisms

• polyps have specialized functions: stalk, water intake, feeding, reproduction

-Subclass Octocorallia, Order Helioporacea (blue corals)

• massive lobed calcium carbonate skeleton

• only octocoral to produce massive skeleton

• blue skeleton, brown polyps

-Subclass Octocorallia, Order Gorgonacea (gorgonians)

• sessile colonial polyps with horny skeleton

• some with zooxanthellae

-Class Scyphozoa (jellyfish)

• symbiotic zooxanthellae

• medusa stage occupies main part of the life cycle but they still develop from a polyp

-Class Hydrozoa

• medusa and polyp stages

• solitary and colonial (multiple connected polyps)

• polyps connected by chitinous stalk

• feathered polyps

-Class Hydrozoa (bluebottle)

• form colonies of specialized individual cells; each has function like feeding, reproduction, digestion, floating

• trailing tentacles over 10 m long

• severe sting

-Class Hydrozoa (Portugese Man O War)

• Order Siphonophora

• colonial organism made up of 4 types of polyps/medusa

  • sail, defense, reproduction, feeding

• severe sting

-Class Hydrozoa (Hydroids)

• colonial with multiple polyps connected by chitinous tube-like structures

• feather of fern-like appearance

• a significant portion of life stage in both polyploid and medusoid stage

• severe sting

-Class Hydrozoa (fire corals)

• not true coral

• colonies with calcareous exoskeleton

• symbiotic zooxanthellae

• severe sting

-Class Hydrozoa (lace corals)

• not true coral

• colonies with delicately branched skeleton

• polyps differentiated for specific functions like predation and defense

-Class Cubozoa (box jellies)

• medusa form is cuboidal with groups of tentacles from each edge

• some deadly

• large, transparent, bell-shaped bodies up to 30 cm across, each with a large, trailing clump of tentacles up to 4 m long, containing millions of nematocysts

-Class Staurozoa (stalked jellies)

• no alteration between medusa/polyp forms…they are in a medusa stage that is attached by a stalk

• common in cold water

Tutorial Questions

Structural characteristics for Cnidaria:

Week 8: Ctenophore, Annelida, and Mollusca

Key Words

chemosynthesis: chemical-based food-making process for marine worms

anterior: front

posterior: back

dorsal: top

bottom: ventral

ctenidia: gills

radula: modified mouth piece that scrapes food off rocks

veliger: planktonic stage of Mollusca

Key Concepts (Ctenophore)

Characteristics:

• radial symmetry

• rows of cilia that beat in a comb-like manner

• free-swimming and part of the plankton family

• tentacles

Key Concepts (Annelida)

Characteristics:

• worm shape

• segments with bristle appendages

• head with eyes and tentacles that are reduced in tube-dwelling form

Marine Worms:

• survival depends on symbiotic relationship with billions of bacteria that live inside them, converting chemicals into food for the worm

• no mouth or digestive tubes, they absorb food thru skin

Class Polychaeta:

• includes free-swimming, tube-dwelling, and burrowing

• marine worms that live in and under rocks, corals, shells, or on the backs of other animals

• leg-like bristles along their length

• 4 distinct part: anterior, posterior, dorsal, and ventral

• anterior has mouth and sensory parts

• middle regions have digestive and reproductive parts

• posterior is for excretion

• pharynx can be everted to catch prey and teeth can be seen

• importance: process dead and decaying matter, aerate mud, and filter food

• source of food for mud flat birds

• can be gonochoric (separate sexes) or be hermaphroditic (both male and female reproductive organs)

• once fertilized, eggs change into free-swimming larvae and drift in the plankton until they grow into adults and settle on sea floor

Key Concepts (Mollusca)

Characteristics:

• head and foot

• mantle": tissue membrane that either lines the shell or covers the soft body

• bilateral symmetry

• ctenidia (gills)

• no segmentation

• soft body covered with shell

• foot can fix body to rock for protection

• radula is a modified mouth piece that scrapes food off rocks. in carnivorous molluscs, radula can bore into other animals like oysters. other molluscs filter feed by drawing water into their bodies through siphons

• food goes from mouth to digestive tract to anus

• molluscs breathe through gills located in the mantle on top of the foot. muscular contractions suck in water and drawn over gills’ surfaces where oxygen is extracted

• two-chambered heart pumps oxygen-rich blood from the gills to a single aorta which branches into smaller blood vessels then leaks out into body. it’s returned to gills then back to heart (open blood system)

• cellular waste is removed by a kidney that excretes them into the mantle cavity

• a nerve ring with two pairs of nerve cords that operate the foot and the organs

• mainly male and female molluscs, some are hermaphroditic though

• sperm and eggs are produced by gonads. a planktonic stage called veliger emerges from the eggs. they feed by rows of cilia which move food to a food groove by mucus

Class Amphineura:

• Chitons

• 8 sections to shell

• cling to rocks in surf zone

• slow moving herbivores, graze on algae

• only male and female chitons

• sperm and eggs are released into water where they fertilize and drift with the plankton

Class Gastropoda:

• largest class

• spiral shell

• Torsion: a developmental process where the body twists 180 degrees, moving the anus and mantle cavity to the front, affecting their internal organ arrangement.

