Marine Enviro Final
Anthozoan characteristics
70% of cnidarians, only polyp, polyp produces egg and sperm for larvae, asexual reproduction also occurs
Caribbean reefs
9% of world's coral reefs, multiple assaults in recent years (Diadema die off (inc in algae) bleaching events, hurricanes)
Value of reefs
$375 billion in goods and services, 500 million people have some dependence on coral reefs, provision of food, biodiversity (32/34 animal phyla found on reefs), development of drugs, tourist industries, building materials, protection of coastlines, cultural objects, recreational fisheries, BEAUTY
Phylum Chordata (sea squirts, amphioxus)
*Missing link between invertebrates and vertebrates* 3 cell layers, complete gut with anus, tripartite division of body, internal skeleton when present, complete circulatory system, share 3 vertebrate features (sub-phylum urochordata--tunicates have all three vertebrate features)
Herbivorous functional groups
--Browsers (grazers): selectively consumes parts of or whole algae --Scrapers: scratch surface of reef and directly consumes polytaxonomic autotroph assemblages, non-selective herbivores that feed on algae that is closely affixed to substratum (parrotfish) --Excavators: take large bites out of live coral potentially to access endolithic algae, also consumes fleshy benthic algae
Protandrous v Protogynous
--Female fecundity almost always increases rapidly with size, often a cubed relationship --differences in the direction of sex change are determined primarily by variation in how MALE fitness varies with size: Protogynous--male fitness must increase even more rapidly with size Protandrous--male fitness increases little or not at all with larger body size In both: sex ratio biased towards first sex (more so in protogynous)
Coral reef fish diversity
0.17% of Earth surface but have 18% of fish species; most reef fish are perciformes (largest vertebrate order, radiation coincided with that of modern Scleractinian corals); rapid speciation of reef fish in Miocene coincides with global reorganization of coral reefs and expansion of fast-growing corals; predation rates on reefs are higher so have influenced fish life cycles a lot; overfishing can have major influence on reef structure
Piscivores--pursuers
1. Open water species that pursue their prey (sharks and jacks); Morphology--streamlined bodies with deeply forked caudal tails to increase swimming speed 2. Species that pursue prey within crevices (moray eels) Morphology--long lateral line and dorsal fin, caudal fin small; have pharyngeal jaws (second set of jaws that can extend out and grab food)
Bathypelagic--aphotic
1000-4000 m, no light except that from bioluminescent animals, ~4C (constant temp in this zone), feed on detritus and other animals in the zone (fish, mollusks, crustaceans, jellyfish); vampire squid is CRAY and engulfs their prey, copepod, dragon fish, slime stars
Leatherback Turtle
2 m long, pelagic, cold and deep water (function as if warm blooded due to large body size), metabolism=more efficient can move into deeper waters, eats gelatinous prey
Rocky shores
2 obvious gradients: wave exposure (vertical with depth, horizontal along shore), tidal gradients (regular exposure to air, areas higher on shore exposed for longer periods--associated probs of desiccation, thermal stress, loss of food supply/oxygen/support)
Mesopelagic--disphotic
200-1000m, insufficient light for photosynthesis, "twilight zone", large eyes make use of very low light (pointed up), bioluminescence, greatest temperature gradient (thermocline); Animals have large mouths and sharp fangs to help catch prey (thin bodies to make them harder to see); can eat prey bigger then themselves due to expandable jaws and stomachs; many animals in zone rise to photic zone to feed at night; some are very large and delicate
Great Barrier Reef
2100 km long, 5-10,000 years old in latest build, did not exist during last ice age, made up of 70 different officially recognized habitat types
Phylum Mollusca
3 cell layers, bilateral symmetry, not segmented, often hard external shell that may be secondarily lost, complete gut with an anus, open circulatory system, radula for feeding
Class Crustacea
3 cell layers, bilateral symmetry, segmented exoskeleton (first with exoskeleton), jointed appendages, complete gut with an anus, circulatory system
Phylum Annelida (polychaete worms)
3 cell layers, bilateral symmetry, segmented worms, parapodia ("legs/paddles") with chaetae (stiff bristles), complete gut with an anus, circulatory system--first group with segmentation (each with a fleshy leg/paddle), head end has lots of sensory material (big mouth parts, big filtration apparatus)
Phylum Platyhelminthes: Flat worms
3 cell layers, bilateral symmetry, simple gut (one opening for mouth and anus), simple body plan (flat, diffusion limited structure), not segmented worms, still diffusion across body wall for breathing
Phylum Echinodermata (seastars, cucumbers, urchins)
3 cell layers, pentamerous radial symmetry in adults, not segmented, calcareous ossicles forming endoskeleton (made out of calcium carbonate, kinda remnant of the shell), complete gut with anus, water-vascular system and tube-feet, mutable connective tissue, amazing powers of regeneration (only need part of central system of sea star), produce coelomocytes (recognize and fight bacteria, transport oxygen, fight wounds), gut complete or secondarily absent, gonochoric spawning most common, circulatory system restricted if present, nervous system diffuse and decentralized
Piscivores--stalkers
3. Species that slowly stalk their prey (trumpetfishes and cornetfish); suction feeding (using a mouth like a syringe) 4. Species that stalk prey by habituating them to an illusion that they are non-predatory (groupers and snappers)
Shark attack in Aus
35,000 km coastline, attacks are rare: ~1 fatality/year; last 5 years, 2 unprovoked deaths/year (~1/4 of attacks are fatal) Avoid by swimming at patrolled beaches and avoid swimming: with shiny swimwear/jewelry, at dusk/dawn/night, in murky/cloudy waters and after storms, in deep channels/steep drop-offs/river mouths, where sharks feed, or alone
River dolphins
4 fams, 4 genera, 4 species; atrophic eyes, mobile necks, long narrow beaks with many teeth; small groups in large river systems, live in murky, polluted, overfished waters with boat traffic, all in jeopardy
Porpoises
4 genera, 6 spp, small, no beak and spade shaped teeth, most coastal
Piscivores--ambushers
5. Cryptic species that ambush their prey (lizardfishes and stonefish)
Sharks (general)
530 million years, 350 extant species that are very similar to ancestors, nearly all marine but some estuarine and few permanent freshwater, 80% are >2m adults; breathe via buccal pump or ram ventilation
Marine mammals in Aus general
57 species; seals, whales/dolphins, dugongs; evolved from terrestrial mammals so are secondarily aquatic but all returned to ocean around the same time (~50 mya)
Beaked Whales
6 genera, shy, cryptic deep water whales, widely distributed, in small groups, most affected by noise pollution
Shark sensory system
6 senses used for different distances to prey: Hearing (low frequency sounds, >1 km), Olfaction (>100 m), Pressure (lateral line system, <100 m), Vision (duplex retinas, tapeturn lucidum, nictitating membrane, <100 m), Electrical perception (ampullae of Lorenzini, <50 cm), Touch and Taste
Killer whales of Twofold Bay
>20 whales cooperated with whalers to hunt baleen whales, alerted the hunter to their location, assisted to herd, kill and haul, and were fed tongue and lips (mutualism)--1840-1930
Dugongs--difficulties to studying
>98% of life underwater, live in murky waters, cryptic, shy, secretive, all look alike Have used aerial surveying, necropsy and telemetry in the past
Characteristics of beaches
Accumulations of sediment deposited by waves and swash (where waves expend last of their energy), upper swash limit is 3-5 m above sea; zones from water to back beach: lower nearshore ripple area, breaker zone, surf zone, swash zone, upper dry sand zone, dunes, backshore
Effects of ocean acidification on reefs
Acid conditions slow growth/reproduction for many aquatic animals, CaCO3 shells harder to produce, food webs disturbed, change in exchange of gases through gills, harder for larger marine animals to get as much oxygen from water, problems with jet propulsion
Southern bluefin tuna
Adaptations for fast pelagic marine life: extreme streamlining, ram ventilation with no buccal pump, large complex gills, must swim continuously at >1 body length/second, hydrodynamic body shape (fins retract into grooves), swimming biomechanics (rigid, minimal undulation, high tail beat frequency), Muscle physiology (high myoglobin holds O2), Circulation (high core temp, counter-current heat exchange, large efficient hear, high hemoglobin levels) Spawn in N Indian ocean, larvae down W coast Aus, feed around S Aus Critically endangered due to fisheries
Invertivores with specialized diets
Adaptations include highly specialized mouth parts to facilitate predation on awkward prey; Angelfish feeding on sponges; butterfly fish with forcep-like mouths with fine comb-like teeth to feed on coral; orange-spotted file fish has long mouth to target coral polyps
Ray anatomy
Adapted for benthic life, dorsal eyes and spiracles (spiracle=incurrent, external respiratory opening), ventral mouth and gills, disk=body and pectoral, thin whip-like tail
Green Turtle
Adult coastal, along reefs, herbivorous
Hawksbill Turtle
Adult coastal, coral reefs, omnivores, eats sponges
Osteichthyes: Bony fishes
Advances over Chondrichthyes: bony skeleton, gill operculum, seperate anal and urogenital openings, scales
Sex change theory
Advantages are that individuals get 2 chances to reproduce, reproduction while still growing, successful fishes can dominate fertilization of the rest of the group; sex allocation theory suggests that sex change is favored when the reproductive value of an individual varies with age or size and the relationship is different for males and females
Sea snake feeding
All carnivores/active hunters, mainly feed on small prey that can be eaten whole, initially use chemical cues (Jaobsen's organ, an olfactory pit in mouth) then visual when they get closer, venom is neurotoxin, just immobilizing (not chewing) teeth, recurved teeth so prey can't escape, Have large meals and slow metabolism (infrequent meals)
