Student: Daphne Hamilton
Graduation date: May 2014
Type: Concentration (single major)
Date approved: November 2012
Summary
Biodiversity is valuable to humans not only because it is beautiful and fascinating, but also because it is necessary for maintaining a sustainable and productive ecosystem. The oceans are an important food resource for humans, and they also provide half of the world’s oxygen supply through photosynthesis. Certain types of marine habitat are particularly important to maintaining the ocean’s biodiversity because they are home to a disproportionately wide variety of organisms, including valuable food species. Because humans rely on ocean ecosystems for resources, it’s important to assess the quality of marine habitats and what impacts, anthropogenic and non-anthropogenic, could be affecting them. For my concentration, I am interested in situating in three critical marine habitats- sea grass beds, kelp forests, and coral reefs- and looking at the current state of these habitats and how they may be changing over time in terms of size and functionality. These three habitat types all play an important role in maintaining the biodiversity of the oceans, and are distinct from other ocean features such as beaches, rocky intertidal zones, and the deep ocean due to their particular biotic compositions. Kelp forests, which occur throughout coastal areas of the Pacific Ocean, are highly productive habitats which support a wide variety of shellfish and other invertebrates, fish, marine mammals, and sea birds (Erlandson et al. 2007). In addition to providing a habitat for fish and other organisms that humans rely on for food, kelp itself, a large multicellular algae, is also harvested industrially as a food resource (Lorensten et al. 2010). Sea grass beds occur in sandy coastal areas in temperate, tropical, and subarctic regions (Short et al. 1996). They serve as foraging sites and sheltered areas for small marine organisms and juveniles, including fishery species which humans rely on as a food resource (Gibson 2001). Coral reefs, which support a huge proportion of the ocean’s biodiversity, occur in shallow tropical waters. A coral is made up of a symbiotic relationship between a group of polyps and a photosynthetic algae, which creates a structure around which many marine invertebrates and fishes make their homes (Glynn 2004). These critical habitat types are vulnerable to certain impacts which can reduce their ability to support organism populations. Both human behavior and natural processes can be disruptive to the ecosystem. Seagrass losses can occur through weather events, geological activity, overgrazing, and disease, as well as dredging and pollution (Short et al. 1996). Ocean acidification, which occurs as a result of both carbon dioxide emissions by humans and the upwelling of acidic water from the ocean floor, can interfere with the ability of calcifying organisms such as corals and mollusks to grow, reproduce, and build their shells (Albright 2011). Kelp forests may be impacted by the harvesting of kelp as well as overfishing, which can disrupt the complex food chains that occur within them (Lorensten et al. 2010). Although certain human behaviors can impact marine habitats, we also need these habitats to be healthy so that they can continue to provide for us. Societies rely on ocean resources for food and the economic development brought by fisheries. In addition, many people have an intrinsic value for biodiversity and habitat areas that are unaffected by humans. As a result, some regulations have been put in place in an attempt to prevent the degradation of habitat and the overconsumption of resources. Marine Protected Areas are zones of ocean habitat which are governed by laws that strive to control or prevent human impact through fishing or other behavior, often with the specific goal of maintaining resources for continued consumption (van Son et al. 2007). Other types of regulation include fishing catch limits and management by the Endangered Species Act. However, while these regulations strive to conserve marine resources in part for human benefit, they can also be frustrating to fishing industries who might prefer unlimited access to fish for greater economic gain. This concentration is relevant to Environmental Studies because it incorporates human and non- human biology and interactions. Often the line between anthropogenic and non-anthropogenic impacts is blurred, since human behavior can have an effect on natural phenomena such as weather, which in turn may impact habitats. My concentration relates to the “Threats to Coral Reefs” and “A Disappearing Jewel: Biodiversity Loss on the Great Barrier Reef” themes because these discuss coral reefs, one of the habitat types I am focusing on, and what processes are impacting them, including ocean acidification, climate change, and overfishing. The “Is Something Fishy? Salmon Fishery Management in Local and Global Contexts” is relevant to my concentration because salmon, an important food species consumed by humans, relies on key marine habitats including sea grass beds for food and shelter during certain life stages. This means salmon are impacted by the state of these habitats, and they also play a role in the ecosystem’s food chains.
In Kenya, Marine Protected Areas have been established in un-managed coral reef habitat areas by the government in an effort to conserve the country’s natural resources. As a result, significant re-population of dominant fish species has occurred, helping to return the reefs to a productive state (Calnan et al. 2007). However, this has also impacted the livelihoods of fishermen and tour guides who rely on access to the reefs for economic gain, and can result in the increased consumption of resources in unprotected reef areas. In San Diego, California, kelp forests have been monitored over periods of disturbance due to weather and climate events and intense grazing by sea urchins, one major consumer of kelp (Dayton et al. 1992). Kelp deforestation can occur when sea urchins are plentiful, but increased urchin mortality can result in the recovery of kelp habitats. According to this study, large scale disturbances including El Nino, La Nina, and rare storms can significantly impact kelp habitats, but recovery often occurs promptly, leading to a fluctuating trend in kelp forestation over time. This trend results in periodic changes to populations that inhabit kelp forests and the availability of resources from the habitat for harvesting and fishing by humans. These situated examples show how critical habitats can be affected by various impacts, and how human societies can be affected by changes to critical habitats.
References
Albright, Rebecca. 2011. “Reviewing the Effects of Ocean Acidification on Sexual Reproduction and Early Life History Stages of Reef-Building Corals.” Journal of Marine Biology 2011. http://www.hindawi.com/journals/jmb/2011/473615/.