• includes whelks, limpets, nudibranchs, periwinkle

Class Gastropoda (mud whelks):

• live in muddy areas like mangrove swamps

• feed on plankton and debris from dead organisms

• mouth is ventral with outer and inner lip that can be closer with a cap called an operculum to stop predators or to stop drying out

Class Gastropoda (cone shells):

• Dangerous to humans

• venom gland inside shell

• prior to stinging, the radula teeth are released into the pharynx and from there into the proboscis which has a venomous tooth. venom is then forced down the venom duct and into the pharynx to kill prey

Class Gastropoda (nudibranch):

• “naked gills”

• tail end has gills that allow oxygen exchange

• front end has pair of tentacles called rhinopores and sensitive chemical receptors for prey

• covered in papillae that secrete noxious chemicals for protection from predators

• feed on hydroids which contain nematocysts. nudibranch can separate stinging cells from the hydroid in their digestive tract then move them to their own skin for protection

Class Bivalvia (bivalves):

• oyster, clam, scallop

• pearls from genus Pinctada

• two shells are hinged and open/close with muscles

• giant clam has a unique relationship with zooxanthellae which make the food for the clam as they photosynthesize

• some bivalves attach themselves to rock or burrow in the sand

• commercial importance (human food)

• suspension feeders: filter water for edible particles with its cilia on the gills

Class Cephalopoda:

• octopus, squid, cuttlefish, nautilus

• group of tentacles around the mouth

• highly developed eyes and large brain

Class Cephalopoda (octopus):

• 8 arms

• live in rock pools

• can flatten body

• can squirt ink and use jet propulsion to escape predators

• eat crabs which they break up with their beaks inside their mouths

• suction discs on arms

• camouflage

Class Cephalopoda (squid):

• largest invertebrate is giant squid

• live on continental shelf

• have a long, elongated body with triangular fins extending along a quarter of the body

• common Pacific squid will congregate and mate in large groups

• males approach a female with arms and tentacles ablaze with red and white markings changing to solid maroon when copulation occurs

• male picks up sperm packet (spermatophore) with its tentacle and transfers it to the female’s mantle cavity where the eggs are fertilized

• female produces long cases containing eggs where they develop and emerge as juveniles

Class Cephalopoda (pearly nautilus):

• active at night and rests during the day

• gas-filled chambers keep the shell upright

• can dive to 600 m

• swims by ejecting water through a siphon by the contraction of muscles in the mantle

• only cephalopod that can contract itself into its shell and seal itself with its hood

• eat crabs and fish

Tutorial Questions

What is the biological importance of marine worms?

• Marine worms process dead and decaying matter, aerate mud, and filter food

What structural characteristics do cephalopods have that make them adaptable to any environment?

• tentacles and arms: grab prey

• no skeleton: gives them flexibility

• siphon/funnel: pumps water and allows for jet propulsion

• chromatophores: used for camouflage

• beak: consuming and ripping apart prey

Week 8: Arthropoda and Echinodermata

Key Words

vertical migration: when copepods spend the day in deep, dark waters and move towards the surface at night

chitin: the substance that makes up the arthropod exoskeleton

Artemia: brine shrimp used for feed in aquaculture

water vascular system: a unique system of water-filled tubes found in echinoderms that assists with locomotion and feeding

Aristotle’s Lantern: sea urchin jaw that consists of five plates of calcium carbonate that is moved by sets of muscles

Cuvier’s organ: this organ in a sea cucumber shoots sticky tubules out of the sea cucumber’s anus to confuse or trap predators while the cucumber escapes

lamellar epipodites: fibrous, feather-like plates on the legs of Artemia that allow for respiration

cirri: a barnacle’s modified legs that it uses for feeding

nauplius: the first larval stage of a prawn

zoea: the second larval stage of a prawn

mysis: the final larval stage of the prawn

ossicles: plates of calcium carbonate on the exoskeleton of echinoderms

Key Concepts

Crustaceans scavenge for dead and decaying matter, cleaning up the sea floor and keeping bacteria and algae growth to a minimum.

