Ocean Discussion Assignments | Online Homework Help
Please read the article ”
UNIT 3-Ocean Ecosystems, History, Shifting Baselines, Fisheries” and following the requirements. Please look at the 4-point example carefully.
UNIT 3-Ocean Ecosystems, History, Shifting Baselines, Fisheries
Baptised by Mother Ocean…….. kr
The ocean has played a giant role in my life. As a kid, it was the beach, and body surfing. We didn’t have boogie boards back then just blow up mats. My parents must have either loved the beach, or that it distracted us and left them alone. We took frequent trips to different shores. It was a new environment where the more you explored the more you could learn. My experiences led me to want to look further, a few thousand times.
In 1972 I started surfing. An older friend from the wrestling team who had a driver’s license would take me to different spots and for some reason I wanted to go again. It was hard to catch waves but it was worth the effort. It always felt good. Surfing has taken me so many places that I would have never gone. The experiences have been essential to my overall knowledge and well-being. I ended up studying and practicing science. Then teaching earth and ocean sciences. I have benefited greatly from my time spent in nature, in the ocean, and along the shore. As a surfer you get a feel for the rhythm and power of the ocean by being in the waves. But you need to go under them to experience the amazing aquaworld.
I vividly remember my certification dive on the south side of Anacapa Island, now part of the Channel Island National Park. I think it was 1975. The kelp forest environment was too much to take in at first. I was not prepared and marveled at the sights. On descent I had trouble clearing my ears, my buddy went down without me. When I got to the bottom I was all alone. Except for some big fish and pretty soon a moray eel. I had a hard time relaxing. Too thrilled to be calm and breath slow. Consciously I had to try and focus on little things. It was an awesome new world.
I wanted to look everywhere. I weaved my way through the kelp and it brought the world right up in my face. My mind and breathing had slowed. There were little fish everywhere. The kelp was mesmerizing. Feeling super alive, I moved through the swaying forest which stretched up and fanned outward providing a sense of shade and shadow like other forests. This was a strange and wonderful experience. I floated through this scene like a spirit, not grounded at all. Garibaldi’s highlighted the muted, mostly green-grey colors. From above there was a dancing glow of gold with moving spotlights like an underwater disco.
A sea lion zoomed in from the kelp, stopping to say hi, I guess. Well at least it seemed that way. I started swimming away when I felt a tug on my flipper. I turned to confront and off the puppy swam. She came back. Either she wanted to play or she was telling me I was in her territory. She eventually swam by my side for a short time. Once she was gone, I was out of breath, or I should say, out of air.
My tank was empty, so I ascended up into the atmosphere again, darn I was just getting used to it. The magic time was over. I stroked back to the boat and worked out of my gear. Beside being really cold I remember feeling quite euphoric. I had been exposed to divine insight. I never would have known. I’m so glad i went for it.
This quote sums it for me…
“The sea, once it casts its spell holds one in its net of wonder forever” Jacques Yves Cousteau
The Modern Ocean: Diverse and a bit Scary
QUICK READ: Scripps Researchers Identify Three Distinct States of The Ocean Ecosystem in the last 85 million Years
Ocean abundance was very high in the Paleogene. Diversity kept increasing and creature size reached a maximum in the Modern Oceans. By the Pleistocene oceans had cooled off to a point where mixing was invigorated and productivity increased. This led to some species attaining exceptionally large sizes, a good example of long term bottom-up sustinence. Still around is the Blue Whale which surpasses any other Earth species in terms of size, ever. One such creature that grew large in the modern ocean was the Megladon shark. It dwarfed the largest of its Great White relatives. But getting big is not always a good biological plan. Especially if one needs to eat a lot of food. Any change to lower trophic levels would effect the big species the most. The middle Pleistocene said goodbye to Megladon.
Bye bye big bad shark!
Why might the Blue Whale still be around? What is different about its survival strategy. How might the Blue Whales diet give it an advantage over Megladon?
American-Human History (ancient baseline changes)
You don’t have to search too far back into history and literature to find descriptions of a wild and untamed ocean (e.g. Moby Dick, 1851). For centuries coastal and continental shelf ecosystems provided what seemed to be endless bounty. From San Diego, you don’t need to travel far to see some of the best evidence for an early maritime culture. Long before the years of ocean lore described in Mobey Dick (15,000 years), early cultures were integrated with seafaring and ocean subsistence. Coastal waters facilitated travel. There would always be food to find along the way. Early hunter-gathererinhabitants to the Americas resided in what is now Channel Islands National Park, California where a paleocoastal culture is well documented. Even in pre-historic times data tell us that the baseline was already changing.
From a 2010 Department of Interior: Archeological Assessment Report on Channels Island National Park: (for reference only-not required reading) https://www.nps.gov/chis/learn/historyculture/upload/Final-Arch-Overview-May-2015.pdf
“Currently, more than 50 archaeological sites on San Miguel, Santa Rosa, and Santa Cruz islands have been radiocarbon (14C) dated between about 13,000 and 7000 BP —one of the largest and most significant clusters of early coastal sites known in the Americas. Many more early sites undoubtedly lie buried beneath the waves and younger dunes, alluvium, or shellmounds”.
