Guest Flashcards
What is biological oceanography
• The study of life in the ocean
– distribution and abundance of marine species
– processes that govern spread and development
• A range of scales
– smallest microbes to largest whales
– Submesoscale processes to the global ocean
• Passive movement thru to behaviour
East Australian Current
• Warm saline water; • Has spent 2 years crossing the Pacific Ocean to Australia; • An oligotrophic ocean – “no nutrients” • Unstable; wobbles and eddies • Australia has the 3rd largest fishing zone and the 55th largest fishery!
Fronts as Ocean Oases
• Boundaries between distinct water masses with sharp
gradients in temperature or salinity
• Increase patchiness through flow convergence and
increase vertical mixing and nutrient supply
• Overlap of prey and predators can be immense
• Cascade of impacts across multiple scales from local
prey size structure to global biogeochemical fluxes.
• PP is considered to set the limits of fishery production
and drive ecosystem functioning
• Patchiness may be the main regulator of production
Tasman Front influences biological communities in
many ways- 6 points
• Connectivity and dispersal of coastal organisms
(Roughan et al., 2011, Everett et al. 2017)
• Genetic structure of sea-urchin populations (Banks
et al., 2007)
• Microbial community composition (Seymour et al., 2012)
• Distribution of fisheries such as southern bluefin
tuna (Hobday and Hartmann, 2006, Schilling et al. 2017)
• Diet of top predator species (Revill et al., 2009)
• Size-structure of zooplankton communities (Baird et
al., 2008, White et al. 2018)
Continental Shelves
• 363 million square kilometres of ocean
• Make up less than 7% (< 200 m depth)
• Generate the biological production
supporting over 90% of global fish catches
• Directly contribute 75 % of fish catch
• In particular Eastern and Western Boundary
Current systems
how many new chemicals made each day
15k
how many chemicals tested for saftey
less than 0.3%
define plastic
Definition
• Polymers made from synthetic resins
• Moulded during manufacture
• Pass through ‘plastic states’ during processing
Contamination
• presence of alien materials in environment
Pollution
biological or ecological response to contaminant
Critically & systematically assessed quality of studies
logic, interpretation, experimental design & statistical analysis
PLASTIC CAUSED 74% DEMONSTRATED BIOLOGICAL
IMPACTS OF MICRODEBRIS examples
- Subatomic particle: oxidative stress (7/7)
- Atom: greater concentrations of calcium (2/2)
- Small molecule: toxic metabolites (4/4)
- Macromolecule: protein, DNA damage (67/74)
- Organelle: more micronucleii (7/12)
- Cells: necrosis, reduced immunity, less viable cells (45/54)
- Tissue: inflammation, fibrosis (25/29)
- Organ: change in size, lesions (6/8)
- Organ system: malfunctioning digestive system (5/7)
- Organism: death (4/11)
WHAT PLASTIC DEBRIS CAUSE ECOLOGICAL
IMPACTS IN MARINE HABITATS?
Plastic bottles
• Altering assemblage: soft-bottom benthic habitats
• Adding more organisms & species;
Derelict fishing gear
• Smothering coral assemblage
• Causing mortality: species of corals & associated fauna
tonnes of plastic entering marine environment each year
8 million
Largest country waste output
Asia
CAN DATA-SYNTHESES PROVIDE GLOBAL PICTURE?
OF CONTAMINATION
- Spatial scale: many small, few large
* Incompatible data: metrics & methods
BETTER METHODS, SURVEYS & EXPERIMENTS
- Generality of patterns across metrics, habitats & locations
- Material flow studies: stocks & flows (season & weather)
- Mircoplastic: procedural vs environmental contamination
% of plastic as microplastic
65
over last 65 years microplastic in the ocean has increased by
450%
Where does microplastic come from?
fragments- not granular
polyester, acrylic and nylon fibres
Australian sewage
more than 70000 litres per person
Sydney harbour storm water
more than 420000 litres per year
habitats that contain sewage sludge contain
250% more plastic fibres
Sewage effluent
contaminated with fibres
polyester, acrylic, polyamide
plastic cloth fibres
mainly fleeces
downwind habitats
over 500% more fibres
NOVEL METHODS TO ASSESS THE ABUNDANCE,
VOLUME & MASS OF MICROPLASTIC
Measure volume: • image-analysis Identity polymer: • vibrational spectroscopy Combine data to estimate mass: • volume • published polymer-densities
Confounded analyses
- Blanks not representative
- Data unbalanced
- Data not independent
- No statistical tests
baking polymers
at 500degreesC reduces their mass and spectral composition
New frameworks for plastic analysis
• Metal containers • Thermal treatment to decompose procedural polymers Robust analyses • Representative blanks • Balanced independent data • Statistical tests
SHORES RECEIVING STORMWATER FROM DENSELY
POPULATED AREAS:
> 50% FEWER SPECIES
tracer studies reveal
microplastic can bioaccumulate in gut • Transfers to haemocytes Stored in tissues & cells • Difficult to detoxify (>months)
Priority pollutants
- 78% US
* 61% EU
Plastics sorb pollutants at concentrations
- 100 times: sediments
* 1 million times: water
> 40 years speculation but only correlative evidence
• CAN MICROPLASTIC MOVE CHEMICALS INTO
TISSUES OF ANIMALS?