Phylum Arthropoda

Subclass Copepoda (copepods):

• body is divided into cephalothorax, abdomen, and telson

• swim by beating antennae or thoracic appendages

• are considered plankton

• participate in vertical migration

Artemia- brine shrimp:

• head, thorax, and abdomen

• are known for ability to tolerate high salinity levels up to 250%

• can produce dormant eggs known as cysts which are used in aquaculture for convenient feed

Subclass Cirripedia (barnacles):

• their shell has a protective coating allowing them to latch on to hard surfaces

• uses cirri to wash food into its mouth as plankton passes by

• no heart, arteries, or gills

• a blood pump behind the oesophagus helps blood flow

• gas exchange in the cirri

• excretion of wastes by the maxillary glands located behind the stomach

• barnacle is a hermaphrodite and creates both sperm and egg. but, they do not fertilize themselves but their neighbor

• fertilized eggs are released from ovaries and float to surface to become plankton

Subclass Malacostraca (prawns, crabs, shrimps, and lobsters):

Prawns (order Decapoda):

• 19 body segments with appendages on each segment

• separate females and males with either oviduct and ovaries or testis and vas deferens

• fertilized egg floats to the surface and starts life as plankton. goes through three larval stages; nauplius, zoea, and mysis. then, they become bottom dwellers in the mangroves. lastly, the adult life is spent in the open ocean.

Coral shrimp (Decapoda):

• uses its feeding appendages to clean mucous and parasites off fish

Alpheid shrimp (Decapoda):

• shares a common burrow with the Gobie fish, exchanging cleaning services for protection

Rock lobsters (Decapoda):

• camouflage and impressive defense

• females hold fertilized eggs on the abdomen until they hatch

Crabs (Decapoda):

• male crabs have small abdomen flaps tucked away

• female crabs have large abdomens for carrying eggs

• mating occurs after females moult and don’t have an exoskeleton in the way

• females hold fertilized eggs on the abdomen until they hatch

Mantis Shrimp (order Stomatopoda):

• powerful and speedy claws can crush and pierce prey

• feed on other crustaceans and small fish

Krill (Stomatopoda):

• colder waters

• whale food staple

• high in protein because they consume plankton

Phylum Echinodermata

Water vascular system:

• water enters through a madreporite and passes down a stone canal to a ring of tissue

• the radial canal delivers water to the ampulla and the ampulla delivers to tubed feet

• the expanded tube foot is moved by muscles which control the arm movements

Echinoderms can regenerate. If an arm falls off, they can replace it.

Feather stars (class Crinoidea):

• attach themselves using their legs to reefs or rocks

• filter feed

• a specialized shrimp can live on their legs and steal their food

Sea stars (starfish) (class Stelleroidea):

• normally have 5 arms centered around the central body section

• eat bivalve molluscs by wrapping their arms around them and pulling them apart

Crown of Thorns starfish:

• cause massive destruction to coral

• high spawning rates

Brittle stars (subclass Ophiuroidea):

• similar to starfish but thinner arms

Sea urchins (class Echinoidea):

• spherical with no arms

• long, brittle spines attached to the test (the shell made up of fused-together body plates)

• some feed on algae and seaweeds, or dead and decaying matter

• Aristotle’s Lantern: 5 plates of calcium carbonate that are moved by sets of muscles for feeding

Sea cucumbers (class Holothuroidea):

• tubed feet at the mouth

• sad grit goes in and fine sand come out (vacuum cleaners)

• can throw up organs to distract predators and then regenerate the organs

• can shoot out sticky tubules from Cuvier’s organ in the anus to entrap predators then escape

• can secrete toxins

• the pearlfish lives inside their anus during the day and leaves at night to feed

Tutorial Questions

What reproductive advantage does the Artemia species have that makes it a very important organism for aquaculture?

• Artemia can produce dormant cysts which can be stored and hatched at will for feeding in aquaculture

How can you differentiate between female and male crabs?

• Male crabs have a small abdominal flap whereas females have a large abdomen built for carrying eggs

What is the biological importance of sea cucumbers?