Shark feeding
All carnivores: fast moving hunters, slow moving hunters, filter feeders (whale sharks are the largest but feed on plankton and small fish)
A few examples of estuaries
Amazon (largest in world, river-dominated, salt wedge cause mixing outside estuary over continental shelf), Chesapeake Bay (Largest in US, partially mixed since salinity varies more longitudinally rather than vertically), Port Jackson (Sydney Harbor, drowned river valley), Spencer Gulf (extensive, hypersaline, inverse estuary where rate of evaporation exceed freshwater discharge--highest salinity just inside shallow estuarine mouth)
Estuaries
Amongst most productive marine enviros (high nutrients from both sea and land), diverse habitats include seagrass and mangroves, important fish nurseries, habitats for migratory birds and endemic species
Parasitism
An organisms which lives in (endoparasite) or on (ectoparasite) another organism to the detriment of the host; Flatworms, crustaceans, and protists are major marine parasite groups
Evolution of bilateral symmetry
Ancestral organism of flattened mass of cells, cephalisation (development of a head), organisation of central nervous system
Cnidarian classes
Anthozoa (corals, anemones), Scyphozoa (jellyfish), Cubozoa (box jellies), Hydrozoa (hydroids, stinging animals)
Wavelength variation with depth
As you go deeper, only blue light makes it down, so some species have adapted to use different wavelengths; different species have differing light requirements-->resource partitioning
General trends within GBR
As you move away from land: nutrients decrease, water clarity increases, coral diversity increases; From south to north: coral cover and diversity increases, reef growth and development increases (due to irradiance and temp)
Coral reproduction
Asexually (growth in corals is an asexual process, polyp production via intratentacular and extratentacular budding) and sexually (generally hermaphrodites-75%, about 85% spawn, fertilization quickly after spawning, development of larvae, planulae drift with currents and then settle and grow)
"Wall of Mouths"
Assemblage of plankton feeders along the reef crest; crucial role in accumulation/retention of nutrients/energy on reefs (few zooplankton escape cloud of fish)
Mutualism
Association where both organisms derive mutual benefit, evolutionarily stable, leads to co-evolution (evolutionary forces likely selected for mutualisms)
Greenhouse effect
Atmosphere acts as a heat trap, ice/clouds/vegetation reflect, concentration of greenhouse gases determine heat trapping behavior--Necessary but bad when enhanced
Sandy shores
Aus has 16,000 km of beach, action of waves/tides on rocks/reefs-->sand, erosional coastlines, low wave systems with high energy surf
Terms used to describe feeding relationships
Autotrophs--organisms that make their own food, producers Heterotrophs--organisms that must consume other organisms for energy Trophic pyramid--model that describes who eats whom Primary consumers--eat producers Secondary consumers--eat primary consumers
Chemosynthesis
Bacteria oxidize inorganic molecules such as hydrogen sulfide or methane to produce carbohydrates from CO2
Chemosynthetic communities
Bacterial mats near methane or sulfur seeps Cold seeps-->high methane and sulfides, diverse community supported by chemosynthetic bacteria Hydrothermal vents-->warm, transient, very rich and diverse communities
Types of estuaries
Based on water circulation, mixing and salinity stratification; can have vertically mixed estuaries, partially mixed estuaries, salt wedges, highly stratified
Food chains on sandy beaches
Beach is not an independent closed ecosystem, dependent on surf zone for primary production (diatoms), organic matter needed by consumers is imported from land and sea
Shark control
Beach protection: shark patrols, shark nets, drum lines (by-catch issues) Alternatives include tag and track (monitoring stations near populated beaches) and electronic shark deterrents (electric field deters sharks)
Intertidal zones
Between high and low tide limits; splash zone is above high tide, pools in mid and low tidal zones
Biota of brackish estuarine system
Biota subject to stress, fewer species and higher taxa compared to fully marine systems, benthic flora is dominated by seagrass, nekton and zooplankton are mostly fish and crustaceans, benthic macrofauna include polychaetes, mollusks and crustaceans, benthic microfauna included protozoans and nematodes (small number of species may reflect lower rates of speciation and higher prob of extinction in unstable enviro
Fishing impact on reefs
Blast fishing (blowing ish up), cyanide fishing (release cyanide plume and you get live fish)-->education/training fishers in alternative methods/developing alternative livelihoods for fishers; overfishing and collecting of reef animals is also a huge issue
Balaenopterids--"rorquals"
Blue whale, fin whale, sei whale, Bryde's whlae, Minke whale, Humpback whale; long sleek bodies, ventral throat pleats (mostly lunge feeders), relatively short baleen, small dorsal fin, Most migratory
Dugongs--health assessment
Body condition (lenth, girths), Blood chemistry (haematology, serum biochemistry-->nutritional status, health and disease, contaminants, stress), reproductive and stress endocrinology, diet analysis (stable isotope levels), heavy metals, microbiology
Impact of storms and cyclones on reefs
Breakage of corals and other fragile organisms, increased competition with algae, disturbance of recruitment-->Significant increase in intensity of these events
Carbonate Coral Reefs
Build a coral substrate--corals growing on dead corals, what we are talking about when we talk about coral reefs
Photosynthesis
CO2+Water+sunlight+chlorophyll-->glucose+oxygen
Aragonite saturation and reef development
CaCO3 is the main reef building compound, so need to have a large concentration of carbonate available in the water, increase in CO2 in the ocean is diminishing carbonate (going to bicarbonate buffer system) and could lower pH to where coral reefs can't develop
Ramifications of increased CO2 on coral
Calcification reduced, dissolution of skeleton, changing of symbiosis and photosynthesis, changing early life history changes, increased susceptibility to bleaching, changing pop structure-->Loss of reef structure, loss of organisms associated with reefs (esp fish), loss of food sources for many animals (Krill for whales)
Invertivores--protection
Camouflage, enlargement or toxin (pufferfish), enlargement and spines (porcupine fish), fused body plates=armor (Trunkfish)
Evolutionary trade offs
Can't have a supersupecies that's optimized to do everything; if you live longer, you have fewer kids; if you live high up on the slope, you don't have much competition or predation but are susceptible to desiccation (etc etc)
Dugong--Mark and recapture pop study
Capture and recapture, identify individuals, collect age/size data-->gain info on pop size and trend, survival and mortality, life history info
Dugong--sampling
Capture via rodeo method, 5-6 min, in-water sampling OR biopsy scraping for mommas with calves Done in Moreton Bay over 16 summers, opportunistic sampling, >2000 dugong captures
Ray feeding
Carnivores, feed at night, eat invertebrates and small fish, most have crushing plates, sense prey by smell and electroreception
Class Chondrichthyes
Cartilaginous fish, light & flexible skeleton, subclass Elasmobranchii (sharks, skates, rays) and subclass Holocephalii (ratfish, ghost sharks); Advances over Agnatha: Movable jaws, teeth, ventral mouth, paired lateral fins, denticles (not scales) and teeth
Tides
Caused by rotation of earth-moon system, 28 day cycle, forces of gravitation towards moon from earth, roughly 6 hour tidal schedules
Rays and Skates
Chondrichthyes, 320 extant species, mostly marine, shallow coastal waters, size from <10 cm to >2 m, flattened body plan, tail barbs for self defense, usually docile
Threats to Sea Turtles
Coastal development (pollution, habitat loss, boat strikes), longline fishing, fishing nets/trawlers (Turtle exclusion devices are necessary), predation on eggs, unsustainable harvest, entanglement, marine debris, disease
Coral mucus
Coats polyp, moved by microscopic cilia, used to remove sediment from polyp surface, stops them from drying out during low tide, protects from UV light (Mycosporine-like amino acids), antibiotic properties
Muttonbirds (wedgetailed shearwaters)
Colonial seabird, ground nester on small tropical island, Heron Island, Pisonia seeds cover birds and use corpse as nutrients/fertilizer
Noddy Terns
Colonial seabird, migrate from PNG, nest in Pisonia grandis trees (rely on abundant guano), one large egg per year, nest in canopies
Reasons for developing a shell
Combo of protection from predation and providing external skeleton (comparable to arthropod skeleton), all have shells at some point in their life but not necessarily in their adult life
Rock pools
Continuously wet, more sheltered, may contain plants and animals atypical of intertidal region-->casual users (same as surrounding), refugees from exposure (at low tide), subtidal can extend into intertidal through pools
Biological impact of grazers on reefs
Control of algal populations, facilitation of energy flow through coral reefs, involved in carbonate balance of reefs (difference between CaCO3 added and CaCO3 eroded--scrapers and excavators contribute to bioerosion)
Temperature impact on reefs
Coral bleaching (both warm and cold), growth changes, changes every stage of reproduction, recruitment changes (ideal temp has been passed so declines in growth, lifespan and reproduction of fish)
Effects of bleaching
Coral can live or die, whole cell can be shed or chlorophyll can be lost with zooxanthellae intact; If corals don't die (since ~10% of zx don't die) they are often susceptible to future stress; there was a hypothesis that bleaching is a way to change which clade is dominant (since some are less susceptible) but this is unlikely since the pops don't really change symbionts
Feeding and nutrition of corals
Corals capture and ingest plankton and particulates from seawater and absorb nutrients directly from water, important for provision of minerals and micronutrients; if they can feed well (faster flowing water), they have a better chance of surviving bleaching events
Balance between growth and erosion on reefs
