ENVS 205 Module 5 Activity

.docx

School

University of Waterloo *

*We aren’t endorsed by this school

Course

205

Subject

Geography

Date

Feb 20, 2024

Type

docx

Pages

Uploaded by cayleighbgilbert

Cayleigh Gilbert Module 5 – Learning Activity 1. What are the most biologically productive areas of the ocean? - coastal zones and in parts of the ocean where upwelling from the deep ocean returns nutrients to the surface layers and where photosynthetic activity occurs 2. Given an example of a positive feedback loop related to global climate change and the oceans. Are there any negative feedback loops? - increased freshwater melting from the polar ice caps is an example of a positive feedback loop - One example of a potential negative feedback loop in this context is the plankton chat produce dimethyl sulphide gas 3. What is the relationship between fishing and poverty? Provide one example. - Many of the poorest people in the world are fishers who rely on the sea/oceans to provide them and their families with their livelihoods 4. Explain the concepts of shifting baselines, serial depletion, and fishing down the food chain. - Changes in fish populations are not always obvious, since scientists tend to look only at the most recent data rather than comparing them with historical catches. This problem is known as a shifting baseline in which scientists have no other option than to take the current degraded state as the baseline rather than the historical ecological abundance - Serial Depletion is when one stock after another becomes progressively depleted even if the total catch remains the same - We are progressively exploiting lower and lower trophic levels to derive our catch. Fisheries in many areas have now focused on invertebrates, like the Atlantic crab. Large-sized fish no longer exist. This is known as fishing down the food chain 5. What is driving the trend shown in figure 9.8 (size-at-age over the past four decades)? What implications does this trend have for modern fisheries management? - Figure 9.8 shows that fish being caught now are are substantially smaller than ones caught in the past

- By Removing the larger, older individuals of a population, it may actually undermine stock replenishment. Research suggests that for maintaining old- growth age structure can be important for replenishing fished populations 6. Give an example of the destructive effects of bottom trawling. - Bottom-trawling can have damaging impacts on reefs and the seabed (ancient sponge reefs) - Has contributed to the decline of many species and organisms 7. What are the two main forms of chemical pollutants in the oceans, and what are their main effects? - Toxic materials and nutrients - Synthetic organic chemicals and toxic metals tend to concentrate along two main interfaces in the ocean: the boundary between the seabed and water and the boundary between the water and the atmosphere. 8. Discuss the principal reasons behind the collapse of the Atlantic groundfish stocks and some of the lessons to be learned form this experience. - It is possible that colder waters, combined with overfishing in the previous two decades, prevented or inhibited the shrunken stocks from regenerating - poor physiological condition of many predator fish in the area also suggest an overall lack of prey - The collapse highlights how some contemporary resource management practices may encourage resource liquidation. 9. List the three main principles underlying Canada's Oceans Strategy? - Sustainable development, Integrated management, precautionary approach 10.Discuss the positive and negative aspects of aquaculture production. - As the fisheries continue to decline, new livelihoods will need to be devised and are even now appearing with the growth of low-input aquaculture - Development along the coastal fringe and catchments relating to fishing/aquaculture, industries and other activities leads to multiple and diverse alterations in the environment - Fish farming and fish-processing activities provide full-time jobs and opportunities economically

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help