• They are the vacuum cleaners of the ocean. They clean up dead and decaying matter that would otherwise take up oxygen. They poop out clean sand that forms the ocean floor

Week 9: Marine Vertebrates Part 1

Key Words

Class Chondrichthyes: cartilaginous fish

Superclass Osteichthyes: bony fish

notochord: a stiff but elastic rod of glycoprotein that serves as a backbone

hollow dorsal nerve chord: develops into the spinal chord, aids the central nervous system

pharyngeal slits: form gills

spiracle: draws oxygenated water over the gills on sharks

ampullae of Lorenzini: pores over the head and snout that allow sharks to pick up the faintest of electrical fields from prey

neuromasts: sensory cells that run along the lateral line to pick up changes in water pressure

myotomes: muscles in V-shaped blocks that contract and expand to produce a smooth body wave

epaxial: muscles above the lateral line

hypaxial: muscles below the lateral line

oily liver: a liver filled with low-density oil such as squalene to help animals like sharks maintain neutral buoyancy

viviparity: live birth

ovoviviparity: fetus develops and is fed inside egg inside mother then egg hatches within mother and live birth occurs

claspers: a male shark’s and ray’s reproductive part that is inserted into the female cloaca during reproduction

pylorus: a constriction between the stomach and intestines in bony fish that opens and closes to let food pass into the intestine for digestion

Key Concepts

The skeletal and muscular systems of fish are designed primarily to provide locomotion as the surrounding water provides support.

Saltwater fish actively maintain osmotic balance by drinking seawater and excreting excess salts.

Organisms like sea squirts and lancelets link invertebrates to vertebrates because of their appearance of a backbone.

Fish with short intestines are usually carnivores.

Many fish perform courtship displays, changing color, size, or shape, or building nests or performing dances.

Tutorial Questions

What common characteristics do all Chordates have?

• a stiff rod or notochord

• gill slits in the pharynx at some stage in life

• bilateral symmetry

• hollow dorsal nerve chord

• post-anal tail

Week 9: Marine Vertebrates Part 2

Key Words

endothermic vertebrate: a vertebrate that can regulate its body temperature internally, like seabirds

preen: a special gland that secretes oils that birds rub through their feathers to repel water and trap air, keeping them dry and afloat

temperature-dependent sex determination: incubation temperature determines what sex an embryo develops into

Key Concepts

Superclass Tetrapoda includes birds, turtles, snakes, crocodiles…

Class Sauropsida (reptilia):

• lay eggs

• reptiles have 3—chambered hearts & crocodiles are the only one with 4-chambered hearts

• lungs

• scales with salt glands to remove excess salt

• bask in sun for body temperature

Turtles (order Testudines):

• All turtles are from the same family (Cheloniidae) except for Leatherbacks (family Dermochelyidae).

• herbivores or omnivores based on species

• front limbs for propulsion in water

• hold breath for ½ hour

• excrete excess salt through glands next to their eyes

• light bones and fatty deposits to stay buoyant

• migrate from feeding ground to breeding ground in two separate places

• females will lay multiple clutches of eggs in one season and then return to feeding grounds

• baby frenzy: turtles hatch and swim in the sea for several days without stopping or feeding

• warmer temps cause female eggs and lower temps cause male eggs

Sea snakes

• tropical waters

• can spend long periods underwater because they have an elongated right lung that spans the length of their body

• lay eggs on land

Sea birds

• feathers, toothless beaked jaws, laying of hard-shelled eggs, high metabolic rate, 4-chambered heart, and a strong yet lightweight skeleton

• warm-blooded unlike their reptile relatives

• excrete excess salt through nostrils

• waste is called Uric acid

• some birds adapted for swimming over flying

• huge migrations each year

• plastic is a huge problem for them

Tutorial Questions

What is the homing mechanism in turtles?:

• The homing mechanism in turtles allows them to navigate back to their nesting sites after foraging or migration. They use a combination of environmental cues, such as the Earth's magnetic field, visual landmarks, and olfactory signals, to find their way. Sea turtles, for instance, can detect the magnetic fields of their home beaches and use them to guide their journey. This ability is crucial for returning to the same location to lay eggs.

What do the turtle and the sea snake have in common?:

• They both return to land to lay eggs

• They both can hold their breath but eventually still need to surface

Week 10: Marine Vertebrates Part 3

Key Words

“lawn mowers” of the ocean: dugongs and manatees

echolocation: underwater sonar capability

Key Concepts

Mammals (class Synapsida):

• 4-chambered hearts

• endotherms (warm-blooded, regulate own body temp internally)

• majority give birth to live young

• fur/hair at some stage in life

• three orders of marine mammals are Sirenia, Carnivora, and Cetacea

Order Sirenia:

• manatees, dugongs, sea cows

• tropical waters

• feed on sea grass (have special lip and tooth adaptations. upper lip is split with each side moving independently. the lower lip and jaw have horny pads that allow them to grasp plants)

• give birth to one calf every 3 to 5 years

Order Carnivora:

• seals, sea lions, walruses

• leave water for breeding

• “pinnipeds”= fin foot

• well adapted to the cold with numerous oil glands and a thick layer of blubber

• all 3 in separate families

• seals: no external ear flap, cannot walk on all fours

• sea lion: external ear flap, can walk on all fours

Infraorder Cetacea:

• whales, dolphins, and porpoises

• fully aquatic and carnivorous

• found in all oceans on earth, and some brackish bodies of water

• two parvorders: toothed whales and baleen whales

• extensively hunted

a Baleen Whales

• bristles made of keratin instead of teeth to filter krill

• only travel to tropics to calf, live southern or northern during other parts of year

b Toothed Whales

• sperm whales, beak whales, orcas, dolphins, porpoises, Narwhal

• teeth to catch and hold food…then swallow prey whole

• eyesight and hearing is adapted for water and air

• advanced echolocation

Echolocation:

• emit calls and listen for echoes that return

• used for navigation, hunting, foraging, communication

• moving air between head and sinuses to create different sounds

• echoes are detected by an oil-filled channel in the lower jaw that travels to the middle ear

Week 10: Marine Ecology

Key Words

ecology: the study of the relationships between marine organisms and their environment

population ecology: the study of how one species interacts with each other and its environment

community ecology: interactions among multiple species’ populations

ecosystem ecology: the study of how multiple species and their environment interact

biosphere: the entire planet’s interactions

competition: two or more organisms fighting to obtain a limiting resource

consumption: when one organism eats another

cooperation: when two or more organisms interact in a way that benefits all parties involved

transformation: organisms change matter from one form to another

flux: organisms move matter and energy within and between species

eutrophication: an overabundance of nutrients that causes an ecological imbalance

euphotic zone: the 1% of the ocean that receives maximum sunlight

habitat: the physical environment where an organism lives, including abiotic and biotic factors that the organism interacts with

estuaries: where the tides meet rivers and an area that traps runoff sediments

halophytes: trees and shrubs that live in intertidal zones that have adaptations that allow them to survive in saltwater

nursery hypothesis: the idea that young larvae are born in the coral reefs, migrate to mangroves where they live as juveniles, migrate to the seagrass beds as sub-adults, and then finally back to the coral reef as adults

niche: an organism’s role in its habitat including its interactions with the biotic and abiotic factors of its environment

niche specialization: helps reduce competition between species by allowing them to coexist while utilizing different resources or strategies

ecological function: the specific tasks or roles an organism performs within its ecosystem

functional diversity: the range of things that organisms do in communities and ecosystems

functional redundancy: different species perform the same functional role in ecosystems

Key Concepts

Ecology is the study of how living organisms interact with each other and their environment. It encompasses three main branches: population ecology, which examines the dynamics of species populations and factors affecting their size and growth; community ecology, which focuses on the interactions between different species within a particular area and how these relationships shape community structure; and ecosystem ecology, which looks at how living organisms interact with their physical environment, including the flow of energy and the cycling of nutrients within ecosystems.

Transformation is when an organism turns one matter form into another, like nitrogen fixation.

Flux is when organisms move matter and energy within and between species, like when seabirds forage offshore and return to their island and defecate, fueling productivity with new nutrients.

Energy transfers up through the food web but only 10% goes from one trophic level to the next.

Higher amounts of primary production create the potential for more tropic levels because there is more energy to be shared.

Upwelling brings nutrients from deeper water to shallow waters and in these zones, there is very high productivity because there are so many nutrients.

Eutrophication is an overabundance of nutrients which can be cause by runoff my agricultural practices. It causes excessive algae growth which takes up oxygen and cuts off sunlight, making it hard for corals to grow.

Nutrient cycles of carbon, nitrogen, and phosphorous have high ecological significance because they support primary production by phytoplankton which are at the bottom of the food web. Everything depends on them.

Tropical ecosystems usually have the least nutrients (besides coral reefs).

The neuston consists of the plankton at the very top of the ocean who provide photosynthetic processes and are crucial for energy transfer.

Estuaries act as a dumping ground, filter, and absorber of nutrients and pollutants. Nutrient-rich sediments limit benthic organisms. They are excellent nurseries.

Mangroves are halophytes and have adaptations that allow them to survive in saltwater. They have little competition in these intertidal zones. They trap nutrients that protect nearby reefs, provide habitats for juvenile fish, and prevent coastal erosion.

Seagrass beds stabilize sediments and provide shelter and habitat. They are rooted and live entirely underwater. They extract oxygen from the water to breathe. They release pollen into the current to reproduce. They are heavily grazed by microbes, invertebrates, turtles, fish, and manatees & dugongs.