Currently, calcification beats out erosion by 10% so reefs still grow, but in the future, erosion will be larger than calcification (at higher CO2 concentrations) and we will lose reef structure
Dredging in Aus
Decided not to dump at sea (would have caused increase in coral disease), instead dumped in wetlands with no environmental impact assessment-->lots of weird politics and politicians not paying attention to anything other than money
Patterns of coral reef distribution
Decline as they move away from equator, region size and isolation important factors, great ocean distances are isolating barriers , Better on eastern side of countries (upwelling brings high nutrients and cold water)
Sea snake distribution
Decline in diversity from tropics to subtropics, 16 species in N GBR, 7 in S GBR, 1 in Moreton Bay, generally not found in colder, temperate waters
Land-based activities impact on reefs
Deforestation, poor agricultural practices, poor land use practices-->increased run-off of pesticides/fertilizers/sediment due to loss of riparian zone-->reduces light levels, poisoning of reef organisms, nutrient enrichment *should stop agriculture right next to reefs or restore riparian areas*
Compensation depth
Depth where photosynthetic output of an organism equals its consumption by respiration; depends on wavelength, angle of incidence, turbidity; Variation across species, seasons, and latitudes; above compensation depth-->net production; below compensation depth-->net consumption
Zooxanthellae
Dinoflagellates located within endodermal cells of host corals, provide photosynthesis (energy), glycerol that helps to make fat (impt for eggs), and assist with calcification; coral provides protection and a safe place to live and nutrients (mostly from waste material); different clades of zooxanthellae in corals, most coral have multiple clades but there is typically a dominant one; internal recycling of nutrients, up to 95% of photosynthetic production is translocated
Myth of zonation and actual patterns
Distribution on shoreline is due to more than just waves and exposure, these likely determine upper limit but other factors control lower limit (predation, herbivory, competition), width of zone determined by slope of shore, tidal range and wave action
Recovery from disturbance
Disturbances such as large scale bleaching events or cyclones lead to high mortality of corals; herbivory essential for recovery; After disturbance, reef can favor algae, so herbivory allows corals to resettle and redominate
Fish feeding
Diverse feeding strategies: carnivory, herbivory, plankton, benthic invertebrates' Cranial kinesis (mobile jaws)--in modern bony fishes, jaw bones move relative to skull, gape and suck feeding
Phylum arthropoda
Diversified in all habitats, largest assemblage of species in animal kingdom (80% of all species)
Non-carbonate coral reefs
Don't build a coral substrate, coral grow on rocks not dead corals, still can have high diversity and coral cover, higher proportion of brooding corals, in competition with macroalgae, often in higher latitudes or other marginal habitats
Beach habitats
Dry upper beach, swash zone (wetted during high tide), energetic surf zone (strong currents, unstable seabed), increasingly less disturbed nearshore zone in deeper water, water column above surf, ripple zones
Coriolis Effect
Due to earth's rotation, zero at equator and max at poles; deflects to the right in N hemisphere and left in S hemisphere
Eddies
Due to friction between continent and strong currents, external torque flow, coriolis/centrifugal/gravitational flow due to pressure are all in balance-->thermocline deflected upwards *upwelling in interior of eddy, so deep cool nutrient rich water brought to surface*
Waves
Due to wind on ocean surface, as waves develop, there is more surface area for wind to act on; wave size is dependent on wind speed (increase with 4th power), wind duration and fetch; Strong winds of long duration generate largest waves-->degree of exposure to wave action at the coast dictates both the substrate and community (grasses and soft sediment versus rocks and encrusted animals)
Osmoregulation in marine fishes
Fish tissue has internal osmotic concentration lower than sw (tends to lose water and gain salt), drinks seawater, active excretion of salts across gills, little urine produced; Stenohaline (restricted wrt salinty, most fishes) or Euryhaline (can move across salinities, SALMON)
Foraminifera
Ecologically very important (esp in reef development), multichambered tests of calcium carbonate, both planktonic and benthic
Body layers of flat worms
Ectoderm (body covering), mesoderm (tissue filled region) and endoderm (digestive tract)
Eckman Transport
Effect of wind on surface of water on a global scale; Prevailing winds that go around the plant drive surface water flow but Coriolis effect deflects this (R in N hemisphere and L in S hemisphere)-->Eckman spiral
Cell layers in cnidaria
Endoderm (inner, has pseudopods to capture food, glandular cells, food vacuoles and zooxanthellae), Ectoderm (outer, has nematocysts), and Mesoglea (between, gelatinous, non-living but may contain living cells, impt in jellyfish)
Hella coral symbioses
Endolithic algae (give carbon to corals, important during bleaching), Bacteria in mucus (inhibits growth of invasive microbes, antibiotic, lost during bleaching events), some have N-fixing bacteria, hydroid, Trapezia crab (protects them from Crown of Stars), boring bivalves (roughs up surface of coral allowing more nutrients in)
Food chains and webs
Energy flows inefficiently up the chain--only 10% to next step, biomass at bottom>>biomass at top, no more than 5 steps in Pelagic systems, much more complex relationships leading to food webs in benthic systems Trophic Pyramid Coral Reef: primary producers (zooxanthellae, algal mats, etc), primary consumers (coral, clams, crustaceans), secondary consumers (sea anemones, seastars, parrot fishes), tertiary consumers (eels, octopuses, barracuda)
Tissue layers of coral
Epidermis (epitheliomuscular cells, nematocysts, mucus secreting cells, receptor and nerve cells) AND gastrodermis (muscular cells are ciliated and have microvilli, enzymatic glands, symbiotic dinoflagellates--zooxanthellae)
Marine regions
Epipelagic--only zone for photosynthesis Mesopelagic--light but no primary production Bathypelagic--cold, new adaptations to the dark Abyssal--very cold, very dark Neretic--lives over shelf Oceanic--lives in deep ocean
Light in ocean
Euphotic zone (to ~70 m)--photosynthesis and vision, most biological productivity here Disphotic zone (up to ~600m)--vision only, but not enough for photosynthesis Aphotic zone (below 600 m)--vast bulk of ocean, no sunlight reaches
Coastal dead zones
Excess nutrients fertilize plankton blooms, dead plankton provides food for benthic bacteria, bacterial explosions deplete oxygen (hypoxia), lead to dead zones
Australian whaling
Exploited annual migration and operated out of Moreton Island in 1952-1962, severe impact on pop (40,000 to 200-500), pop is recovering 11-12% per annum (19,000 in 2013) Aus now has a whale sanctuary surrounding all land masses
Seagrasses
Extensive intertidal and sub-tidal beds, impt habitats for invertebrates and juvenile fish, detrital-based food webs, limited direct grazing (fishes, dugongs, green turtles)
Choanocyte
Feeding cell. Flagella generates feeding currents, food particles stick to mucus, food distributed around sponge by amoebocytes
Moreton Bay and shorebirds
Feeding ground, important, 40,000 migratory waders visit each summer, including Eastern curlew (shorebird with longest bill, from Arctic regions, capable of flying long distances non stop)
Plants of sandy beaches
Few plants, no large plants cause no stable substratum for attachment, 2 types of plant: Benthic microalgae (single-celled plants on benthos) and phytoplankton (small drifting forms)
Fish-invertebrate symbioses
Fish live in and amongst invertebrates such as corals and anemones--mutualisms?? YES: anemone fish and anemones (protection of fish by anemone, fish bring nutrients to anemone), fish and coral (hide in coral during day, bring in nutrients from hunting), goby and shrimp (shrimp digs hole and goby watches for predators)
Herbivorous keystone species
Fish that can mow down large established fleshy seaweeds (have a disproportional role relative to abundance); arms race between grazers and leathery seaweeds--need to have adaptations to counter defenses such as tough skins and chemicals
Ship based activities impact on reefs
Fishing practices, oil pollution, ship groundings, anchor damage, introduction of pest species (ballast water), antifoulants (TBT causes malformations of cell membranes, copper can be toxic)-->often associated with direct physical damage (there are some shipping regulations around GBR)
Cleaning symbioses
Food source and reduced predation for the cleaner, cleaned fish loses ectoparasites and is healthier after being cleaned
Diatoms
Found all over, 2 orders (Centrales, Pennales); Glass/silica shell helpful because light is able to penetrate but is impermeable so needs perforations to take up nutrients and expel waste; Needs turbulence and wave energy to stay afloat since they are heavy; Diatoms divide asexually but continually shrink in size until sexual reproduction to get big again (trade off for living in a glass house); Hugely abundant and diverse; up to 40% of total phytoplanktonic photosynthetic output, impt in "marine snow"
Whales: order Cetecea
Found in polar to tropical regions, many are migratory, excellent fossil record so we can track body changes; 2 suborders: Mysticeti (no teeth, just baleen plates) and Odontoceti (toothed whales)
Equatorial upwelling
From tradewinds, water deflects at equator so lots of nutrient rich water comes up; algae blooms from equatorial upwelling (forming habitats in middle of the ocean)
Dugong (general)
Fully marine, no freshwater dependence; globally vulnerable due to loss/degradation of coastal habitats, position as a seagrass specialist, and an extremely slow breeder
Animals on rocky shores
Gastropod snails (drill holes and spit digestive enzymes into prey and suck it all up), Filter feeders on lower shore (oysters, mussels, barnacles, tubeworms, sea squirts), strong well attached animals on lowest shores (chitons, sea urchins, starfish, crabs)
Why is coral triangle so diverse?