• DOES THIS DEGRADE FUCTIONS THAT MAINTAIN
HEALTH & BIODIVERSITY?
CASE STUDY plastics
ecosystem engineering worms
EVIDENCE MICROPLASTIC MOVES CHEMICALS INTO TISSUES
Healthy worms maintain diversity by eating sediments
HELPING GOVERNMENTS TO MAKE EVIDENCEBASED
DECISIONS
Chlorofluorocarbons Persistent organic pollutants reclassified as hazardous • Montreal Protocol 1989 • Stockholm Convention 2004 Existing policy & law • US EPA CERCLA/SUPERFUND • EU Directive 2008/98/EC
POLICY: POLLUTANT
ANY MATTER THAT CAN CAUSE
PHYSICAL, CHEMICAL & BIOLOGICAL CHANGE IN WATERS
OR HARMS AQUATIC LIFE
OPTIONS FOR MANAGING PROBLEMS
analysis and synthesis–> scope of problem
surveys–> options for managing the problem–> choose actions to solve the problem
experiments–> was the problem solved?
no? new theories and understanding
yes? back to the start
plastic policy 4 points
avoid
intercept
clean-up
redesign
Artificial Structures
Loss and/or fragmentation of natural habitats Alter flow and sediment deposition Shaded structures Vertical and homogeneous surfaces Invasive species
Landscape connectivity
involves the movement of organisms and resources across the landscape- links organisms through predator-prey interactions. Happens on multiple scales and resources
Artificial structures
act as barriers to movement of organisms are resources- impermeable or semi permeable
ECOLOGICAL
ENGINEERING
Eco-engineering is the attempt to combine
engineering principles with ecological
processes to reduce environmental impacts
from built infrastructure.
IMPORTANT CONSIDERATIONS
(I) THE REGION WHERE SPECIES ARE CURRENTLY
SITUATED
(II) THEIR ADAPTIVE POTENTIAL TO PERSIST AND
FUNCTION UNDER PREDICTED ENVIRONMENTAL
AND ECOLOGICAL CONDITIONS
(III) INTERACTIONS BETWEEN GLOBAL AND LOCAL
STRESSORS, E.G. CLIMATE CHANGE AND
CONTAMINATION.
PHYSICAL MODIFICATIONS
ADDITION OF WATER RETAINING FEATURES CREATION OF CLIMATE REFUGIA MATERIAL THAT INCREASE ALBEDO ECOLOGICAL CORRIDORS (ASSISTED MIGRATION) FLEXIBLE STRUCTURES
BIOLOGICAL MODIFICATIONS
SEEDING KEY SPECIES (VIABLE OR GENETICALLY SELECTED) ‘DESIGNED’ ASSEMBLAGES (TRAIT-BASED MODELS) ‘GARDENING’ STRUCTURES
HOW TO DECIDE? on how to ecoengineer
(1) Conservation and managerial goals
(2) The habitat in which strategies are being
implemented
(3) The biogeographical location
(4) The socio-economic circumstances at the
time of intervention
(5) The ecological risks and uncertainties
associated with the proposed approach
What is Fishery Enhancement
‘FE’ is the manipulation of the marine environment to enhance
or restore fisheries in natural systems
How is FE done?
1) Manipulating the target organism (Stock Enhancement,
translocations)
2) Manipulating the habitat (Artificial Reefs, FADs, habitat
restoration)
3) Manipulating the foodweb (artificial feeding, nutrient
fertilisation, predator control)
FE in develloped countries
for conservation and recreation; based
more on preserving natural environmen
FE in undevelloped countries
In developing countries: for income and food; based more on
intensive production
Who is doing FE?
‐ Government agencies (e.g. NSW DPI: fish stocking and
artificial reefs)
‐ Commercial industry (e.g. reefs for abalone fishers; FADs for
tuna fishers)
‐ Artisanal fisheries in developing countries
Why is FE different to aquaculture
it focuses on the natural environment
but often relies on aquaculture technologies
What is SE- stock enhancment
he release of hatchery
reared animals to supplement
wild supply
Why is SE used
1) to increase biomass of the species for later harvest (e.g. prawns, mulloway in Aus.) 2) for conservation/restoration of the species (e.g. murray cod) SE is now done on a very large scale (majority in freshwater), in ~100 countries
The process of SE
- Select a target species
- Collect wild breeding animals
- Induce spawning
- Grow up larvae until certain
age (juveniles) - Release juveniles in to wild (if
released into altered habitats,
it’s called ‘sea ranching’) - Return at some point to
harvest adults
What are some risks of SE?