Niche=how a species uses resources, behavior, interaction with other species, etc

Ecological function= contribution a species makes to the ecosystem such as pollination, predation, parasitism, decomposition, nutrient cycling, etc.

The niche of the parrotfish is living on coral reefs and eating algae off the rocks and coral. The ecological function is eating algae to prevent overgrowth so the reef can succeed.

Human impacts:

• overfishing: fishing too much of one species, or fishing over the allowed quota

• eutrophication: too many nutrients causing harmful algal blooms

• pollution: specifically plastic

• habitat destruction: causing coral, mangrove, and other organisms to perish

• carbon dioxide emissions: causes ocean acidification

Tutorial Questions

What do you mean by high productivity regions? Give examples:

• High productivity regions are areas where life thrives due to great environmental conditions like high concentrations of nutrients.

• Upwelling areas & estuaries

What is the difference between a niche and a habitat?

• A habitat is the physical environment where an organism resides and a niche is that organisms lifestyle in that environment.

Week 11: Coral Reef Ecology

Key Words

corals: marine animals in the Class Anthozoa of Phylum Cnidaria, typically living in compact sessile colonies of many identical individual polyps

zooxanthellae: symbiotic algae that lives on corals, exchanging energy for protection

cnidocytes: specialized stinging cells

nematocysts: the stinging organelle/ structure

coral reefs: massive deposits of calcium carbonate (CaCO3) produced by corals, calcareous algae, and CaCO3-secreting organisms like mollusks and sponges

coral bleaching: occurs when corals expel zooxanthellae living in their tissues, causing them to turn white, due to increased sea surface temperatures

Key Concepts

Taxonomy of Scleractinian corals:

• Phylum: Cnidaria

• Class: Anthozoa

• Subclass: hexacorals

• Order: Scleractinia

Zooxanthellae and corals:

• Zooxanthellae gets protection, nutrients, and carbon dioxide

• Coral gets sugars, which are used for skeletal formation, growth, reproduction, and secretion of dissolved organic carbon (mucus)

• Coral also gets UV protection and oxygen (from photosynthesis)

Parrotfish:

• Niche: algae-grazing herbivore and bioeroder

• Herbivory function: control algal growth on coral surfaces, maintaining coral health and ecosystem balance

• Importance of functional redundancy of herbivorous fish: high functional redundancy ensures that if one herbivorous species is lost due to overfishing or disease, another species can take its place and the ecosystem will stay balanced

Major impacts on coral reefs:

• emissions: causes ocean acidification

• ocean acidification: increase in seawater acidity when there’s too much carbon dioxide. Causes descrease in avaialable CaCO3 which corals use to make their skeletons. Skeletons weaken and dissassociate. Acidity slows growth, and can also make them stressed and expel zooxanthellae, causing bleaching.

• runoff: excess nutrients from things like fertilizers and sewage can cause eutrophication which blocks zooxanthellae on corals from photosynthesizing

• high temperatures: causes coral to expel zooxanthellae and bleach themselves

• overfishing: removes key species which deestablishes food webs. loss of herbivorous fish leads to algal growth which outcompetes corals

Coral reefs grow in low nutrient, clear, shallow, tropical water.

Coral bleaching:

• occurs when coral expels zooxanthellae and coral turns white

• caused by stress, usually high temperature

What can be done about threats to coral reefs?:

• global initiatives to reduce greenhouse gas emissions

• set up marine protected areas for fish communities

• management of key species

• fishing restriction

• programs to improve coastal water quality

• coral restoration

Tutorial Questions

Describe the types of effects that coral bleaching has on corals:

• reduced energy: zooxanthellae gives them energy. they expel zooxanthellae and don’t have that major source of energy

• reduced growth

• decline in health

• loss of reef structure

• mortality: being bleached for too long causes death

Week 11: Aquaculture

Key Words

aquaculture: the farming of aquatic organisms such as fish, shellfish, and plants in a controlled or semi-controlled environment

wetland filters: mangrove and wetland communities could be utilized as bio-flilters

bio-filtering: use of seaweed and bivalves in outlet channels can be used for marine aquaculture wastewater

effluent: wastewater from aquaculture facilities

Key Concepts

Aquaculture can be done almost anywhere; on land, lakes, rivers, or the open ocean.

Asia dominates the aquaculture industry, producing 91.6% of the total.