Geological history--southern half is tectonically unstable so constantly changing geography leads to habitat complexity and evolutionary change, plus it's characterized by complex island shorelines that create diverse shallow habitats adjacent to deep water; Dispersion--CT acts as a catch for all larvaefrom both S Equatorial and N Equatorial currents
Fish respiration
Gills are filamentous/vascularized, large surface area, sit in common chamber, protected by bony operculum Ventilation through movement of oxygenated water across respiratory surface, water drawn in through the mouth and expelled across gills, more difficult than extracting O2 from air, gills are 80% more efficient than lungs Gas exchange: short diffusion distance for O2, counter-current circulation, water flows in 1 dir only, ventilation by suction-pressure pump
Biological factors for distribution of reefs
Global patterns of water movement, reproductive strategy (larvae that live for a long time can travel along currents for a while and have a large distribution, not with short larvae life though)
Simultaneous hermaphroditism
Gonad partly male and partly female, only seen in the Hamlets, prefer to mate with individuals of the same color pattern
Apogonidae (Cardinal fish)
Gonochoristic mouth brooders, exceptions to the no pelagic larval stage (mouth brood until the larvae are pretty large)
Acanthuridae (sturgeonfish and tangs)
Gonochoristic, broadcast spawn in groups at dusk, larvae planktotrophic, pelagic larval duration is 2+ months prior to settling, immediately commence their adult diet upon settling
Blenniidae and Gobiidae
Gonochoristic, males usually larger and more colorful; male guards the eggs which are laid in burrows, crevices, under rocks or in abandoned shells
Fish Reproduction
Gonochoristic: fish maintain the same sex throughout their entire lifespan Most reef fish are hermaphrodites Sequential hermaphrodites: Protandrous (male to female) or Protogynous (female to male) Level of parental care varies among fish Some have internal fertilization (sharks, rays, seahorses)
Tides
Gravitationally influenced, more influence by the moon due to shorter distance; Causes water to bulge directly towards and away from moon (not straight cause of friction due to earth's rotation); Spring tides-->larger tides cause moon and sun align (pulling in parallel directions); Neap tides-->smaller tides cause moon and sun don't align (pulling in perp directions); Diurnal inequality is due to the changing angle of the moon relative to the equator (causes different heights of tides in a day or only 1 tide, etc) *All influence how animals adapt/trade off in intertidal zone*
Class Holothuroidea (sea cucumbers)
Greatly elongated along oral/aboral axis, ossicles reduced to spicules embedded in body wall, respiratory trees are highly branched, can throw out whole gut and sticky tentacles to distract predator, lost tube feet that face away from substrate, flexible tissue, reproducing through spawning
Threats to seabirds
Habitat loss through coastal development, introduced feral animals (foxes, cats, rats, mice, skuas), oil spills, fisheries bycatch (esp longline fishing which drowns 300,000 seabirds a year)
Grey Nurse Shark
Has an undeserved reputation due to fierce appearance, found around S Aus; Critically endangered on east coast and vulnerable on west coast due to past fishing
Class Bivalvia
Have 2 shells and a hinge, sessile or burrowing (don't need much of a head), shell composed of 2 halves (=valves), no torsion, huge gills used for respiration and filter feeding (very effective filters), Tridacnid clams support zooxanthelae
Hydrozoa characteristics
Have both polyp and medusa in life cycle, no cells found in mesoglea, can have specialized polyps for feeding and reproduction
Flagellated protozoans
Have flagella, have pellicle for definite shape, 7500 species, one causes sleeping sickness
Class Cephalopoda
Have remnant shells (soft), Blue-Ringed Octopus (SUPER toxic venom in a tiny guy), Nautiluses (deep water, externally shelled cephalopod, move very fast, mating through sex, no larvae (juveniles w/o larval stage))
Fishes=non-tetrapod vertebrates
Have: skull and backbone, fins, gills (or lungs), scales, larvae, ectothermic; Sensory systems: large brain, eyes, olfaction, lateral line system, electric currents (some)
Zooplankton
Herbivorous feed on phytoplankton; carnivorous feed on herbivorous zooplankton; vital link in transfer of energy from primary producers to higher animals; crustaceans (esp copepods) dominate, krill too; some have mucus to protect themselves and catch food (??); Have members of hydrozoa, gastropoda, nudibranchia
Aquaculture impact on reefs
High concentrations of sediments and nutrients, can be highly saline, risk of disease due to exotic parasites and pathogens
Plants on rocky shores
Higher levels of shore--hard encrusting algae, lower levels--foliose algae (branched complicated bodies, canopy for small animals at low tide), microscopic plants, at waterline and subtidal--tough wiry or flexible algae
Grey Whale
Highly migratory, benthic feeder, both populations nearly hunted to extinction, Baleen
Plankton info
Holoplankton (entire life planktonic) and meroplankton (part of life planktonic most fish and crustacean larvae are part of meroplankton)
Effects of ocean acidification on fish
Huge decline in fish pops when coral dies, larval fish lose ability to detect predators, hide less and take more risks, less likely to survive, impairs olfactory discrimination (can't go home, go towards predators)
Estuaries--effects of salinity
Huge variation across estuary; estuarine animals can tolerate much less salinity than marine animals, have osmoregulators (body salinity stays constant, excrete excess water, actively retain salts, energetic cost) and osmoconformers (body salinity changes, fitness cost, many cannot survive estuaries)
Dif types of corals
Hydrocorals, black coral, soft corals, sea fans, and Scleractinia (stony/reef building corals--most impt)
Dugongs--identity and info
IDed mostly by gene tag now; sex found by anal-genital distance or now molecular markers (male-specific genes); Body size (specific markers that it should be at for dif life stages) and girth (peduncle, anal, maximum, axilla) and body condition rank; Maturity and reproductive status (fecal hormones and secondary sex characteristics--GOT FIRST LIVE SPERM)
Aggression and competition in corals
Important for determining reef structure, compete by sending out mesenterial filaments to attack offending animal (extensions of mesenteries and full of nematocysts)
Ecological role of seabirds
Important in nutrient transport, top-down control of fish populations, colonization of coral cay vegetation, impacts on benthic invertebrate communities is unknown
Improve conditions for remaining coral so they can withstand climate change
Improve water quality, control fishing pressure, regulate tourism/shipping, protect areas (zoning has provided refuge for protected species, boosted species numbers, increased abundance of fish)
Locomotion of turtles
In water, use hydrodynamic shells and flippers; only females move on land for nesting, some bask on black sand beaches, some feed on intertidal mangroves
Combined impacts of different drivers on reefs
Increased temp causes decreased reproduction, faster development, limited dispersal, diminishes recruitment, higher metabolic rates-->juveniles are smaller and fewer, fish pops decline
Coral triangle
Indonesia, Philippines, PNG, N Aus; highest coral diversity (influenced by closing of Tethys sea by India), most people in these heavily populated areas depend on reef for work/food/livelihood Less than 1% of earth's surface but has 76% of all coral species and >37% of all reef fish species-->center of biodiversity for countless marine organisms
Tourism impact on reefs
Infrastructure development, over-fishing, bad diving practices, anchor damage, pollution-->getting better (tie boats to moorings, banning fins) because they are protecting their own industry
Inshore v offshore reefs
Inshore (dominated by fringing reefs and continental islands, soft corals dominate, close to land-use issues, warmer) VERSUS Offshore (better developed, more biodiversity)
Adaptations to living at sea (birds)
Insulation (feathers and fat reserves), waterproofing (Uropygial gland--oil gland above base of tail), salt excretion (salt glands above eyes)
Colonial coral polyps
Integration, allocation, translocation--carbon from other polyps can be passed around to help healing or feeding if a polyp is damaged/blocked, nervous messages may be able to be transferred
Grazing fishes
Intensive feeding by grazing fishes consumes 50-100% of total macro-algal production, eat a lot to make up for the fact that much of the carbon in algae is in the form of cellulose which only 20-70% of that carbon assimilated by herbivore (rest excreted as feces so detritivores are happy); Grazing stimulates primary production
Grouper-Eel cooperative hunting
Inter-species cooperation, initiated by head shaking given by grouper, presence of complementary hunting strategy, only initiated by hungry groupers *cooperation makes hunting 5 times more successful for both parties* even though only one party gains from any particular hunt
Shark Reproduction
Internal fertilization, claspers used during sperm transfer to females; Egg development: Viviparous (eggs hatch internally, nourished by placenta--whitetip reef shark), Oviparous (fertilized eggs laid in ocean--cat sharks), Aplacental viviparity (eggs hatch, pups develop internally, cannibalism on siblings and eggs--grey nurse, Tiger, Great White)
