marine ecology - human impact

atlantic bluefin tuna group

thunnus thynnus

true or false: bluefin tunas are the largest tunas

true

how long can bluefin tuna live?

up to 40 years

true or false: bluefin tuna migrate across oceans and dive more than 4,000 feet

true

what are bluefin tuna built like?

torpedos

true or false: bluefin tunas are tremendous predators from the moment they hatch

true

blue fin tuna body composition

retractable fins and eyes are set flush to their body

great white shark group

carcharodon carcharias

great white shark finding nemo character

bruce

true or false: great white sharks can detect one drop of blood in 25 gallons of water

true

true or false: great white sharks can sense large amounts of blood in water up to 3 miles away

false

true or false: great white sharks are the smallest predatory fish on earth

false

how much do great white sharks weigh?

up to 5,000 pounds

how fast can great white sharks swim?

up to 15 mph

why are great white sharks listed as endagered?

due to overfishing and accidental catches in gill nets

true or false: the exact number of great white sharks in the world is unknown

true

american lobster group and name

homarus americanus aka maine lobster

how big can lobsters get and what are they the largest type of?

weigh over 45 pounds and largest type of crustacean

where do lobsters live?

on rocky, sandy, or muddy bottoms close to the shorelines to beyond the edge of the continental shelf

where does the lobster prefer to live?

shallower ocean water

how old do lobster get and what happens as they get older?

100 years old sometimes older and continues to grow in size

antarctic toothfish group and common name

dissostichus mawsoni aka chilean sea bass

what are antarctic toothfish?

large, pelagic predators

where do antarctic toothfish live?

southerly waters influenced by the antarctic circumpolar current at depths between 300 and 2,500 meters

how old do antarctic toothfish live?

up to 48 years

when do antarctic toothfish reach sexual maturity?

between 13 and 17 years of age

white shrimp group and common name

litopenaeus setiferus aka common shrimp

how many legs do white shrimp have?

ten walking legs and five pairs of swimming legs located on the front of the abdomen

where do young shrimp live and grow?

nursery areas with muddy bottoms and low to moderate salinity

where do white shrimp commonly inhabit?

estuaries and coastal areas out to about 100 feet offshore

striped marlin group

kajikia audax

where is the striped marlin found?

in tropical and warm temperate waters of the indian and pacific oceans

what is the striped marlin's seasonally migratory pattern?

moving toward the equator in cold season and away again during warm season

what is the striped marlins most distinguishing charactersitic?

high, pointed first dorsal fin, which normally equals or exceeds the greatest body depth

nile tilapia group

oreochromis niloticus

true or false: tilapia is the most aquacultured fish in the world

true

what makes tilapia good?

they are low in saturated fats, calories, carbohydrates and sodium and a good protein source

true or false: tilapia always compete with other "pond" fish for food

false

what do tilapia consume

plants and nutrients unused by other fish species and substantially reduce oxygen-depleting detritus

what happens when adding tilapia?

often increases the population, size and health of other fish

polar bear group

ursus maritimus

why are polar bears classified as marine mammals?

they spend most of their lives on the sea ice of the arctic ocean

since polar bears are considered talented swimmers, how do they swim?

sustain a pace of six miles per hour by paddling with their front paws and holding their hind legs flat like a rudder

why were polar bears the first species to be classified as endangered?

global warming

goliath grouper group

epinephelus itajara

groupers mature as females but can change their sex when?

after sexual maturity

how do goliath groupers eat their food?

swallow their prey and chew it using huge crushing tooth plates in their pharynx

how big was the largest grouper ever recorded?

weighed 686 pounds

red volitan lionfish group

pterois volitans

how long can a lionfish live without food?

3 months

how much body mass do lionfish lose when not eating for 3 months?

only 10%

what do obese lionfish look like?

internal organs completely covered in fat and suffering from liver damage

where are lionfish being found?

brackish water where water salinity is about 6 parts per thousand compared to the ocean at 33 parts per thousand

fisheries

concentrated in the waters overlying the continental shelves around the world

aquaculture

the rearing of selected aquatic plants and animals under controlled conditions to increase the amount of food available to humans

ghost fishing

when lost nets or traps may continue to capture

pfiesteria

a toxic dinoflagellate responsible for immense fish kills in NC estuaries

pollutants

chemicals, nutrients, oil - Harmful substances in the air, water, or soil

maximum sustainable yield

the largest number of fishes that can be harvested year after year without diminishing the stocks

bycatch

refers to nontarget organisms and undersized target organisms that are captured by the fishing gear

invasive species

are species that are deliberately or accidentally introduced into an ecosystem by humans

anadromous species

live part of their lives in fresh water and part in salt water - part of fish ranching

biological magnification

chemicals are transferred through food chains, becoming more concentrated through the process

all of these are common effects of fishing (and overfishing) except:

a) species extinctions

b) alteration of size structure and prawn fisheries

c) a reduction in species diversity

d) alteration of population sex ratio

d) alteration of population sex ratio

which of these animal types seems to be most vulnerable to oil spills?

