Intro to Environmental Studies
Intro to Environmental Studies
Popular in Course
Popular in Environmental Science
This 5 page Reader was uploaded by Olivia Tenery on Monday April 14, 2014. The Reader belongs to a course at University of Oregon taught by a professor in Fall. Since its upload, it has received 169 views.
Reviews for Intro to Environmental Studies
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 04/14/14
ENVS 202 41414 1114 PM Salmon in the pacific NW have been and still are important Culturally for many people in the PNW salmon were and are closely tied to ways of life food identity and culture Ecologically as indicator species salmon might tell us about the functioning of watersheds They may also function to add nutrients especially phosphorous to streams nitrogen of cycle Economically fish markets food What comes to mind when people are buying fish Toxins Parasites Tapeworm you cant get this from fish that have never been in freshwater like tuna but you can get that from salmon mercury So human health Beneficial things Fatty acids Wild vs farmed Sustainable There is a message that farmed fish is bad and we should eat wild fish Do we ask ourselves these questions about grains beans fruit Most all the vegetables fruit we eat we farm So it is interesting to wonder about why there might be different circumstances What is aquaculture Aquatic organisms being farmed o Intervention in the rearing process to enhance production 0 Ownership of cultivated stock Vs Capture Fisheries o Disadvantage of capture fisheries bycatch and waste 2 as much as 40 of total catch expensive and difficult depleted stocks of many fish see fish stocks pie chart between 1413 of fish are over exploited o Concerns about aquaculture Ecological consequences of obtaining food for the fish Intentional fattening might include food more rich in PCB s Fish sometimes fed a dye to color flesh Antibiotics sometimes used to control disease Parasites or disease might flourish and spread to wild populations sea lice video So will we give up eating fish Or should we think about what kinds of fish are being farmed Roughly 13 of fish come from aquaculture Some fish are more efficient in converting food to body tissue They are the same temp as their environment they don39t have to spend more energy getting warm poikilothermic Neutrally buoyant So if we farmed those we wouldn39t be using as many other resources What are Barramundi Large scaled silver fish Aka Alaskan sea bass giant perch Australian sea bass Native to northern Australia up to southeast Asia Live in fresh water saltwater and estuaries Have been recorded up to 4 feet long and weighing nearly 90 lbs What makes them attractive for aquaculture Tiny heads with broad meat yieding flanks Can convert plant material into fatty acids in their eggs for their young Tuna and carp video Tuna live in the ocean and eat other fish Tuna are top predators Carpperch are freshwater o Able to feed on vegetation Video notes Two Fish Bluefin tuna is highly prized Eating bottom feeders carp is the future of aquaculture In the last 50 years fish stocks have been depleted by 90 Since 1975 the eastern Atlantic Bluefin tuna reproducing tuna percentage has fallen by 75 Tuna ranchers fins fish in the wild and fatten them up in pens Countries break their fishing quotas every year by around 4050 on average Sustainable Agriculture What foods provide humans with most of our caloric intake 0 Plant species Decreasing use these plants are Wheat maize rice barely soybeans sugar cane sorghum potatoes oats sweet potatoes What do we need besides calories 0 Nitrogen proteins minerals etc Globally what limits humans diet 0 Lack of food What are some common problems of or in agriculture 0 We rely on one particular family of plants 0 They are annual plants 0 Plants photosynthesis and they need light water and carbon dioxide What else do they need to grow 0 1 What kinds of compounds are plants made of sugar cellulose fiber protein fatty acids fatsoils o 2 What kinds of chemicalselements make up these compounds C H O sugars N S proteins A lot of these nutrients come from the soil solution or soil organic matter and the atmosphere What is soil 0 Soil is what dirt was before it got on the floor stan cook 0 Soil is a natural resource Hans Jenny 0 Soil has major components mineral matter organic material Is most agriculture done in areas that are were 0 Deserts o Grasslands 6 correct 0 Or forests Why is organic matter important for soil 0 It holds water it holds air and gives off mineral nutrients when it decomposes o Serves as a stable reservoir of nitrogen and phosphorous 0 Good balancer of water retention and drainage What are some problems that threaten agricultural soils 0 Erosion subsidence salinization Erosion a lot of erosion is not visible When things are tilled it opens up the soil for erosion or water can make this happen 2 What is the best way to prevent erosion 0 Don39t till the soil perennial crops would reduce soil tillage place crop strips and barriers There was a reduction in erosion from 19822003 because of the government paying the companies for not tilling soil Salinization evaporation from the surface water draws salt to the surface What does Wes Jackson propose as one solution 0 Use of both herbicides and pesticides o Polyculture of perennial grains oilseeds and legumes If we could do this we would have more carbon in the soil be less susceptible to drought less need for nitrogen fertilization less need for fossil fuels use less need for tilling less reliance on fossil fuel for traction reduces erosion less weed growth which creates a reduced need for herbicides The Land Institute Purpose is to develop an agriculture that will save soil from being lost or poisoned while promoting a community of life that is prosperous
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'