test 2 Flashcards
1
Q
Post-industrial revolution
A
Human populations increase exponentially – Steam engines allow efficient trawling – Fishing gear improvements – Huge factory ships
2
Q
Post WW II
A
Development of sonar
• Huge industrial fleets
3
Q
Food and Agricultural Organization
A
16.6% of global intake of animal protein (increasing)
4
Q
2009 global intake of animal protein
A
16.6% (increasing)
5
Q
Increasing demand for fish met by
A
aquaculture production
6
Q
FAO 2010 State of World Fisheries
A
Most stocks fully exploited or
overexploited
7
Q
Bottom fishes
A
overexploited
8
Q
Pelagic fishes
A
fully exploited
9
Q
Some cephalopod stocks
A
underexploited
10
Q
Typical History of A Fisheries
A
Discover a new stock • Fish the heck out of it • Populations decline reducing profit • Call in the fisheries scientists • Scientists declare it is too late….
11
Q
Fisheries Management Attempts to
Avoid Overfishing
A
Use Yield Models to manage
12
Q
MSY
A
Maximum Sustainable Yield:
– Catch & Effort
13
Q
Problems with Fisheries Management
Attempts to Avoid Overfishing
A
Often a single TARGET species • Stock Assessments typically on just the target species • Rarely a single catch and therefore ecosystem changes with fishing • Bycatch often discarded
14
Q
Multispecies MSY
A
Both target and non-target species collapse with increasing exploitation rate
15
Q
Gadus morhua
Atlantic cod
A
Complete collapse of fishery in
1990’s with loss of 2.5 billion adults
– Continued lack of recovery despite
stringent controls on the fishery
16
Q
Top predators in worldwide decline
A
– Estimates as high as 90% in some regions
17
Q
Predators typically keystone species
A
Impact on community disproportionate to
abundance
18
Q
Antipredator behavior
A
Risk Effects.
19
Q
Direct predation –
A
natural mortality
20
Q
Blacktip declines
on east coast of US
A
Direct predation
– Risk effects
21
Q
Shifting Baselines
A
Pauley: young scientists fail to remember what historical populations were like “Each generation accepts a baseline the stock size and species composition that occurred at the beginning of their careers.”
22
Q
“Destructive fishing
A
-Outright habitat destruction
• Overfishing
23
Q
Habitat Destructive Fishing Practices
A
Explosives: ‘dynamite fishing’, ‘blast fishing’ Muro-ami & Kayakas • Poisons Bottom Trawling
24
Q
Inappropriate Fishing Practices
A
Beach Seining Large-scale pelagic fishnets/gill nets/ drift nets Tuna fisheries & dolphin/shark bycatch Shark fining: – Excessive bycatch – Push netting – Highgrading
25
Marine Pollution:
Almost all land origin
introduced to oceans from runoff, wind
& rain (also direct dumping of wastes)
26
Dichloro-Diphenyl-Trichloroethane
first used
as pesticide in 1939 – cheap & easy to make
• Widely used to eradicate fleas carrying typhus in
1940’s
• Used against malaria (mosquitoes) in Asia
• Widely used in agriculture
• Long-lasting & persistent in environment
• now banned in many countries
27
(bioconcentrated)
Dissolve in fats (lipophilic) & not
| excreted
28
(biomagnified)
```
Accumulates at higher levels of the
food chain (
```
29
DDT Biomagnification
```
Brown pelicans formerly abundant,
became rare; calcium not deposited in
egg; nesting destroys eggs
• Also seen Bald eagle &
Osprey
```
30
DDT Biomagnification
Sealion & seal die off in Salinas Valley,
CA: liver concentrations of DDT at 89
ppm
31
Synthetic organic chemicals
```
Organochlorines (e.g. DDT),
organophosphates, polycyclic aromatic
hydrocarbons (PAHs), organometals
Often high persistence & toxicity
• Also lipophilic xenobiotics:
• bioconcentration & biomagnification
• Sub-lethal effects include
• Impair reproduction
• Carcinogenic, mutagenic, teratogenic
```
32
Organochlorides
• Also called Halogenated Hydrocarbons –
organobromines and organoflourines
• Neurotoxin, immunosuppresor, repro effects,
carcinogen, liver toxicity, behavior changes
• Typically persistent & lipophilic & therefore
• Bioconcentrate and biomagnify
• Examples: PolyChlorinated Biphenyl, DichloroDiphenyl-Trichloroethane, PolyChlorinated
Dibenzo-p-Dioxin
33
PCB:
polychlorinated biphenyl
• Widely used since 1930s: insulation & coolant
fluids in electrical systems, hydraulic fluids,
lubricating fluids, paints, paper production,
caulking, sealants etc etc
• Banned in many countries in 1970’s
(carcinogenic)
• 8-10 year half life
• 1 million tons produced
• Most ended up in oceans
34
Dioxins & Furans
Created incidentally in production of herbicides
& in wood processing, especially pulp
processing
• Agent orange is a source of dioxins
• Lipophilic & persistent; carcinogenic
• Contribute to organic pollution effects on sea
birds & marine mammals
35
Lindane
Used as anti-insect smoke in Africa/Asia
• Neurotoxin, used as pesticide
• Persistent, bioconcentrates and biomagnifies
• Possibly carcinogenic
• Contributes to organic pollution loads in coastal
waters
36
Hexachlorobenzene (
Anti-fungal agent & aluminum smelting by
| product
37
Toxaphene