Natural and Capture Fisheries:

• harder to catch stock

• depletion of wild stocks due to overfishing

• disregard for sustainability of resources

• degradation of the environment by human activities

• future issues: climate change, human population increase

Why is the Pacific a good place for aquaculture?:

• close proximity to markets in Asia

• aquarium trade

• pharmaceutical trade

• pristine habitats

• cheap labor

• tradition of working with marine resources

Aquaculture benefits:

• food production & food security

• reduction of fishing pressure on natural stocks

• biodiversity preserved

• income generation & employment

Aquaculture disadvantages:

• environmental problems: wastewater, excess nutrients, introduced species, biosecurity

• use of land and aquatic system: habitat destruction

Aquaculture constraints:

• lack of juveniles and post-larvae

• lack of feeds from a local supply: imported = $$$

• not enough trained personnel

• government: laws, policies, fees

• water: availability, quality, ownership

• land and sea: ownership, land laws

• climate: floods, droughts, cyclones, climate change

Future Development of Aquaculture Requires:

• more scientific info on native species, the feeds, technology

• trained personnel (locals!)

• sustainable practices

• financial investors

• government support

Important Aspects of Aquaculture:

• species and where to farm

• water quality

• availability of juveniles

• appropriate feeds

• animal management

• stocking density

• sustainability

To Minimize Effects of Effluent:

• settlement ponds or beds: wastewater flows into a separate pond/bed and since it moves so slow the particles can settle there

• filters: mangroves, seaweed, bivalves, etc

• bacteria: bacterial cultures can eat excess nutrients in water

• management: feed management and good farming techniques to help reduce waste

• getting disease-free fish from trusted sources

• optimum stocking density, don’t overcrowd

• control use of chemicals and hormones and antibiotics

Tutorial Questions

What is the importance of aquaculture in the current fisheries scenario?

• capture fisheries are declining so aquaculture is needed

• the supply is low and the demand is high

• aquaculture can help capture fisheries meet demand

Week 12: Marine Pollution

Key Words

marine pollution: any material discharges into the sea by humans that causes some negative change in the environment

marine contamination: the presence of elevated concentrations of substances in the environment above the natural background level for the area and for the organism

point source pollution: direct input into oceans like sewage and mines

non-point source pollution: indirect input into oceans like runoff and atmospheric deposition

classical contaminants: previously established containants. Data on their effects and toxicity to the aquatic ecosystem is known and thus regulations exist

emerging contaminants: “new” contaminants. Have been detected in the environment and pose threats to the ecosystem but a lack of data exists to properly regulate these

toxicology: a multidisciplinary field concerned wit the adverse effects of chemical, biological, and physical agents on living organisms

ecotoxicology: the study of harmful effects of chemicals upon ecosystems and includes effects upon individuals as well as consequent effects at the levels of populations and above

biological oxygen demand (BOD): the measure of the amount of oxygen that will be consumed when organic matter decomposes

oxygen sag curve: shows the relationship between dissoled oxygen and biological oxygen demand

blackwater sewage: wastewater from toilets

graywater sewage: wastewater from all domestic sources except toilets like sinks, showers, dishwashers, etc

conservative pollutants: they are not degraded, or are degraded very slowly, by chemical or bacterial action so are “permanent” additions to the environment, like persistent organic pollutants (POP’s)

non-conservative pollutants: easily broken down and dissipate within a “short” time span

essential elements: elements that are required for proper metabolic functions generally not toxic under normal conditions

essential metals: Most of the light metals and some of the transitional metals. Most are toxic at high concentrations

non-essential elements: These are elements not required for metabolic function. Most can be tolerated at low concentrations, but all are toxic at higher levels

black list metals: metals that cannot be dumpes into the environment like cadmium and mercury

grey list metals: less harmful but still bad metals. A permit is required for usage/dumping

radioactive pollution: the presence or deposition of radioactive material where it presents environmental threat

half life: the time required to lose half of the activity when breaking down

greenhouse gas: any gas that absorbs radiant energy within the thermal infrared range

primary microplastics: are manufactured and are a direct result of human material and product use

secondary microplastics: are microscopic plastic fragments derived from the breakdown of larger plastic debris like the macroscopic parts

Key Concepts

Marine pollution is when material is discharged into the sea by humans and it has a negative effect. Marine contamination is when there are higher levels of a substance than there normally are and it has a negative effect. Pollution is introducing new things to the environment while contamination is increasing substances that are already there. Both can have negative effects.

Effects of pollution on different levels:

• individual: biological changes are measured in regards to health condition

• population: dynamics are measured, including survivor and mortality rate, male to female ratio, etc

• communities: dynamics are measured, including presence or absence of key species and relationships between populations

Ecotoxicology is the study of harmful effects of chemicals upon ecosystems and includes effects upon individuals as well as consequent effects at the levels of populations and above. An ecotoxicologist could do many assessments, including conducting toxicity tests on fish to determine lethal dosage amounts, or studying how agriculture runoff affects species diversity in estuaries.

