Congratulations! You have won a ticket allowing you to accompany James Cameron m
ID: 177445 • Letter: C
Question
Congratulations! You have won a ticket allowing you to accompany James Cameron m his deep-sea exploration of the oceanic ocean bottom in his new and larger submarine the "Deepsea Challenger-2". Describe your oceanic voyage from the surface to the bottom of the ocean floor. Your description should include all of the zones and their respective depths, all of the major environmental changes you observe as you descend through these zones, examples of organisms that you encounter in each major zone, the major challenges that they encounter within each major zone, and the adaptations that each has evolved in order to survive the challenges within each zone. Note: I am expecting a thorough answer for this question and adequate space has been provided. Compare and contrast migration and dispersal. In regards to migration, what is the benefit of undergoing seasonal migrations? Provide a detailed description of the seasonal migration of a marine species (i.e., where does it go. why is it undertaking the migration, etc.). In regards to dispersal, describe/discuss planktonic larval dispersal (PLD), its relevance to the distribution of a species, the key factors that affect where larvae disperse to. factors that limit the duration of PLD, triggers for settlement and how successful this strategy is for establishing the next generation (i.e., what are the pros/cons of this strategy?). Compare and contrast asexual and sexual reproduction. When is asexual reproduction beneficial? Provide examples of asexual reproduction and the potential problems associated with asexual reproduction. Describe three disadvantages of sex that lead to the "paradox of sex". Describe three strategics that enhance the fertilization success of broadcast spawning species. How does internal fertilization increase reproductive success and what challenges still remain for internally fertilizing species? Define/describe oviparity, aplacental viviparity, histotrophy, placental viviparity, and intrauterine cannibalism and provide the cost/benefits to each of these reproductive modes. Provide an example of either a protogynous or a protandrous sequential hermaphrodite, the initial and terminal phases of the species, what drives the sex change within the environment and the evolutionary benefit of this reproductive strategy. Describe the flow of energy (trophic structure) within a marine community composed of at least 5 trophic levels (you'll need to indicate "who" is at each level, they're role, and whether they transfer or receive energy (or both)). Provide an explanation for why the amount of available energy to each "higher" trophic level decreases. What are the limiting resources for most marine species and why are they important? Describe vertical mixing and the effect of the compensation depth, mixing depth, and critical depth on net primary productivity. How does vertical mixing change the concentration of nutrients in northern temperate waters seasonally and what conditions would lead to a summer algal bloom? Briefly, describe the pattern of succession at a whale fall, at least one major organism for each phase of the succession, and the average amount of time that whale fall communities exist. Riftia are the dominant benthic organisms in black smoker hydrothermal vent communities. Riftia has no mouth, nor gut (digestive tract), or anus. How does Riftia, a heterotrophic worm, obtain sugars for cellular respiration? What is the relevance of hydrothermal vent communities for the origin of life? Briefly, describe a vertical migration trap and its importance for the productivity of seamounts. Of the numerous predicted scenarios of ongoing global climate change, briefly describe 3 of these scenarios and how climate change affects them. Describe the possible effects of removing estuarine habitats (e.g. mangroves or wetlands) on neighboring ecosystems/habitats. What is meant by the term "overexploitation" and how does this practice affect the longevity of a population/species? What is a shifting baseline and how does it affect our undemanding of the "health" of a marine ecosystem and its diversity? Provide an example of an invasive species, its effect on its new ecosystem, and what allows the species to invade its new ecosystem.Explanation / Answer
Compare Migration and dispersal:
Migration is defined as the movement of large numbers of a species from one place to another, generally leaving none behind. Daily movements and seasonal movements are two types of migrations. Migration can be one direction, no return journey or one to-and-fro movement or multiple return journeys.
Dispersal is the spreading of individuals away from others, leaving others in the original area. Dispersal varies between species and it also differs between sea and freshwater animals. Variation in dispersal occurs between species in different habitats, between sexes, body forms, and individuals of different social status.
Both are affecting population size of realized niche.
Seasonal migration of animals or birds mainly occurs due to shortage of foods or climate conditions. Some birds fly south to Britain in winter, then north to Iceland, Norway and the Arctic in summer. The benefit of this migration brings the ecological balance in the flora and fauna.
More than 80% of marine life is migrating to different places for their breeding and feeding patterns due to warming waters. Marine species are migrating 10 times faster than land animals in climate change. Marine animals time their reproductive and migratory cycles around prey, such as whales migrating to the Arctic to feed on krill in the summer and salmon migrating to the oceans for seasonal nutrients. Arctic Cod prey on a specific zooplankton in the Gulf of Marine and Georges Bank. Higher sea surface temperatures along the US Northeast continental shelf are causing the zooplankton to shift to cooler waters. It was found that populations of Atlantic Cod in areas where zooplankton have shifted seem to have lower reproductive success.
Planktonic Larval dispersal:
The planktonic larval dispersal places greater emphasis on mechanisms that retain larvae near natal habitats or return them to those habitats. It has important implications on our understandings that gene flow is always an overwhelming force that homogenizes populations or that strong physical barriers are required to isolate populations. The simplest model of planktonic dispersal treats larvae as passive particles advected in a uniform flow; dispersal distance is then the product of the length of the planktonic period and the flow's velocity. Larvae spawned in shallow waters do not immediately enter offshore currents, but remain in the relatively sluggish coastal areas for days or longer. Tidal fluxes can export larvae away from shore on the ebb tides and return them on flood tides, and the larvae of some decapods vertically migrate to take advantage of tidal transport shoreward and into estuaris.