Bakun, A. 1990. “Coastal Ocean Upwelling.” Science 247 (4939) (January 12): 198–201. doi:10.1126/science.247.4939.198.
Buchheim, Jason. 1998. “Coral Reef Bleaching”. Odyssey Expeditions- Marine Biology Learning Center Publications. http://www.marinebiology.org/coralbleaching.htm.
Dayton, Paul K., Mia J. Tegner, Paul E. Parnell, and Peter B. Edwards. 1992. “Temporal and Spatial Patterns of Disturbance and Recovery in a Kelp Forest Community.” Ecological Monographs 62 (3) (September 1): 421–445. doi:10.2307/2937118
Erlandson, J, M Graham, B Bourque, D Corbett, J Estes, and R Steneck. 2007. “The Kelp Highway Hypothesis: Marine Ecology, the Coastal Migration Theory, and the Peopling of the Americas.” JOURNAL OF ISLAND AND COASTAL ARCHAEOLOGY 2 (2): 161–174.
Fox, Helen, and Roy Caldwell. 2006 “Recovery from Blast Fishing on Coral Reefs: A Tale of Two Scales.” http://www.jstor.org/stable/40061737?&Search=yes&searchText=coral&searchText=reefs&searchText=fishing&list=hide&searchUri=%2Faction%2FdoBasicSearch%3FQuery%3Dcoral%2Breefs%2Bfishing%26acc%3Don%26wc%3Don&prevSearch=&item=2&ttl=2418&returnArticleService=showFullText.
Gibson, R. N. 2001. Oceanography and Marine Biology, an Annual Review, Volume 39: An Annual Review: CRC Press.
Glynn, Peter W. 2004. “High Complexity Food Webs in Low-Diversity Eastern Pacific Reef: Coral Communities.” Ecosystems 7 (4) (June 1): 358–367. doi:10.2307/3658822.
Jentoft, Svein, Thijs C. van Son, and Maiken Bjørkan. 2007. “Marine Protected Areas: A Governance System Analysis.” Human Ecology 35 (5) (October 1): 611–622. doi:10.2307/27654227.
Lorentsen, Svein-Håkon, Kjersti Sjøtun, and David Grémillet. 2010. “Multi-trophic Consequences of Kelp Harvest.” Biological Conservation 143 (9) (September): 2054–2062. doi:10.1016/j.biocon.2010.05.013.
McClanahan, Tim R., Nicholas A. J. Graham, Jacqulyn M. Calnan, and M. Aaron MacNeil. 2007. “Toward Pristine Biomass: Reef Fish Recovery in Coral Reef Marine Protected Areas in Kenya.” Ecological Applications 17 (4) (June 1): 1055–1067. doi:10.2307/40061897.
Orr, James C., Victoria J. Fabry, Olivier Aumont, Laurent Bopp, Scott C. Doney, Richard A. Feely, Anand Gnanadesikan, et al. 2005. “Anthropogenic Ocean Acidification over the Twenty-first Century and Its Impact on Calcifying Organisms.” Nature 437 (7059) (September 29): 681–686. doi:10.1038/nature04095.
Pomeroy, Lawrence R. 1974. “The Ocean’s Food Web, A Changing Paradigm.” BioScience 24 (9) (September 1): 499–504. doi:10.2307/1296885.
Short, Frederick T., and Sandy Wyllie-Echeverria. 1996. “Natural and Human-induced Disturbance of Seagrasses.” Environmental Conservation 23 (01): 17–27. doi:10.1017/S0376892900038212.
Questions
- What changes in size and quality or state have been occurring to critical marine habitats, and how are organism populations responding to these changes?
- What broader environmental circumstances, such as human and non-human impacts, may be contributing to these changes? In the case of anthropogenic impacts, what roles do humans play, and how do their contributions to environmental change relate to human lifestyle and society?
- What regulations are being implemented to control potential impacts on the environment, and what social and economic impacts do these regulations have on humans? What biological and ecological implications do they have?
Concentration courses
- Environmental Sciences 103 (Society and the Oceans, 3.33 credits). This course is focused on the way humans interact with the oceans, and the way human behavior has impacted marine areas, for example through fishing, waste, ocean acidification, and related regulations.
- Atmospheric Sciences 111 (Global Warming, 3.33 credits). This course covered the science and impacts of global climate change, including the impacts of greenhouse gasses and the feedback loops of melting ice, which is relevant to my concentration because I plan to look at the potential impacts of climate change and ocean acidification on marine habitats.
- Environmental Science and Resource Management 210 (Soils, 3.33 credits). This course is relevant to my concentration because we studied soil composition and how substances move through the soil, including organic matter and pollutants, which is an important part of ecosystem function.
- Oceans 121 (Deep Sea Vents, 1.33 credits). This course focused specifically on the chemistry and biology of hydrothermal vent environments, providing a study of one type of marine environment and how organisms can interact within them.
- Environmental Studies 499 (Independent Study, 1-4 credits), spring 2013. This course may be a good option for me as it would help me meet the 300 level requirements for the concentration within my time limits, and could be a way for me to take a marine biology or ocean sciences based course (given that marine biology may not be offered during my time here).
- GEOL 240 (Spatial Problems, 5 credits), spring 2013. This course provides practice using important research and data processing methods that I can utilize throughout my concentration and thesis work, and an opportunity for individualized research which I can tailor to my concentration.