LEC 22 - HUMAN IMPACT + ENVIRONMENTAL CONCERNS

Question 1

plastic bad? (3 reasons)

Answer 1

yes
- accummulate in ocean at lee shores and gyres
- animals ingest
- breakdown bit by bit into microplastics (can be seen in larvacean nets –> it cascades up the food chain)

Question 2

how does stirring up sediment impact the ocean?

Answer 2

• sediment run off can make water murky (impede photosynth) + affect filter feeding by clogging filter structures + just in general smothers animals

Question 3

what did we used to do w sludge + what do we do now + why did we make the change

Answer 3

pre 1998 we removed solids using bacteria and deposited the rest into the ocean

now we turn it into fertilizer

dumping into the ocean seemed to be innocuous but it actually introduced a ton of oxygen

Question 4

what are PCBs + how fucked are we

Answer 4

polychlorinated biphenyls

accumulate in fats

increase susceptibility to infection + inhibit reprod

Question 5

mercury in da water. how does it get there + what are implications for wildlife

Answer 5

mercury gets incinerated which puts it in the air, and it falls back into the ocean. also effluent from coal plants

this effluent is warm water, which manatees like to chill in to warm up

Question 6

what is TBT?

Answer 6

tributyl tin, found in paint

can act as an immunosupressor + causes sterility in snails by creating ‘imposex’ (females grow male reprod organs)

Question 7

if nutrients are necessary for growth, why is eutrophication bad?

Answer 7

incr microbial pop depletes the area of oxygen –> dead zones (esp bad bc deadzones are being made off coasts where its supposed to be productive)

Question 8

aside from dead zones, how can algal bloom be harmful

Answer 8

some just create neurotoxins, which fish eat + sequester

also dinoflag just eat fish scales??

Question 9

what are ice cores? how do they indicate climate change?

Answer 9

layers of ice drilled from glaciers that contain bubbles of trapped air. by looking at these air bubbles, we can look at atmospheric conditions over the years

while CO2 definitely incr and decr w trends, recent trends are literally off the charts

Question 10

how have invasive species been transferred due to human activity? how have we accounted for it?

Answer 10

ballast water, used to stabilize ships, carrying invasive species

when u unload cargo, u take in ballast water. when u reload cargo, u empty out ballast water. in this process, u can introduce invasive species

we now treat water through sterilization, heating, filtration, etc

Question 11

where + how did comb jelly (ctenophores) get introduced? what problems do they cause?

Answer 11

got into black sea + eat hella copepods

Question 12

where + how did lionfish get introduced? what problems do they cause?

Answer 12

from pacific to atlantic, eat herbivorous fish that graze coral algae. when algae buildup is too great, it can hurt the coral