Suppose you own a fishing business located at approximately 38° N latitude off the coast of Maryland. Most of the fish you catch are Atlantic cod, and your primary means of catching fish are gillnetting and longlining. (10 points)a. Describe two advantages, related to thermohaline circulation and surface ocean currents, of your fishery’s location.b. Explain what happens during El Niño-Southern Oscillation. Describe two ways that an El Niño event can alter the number of fish you catch in a year.c. Are your primary methods of fishing sustainable? Explain your answer. Describe two alternate fishing methods you could use, and explain whether each method is more or less sustainable than your current methods.d. Identify two pieces of legislation that regulate fishing in U.S. or international waters, and explain how each piece of legislation affects your fishery.3.03 Ocean Circulation
Ocean circulation is driven by temperature and salinity differences.
Deep ocean currents distribute heat and salts around the world’s oceans.
salinity varies a great deal throughout the global ocean waters.
At the high latitudes, especially in the North Atlantic, cold masses of high-salinity water
sink in deep convection. This sinking of cold high-salinity water is critical to overall
At the mid-latitudes, fisheries often occur where masses of water with different salinities
At the equator, runoff from surface freshwaters and rainfall, affect the salinity of ocean
You’ve already learned some good news: fisheries often occur at the mid-latitudes. You
happen to live at a mid-latitude location—perhaps your business will have an enormous
supply of fish. Now you’ll just have to learn how to find these fish.
ocean water is circulated on a “conveyor belt”
t moves (warm, fresh, less dense, shallow water) toward the poles,
and (cold, salty, dense, deep water) toward the equator.
The global conveyor belt is strongly linked to global climate. If it were to stop, or
even to slow substantially, clima
te change could ensue.
While ocean circulation is driven by differences in temperature and salinity,
surface ocean currents
are driven by winds.
Ocean surface currents are created by strong, steady winds, which exert drag on
the water as wind blows across the ocean’s surface.
Factors that affect ocean currents include
land mass shapes
the Coriolis effect
density and temperature of water
Cold currents flow toward the equator on the western coasts of continents, while
warm currents flow toward the poles.
Ocean currents have a direct impact on climate.