Shark reproduction
Internal fertilization, male has claspers that are inserted into female cloaca, sharks have 3 ways of bearing young (viviparity, ovoviviparity, oviparity)
3 major evolutionary steps in the fishes
Jaws, paired appendages, lungs
Epipelagic zone
Key abiotic factors: sunlight for photosynthesis, turbidity affecting light, seasons affecting light/temp/photosynthetic rate Key biotic features: Primary producers (phytoplankton* and algae), Primary consumers (zooplankton), Secondary consumers (larger inverts, fish, reptiles, mammals) *Almost all open ocean production* Almost no outside input of organic energy source off shore--distribution by currents
Turtle eggs
Laid above high water line, lay 50-130/clutch and 3-8 cluthes/season, no parental care, temperature-dependent sex determination, hatch at night (80% success), hatchlings often have a 'lost years' pelagic phase with ocean circumnavigation
Coastal development impact on reefs
Land reclamation and dredging-->increased sedimentation-->reduced light levels, smothered corals, direct physical damage to reefs, interfere with sensory abilities of larval fish; Increases in N and P-->allows more algae, less light penetrates, too much zooxanthellae makes it less mutualistic; Increase in pollutants--> poison plants and animals
Crown of Thorns starfish outbreaks
Large spined seastar that eats coral tissue, outbreaks due to increased nutrients that increase larval survival and human removal of main predators-->totally f-ing up the reef right now, can breed in huge numbers very fast and takes a lot to kill it
Right and bowhead whales
Large, stout whles, no ventral pleats or dorsal fin, large heads (1/3-1/4 of body), skim feeders (most of time spent at surface feeding), large baleen; All 4 species are threatened or endangered (basically no N Atlantic Right whales left); S right whale in Aus has been heavily whaled but is starting to recover, range expansion, hella threats (whaling, coastal disturbance, habitat degradation, pollution, food availability, ship strike, entanglement)
Dolphins
Largest and most diverse family, live in all oceans, primarily fish eaters but some squid/mammals, very smart so very adaptable, opportunistic feeders; round conical teeth for grasping fish; Variable social structure
Sperm whales
Largest toothed whales, well studied, complex social structures, deep water, world-wide; Pygmy/dwarf sperm whales are widely distributed, heavily affected by whaling
Sea turtles of Australia
Leatherback, Loggerhead, Green, Hawksbill, Olive-ridley, Flatback (all threatened or endangered)
Flow of energy through living systems
Light energy from the sun is converted to chemical energy (carbohydrates, etc) by producers and this is converted to energy of movement/waste/heat/entropy by consumers and will go to space
Sea snakes of GBR
Little known of ecology and population, low recapture rates, distribution data from trawler by-catch but no pop data (Trawlers are HUGE threat to sea snakes, up to 100,000 capture yearly in one area)
Diagnostic features of whales
Live: location, body, fin size and shape, blow shape and size, diving and surfacing behavior, social grouping, reaction to vessel; Carcass: location, body, fin size and shape, head/skull characters, no and size of teeth or size, color and number of baleen plates, color pattern, number stranded
Antartic Icefish
Lives in polar water, clear blood with no hemoglobin (O2 dissolved in plasma, low metabolic rate, high solubility of O2 in cold water), O2 carrying capacity <10% compared to other fish (larger blood vessels, 4 times more blood, bigger hearts, low viscosity blood)
Sarcopterygii
Lobe-finned fishes (LUNGFISH), links to tetrapods
Sea snake biology
Locomotion--have a laterally compressed body and paddle-like tail, belly scales reduced; Respiration--valvular nostrils at top of snout, single lung (oxygen store and buoyancy), some have cutaneous respiration; Salt balance---tongue glands excrete excess salt cause salt can be toxic in high levels
Life history of cetaceans
Long lived, long pre-reproductive period of 3-20 y, typically 1 offspring/season, gestation 10-17 months, lactation for >1 year, long intercalving interval, slow rate of population increase (2-10%/year)
Dugong--reproduction
Long lived, slow growth, slow reproduction: female matures 13-17 y, 1 calf/season, 13 month gestation, lactation 2-4y, 3-7 y between calves, calves often stay with mum until another calf comes along
Reproduction of sea birds
Long-lived, slow to reach sexual maturity, nest on land, most breed in large colonies/have mating rituals/mate for life/nest on ground/lay large eggs/rear their young
Migrations of seabirds (Sooty shearwater)
Longest animal migration (40,000 miles per year), breed in NZ, migrate to N hemisphere in summer, migrate for food, use prevailing winds
Body plans
Look at ratio of oral-aboral axis (LOOK AT SLIDE 32 IN INVERT 3)
Coral bleaching
Loss of colored zooxanthellae and/or the loss of their photosynthetic pigments, results in the coral losing color; caused by high sea surface temperature or high levels of light (mass bleaching events) or high turbidity/sedimentation/cyanide/pollution (localized bleaching events)
Nutrient availability in ocean
Low nutrients (compared to soil), limits NPP, nutrients often associated with human derived enrichment of coastal waters; N and P low but Fe is VERY low (rapidly oxidized)-->lots of nutrients end up at the bottom but light is on top so photosynthesis is hard
Microphytobenthic communities
Made up diatoms, dinoflagellates, chlorophytes, cyanobacteria; form as films on sediments, rocks or surfaces where there are enough light and nutrients for photosynthesis; episammic (attached), epipelic (free-living), epiphytic (on other marine plants/algae); Important in PP, support important/diverse grazers (rich in lipids, nucleotides and AAs); algal turfs contribute to reef productivity by growing on dead coral
Location of nutrient generation/recycling activity
Main sites on a reef--surfaces (mats and surfaces line intertidal and subtidal areas), sediments (much of reef is sediments, not coral) and slicks (aka blooms, can involve significant increases in waterborne cyanobacteria)
Hagfish--slime hag
Mainly marine, vestigial eyes, no larval stage; necrophagous (carrion, soft invertebrates), circular mouth, sensory tentacles, "tooth" plates, eats insides of rotting fish, can tie itself in knots, noxious slime=defense
Life styles of polychaete worms
Majority are free living, a few are parasitic, some are commensal on other organisms, some are highly mobile, some are relatively sedentary, some are entombed in hard substrates, all sorts of different feeding modes (carnivores, herbivores, filter feeders)
Coccolithophorids
Make plates from CaCO3 (lock up carbon as a stable carbonate--cliffs of Dover), dominate phytoplankton in cold waters (few diatoms and dinoflagellates); When they die they sink and transfer carbon through food web; Locking up carbon as carbonate is important climate change buffer (CaCO3 plate formation not affected by ocean acidification)
Mangrove forests
Marine angiosperms, intertidal; provide habitat/protection from erosion/carbon sequestration/nutrient and sediment retention/nutrient recycling; prefer soft/nutrient rich sediments; highly productive in fixing carbon; successful because need low oxygen/salt tolerance (ways to exude/secrete salt)/reproduction (floating seeds); diversity increases closer to equator (warmer, wetter, less saline); Trade off is that the trees are smaller since it takes so much energy to exude salt and grow in this enviro; Threats from development, human habitation, clearance for agriculture and aquaculture, agent orange
Seagrasses
Marine angiosperms, roots derive nutrients from substrate (can live in warm, clear, nutrient poor water--where algae isn't), reproduce asexually and sexually, support dugongs and turtles; Threats include light requirement, nutrients, turbidity, run off, invasives and competitors (Caulerpa common in aquariums then discarded in ocean, outcompetes seagrass); Trade off is that it can survive in nutrient poor water but is outcompeted when there are lots of nutrients (???)
Where does the food come from?
Marine snow (plants and animals that have died at the surface fall down into deeper water; has possibly been eaten and defecated multiple times); wood (wood sinks, broken down by bacteria); whales and other large animals that have died (provide food for long periods of time--from fish and blubber, then left over bits of flesh/bacteria, digestion of bones, sulfide mats that feed things for ages)
Sea snakes (overview)
Marine, cold-blooded, evolved from terrestrial snakes, 2 groups that have diversified hugely (no sea kraits in Aus)
Scyphozoan characteristics
Medusa dominant (polyp short-lived, small or absent), mesoglea well developed to form jelly
Turbellarian structure
More material now: eye spots, mouth, simple gut, nephridia, nervous system, start of a kidney, more form to the gut
Impact of reef loss due to climate change on the world
More than $6 billion annual earnings from GBR reef-associated industries, GBR vital for tourism, 100 million supported directly by reefs, loss of coastal protection, loss of protein sources,
Copepods
Most abundant animal on the planet (incredibly important in food webs), only 1 eye, usually only 1-2 mm, key component of plankton, half parasitic
Fish (very general)
Most ancient vertebrates, most abundant, most diverse (27,000+ species), about half of all existing vertebrates, 58% are marine
Who are planktivores?
