APES Ch 8 Aquatic Biodiversity

Where are coral reefs located?

form in clear, warm coastal waters of tropics and subtropics --> along equator

How are coral reefs formed?

formed by massive colonies of polyps

What do coral reefs require?

- dissolved oxygen
- light
- nutrients

How do coral reefs bleach?

from loss of algae that colors and nourishes them and lack of dissolved oxygen, light and nutrients

coral reefs threats

- chemical pollution
- global warming
- extra UV
- excess sediment from rivers (cloudy water)
- human contact (collect)
- predators (organisms)

natural services of coral reefs

- algae do photosynthesis and take in carbon dioxide
- protect coastline --> natural barrier for waves, less erosion
- build habitats for organisms to hide

plankton

free-floating, drifting organisms

types of plankton

- phytoplankton (plant-like)
- zooplankton (animal-like)
- ultraplankton (tiny)

nekton

fish, turtles, whales (not drifters)

what are the majority of decomposers?

bacteria

benthos

bottom dwellers (clams, oysters, crabs, tube worms)

what varies btwn aquatic system layers?

temp, sunlight, dissolved oxygen, nutrients

euphotic zone

- top layer of aquatic system
- sunlight can penetrate
- lots of light
- low nutrient levels (sink)
- high photosynthetic activity
- high dissolved oxygen

bathyal zone

- middle layer of aquatic system
- dim/twilight area of open sea

abyssal zone

- bottom layer of aquatic system
- dark
- cold; low temp
- no photosynthesis
- high pressure
- low dissolved oxygen
- some nutrients (bc dead things)
- organisms blind and produce own light to attract prey

coastal zone

- where most action is
- high productivity
- warm
- nutrient-rich: sediments
- shallow water
- makes up less than 10% of world's ocean area but contain 90% all marine species

what is open ocean made up of?

90 % ocean area and 10% marine species

human impacts on aquatic habitats

- dams
- cities
- farmland
- suburban development
**cities and farmlands add pollutants and excess plant nutrients to streams and rivers that go to ocean**

temperate zone locations

above and below tropical zones

tropical zones locations

- area near equator; btwn tropic of cancer and tropic of Capricorn
- coral reefs and mangroves (special trees)

where do kelp forests grow?

in coastal zone (ex: by channel islands) grow 2 ft per day

Microcystis

- not a plant (algae)
- AKA giant kelp
- provides shelter for many organisms
- provides food
- higher biodiversity than rainforest

ecological services of kelp forest

- provide habitats
- absorb carbon dioxide (carbon sink)
- increase oxygen levels

structure of kelp

- holdfast attaches kelp to rock
- reproduces by spores that float and settle in new location
- fronds: leaves
- air bladder helps fronds stay near surface (sunlight)

what part of kelp do sea urchins eat?

eat base of holdfast and release kelp which washes up on shore (storms also break kelp and push them to shore)

how do sea urchins move?

move in herds and can destroy 30m of forest per month (urchin barrens)

keystone species

presence / absence of species profoundly affects ecosystem

why did hunters kill sea otters?

for their fur for trade

current sea otter threats

- oil spills
- polluted water --> pollutes food and toxins build up in body

kelp forest benefits

- washed up kelp become food for other organisms
- beach hoppers --> become food (ex: snow plovers --> endangered)

how are gopher tortoise keystone species?

make burrows for frogs, snakes, owls

how are American alligators keystone species?

gator holes and nests

how are red mangroves keystone species?

prevent coastal erosion, provide hiding places and habitats

how are beavers keystone species?

make areas of still water

how much of earth's surface do saltwater and freshwater aquatic life zones cover?

almost 3/4

functions of aquatic environments

- dissolves nutrients --> cycles
- dilutes toxins
- prevents changes in temp

intertidal zone

area btwn high and low tide

what do organisms in the intertidal zone have to deal with?

- changing temp
- changing salinity
- wave action
- desiccation (drying out)

estuaries and coastal wetlands

- centers of productivity
- where fresh and salt water mixes
- plants have to be salt tolerant
- tolerant of change in temp/salinity

where are estuaries and coastal wetlands located?