- Reduce genetic diversity (inbreeding); domestication
- Exceed carrying capacity
- Alter foodwebs (e.g. increase predation)
- Introduce diseases
- Waste of fish/money (no real benefits)
How to manage risks of SE
• Reduce genetic diversity (inbreeding); domestication
Use sufficient broodstock; monitor genetic diversity;
only use broodstock from stocking locations
• Exceed carrying capacity
Estimate stocking density (modelling)
• Alter foodwebs
Consider requirements of prey, competitors etc. in
modelling (but can be difficult to predict and thus avoid)
• Introduce diseases
Waste of fish/money (no real benefits)
Bio‐economic modelling; careful balancing of stocking
small fish (high mortality) with stocking larger fish (high
cost)
Encourage wild behaviours in hatchery fish – ‘life‐skills
training’ to improve survival
Thorough disease testing in hatchery
artificial reefs
Another common Fishery Enhancement tool is artificial reefs. These are variously deployed for: • Tourism sunken vessels • Conservation re‐seeding coral reefs? anti‐trawler function • Enhance production/fishing Designed reefs Can be used for commercial harvest main goal- produce fish
Combining ARs with stock
enhancement
Greenlip Abalone in Augusta W.A., grown in a hatchery, stocked on custom ‘abitats’, then harvested ~12 months later This ‘sea ranching’ may be a big use for ARs in the future
How do ARs work
• Hopefully, they provide food and shelter, which promotes residency and ‘fish production’ • But it’s thought behavioural responses (thigmotaxis) also occur, which do not promote production • This variety of processes complicates the monitoring of ARs • The trade‐off between these processes is often termed ‘production versus attraction Re‐schooling Sociality Rest Food Space (survival and food) Attraction, with little benefit to survival or growth
Attrection artificial reefs
attraction is the redistribution of existing fish
if attraction exists, then a fished AR can have a negative impact
because an AR gives anglers a ‘better target’
below, production = 2 fish, but harvest increased by 4 fish
to manage this issue, we need to measure production & harvest
Production AR
Production & Attraction are very difficult to distinguish
Production may take time to occur, and may operate indirectly
through biota like seaweed
Fishing may also change locations, so what is overall change in
harvest?
why is it so important to distinguish between production and attraction
way to find if P
visual surveys (ok)
fish tracking (good)
food web or ecosystem modelling (great)
On sydney AR
The research and monitoring is focused on:
1) Which species are using the reef?
2) How much fish production is occurring?
This is being answered using:
1) Visual surveys (video)
2) Fish tagging and tracking
3) Settlement plates
4) Reef and ecosystem modelling
‘Ecopath with Ecosim’
an ecosystem modelling approach and software
basically, you create a food web, and simulate how it changes
when you alter things (like habitat, or harvest rates)
Ecosystem modelling
Create costal ecosystem off Sydney
create the food web
alter area of reef and measure changes to food web
• By adding more reef, we produce about 6‐20 g of fish per
m2 reef
• This is a fraction of the biomass that uses the artificial reef
(720 g per m2 of reef)
• This tells us that ARs can be great habitat, but probably
‘attract’ much more biomass than they produce
• This will vary greatly with each ecosystem, and how much
‘spare’ energy it has
Things to remember!