Pesticide used on cotton & vegetables
• Very toxic to fish
• Now banned (part of “Dirty dozen” banned by
Stockholm Agreement (Convention on
Persistent Organic Pollutants, signed 2001,
effective 2004: also HCB, PCB, DDT, PCDD)
• Also banned Aldrin, Endrin, Heptachlor
• Seed protectants; toxic to mammals
38
Butyltins
```
class of organometals
with toxic effects on marine organisms
• Monobutyltin & dibutyltin used as
stabilizer in production of silicones and
polyurethane foams
High levels found in cetaceans
• Disrupts immune system in cetaceans
• Linked to mass mortality of cetaceans in
Florida
• Linked to hearing/ acoustic damage in
cetaceans
```
39
Tributyltins
•Widespread use as anti-fouling paint since 1960’s
•In 1970’s & 1980: Toxic at extremely low concentrations
•Causes deformities and disrupts reproductive success of
invertebrates
40
climate change
```
increase in greenhouse gases
Methane
• Landfills, coal mines, oil
& gas processing,
agriculture
• Nitrous oxide
• Also from burning fossil
fuels, fertilizers, industry
• Tropospheric ozone
• Chloroflourocarbons
```
41
Rising Atmospheric CO2
```
Most critical problem to oceans
• Globally pervasive & irreversible in ecological
times scales
• Direct consequences
• Increase in ocean temperatures
• Increase in acidity
```
42
Climbing temperatures other physical effects:
```
• Increased temp & lower pH
• Rising sea level
• Potentially dramatic coastal community
changes
• Decreased sea-ice extent
• Altered ocean circulation
• Increased ocean stratification
• Altered precipitation
• Altered freshwater input
• Reduced subsurface oxygen concentrations
• Increased weather anomalies
```
43
Warmer SST feed energy & moisture
| to tropical storms
```
Atlantic cyclones
may not increase
but short duration
storms increasing
– Upwelling could
moderate in some
places
```
44
Sea Surface Anomalies
Ocean circulation
• Spatially variable winds
• Interactions with ENSO etc
45
Changes in Polar Ecosystems
Strongly tied to sea ice extent/ temps
• Most fish & inverts very stenothermal
• Penguin population changes
46
acclimatization
Changes that increase function of an individual (such as exercise), but can not be transmitted to offspring
47
adaptation
is reserved for increases in function that are the result of genetic change of the population.
48
Ectothermic species metabolic processes
```
Rise exponentially with temperature
• Phytoplankton 37% increase with 2
oC
• Heterotrophs: raises respiratory
demand => less energy for growth &
reproduction
```
49
distribution patterns
50% increase in species richness in
North Sea 1986-2005 (small southern
species)
50
No-analog ecosystems
no shared evolutionary history
51
phenology
Timing of life history events
| • Mismatched in trophic trophic synchrony
52
Increased consumption rates with strong
| top-down effects
Herbivores feeding on seaweeds
• Zooplankton feeding on phytoplankton
• Benthic predators feeding on bivalves
53
Shifting food webs
In 4 regions shift toward suspension & deposit
| feeders (also because of harvest of large fishes
54
Bleaching
a result of expulsion of zooxanthellae
symbionts (Symbiodinium) or loss of symbiont
pigments
55
Physiological Responses Corals
```
Sustained warming of as little as 1oC
above pre-industrial levels causes coral
bleaching
• Sustained temperatures above 2
oC above
pre-industrial drive unsustainable
frequency of mass coral bleaching events
• ¼ of all marine species associate with
coral reefs
```
56
Ocean Acidification
Atmospheric CO2
increases 40%
• 280 ppmv -> 384 ppmv in 2007 -> 398.03 in 2014
• Faster than millions of years, highest in 800k yrs
57
Role of Calcium Carbonate
```
Long term ability to absorb CO2
depends on CaCO3 dissolution
• Mineral CaCO3 derived from
• shells & skeletons of marine
organisms
```
58
Aragonite
Relatively soluble form CaCO3
• Corals, molluscs, many other inverts & algae
saturation is is highest in shallow, warm
tropical waters, and lowest in cold high-latitude
regions
59
Depth Distribution of CO2 &
| Saturation Levels
Increase solubility with increasing Pressure &
| decreasing temperature
60
Deepwater Coral Responses
Deepwater corals, without symbiotic
algae at depths of 200-1000 m
• Typically long-lived, up to 1,500 years old
• Support high biodiversity at depth
• Maximum depth at depth of aragonite saturation
horizon
• With increasing acidification, depth
distribution will contract
61
Fishes Olfactory Detection
Larvae locate suitable settlement
habitat using olfactory senses
• These senses are impaired by
reductions in pH level
62
Fish Larvae Olfactory Detection
Newly hatched larvae detect predators
using olfactory cues
• In an experiment, larvae were exposed to
a pH expected by 2100
• Settlement stage larvae became strongly
attracted to smell of predators
• Lost ability to discriminate between predators
and non-predators
63
Biogeochemical Cycles
```
Dynamics of calcium
carbonate, organic
carbon, nitrogen,
phosphorous & etc. will
all change
```