Most fishes are planktivorous as larvae, generally only specie with appropriate adaptions remain obligate planktivores as adults Virtually every major family includes planktivorous species (groupers, butterflyfish, wrasses, cardinalfish, etc)
Olive-Ridley Turtle
Most numerous and smallest turtles, deep water, eats jellyfish, salps and crabs
Phytoplankton
Most of ocean's primary productivity, produce half of all atmospheric oxygen, unicellular or simple chains of microalgae, diatoms/dinoflagellates/nanoplankton most impt (seasonal and latitudinal variation)
Agnathans--jawless fishes
Most primitive vertebrates, no jaws around mouth, cartilaginous skeleton, smooth scale-less skin; Ancient agnathans known from fossils only, sediment pumpers or grubbers, diverse & successful; lampreys and hagfish are only living representatives
Sharks in freshwater
Most sharks can't live in freshwater; bull sharks and some stingrays can lower urea concentrations in blood to enter freshwater (still large influx of water and salts, rectal gland stores excess salt, large amounts of very dilute urine), female bull sharks give birth in Brisbane River
Basic anatomy of a mollusk
Mouth with radula (feeding apparatus like a straw), foot, mantle, visceral mass (LOOK AT DIAGRAM, SLIDE 6, 3rd INVERTS)
Seaweeds
Multicellular marine algae, attached, no roots/vascular system--get nutrients from water, only net production on 33% of shelf; Live anchored to substrate so are subject to high wave forces-->most resources go to structural strength and strong anchorage (holdfast) not growth/reproduction; Must allocate resources to deter predation; High surface area to volume which allows max diffusion of nutrients directly into tissues and maximum light capture; Threats from increase water temp, increased urchin grazing due to removal of lobsters, high sediment run off from forest clearing
Monodontidae
Narwhal (pelagic) and Beluga (shelf waters), live in Arctic ocean, no dorsal fin, both migrate with ice edge, generally in small groups
Plankton bloom
Need abundant light and high nutrients; bloom is self-limiting because it will exhaust its supply of nutrients and block out the available light (cyclical), Iron is limiting as always
Light and reef development
Needed for zooxanthellae to function, reefs are depth limited, turbidity limited, allows corals to be in competition with macroalgae; Influence of rivers and importance of continental shelves--proximal factors for light (need it to be shallow, not at river mouths, etc)
Shark locomotion
Negatively buoyant so have a large oily liver to keep them buoyant, fins are hydrofoils (lifting surface)
Flatback Turtle
No early pelagic phase, "homebody", eats jellyfish and sea cucumbers
Lampreys
No jaws--microphagous, predator/parasite?, oral sucker, horny "teeth, rasps flesh and sucks fluid, saliva has anticoagulant; larva are ammocoete filter-feeder, metamorphosis to adult, fresh and saltwater--breed in freshwater and migrate to sea; minor food source in some countries
Abyssopelagic--aphotic
No light, freezing temperature, high pressure, 4000-6000m, 3/4 ocean floor is in this region
Animals on beaches
No resident vertebrates (transient vertebrates like lots of birds, fish, seals, etc), most invertebrate phyla are present; most common: nematode worms, other worms, crustaceans, mollusks, insects; 2 groups: interstitial microfauna (between sand grains, extremely small) or macrofauna (crustaceans such as soldier crabs, polychaetes, mollusks)
Phylum Porifera--The sponges
No true tissues, no symmetry, simple body plan, filter feeders (v impt in recycling nutrients), lots of symbioses with bacteria
Coral Bleaching
None reported before 1979, high water temp and high light trigger bleaching, cold water bleaching also possible, mass coral bleaching and mortality is increasing, 1998 worst year (16% of all coral died), 2002 worst on GBR, 2005 bad in Caribbean, 2010 bad in Asia, inshore reefs bleach more than offshore, happens when warm waters comes through and sits for a while (high temps for longer, low flow) *likely that we will cross bleaching threshold often, no time for recovery between events*
Bacteria
Not Eukaryotic, play a massive role in nutrient cycling (microbial loop); Cyanobacteria can be unicellular or produce long filaments, may use multiple photosynthetic pigments so they can use more wavelengths, massive blooms; Stromatolites formed by precipitation of CaCO3 by cyanobacterial mats--very very very old and show importance of cyanobacteria in ancient world; Prochlorococcus are some of smallest primary producers, respond well to blue light (NPP deep within euphotic zone), more abundant at depth where it has less competition, more closely related to chloroplasts than E. coli
Summary of Porifera
Not much of an "animal", early and successful, some sophisticated and some primitive attributes, important cause filters lots of water, important as source of bioactive compounds *Have more than one cell but still super simple*
Shorebirds
Not seabirds (no webbed feet), impact on intertidal benthos, most important predators on mudflats at low tide; In Aus, are either resident species, migratory species from breeding areas that summer here, or vagrant species that occasionally visit Aus
Coelomate invertebrate
Now have coelom on both sides of the mesoderm, safe place for organs to sit, Sipuncula was first to develop it
O v M (dentition)
O: Variable depending on diet--dolphins have conical teeth upper and lower, porpoises are spade shaped, beaked whales often only have one pair of erupted teeth, sperm whales only have teeth in mandible M: Baleen from upper jaw, no teeth, used for sieving water, length of baleen depends on prey item, large tongues
Odontocetes v Mysticetes (size)
O: all <10 m long (except sperm whale), <5 tons M: all >10 m long (except minke whales), may be >100 tons
O v M (skull morphology)
O: asymmetrical (right is bigger than left, specialization for sound production?), concave cranium M: symmetrical, high arch rostrum (kinda looks like a C)
O v M (blowholes)
O: single M: paired
Role of Polychaetes
Occupy various levels within the food chain, high productivity, high rates of turnover, bioturbation and sediment reworking, important in getting oxygen into sediments
Ocean acidification
Ocean is huge carbon sink, half of CO2 produced by humans in last 200 yrs is in ocean, becomes carbonic acid and the pH of the ocean is lowered
Global primary productivity
Oceanic productivity can be observed in space due to chlorophyll in water; not uniform worldwide--higher in areas with upwelling and nutrients
Primary productivity in ocean
Oceanic productivity--incorporation of carbon atoms into carbohydrates, measured in grams of Carbon bound into carbohydrates per square meter of ocean surface per year
Commensalism
One member derives benefit from association, other is neutral; barnacles on turtles
Dugongs and seagrass
Only found in 1-10m water, high in protein and sugar but low in fiber, limited to soft, low fiber sea grasses, spend ~1 minute underwater before coming up to breathe, make feeding trails, dig up sea grass and it just breaks down in their mouth *Growth and reproduction determined by availability of seagrass nutrients*
Sea surface
Open sea=pelagic realm. epipelagic--surface layer; photic zone, wind and wave action cause mixing so even temperature throughout; warm and well lit-->photosynthesis Direct interaction with surface (birds!) Complex multi-level food webs
Structure of a coral polyp
Oral disc, mouth, pharynx, gonads, mesenteries (where reproductive material is held, most have both male and female organs), gastrovascular cavity, calcifying ectodermis, external skeleton Size of polyps is highly variable
Class Crinoidea (Feather stars)
Oral side up, body supported above substrate by a long stalk or by a series of grasping claws, suspension feeders (feed by passing particles down pinnae to mouth), arms move independently
Plankton
Organisms that drift with the current (artificial classification based on shared lifestyle), many phytoplankton are autotrophs and make greatest contribution to NPP, transfer carbon to photic zone and form basis for detrital food webs
Class Echinoidea (sea urchins)
Ossicles joined to form a rigid test and spines, have Aristotle's lantern (complex system of muscles and ossicles for grazing and chewing), have spines all over to protection and locomotion, well developed tube feet protrude through pores, pedicellaria well developed and borne on stalks, eat algae (impt for controlling pops so corals survive)
Baleen
Outgrowths of buccal epithelium, medulla=fine tubules with horny matrix, outer cortex layers; both outer cortex and matrix wear down (medulla tubes are exposed and form hairy fringe), 140-430 plates per side; size, color, # of plates is diagnostic of species
Importance of Aus estuaries
Over 1000, ~50% of pop lives within 4 miles of coast, habitat for native plants and animals, high biodiversity, commercial/traditional/recreational fisheries, places for recreation and wilderness experience, benchmarks for coastal health Only 50% are near pristine and 11% are severely modified
Reasons for self-recruitment
Parental habitat is demonstrably of suitable quality for survival and reproduction; probability of encountering better adult habitat by dispersing is low; advantages accrue through local adaptation
Fish feeding on algae
Parrotfishm rabbitfish, surgeonfish, damselfish; Control the vertical growth of algae (space and light competitors of small corals); indirectly control the survival of coral recruits by removing algae; some contribute to and some alleviate reef bioerosion; turf algae produces fast and is mowed down fast; Herbivory is essential for reef recovery from disturbance
Moreton Bay 'estuary'
Partially enclosed body of water, salinity usually same as ocean, tide-dominated, seawater sometimes diluted by floods, high diversity of habitats/biota, overlap between tropical and temperate biota
Loggerhead turtle
Pelagic juvenile then coastal adult, carnivorous, eats crabs, mollusks, jellyfish--opportunistic feeders that will eat most anything
Energy Flow
