Environmental Issues for the Marine Biome

Essential Questions How are humans impacting the marine

biome? What is our role in protecting the marine

biome?

How are humans impacting the marine biome?

One Ocean: The Changing Sea http://oneocean.cbc.ca/series/episodes/4-t

he-changing-sea

Questions provided 45:15 mins

The 5 issues facing the Marine Biome Acidification Coral Depletion Deadzones Overfishing Pollution

What is Acidification An increase in the pH level of the water of

an ocean. The increase in pH is attributed to an

increase in carbon Carbon interacts with other ions in the water to

produce carbonic acid

The pH scale A scale which measures

from 0 to 14 7 = neutral = pure water 0.8 = acidic = battery acid

Typically the ocean ranges from 7.9 to 8.2 pH

Acid Test: The Global Challenge of Ocean Acidification http://www.nrdc.org/oceans/acidification/a

boutthefilm.asp

21:34mins

What causes Acidification Use of fossil fuels Dependence on fertilizers

We are dumping carbon dioxide into the atmosphere at a rate of 28 million metric tons per year

What is the result of Acidification? The more acidic the water, the less ability it has

to absorb CO2

Fish are starved for oxygen Corals and other marine species are deprived of

calcium A proliferation of deadzones Ocean acidification (OA) is the quiet tsunami of

environmental degradation. Within a few decades, OA may devastate some marine

ecosystems and threaten the productivity of our fisheries.

What is Coral Depletion? When the tiny organisms called coral die,

they leave behind a skeleton in the form of bleached coral. As a bleached area spreads, the diversity of life in the immediate area decreases, effectively turning the skeletal remains of coral into a marine cemetery.

¼ of coral reefs are dead 60% of coral reefs are in trouble

One Ocean: Footprints in the Sand Chp. 2 http://oneocean.cbc.ca/series/episodes/2-f

ootprints-in-the-sand

10mins

What causes Coral Depletion? Rising temperatures Increased CO2

Increased acidity Development of

tourism resorts Sediment Debris

Chemical pollutants, fertilizers, pesticides

Overfishing Bottom trawling

fishing A single pass of a trawl

removes up to 20% of the seafloor flora and fauna

Coral mining

Causes of Coral Depletion There is a lack of carbonate ions for corals

to grow There is a lack of zooxanthellae which

protect and feed corals Algal blooms smother the corals

What is the result of Coral Depletion? ¼ of all fish spend some part of their life on a reef May loose these ecosystems in 20-30 years Fish and other sea life found in coral reefs feed

between 30 million and 40 million people annually – providing jobs

Coral reefs also form barriers around coastlines, protecting coasts (and the residences and business found there) from erosion caused by waves and currents.

What are Deadzones? are areas where the bottom water (the water at

the sea floor) is anoxic — meaning that it has very low (or completely zero) concentrations of dissolved oxygen

An area of the ocean devoid of life 40 years ago there were <50 deadzones,

2003 there were 146 2008 there were 405! 2010 there were 415!

Some are as small as a square kilometre (0.4 mi²), but the largest dead zone covers 70,000 square kilometres (27,000 mi²)

What causes Deadzones? Human causes:

Use of fertilizers Nitrogen Phosphorous

Runoff from sewage Urban land use

Can occur naturally in enclosed bodies of water or as a result of coastal upwellings and reduced winds and currents

Nitrogen and phosphorous causes the increase reproduction of phytoplankton The result is algal blooms

Blooms gobble up available oxygen as they spread When the blooms die, they sink to the bottom, as they

decompose (by bacteria) they further deplete the oxygen

Location of Deadzones

What is the result of Deadzones? Bottom-dwelling species often die Reproductive problems in fish involving

decreased size of reproductive organs, low egg counts and lack of spawning

Fish are often quickly rendered unconscious and doomed

Reports of baby octopuses climbing up crab-trap ropes in order to get air

What is Overfishing? the harvesting a fish species at a rate

exceeding the maximum harvest that would still allow the population to be replaced by reproduction

70% of the world’s fisheries are now fully exploited

What causes Overfishing? Use of long-lines

With 60 miles of hooks Bottom trawling Bycatch Illegal fishing Consumer demand

Bottom Trawling Bottom trawlers drag giant weighted nets along

the ocean floor, ripping up or scooping out whatever they encounter, including ancient coral forests, gardens of anemones and entire fields of sea sponges.

Seamounts -- volcanic mountains and hills that rise from the ocean floor but do not break the surface -- are being damaged by these industrial fishing practices, and the wealth of flora and fauna clustered around sea mounts is being wiped out in the process.

