Chapter Three Notes
What is heat capacity?
The amount of heat an object can hold. The ocean has the ability to hold heat and release it slowly.
This relates to us because warm currents slowly release heat and the difference in temp between the
land and the ocean affects the weather. Winters can be milder and wetter as a result.
Cold currents draw heat from the air and make our summers cooler.
Weather is the atmospheres short term conditions. What the weather is today, tomorrow or next week.
Climate is the atmospheric conditions over a long time (30 years) averaged. We have wet mild winters
and cool summers.
Newfoundland and Labrador
Currents
Labrador Current
Gulf Stream
Relative temperature
origin
cold
Greenland
warm
Gulf of Mexico
Responsible for fog- The warm vapor above the gulf stream meets the cold Labrador current and
condenses making fog.
Currents are produced due to wind far out at sea. The wind causes friction on the upper portion of the
water and the energy is transformed to motion of the water in the same direction as the wind.
Convection currents is how the wind forms
As warm air rises, cooler air rushes in to take its place forming wind. The warm air rising over a
continent will cause precipitation. Where it cools and falls it creates a dry climate.
Cause
Relative Temperature of water
El Nino
Every 3-7 years, the trade winds
do not increase after having
slowed down in the Gulf of
Mexico.
The trade winds are not there to
move the water. Hence, there
are no upwelling currents. The
water remains warm at the
surface.
Productivity of marine life
The marine life does not increase
because there are no nutrients
being brought to the surface due
to upwelling currents.
Proper way of solving a scientific problem is
1.
2.
3.
4.
La Nina
The trade winds increase and
continue to blow.
The trade winds are there to
move the water. Hence, there
are upwelling currents. The
water gets cold due to water and
nutrients being brought to the
surface.
The marine life does increase
because there are nutrients
being brought to the surface due
to upwelling currents.
State/identify the problem.
Make an educated guess
Collect data and analysis it
Draw conclusions
Water Quality
Abiotic conditions – See “A Freshwater Case Study” BLM 1-44
Temperature pH
Health Water
Unhealthy
Water
Low, will hold
more dissolved
oxygen
High,
cannot
hold
the
dissolved oxygen
turbidity
Between 5.5- clear
8
Lower than cloudy
5.5 or higher
than 8
phosphates
dissolved
oxygen
Low
levels Above 5 mg/L
below 10 µg/L
High
levels Less than 5
above 10 µg/L mg/L
Looking at bio indicator species are the best way of determining water health.
In a salt water environment you would also look for density and salinity.
Marine Technologies (positive and negative effects)
A technology which may be having a positive effect is the microchip which in inserted into the dorsal fin
of fish species such as cod fish to determine the migration patterns of the cod. This is also an attempt to
get a better understanding of why the population is continuing to decline even with the closure of the
Newfoundland Inshore Fishery.
Offshore oil rigs off the east coast of Newfoundland is having an impact upon some of the organisms
which inhabit our marine ecosystem. Bilge water may cause small spills, are these very small spills occur
before the ship refills, and has had an impact upon some of the bird species such as puffins, gulls and
turrs which live on the rocky coastline of Eastern Newfoundland.
Technology Contribution to Over Fishing
Catch methods have improved over time and as the machinery on board the vessels have been
equipped to lift larger loads, the trawlers now drag much larger nets. This method has increased the
amount of fish that is being caught in specific trips.
Also, vessel types have improved allowing the fisherman to stay at sea for much longer periods of time.
For example, today we have factory freezer trawlers which are able to process and freeze the fish right
on board. As a result, the older vessels would have to return after several day at sea, so that they did
not ruin their catch. Today, the vessels are able to stay at sea for weeks and perhaps months before
returning to offload their catch.
Offshore Oil Impact
Oil spills would be at the top of the list as this would have a negative impact upon surface organisms
such as bird species and mammals such as seals.
Also, the exploration for the oil has had a negative impact because it has scoured the ocean floor
disrupting vegetation and life which may have used this region as its habitat.
The increased amount of traffic which may be a result of the transportation of the oil may have an
impact upon the natural migration habit of some species such as whales.
The emptying of bilge water by the oil tankers may also introduce foreign species (also known as
invasive species) that may have a negative impact upon our native species. For example, the green crab
which is a native species of Africa is now growing at alarming rates which is have a negative impact upon
our lobster and snow crab industry. This green crab was believed to have been emptied from a tanker
when emptying its bilge water. It is extremely predacious and having a negative impact upon our own
fishery.
Potential Impact of Aquaculture
Aquaculture has been seen as a savior for many rural communities in Newfoundland and Labrador as it
permitting these fishing communities to hang onto their heritage using advances in technology as we
farm the fish. However, there has been some negative impacts as well, as some species such as rainbow
trout which are not native to our province, that have escaped from their bins during storms. These trout
moved into rivers and have had a negative impact on trout and salmon populations as they fed on both
species. These fish have also preyed on many species in the marine habitat as well.