Photosynthesis food chain-->sun then chloroplasts then reduced carbon compounds that herbivores eat that carnivores eat *chloroplasts, light, carbon dioxide, water* Chemosynthetic food chain-->bacteria use sulfide energy to make carbon compounds and carnivores eat the bacteria *bacteria, sulfides, CO2, oxygen*
Plant-animal mutualism
Photosynthesizing prokaryotes (cyanobacteria) or eukaryotic plants (green algae, diatom, dinoflagellates)
Photosynthesis and respiration in the ocean
Photosynthetic output regulated by amount of light/nutrients, can only in first 200 m, even less if turbid--most of photosynthetic output used in respiration (NPP only possible in sufficient light)
Reef erosion
Physical: wave action, storms, cyclones; Biological: internal bio-eroders (boring bivalves, worms and sponges through mechanical abrasion and acid secretion) and external bio-eroders (fish and sea urchins through mechanical abrasion)
Manta rays
Planktivores, horn-shaped cephalic fins, highest brain to body mass of fishes, long lived (50 y), slow breeders (5.5 to 7 m) Aus has a migratory species and a resident
Planktivores
Planktivorous guild (fish with dif phylogenies display some convergence since feed on same thing--big eyes, silvery blue color); Major strategy: small and forage together in schools (hide within reef structures, streamlined bodies that are laterally compressed, strike plankton with visually oriented "ram jaw" feeding) OR become super large (whale sharks, manta rays)
Intertidal zonation
Plants and animals on rocky shores live in 'zones' or bands across the shore often parallel to low water levels; high Littorina zone (Blue periwinkles-mollusks with low metabolic rates when exposed), Barnacle zone (crustaceans attached to rocks), Mussel zone (mollusks attached by very strong threads, can withstand waves), Kelp zone (tough strong algae, great holdfasts), Water
Coral morphology of Scleractinia
Platelike, Foliaceous, Encrusting, Free Living, Columnar, Massive, Branching
Feeding strategies of seabirds
Plunge divers (boobies, gannets, some terns), Pursuit divers (Cormorants, shearwaters), Looters (Frigate birds--harass birds until they drop food, snatch offal from surface, eat maturing chicks, are a-holes), Aerial predation (boobies target flying fish), Surface feeders (swimming--gulls, shearwaters; flying--storm petrels, noddy terns)
Fish locomotion
Propulsion via body and fins; To reduce drag: pressure drag (streamlining, spindle-shaped), Friction drag (smooth scales, mucus); Broadside fins counteract roll/pitch/yaw; Buoyancy control via swim bladder
Amphiprionidae (clownfish)
Protandrous, strong hierarchy where large female dominates, mates only with largest male, when she dies the largest male becomes the dominant female and so on; clownfish can keep mating without having to journey to find new anemones/mates; eggs are demersal and deposited near the anemone and tended to
Flood impact on reefs
Pollutants discharged into reefs, flood plumes normally inshore but can extend out, carry sediments and nutrients from land, also heavy metals and pesticides *more frequent and intense floods due to climate change*
Polyp versus Medusa
Polyp (mouth up, tentacles up, almost always sedentary) and Medusa (tentacles and mouth down)--Both have very simple digestive system where mouth/anus/reproduction all have same opening)
Shark water and salt water balance
Potential loss of water due to salty enviro, sharks don't drink, maintain blood and tissues saltier than seawater (urea in blood), reduced loss of water due to concentrated urine, absorb water from the sea by osmosis through the gills, excess salt from blood excreted via rectal gland *sharks do not dehydrate*
Fish diversity drivers
Predation pressure is extreme on reefs leading to both behavioral (schooling or hiding in reef) and morphological (enhance speed and maneuverability) adapations As complexity of reef structure increases--number AND diversity of fish increase
Feeding modes of Echinodermata
Predators (some seastars), Herbivores (sea urchins), Filter feeders (crinoids), Scavengers (many seastars), surface deposit feeders and sifters (sea cucumbers)
Feeding methods of crustaceans
Predators (stomatopods), Herbivores (crabs), Filter feeders (barnacles), Scavengers (prawns), Mutualistic (Periclimenes), Parasites (parasitic isopods on fish)
Class Asteroidea (seastars)
Predators or scavengers, mouth directed downward (feed by everting stomachs over prey and exuding digestive enzymes, most can take stomach out, invert it and then suck important things back in), gonads and digestive tract extend into each arm, move by walking on tube feet with suckers (function in feeding and locomotion, bulb holds the water and will release water into tube feet when it needs to move), can drop arms when threatened, ossicles create stiff arms that have limited bending ability
Pelagic larval stage of fish
Present in nearly all bony reef fish (anywhere from 1 to 64 weeks), present regardless of whether eggs are pelagic, demersal, brooded, or live born Benefit: large dispersal phase to avoid progressive local extinctions in the patchy geography of coral reefs (should act against speciation as gene flow between pops can counter difs in allele frequencies, expect linear correlation between pelagic larval duration and species ranges); 40-60% of larvae make the journey home to natal reefs (capable of directional swimming after hatching, well-developed sensory systems to locate and orient to reefs)
Primary production
Production of organic molecules from inorganic carbon leading to a net gain in organic carbon, through chemosynthesis or photosynthesis
Dinoflagellates
Protists, some produce cellulose plates, 1/2 are photosynthetic, have 2 flagella for swimming, they can swim towards light/nutrients, so occupy dif enviros from diatoms (still water); Lots of toxic dinoflagellates; Bioluminescence
Scaridae (Parrotfish)
Protogynous, some species are diandric (primary male and secondary males (derived from females) and females), travel in schools of a single large gaudy male (derived from a female) with harem of drab females and juveniles
Dugongs--QLD floods
QLD floods in 2010-11, 70% of state flooded, seagrass loss/reduction; had 3 years of pre-flood data so could look at health effects of floods (had a "healthy" baseline); Caused changes in blood chemistry (indications of dehydration and starvation), not chronic but acute stress, movements changed, changes in diet, low nutritional plane, increased contaminants , increased susceptibility to stress, mortality (continued over months)
Radial symmetry versus bilateral symmetry
Radial is great for being sessile or up and down (just floating around or not moving in a particular direction) while bilateral is great for forward locomotion
Cnidaria
Radial symmetry, structural and functional diversity, medusa (jellyfish) or polyp (anemone) body plans, tentacles around mouth, one opening to digestive system. all have nematocysts, two tissue layers, have nerves/muscles but no central nervous system, respiration through diffusion
Sewage impact on reefs
Raw sewage going into ocean-->nutrient enrichment and algal overgrowth-->slow and gradual change in reef structure, algal domination *can be reversed*
Reefs are super productive BECAUSE
Recycling via close association of autotrophs and heterotrophs, internal sources of some nutrients (e.g. nitrogen fixation), and retention of water masses via reef porosity and lagoonal ponding
Darwin's Paradox
Reefs flourish and have enormous productivity and diversity in waters with very low nutrient levels!!!! Key is nutrients, symbiosis and recycling
Estuary from sea to inland
Reefs-Sand flats-sandy shores-rocky shores-mudflats-seagrasses-mangrove forests-saltmarsh-riverine habitat Gradient in wave action, oxygen, salinity, temp, sediment load, turbidity, nutrients
Vacuoles
Regulate osmotic pressure within cell, contractile vacuoles--discharge water from inside cell
General characteristics of an estuary
Relatively sheltered, low wave energy, variable conditions across estuary (salinity, temp, water quality, oxygen), dynamic systems (great temporal variation, unstable, unpredictable)
Diurnal Planktivores
Remove a significant proportion of plankton, major trophic link between ocean and reef as feces are deposited on reef and taken up by coprophagy and detritivores
Biotic features that determine animal distribution
Resources (food, shelter), competition for food, competition for space, predation, recruitment/settlement
Challenges of the deep
Rubbish dumping (6 billion kg of waste), glass and aluminum don't break down, cruise ships hitting golf balls into ocean, unsustainable fishing (they grow slowly and have few young), deep sea trawling destroys fragile animals on bottom, mining of manganese nodules
Dugong--pop dynamics
~1000 dugongs in Moreton Bay, resident pop, mostly isolated and genetically distinct to Hervey Bay, stable over last 20+ y, variable annual recruitment
Order Carnivora, Suborder Pinnipedia
SEALS: 33 living species in 3 fams, 28% of marine mammals; tied to ice or land to breed (semi-aquatic); united by obvious features--Fusiform body (spindle shaped, tapered on each end), Flippers, Insulation; 2 types here--Otariids/eared seals (Aus fur seal, NZ fur seal, Aus sea lion all down south) and Phocids/true seals (Leopard seal, elephant seal)
Diet of seabirds
Schooling species are important, larval and juvenile fish, fish that are forced to surface by large predatory fish, flying fish
Chemosynthesis in aphotic zones
Sea water dips into core, is heated/enriched with minerals and spurts back up into the sea, minerals drop out when it hits cold water, bacteria use this for chemosynthesis (hydrothermal vents); CO2+O2+H2S-->Glucose+S+H2O
Dugong--threats in SE QLD
Seagrass degradation and loss (coastal development, floods/cyclones), net entanglement, boat strikes, hunting, disease/pollution *>80% of QLD dugong deaths are human related*
Photosynthetic communities
Seagrasses, mangroves, attached large seaweeds, phytoplankton (plankton responsible for majority of oceanic NPP), bacteria, photosynthetic symbioses
Seawater versus Air
Seawater is 800 times more dense, 100 times more viscous, less oxygen (21% v <0.0015%), salty (35 ppt), pressure increases with depth
Boring sponges
Sediment builders, impt symbioses with dinoflagellates and cyanobacteria, bioeroders
What is an estuary?