Two common forms of Fisheries Enhancement are Stock
Enhancement and Artificial Reefs
Stock Enhancement is the release of hatchery reared animals to
supplement wild supply
SE has associated risks (e.g. disease etc; remember these)
The main goal of ARs is to produce fish (i.e. create new biomass)
Both ‘production’ and ‘attraction’ are occurring on ARs; these
processes explain why fish can be found near ARs
define an MPA
An area of land or sea dedicatd to the protectoin and maintenence of biological diversity and of natural and associated cultural resources- managed through legal or other effective means
ecosystem or place-based management - sometimes reffered to as spatial management
MPA framework
comprehensive
adequet
representative
How many MPSs in Australia
200, 6 in NSW- jervis, batemans, port stephens
Threat to biodiversity
dredging- contamination, new habitat, lose soil, pollution, turbidity
Issues and planning MPAs
Site ID Site evaluaiton Site implication Biological assessment- stakeholders is it a source or sink site draft zoning extensive stakeholder consultation finalise design implement MPA Review and rezone fter 5 years
Locally managed marine areas
education–> stakeholder buy in–>Compliance–> success
economic benefits
define citizen science
practice of public participation and collaboration in scientific research to increase scientific knowledge- people contribute to data monitoring and collection
REal life survey
quality outputs and consistency data
no siginifacne in data from trained scientists and recreational divers
Ecosystem services
– Direct and indirect effects of disturbances on BEF,
leading to impacts on services
• Degradation reduces the capacity to provide
crucial services (e.g. food, energy)
• Some can be irreversible – new state
• Problem is that some of the indirect drivers of
degradation are desirable and/or necessary
(e.g. coastal development for housing and
protection)
Beyond conservation
• Human activities causing loss of biodiversity
and ecosystem function, leading to losses in
ecosystem services
• Phase shifts difficult to reverse
• Conservation or preservation of natural
systems – 1st action
• Most natural systems already in a degraded
state – in the marine realm, 50-90% remain in
a degraded state despite conservation efforts
Restoration ecology
scientific exploration of ecosystems under repair
• Ecological restoration is the repair work itself:
design and implementation
– “Process of assisting the recovery of an ecosystem
that has been degraded, damaged or destroyed” (SER
2004)
– “Actively return ecosystem structure and function
from a degraded state to a previous, natural
condition”
problem with restoration ecological experiemtn
No reason to assume a past condition is
appropriate now (places change naturally)
– No methods for measuring whether such state has
been achieved
restoration is a scientific ecological problem
scientific, ecological problem
• It is always an experiment
– Specific sampling designs with appropriate reference and control
locations (instead of routine monitoring)
– Adequate replication
– Independent measurements of the variables measured
– Clear hypotheses
– Rehabilitation:
changing the habitat to achieve some defined end
point
projects unable to adopt the target of
full recovery, but still based on a local indigenous
reference ecosystem
– Restoration:
: attempt to return the area to some imagined or
impossible previous state
all projects that aim to ultimately
achieve full recovery relative to an appropriate local
indigenous reference ecosystem (regardless of time
it takes)
Essential that restoration is based on
• Clear understanding and definition of the
problems
• Relevant scientific information about possible
causes of the problem
• Clear predictions about the consequences of any
attempt at restoration
• Social aspects are critical to successful ecological
restoration (not only conservation values, but
also socio-economical, inc. cultural)
wetlands
never possible to achieve past natural state
fragmented
freshwater and tidal input
additional disturbances
mangrove forests Homebush bay- lack of natural flushing to increased tidal flushing
considerations for restoration
Preliminary sampling: ‘impacted’ area vs
multiple, similar reference areas, at multiple
times
– Natural variability
– Need to understand variability at different scales to
design restoration ‘experiment’
• Can populations establish?
– Propagule supply
Alternative models or explanations
• Sample invertebrate community structure at
several Impacted, Control and Reference
locations, several times before and after the
restoration attempt
approaches to coral restoration
• Restore the habitat • Restoration of corals per se - Fragments and transplantation - Coral seeding: sex and larvae Physical habitat restoration - artificial reefs
Re-coral-ation
Coral transplantation • Ecological engineers: the “trees” of the reef • From bed frames to large scale nurseries.
two stage nursery rearing pros
- Relatively simple and “affordable”
2. Can be done by trained volunteers
two stage nursery rearing cons
- Damage to existing donor colonies
2. Low genetic diversity
issue with restoration
mismatch between scale of restoration and degredation
Australia’s southern reef
> 8,000 km of coastline where 70% of population live (c. 71,000 km2 [0-30m depth]) Kelp-dominated 65 t biomass per ha per yr (16x higher than wheat-fields) Biodiversity ‘hotspot’ High endemism A$ 10 billion per yr Less funding A$ 4M vs 55M GBR (5 yrs)
Genetic diversity
donor populations w/ higher resistance/resilience to predicted environmental changes (e.g. warming & acidification)
ecology summary
Restoration is about ecology
• Need clear and sensible goals against which to
measure success
• Good understanding of ecological processes
and interactions operating in the system
• Logical and experimental
• Design is critical
• Public support also critical
how many drownings per year from rips?
100
90% of surf rescues in Aus
methods of observing rips
eulerian
langranian
remote video monitoring
modelling
causes of rip fatalities
ignorance complacency politics reliance on sinage- educational or warning approach? 2nd most dangerour hazrd in Aus funding limited drownings revieve limited media attention inform\tion disconnects
Conventional Rip Advice
- Don’t Panic
- Don’t swim against the rip
- Swim parallel to the beach
- Stay afloat and signal for help
challenge 1 2 rips
: How do we communicate all this complex information
about rip behavior, how to escape a rip, how not to panic, etc?
Challenge #2: How do we make beachgoers care and motivate them to
swim where there are lifeguards or ‘if in doubt, don’t go out’?
people remember visuals, slogans
rip summary
- Science will continue to provide information about rips
- We need more information about people
- Beach safety practitioners need to use
this information in the most effective way - Rip education should be visual
- ‘Disconnects’ will not improve without
knowledge/best practice and collaboration