Pollutants are driven by atmospheric circulation and water currents.

Classical pollutants:

• human waste (oxygen-demanding pollutant)

• oil

• heavy metals

• greenhouse gas

Emerging pollutants:

• pharmaceuticals

• nanoparticles

• microplastics

Marine Pollutants:

Oxygen Sag Curve:

A higher BOD leads to more and more oxygen being consumed, possibly to the point where there is almost none left and the area becomes anoxic.

One of the most important pollution challenge facing the inshore areas of the world oceans, especially Pacific Island Countries, is sewage and eutrophication.

Persistent organic pollutants (POP’s) like pesticides and PCB’s are concerning due to their ability to accumulate and biomagnify, and their persistence.

Oil can cause a range of direct and indirect effects on marine life (ingestion, smothering, death, human food shortages, etc), and it is difficult to clean up despite having properties that prevent it from dissolving in water.

Due to human sources, the composition and ratio of gases in the atmosphere changes and thus the greenhouse effect is enhanced, leading to global warming.

Mitigating pollution:

• address the problem, locate the source, fix the problem, educate communities

• mitigation on an individual level: practice recycling, proper disposal, sustainable methods

• “ national level: national laws regulate use and disposal of many common pollutants, but enforcement is difficult

• '“ global level: international treaties, conventions, and protocols to adress global issues and particularly harmful things

Tutorial Questions

What are oxygen demanding wastes and give examples?:

• Oxygen demanding wastes are those wastes which, as a result of aerobic breakdown of organic matter, result in a decrease in oxygen in the water

• *they break down in the water and steal all the oxygen*

• examples include sewage, household garbage, and food processing waste

• can cause eutrophication

Explain the oxygen sag curve and what it represents:

• The oxygen sag curve illustrates the relationship between dissolved oxygen and the biological oxygen demand

• When organic matter is introduced into the water, microorganisms decompose it, consuming oxygen in the process. As a result, the oxygen levels initially drop, creating a "sag" in the curve. After the organic matter is broken down and the microorganisms' activity decreases, oxygen levels may gradually recover.

• There are 5 sections/zones: clean zone, decomposition zone, septic zone, recovery zone, clean zone

• oxygen levels are critically low in the septic zone

Discuss “the dose makes the poison”:

• The amount or concentration of a substance determines its toxicity. Even beneficial or just neutral substances can be toxic in large amounts

Discuss POP’s and which convention regulates its use:

• Persistent organic pollutants, or POPs, are concerning because they easily accumulate and biomagnify, and are very persistent

• They are conservative pollutants, meaning that they are not degraded or degrade very slowly by chemical or bacterial action, so they are seen as “permanent” additions to the environment

• The Stockholm Convention regulates their use

Week 13: Marine Conservation and Management

Key Words

marine conservation: the protection and preservation of ecosystems in oceans and seas through planned management in order to prevent the over-exploitation of marine resources

marine management: a political process to conserve ecosystem that includes creating marine protected areas, regulating gear use, regulating species harvested, and enforcing fish catch limits

Key Concepts

The natural marine ecosystem is fragile and vulnerable because it relies on an unstable balance of various living organisms and a changing environment

Week 13: Fisheries Issues

Key Words

bycatch: the part of the capture that is discarded at sea, dead or injured to an extent that death is the result

catch: portion of fish retained because it has economic value

selective fishing: catching the desirable sizes of the target species

trawl efficiency device: a trawling net where the smaller target species can pass through the grid, whereas larger organisms such as turtles and skates are deflected out of the net through an escape opening

pelagic longline: using specific bait to target specific catch and avoid bycatch

discard: the unwanted fish that are thrown overboard, usually dead, when they need to make room on the boat

IUU fishing: illegal, unreported, and unregulated fishing

ghost fishing: abandoned, lost, or othwise discarded fishing gear that continues to entrap fish

high grading: when marketable fish are discarded to make space for bigger, more valuable fish

Key Concepts

IUU fishing impacts:

• economic: loss of revenue from licensing

• ecological: damage to sensitive ecosystems

• social: undermines the law

Impacts of ghost fishing:

• continued catch of target and non-target species

• harm to threatened and endangered species

• physical impacts on the benthos: nets damage coral, invertebrates, and bottom dwelling organisms by getting entangled in their habitat

• introduction of synthetic material into the food web

How to adress ghost fishing:

• prevent: avoid letting ghost fishing occur, like marking gear and creating soaking times

• mitigate: reduce the impact of fishing gear in the environment, like developing better materials

• cure: remove fishing gear from the environment, like tracking lost gear with technology or creating gear recovery programs