a) killer whales

b) seabirds

c) sea otters

d) subtidal organisms

b) seabirds

which of these statements best represents the future of the combined marine fisheries?

a) the relatively untapped areas of the continental slopes can more than replace the declining fisheries

b) underexploited squid resources in the southern oceans can more than compensate for declining fisheries

c) the seas cannot and will not be the source of substantial food for an expanding human population

d) current stocks of krill can easily meet the increasing needs of an expanding human population

c) the seas cannot and will not be the source of substantial food for an expanding human population

the best known example of mammal bycatch is the:

a) use of cyanide to stun coral reef fishes

b) trawling nets of shrimp and prawn fisheries

c) tuna purse seine fishery

d) phenomenon of "ghost fishing"

c) tuna purse seine fishery

finding nemo clip: nemo lost - what does it show/mean

nemo taken off reef, yes they do that

finding nemo clip: darla - what does it show/mean

darla taps on glass, bad for fish, darla shakes bag, bad for fish, don't be a darla, all drains do not go to ocean

finding nemo clip: fishing net - what does it show/mean?

shows a fishing net and they all swim down to break net, not possible, purse seine net

where are major fisheries concentrated?

in the waters overlying the continental shelves around the world

why are major fisheries concentrated in the waters overlying the continental shelves around the world?

-inshore waters have much higher productivity

-shallow waters are more accessible to humans

-deep waters cannot sustain large fish populations

where do the largest catches of fishes occur?

on the continental shelves of northwest Europe, western south america and japan

what make up 1% of the global fleet, employ 2% of the world's total crew and harvest 50% of the world's total catch?

supertrawlers

how big are the largest trawlers?

40ft high and 200ft wide - large enough for a 747 jet to fit through

how many species of marine fish make up the majority of catches in fisheries throughout the world?

only a very few

what fish account for the largest tonnage of fishes, accounting for almost half the catch?

herrings, sardines and anchovies

what is the largest number of fishes that can be harvested year after year without diminishing the stocks?

maximum sustainable yield

how many of the world's fisheries are overexploited?

70%

how much larger is the global fishing fleet than needed to catch what the oceans can sustainably produce?

250%

us fisheries are governed by what?

the Magnuson-Stevens fishery conservation and management act of 1976

what does the magnuson-stevens fishery conservation and management act say?

conservation and management measures shall prevent overfishing while delievering optimum yield from each fishery on a continuing basis

what is in the maximum sustainable yield modified by any relevant economic, social or ecological factors?

optimum yield

in recent years, there have been an abundant examples of the decline of what in all areas of the world?

fish stocks of a types

how much have the top 25 ocean predator populations have decreased?

90%

what has been decreasing every year since 1988 even though fishing technologies have improved?

global catch

what may also result in changes in the larger ecosystems or communities in which the target fish reside?

overfishing

the demise of the north atlantic cod and haddock fishery resulted in what?

the increase of dogfish and skates that now fill that niche

what is another source of destruction in fisheries?

bycatch

what refers to nontarget organisms and undersized target organisms that are captured by the fishing gear?

bycatch

in what industry, up to 10 pounds of bycatch are discarded for every pound of what caught?

shrimp

what is a largely overlooked problem that contributes to the death of huge numbers of marine organisms?

lost fishing gear

lost nets or traps may continue to capture in what is termed?

ghost fishing

in the north pacific, some 30,000 to 40,000 km of nets are set per day with a daily loss rate of?

20%

what is the rearing of selected aquatic plants and animals under controlled conditions to increase the amount of food available to humans?

aquaculture

what is the term for marine aquaculture?

mariculture

what involves cultivating fish in a controlled environment?

fish farming

what involves holding anadromous species (live part of their lives in fresh water and part in salt water) in captivity for the first few years, releasing them, and then harvesting them as adults?

fish ranching

how many reasons are there for why mariculture is not widespread?

3

what are the three reasons mariculture is not more widespread?

-it is difficult to maintain proper conditions in ponds or tanks

-many marine species go through different life cycles that require different conditions

-diseases and parasites proliferate under captive or crowded conditions