The report describes the rapidly changing coastal conditions these people experienced:
“Between about 13,000 and 7000 BP, sea levels rose roughly 40 meters (~130 feet), from about 50 meters to 10 meters below modern levels. Rising seas had dramatic effects on the earliest islanders and the landscapes and seascapes they lived in”.
It also describes changing climate, landscapes, vegetation, ocean resources, population, and migration in later years.
Dr. John R. Johnson, Curator of Anthropology at the Santa Barbara gives a brief description of the significance of the earliest human fossil dates from Santa Rosa Island.
QUICK READ: Arlington Springs Man NPS Website
Early humans made it to Santa Rosa island (Arlington Man) by 13,000 YBP maybe earlier but much of that fossil evidence would be underwater or washed away now. There is good evidence some people likely kept going south. There were inhabitants at Monte Verde in Chile by 14,600 YBP. mitacondrial DNA evidence says they are descendents of a 17,000 year old population in the Bering Sea region. Another site in Oregon has DNA evidence of humans by 14,300 and one in Texas gives a date over 15,000 years. These inland locations have supported a theory that a migration came from the north by land. New data has scientists leaning toward the idea that the first people came first along the coast and then dispersed inland, then there was a secondary migration when the ice cap melted a bit.
So why talk about history, archeology and anthropology in a oceans course?
- Evidence is building to show that the coastal environment was already being changed by humans many thousands of years ago.
HOW MUCH HAS THE ECOSYSTEM CHANGED? (Can we know it’s original state?)
SHIFTING BASELINES (history is important)We need to look to the past to get a true understanding of the ocean environment. It is only in this way that we can understand our role. Impacts that occur beyond generational boundaries go largely unnoticed. Humans are most oblivious to all the little changes that happen continuously. We need to remember the sizable and long lasting impacts that have already occurred to the ocean ecosystem. There is historical data for most of the 20 century. Older data is archeological, anthropological, geological, cultural, sociological, biological. To know about today’s ocean we need to know about yesterday’s. A 160 years ago when the Eighty Eight Fish Mural was painted the oceans were radically different. There is good historical evidence of depletions occurring 300-400 years ago and some anthropological evidence of much earlier changes to the ecosystem. What was the ocean baseline before humans? What is your baseline?
Termed the concept “shifting baselines”
FISHING DOWN THE FOOD CHAIN
Fishing deeper, and farther down the food chain happens as big fish disappear. Each successive generation of fishermen see smaller fish. Each generation sees less fish. They see less diversity, but each of those generations see what they see and are not aware of the previous declines. They still need to catch fish
ISCUSSION POST GUIDLINES
PLEASE FOLLOW THESE GUIDELINE WHEN MAKING A DISCUSSION “TEST QUESTION” POST
- 1-Don’t copy any of my discovery questions
- 2-NO COPYING ANY PREVIOUSLY POSTED TEST QUESTION (review before you post)
- 3-NO FORMATING, NO indentations, NO BOLD, CAPITALS, ETC
- 4-INCLUDE AN EXPLANATION AND Resource
- 5-When you write an incorrect response, check it out. Some people create responses that are worded terribly, make no sense, or are actually correct.
1-Point QUESTION (is a very poor effort)
-if you write a True-False question, make a very meager effort or make multiple errors
-a two point question shows minor effort and creativity—it is not thought provoking
-there are either misspellings, major grammatical errors, or it makes no sense
-any question that asks for a numerical answer (like a percentage)
What is the percentage of Earth’s water that is tied up in glacial ice?
- A) 3% B) 10 % C) 30% D) 50%
Explanation: 3% or Earth’s water is tied up in Ice
-a three point question promotes a bit of thought but is still quite simple
-if there are not four “unique” response or you use…. D) all the above, or none of the above
– if you write a decent question but make too many spelling or grammatical errors
IN the ITCZ, or inter-tropical convergence zone, there is a tendency for the warm humid near the ocean to move this way?
- A) north B) south C) up D) down
Explanation: The ITCZ is where the atmosphere is the hottest, most energetic and is the zone on Earth where low density air is constantly rising. (link input here)
-well written, thought provoking, no major mistakes
-good job of referencing and explaining
According to the otter-urchin-kelp interaction example illustrated in the article “The Functioning of Marine Ecosystems”, which of the following species will be categorized as a keystone species?
- A) Kelp, because the productivity of kelp determines food abundance for marine animals.
- B) Urchin, because urchin prevent food overabundance provided by kelp.
- C) Urchin, because urchin are an important food source for higher trophic level marine animals.
- D) Sea otter, otters stabilize the system in the kelp forest by reducing urchin grazing.
Explanation: The keystone species is one “whose impact on its community or ecosystem is large, and disproportionately large relative to its abundance” (Power et al., 1996). In this example, the sea otter is a high trophic level marine animal. Therefore, their abundance determines the abundance of the other two species. Although option A, B, C are facts, urchin and kelp are not keystone species.
Grading will be based on
4-Depth of Thought and Inquiry
7-Citation and explanation
4 POINTS POSSIBLE
- 1 POINT=POOR QUESTION, or too many errors
- 2 POINTS=AVERAGE QUESTION, slight errors
- 3 POINTS=GOOD QUESTION, no errors
- 4 POINTS= VERY GOOD QUESTION (full credit)