- water along coast that is partially surrounded by land
- river mouths, inlets, bay, salt marches in temperate zones
- mangrove forests in tropical zones

halophytes

salt grass, pickleweed, cordgrass

estuaries and coastal wetlands natural services

- filter toxic pollutants
- remove excess plant nutrients
- trap sediment in runoff
- absorb waves --> erosion protection
- storing excess water --> prevents flooding
- provide food, habitats and nursery sites for many aquatic species

macro

seen w/o microscope

invertebrates

animals w/o backbone

aquatic macroinvertebrates

valuable indicators of health of aquatic environment

benthic

- typically found on bottom of stream/lake and do not move over large distances
- small, not move quiz/easily (away from pollution)

dif environmental stressors for macroinvertebrate species

pollution, sediment loading, habitat changes

what can indicate condition of body of water?

quantifying diversity and density of dif macroinverts at given site

intolerant vs tolerant macroinverts

- intolerant: die when exposed to environmental stressor
- tolerant: move in and often inhabit spaces vacated by intolerant organisms when exposed to environmental stressor
- result in dif populations of organisms

what type of macroinverts will be in a healthy body of water?

intolerant species

intolerant macroinverts

- mayflies (ephemeroptera)
- stoneflies (plecoptera)
- caddisflies (tricoptera)

tolerant macroinverts

- leeches (hirudinea)
- tubifex worms ( tubifex sp)
- pouch snails (gastropoda)

barrier islands

low, narrow, sandy islands that form offshore from a coastline --> protect coast, erosion

what protects land from erosion by sea?

primary and secondary dunes on gently sloping sand, barrier beaches

what are reasons for variation in amount of oxygen in water?

- number of consumers (respiration)
- number of producers (photosynthesis)
- number of decomposers (bacteria can take high lots of oxygen)
- temp (cold hold more)
- turgidity (rough water dissolves more)
- turbidity (how cloudy water is)

source zone

- fastest flowing water
- coldest
- high turgidity
- low turbidity

floodplain zone

- shallow
- flat with slow flow
- warm
- nutrient rich
- low turgidity
- high turbidity

lakes

during summer and winter, deep temperate zone lakes become stratified into temp layers that overturn

overturns

equalizes temp at all depths

what is brought from surface to bottom in a lake?

oxygen

what is brought from bottom to surface in a lake?

nutrients

thermodyne

layer btwn warmer and colder layer

what causes overturn?

changed in temp from change in seasons (fall and spring)

what seasons produce most defined thermoclines?

summer and winter

cultural eutrophication

human inputs of nutrients from urban and agricultural areas can accelerate eutrophication process

anthropogenic

human created/caused

standing (lentic) water

lakes, ponds, inland wetlands

flowing (lotic) systems

streams and rivers

littoral zone

- near shore
- light can still penetrate
- v shallow
- lots of plants (more food, high biodiversity, more hiding spots)

limnetic zone

- not near shore
- light kinda penetrate
- top

profundal zone

- middle
- dark water
- low biodiversity

benthic zone

- decomposers
- low light

oligotrophic (poorly nourished) lake

- newly formed lake w small supply of plant nutrient input
- rocky bottom
- nutrients trapped in water

eutrophic (well nourished) lake

over time, sediment, organic material, inorganic nutrients wash into lakes causing excessive plant growth

inland wetlands natural services

- natural sponges
- provide variety of wildlife habitats
- filter and degrade pollutants
- reduce flooding and erosion by absorbing slowing releasing overflows
- help replenish stream flows during dry periods
- help recharge ground aquifers

natural sponge

absorbs and stores excess water

fresh water inland wetlands economic services

- recreation
- fish for food
- tourism
- jobs

migration banking

- an agreement to restore whatever wetlands u ruin
- specifically for wetland
- restoration, creation, enhancement for unavoidable wetland losses
- must occur in advance of development
- helps to consolidate small, fragmented wetland mitigation projects into larger sites
- generally approved by wildlife agencies

how to test water quality of river/lake

- smell
- color
- bacteria in culture
- turbidity
- test nitrogen level and phosphate
- test pH
- examine what is living in it

organisms in which area must be able to tolerate the greatest differences in salt concentrations?

estuary