Semi-enclosed body of water connected to the sea and with one or more rivers or streams-->transition zone between river (water flows, sediment) and ocean (tides, waves) enviros
Whales in Aus
Short-finned pilot whales (rare in Aus water, need more data), Long-finned pilot whales (common, no pop estimates, possibly abundant), Offshore Bottlenose Dolphin (common, up to 4m, social pods, coastal and oceanic waters), Inshore Bottlenose dolphin (light grey belly, up to 2.6 m, shallow inshore waters), Australian humpbacked dolphin ("discovered" in 2014), snubfin dolphin ("discovered" in 2005), Southern right whale, pygmy blue (both surface feeders, migratory), Blue, Fin, Sei (open oceans), Bryde's, Minke, Pygmy blue whales (up to 24 m), humpback whale (feed in Antarctica but breed/calve in GBR region, migration led by young males, adult males sing)
Turtle life history
Similar life cycles, slow growth, 30-60y to reach maturity, slow reproduction, migrate between feeding and breeding grounds (most of life spent in feeding ground), migrate back to beach where they hatched using a biological compass, direction of sun/waves, coastal sounds/smells, mate in water
Circulation in fish
Simple single loop system, one directional flow, heart with 4 chambers in series, low blood volume and pressure, slow flow
Thermoregulation for marine mammals
Since they're warm blooded, lose heat to water; high metabolic rate due to eating lots of food-->direct heat to core, insulation, large body to maintain heat due to low surface area to mass ratio
Protistans
Single celled (lots of specialized organelles), all algal/plant/animals evolved from protistans, some ingest food and others photosynthesize, some take up dissolved organic matter across body surface *Specialization of organelles instead of cells and tissues*
Calcification of corals
Skeletons made of aragonite (CaCO3), take calcium from seawater by diffusion and active pump, corals control local chemistry to increase pH in calcifying space to increase carbonate (makes them grow faster), occurs between polyp and skeleton
Polyplacophora (Chitons)
Slow marine herbivores (algae), shell of 8 transverse plates, strong muscular foot and mantle, multiple gills
Class Gastropoda
Snails and nudibranchs, largest mollusk class, exceptionally diverse mobile grazers and predators, well-developed head, torsion shows shell and visceral mass twisted during development (twisted so anus is not on top, excrement can move out of shell and be washed away), nudibranchs and sea slugs have no or reduced shells as adults
Class Sclerospongiae
Solid basal skeleton of calcium carbonate, often heavily calcified and old, *used in climate work*
Yellow Saddled Goatfish
Solo forager using barbels to find immobile prey hidden in sediment/sand Group foragers that team up when hunting amongst corals for mobile prey (fish), have chasers and blockers *different individuals assume distinctive roles in the hunt, coordinating their attack*
Reproduction in the dark
Some animals use lights or chemical scents to signal, some are hermaphrodites to double their chances or eliminating the need for a partner by self-fertilization; parasitism is also used (male parasite in angler fish); male dragonfish has no gut and only lives long enough to mate
Effects of coral bleaching
Some coral die, all more vulnerable algal overgrowth, disease, weakening of reef structure-->overgrowth of algae prevents recolonization of new coral recruits-->community shift from coral domination to algal domination
Protozoan feeding
Some take up dissolved organic matter across body surfaces, suits parasites/those living in decaying matter, food vacuoles formed when food surrounded by membrane
Phoresis
Specialized from of commensalism where one organisms uses the other as a transport host (sometimes mutualism if cleaning), may have other benefits (eg remora being carried to feeding sites); Sharks, manta rays and turtles have this happen
Patterns of species distributions on sandy beaches
Species richness and abundance decline with wave action, some species influenced by sand grain size, larger beaches with larger swash zones have more species (more plankton and larvae), many animals migrate to swash zone (more food, frequent wetting, more dissolved oxygen, low predation)
Feeding seabirds
Spend >50% of life foraging at sea, cope with dispersed and cryptic prey, forage far and wide, usually migrate, strong beaks to feed on fish and crustaceans
Seabirds (general)
Spend a significant part of their lives at sea, feed on marine organisms, nest on land, webbed feet; 3% of bird species including penguins, tubenoses, pelicans and allies, and gulls and allies
Epipelagic nekton
Squid, sharks, fish, turtles, whales, dolphins--all predators (hunters and filter feeders); most carnivores, some planktivores; fish have good vision, sensory systems and speed
Antarctic whaling
Started at start of 20th century, Lancing was the first factory ship in 1925--huge impact on extent of whaling, could process a 20m fin whale in 45 min >2,000,000 whales killed in ocean in Southern Ocean in 20th century One of the greatest mass-slaughters of wildlife in history in both biomass and numbers
Breathing during dives for marine mammals
Still breathe air, but have very efficient air exchange (>80% with each breath), increased oxygen store in blood and muscle (high blood volume, haematocrit, Hb, myoglobin in muscle--all hold O2), will close everything and exhale before diving to decrease effects of decompression, economic in oxygen use (blood flow and heart rate decreases, only vital organs get O2)
Nematocysts
Stinging cell, unique to cnidaria, rounded capsule contains long hollow tube that shoots out explosively turning inside out as it goes
Invertebrate eaters
Strategies include solitary foraging (interesting methods to protect against predation), preyed items tend to be cryptically distributed, cleaning with fish removing parasites from other fish
Shark anatomy
Streamlined body, rostrum, underslung jaws and teeth, paired fins (stability in water), caudal fin (propulsion), septate gills, jaws are a pair of modified gill supports
External anatomy of whales
Streamlined for swimming, horizontal flukes, hindlimbs lost, pectoral fins/flippers, must have dorsal fin, dorsal nares (=blowholes), no external genetalia or mammary glands, loss of hair, loss of outer ear, telescoped facial features (long and linear)
Locomotion of marine mammals
Streamlining of body, buoyancy due to integument and blubber, propulsive force from axial body and tail (limbs in seals), steering from fore flippers
Locomotion of sea birds
Streamlining, webbed feet, diving and swimming adaptations
Reproduction and life history of sea snakes
Strongly seasonal reproductive patters (all at same time), females larger, internal fertilization, viviparous (give birth to live young), small litters
Geostrophic Flow
Surface of the ocean is not flat (differing atmospheric pressures); Gravity forces water down and Coriolis effect deflects this-->Geostrophic gyres
Temperature variation in ocean
Surface temp varies greatly both seasonally and globally, hotter water in hotter regions; Very little change in temp at depth; thermocline is the abrupt temperature gradient
Mechanisms of retention of nutrients in reefs
Symbiosis (hella) or reef structure (wall of mouths that capture plankton at reef edge, plankton have lots of N and P)
Ocean temperature
Temp influences metabolic rate, growth rate and breeding
Thermohaline flow
Temperature and salinity both affect the density of water (saltier water goes under, warmer water comes in behind it, whole thing circulates)-->differing densities cause things to circulate around the globe
Impacts of climate change on reefs
Temperature increase, increased CO2 in the water, increased storm activity, sea level rise
Important factors in the formation of coral reefs
Temperautre (18 degree minimum rule), Currents (connectivity between areas and hence ability for larvae to travel between reefs), Light (light is crucial for the function of the symbiosis), sediment/turbidity (as well as affecting light, sediments can smother benthic organisms like corals), low nutrient levels *light and temp likely the most important*
Nocturnal planktivores
Tend to be more scattered, fewer prey items consumed so feces more dispersed, contributed to reef energetics mostly as captured prey by piscivores during day-night transitions; many nocturnal planktivores are invertebrates (coral)
Global ocean currents
The body of water is in constant motion; Plankton moved around on currents, turtles follow currents to save energy, rubbish gets circulated (LEARN NAMES OF AUS CURRENTS--OCEANOGRAPHY 3 SLIDE 10)
Sad history of sea cows
Thought they were sirens, were basically all slaughtered
Spicules
Tiny structures made of calcium carbonate or silica, all the way through the cells of a sponge, help sponge stand upright
Mangroves
Tolerate large salinity range, high productivity, detrital-based food chains, nutrient cycling
Piscivores
Top levels of food chain; Major hunting strategies include pursuit, stalking, ambush, cooperative hunting; Major physical adaptions include streamlined bodies, small mouths with lots of suction or large mouths with lots of teeth, camouflage
Adaptation
Trait that confers some fitness on a living organism and it can also be the process by which that trait arose-->anatomical, physiological or behavioral trait that contributes to an individual's ability to survive and reproduce
Tiktaalik
Transitional fossil; Fish features of gills and scales; half fish and half tetrapod limb bones, joins, ear region; tetrapod ribe bones, mobile neck, tetrapod-like lungs
Vulnerability of estuaries
Traps for nutrients/pollutants, short food webs (heavily reliant on detritus), sediments play a key role in productivity, estuarine organisms live near limit of their tolerance range, freshwater input is very important and is easily modified
Hadalpelagic--aphotic
Trenches (6000-11000m), high pressure (48 Boeing 747s per inch), freezing temperatures, zero light, foraminifera (protists with CaCO3 shell) found in deepest trenches
Family Hydrophiidae
True sea snakes, fully aquatic, evolved ~30 mya, fairly small (1-2 m), venomous, air breathers, 54 known species generally in shallow, warm, murky waters
Sub-class Cirripedia
Turtle and gooseneck barnacles, acorn barnacles (cemented to the ground, same elements as other crustaceans but use them differently--exoskeleton is a shell, jointed appendages--filter feeding apparatuses)
Locomotion of protistans
Use cilia (tiny little hairs that move together to move cell), flagella (basically a tail) or flowing cytoplasmic fingers
Sea level rise and reefs
Variation in studies is huge; inundation of land will bring more harmful runoff, changes in amount of light reaching some corals, reefs may 'drown', some could bleach due to less light
Ocean salinity
Varies globally/locally/temporally (due to rainfall, river flow, tides, temp, depth); saltier in subtropics (more evaporation, less rainfall); Lower salinity in tropics (more rain) and polar regions (melting ice)-->Saltier water is more dense
Protozoans
Very abundant and speciose, unicellular eukaryotes, no chitonous cell walls, originally no photosynthesis, food ingested internally, occur wherever there is moisture
Dugong--population status
Vulnerable, likely endangered or critically endangered along QLD coast; need regional data on pop dynamics, reproduction and life history, movements, pop connectedness, health
Effect of Eckman on coast
Water moves with wind down the coast, deflected away from shore, so surface water moved away, so cold, nutrient-rich water from deep ocean comes up and replaces the moving surface water (UPWELLING)-->hella plankton and hella fish and ish
What is a reef?
Wave resistant organic carbonate structure, first found 540mya (not corals); can have coastal fringing reef, island fringing reef (along continental island), platform reef (along coral cay on shelf), Barrier reef (at end of continental shelf)
Effects of waves on reefs
Wave resistant reefs--complex communities, high niche and species divesities; non wave resistant reefs--not high or large enough to disperse waves, ecologically homogeneous
Class Ophiuroidea (Brittle starfish)
Well developed small ossicles in arms form articulating arms around central disk, deposit or suspension feeders, some change color through light sensitive chromatophores, mouths on bottom with tube feet