Bottom Trawling continued Many rare, ancient and even unknown species --

some of which hold promise for biomedical research or are critical to undersea biodiversity -- are at risk, including: Cold-water corals, which are as exotic and colorful as their

warm-water counterparts. Red tree corals form ancient forests, stretching up to 7 feet

tall and 25 feet wide, providing shelter for fish, shellfish, and sea stars.

Corals on seamounts can live up to 8,000 years and tend to take branching, tree-like forms, making them particularly susceptible to trawl damage.

Sponges form giant fields in the deep, creating stretches of habitat up

to a mile long and 50 feet high. Fish

including orange roughy, which take decades to mature and can live for 125 years.

Bottom Trawling continued New species of flora and fauna tucked away on

seamounts and other deep-sea habitats. Just like the creatures of the Galapagos Islands, many

seamount species have evolved in isolation, resulting in unique species.

Scientists studying a cluster of seamounts near New Caledonia have determined that nearly one-third of the species there have never been seen anywhere else.

Novel chemical compounds that hold promise for the treatment of cancer and other diseases after their discovery by scientists investigating the biomedical properties of deep-sea organisms.

By-Catch Unwanted and undersized fish hauled up

by bottom trawlers are thrown back dead or dying -- in some areas, as many as four pounds of fish are discarded for every one pound brought to market.

What is the result of Overfishing? If we don’t stop overfishing, all of the

planet’s fish will have been caught by 2048

A chain reaction occurs when we overfish a particular species which can decimate other fish species and even an entire ecosystem

What is Pollution? Every 2.59 square kilometers of the global

ocean contains an estimated 46,000 pieces of floating plastic

Farm and yard fertilizer runoff, sewage, and other land-based sources that contributes to harmful blooms of algae, which in turn lead to fish kills and swimmer illness, and ocean deadzones

What causes Pollution? Discarded plastic bags, six pack rings and other forms of

plastic waste Fishing nets, usually made of plastic, can be left or lost in

the ocean by fishermen Toxic additives used in the manufacture of plastic materials

can leach out into their surroundings when exposed to water

Heavy metals are metallic chemical elements that have a relatively high density and are toxic or poisonous at low concentrations Examples are mercury, lead, nickel, arsenic and cadmium

Oil spills – accidental, leaks, explosions It is estimated that approximately 706 million gallons of waste

oil enter the ocean every year, with over half coming from land drainage and waste disposal

Tracking the BP Oil Spill http://www.nytimes.com/interactive/

2010/05/01/us/20100501-oil-spill-tracker.html

What is the result of Pollution? Plastic

Aquatic life can be threatened through entanglement, suffocation, and ingestion.

Fishing nets fish, dolphins, sea turtles, sharks, dugongs, crocodiles, seabirds, crabs, and

other creatures, restricting movement, causing starvation, laceration and infection, and, in those that need to return to the surface to breathe, suffocation

Plastic Additives Some plastic additives are known to disrupt the endocrine system when

consumed, others can suppress the immune system or decrease reproductive rates

Oil Spills If oil waste reaches the shoreline or coast, it interacts with sediments such

as beach sand and gravel, rocks and boulders, vegetation, and terrestrial habitats of both wildlife and humans, causing erosion as well as contamination

Immediate effects include mass mortality and contamination of fish and other food species

Long term effects include poisons the sensitive marine and coastal organic substrate, interrupting the food chain on which fish and sea creatures depend, and on which their reproductive success is based

The North Atlantic Garbage Patch is an area of marine debris found floating

within the North Atlantic Gyre estimated to be hundreds of kilometers

across in size, with a density of over 200,000 pieces of debris per square kilometer

area shifts by as much as 1,600 km north and south on a seasonal basis

The North Pacific Garbage Patch is an area of marine debris found floating

within the central North Pacific Ocean located roughly between 135° to 155°W and 35° to 42°N

estimates ranging from an area the size of the state of Texas to one larger than the continental United States

high concentrations of pelagic plastics, chemical sludge, and other debris that have been trapped by the currents of the North Pacific Gyre

The North Pacific Garbage Patch continued In samples taken in 1999, the mass of plastic

exceeded that of zooplankton (the dominant animal life in the area) by a factor of six

Ninety percent plastic, this debris accumulates on the beaches of Midway where it becomes a hazard to the bird population of the island. Midway Atoll is home to two-thirds (1.5 million) of the

global population of Laysan Albatross. Nearly all of these albatross have plastic in their

digestive system and one-third of their chicks die.

An Ocean's MemoryThe Endless Voyage Series http://learning.aliant.net/Player/ALC_Player

.asp?ProgID=INT_ENDVOY12

Answer the Self-test questions after the video

27mins

What is our role in protecting the marine biome?