Fall 2015 Final Project

Summary

Figure 1.   California Kelp Forest     Source: 14

Kelp forests are one of the oceans most diverse ecosystems that’s biodiversity is comparable to a coral reef’s, and kelp forests are found throughout the world’s oceans although some of the most diverse kelp forests are located along California’s coast. Kelp forests thrive along coastlines that have cool nutrient rich currents, and hard rocky sea floors where their root system known as a holdfast can attach itself. In a similar structure to tertiary forests kelp forests have a canopy, undergrowth, and floor where over one thousand species reside; so this biome is very important in maintaining an overall healthy coastal environment. Some of the California’s most ecologically diverse kelp forests are found throughout the Central and Southern coastal regions of the state, but increasingly anthropogenic sources have resulted in decreases to the overall area of kelp forests along California’s coast. Within a kelp forests there are various algal species present, but Macrocystis pyrifera (Giant Kelp) a species of brown algae is the most important because it provides the forest’s foundation and without it kelp forests wouldn’t be able to fully develop into the complex biome that they can become (10, 12).

Figure 2. Monterey Bay Kelp Forest
Source: 15

History

California’s kelp forests also play a very important role in supporting the surrounding ecosystems too; although historically California’s kelp forests were far more extensive and the ecosystems were more diverse then their current composition especially Southern California’s forests. It is being speculated that kelp forests were what lead people to migrate from Asia over to America, for there is an almost continuous kelp forest trail between Japan and California (5).  Although over the last two Centuries in particular Southern California’s kelp forests have been decimated by overexploitation, pollution, and development resulting in some areas losing up to 80 percent of their historical kelp forests like Orange County. During the early decades of the 20^th Century kelp forests were recorded along both Los Angeles’ and Tijuana’s coast, but pollution and sewage resulted in their disappearance as early as the 1950’s (2, 6). The leading reason for the decline of Southern California’s kelp forests are anthropogenically based sources that for centuries have been reducing suitable areas for Macrocystis pyrifera to colonize and is continuing to happen today too. One of the most devastating losses to Southern California’s kelp forests was during the 19^th century when the southern sea otter a keystone species went extinct because they were heavily overexploited throughout California, and they were even thought to be extinct throughout the remainder of the 19^th century until a single colony of fifty were found in the 1930’s around Big Sur, California (12, 7).

Anthropogenic Impacts

Figure 3. Sea Otter Eating Urchins     Source: 16

Figure 4. Graph Comparing Wave Disturbance to Primary productivity
Source: 17

One of the most important species that’s responsible in large part for maintaining a healthy and balanced kelp forests are sea otters so they are considered a keystone species, for without them Southern California’s kelp forests began to decline due to an increase in sea urchins whose preferred food source is Macrocystis pyrifera and who is primarily preyed upon by sea otters. Regrettably sea otters were highly prized for their pelts and were hunted to extinction in the 19th century, but luckily in the 1930’s a colony of around fifty were found around Big Sur California and today there are over two thousand but none still in Southern California. The exploitation of sea otters wasn’t the only anthropogenic form of destruction, for pollution and erosion are responsible for reducing the range of Macrocystis pyrifera because it needs a rocky substrate in order to colonize an area not soft, sandy sediments that erosion deposits. The 20^th century brought about drastic increases in urbanization, agriculture, and immigration resulting in ever increasing amounts of pollution that the state still struggles to cope with (8, 1). Fishing is a very detrimental practice for kelp forests especially commercial fishing since typically the fish targeted by humans are apex predators such as Sheepshead fish and spiny lobsters that play an important role in regulating the population of grazing fish species to keep the kelp forests density healthy and balanced (12), but they are also affected adversely by pollution as well.

Figure 5. Effect of Each Environmental Predictor on Kelp Canopy Biomass
Source: 18

California is the most populous state in America and most of the population resides within Southern California, so counties like Los Angeles, Orange, and San Diego have been seen a decline in kelp forests due to pollution entering the ocean when through gutters during the rains contaminating the local epipelagic zone (1). Along California’s coast there is where California had located three nuclear power plants (Diablo Canyon, Humboldt Bay, and San Onofre), which would intake massive amounts of sea water containing various aquatic organisms resulting in the drastic decline of species in local kelp forests but today only Diablo Canyon remains operational. This year one of the most devastating events to all of California’s kelp forests is a natural phenomenon that is set to occur this year called El Nino Southern Oscillation (ENSO) an event that results in increasing precipitation across the state, but also results in an increasing sea temperature which results in decreasing kelp forests density and destroying many others. Macrocystis pyrifera thrives better in cold nutrient rich water so the warm water hampers the growth of kelp forests and stresses them out. Kelp forests historically have adapted to the El Nino phenomenon but compounding El Nino with high amounts of pollution, runoff, and erosion it becomes very challenging for kelp forests to persists since they already struggling with anthropogenic factors let alone combining those factors with an increase in storms. Since the 1960’s and 70’s California has been monitoring their kelp forests and especially since the beginning of the 21^st century various efforts are h to protect and restore Southern California’s kelps forests (6, 10).

Figure 6. Southern California MPA's
Source: 19

Outlook

Throughout the region there are both governmental agencies as well as non-profit organizations who have been working to restore the forests, but this is a relatively new trend that will have to continue for years to come in order to ensure their protection for future generations to enjoy. At the local level there are cities like Laguna Beach, California that have completely outlawed any fishing off the coast by creating marine-protected areas (MPA) which has far reaching benefits especially to the surrounding coasts and ecosystems. Throughout Southern California there are fifty MPA’s that oversee and protect over 350 square miles of California’s coastal waters, and they are like National forests but for aquatic environments so that these important resources will be conserved

Figure 7. Benefits of MPA's     Source: 20

ensuring future generations will be able to enjoy them too (4). MPA’s benefit the surrounding waters too because it provides a safe haven from anthropogenic activities primarily fishing, so many species can recover and since they’re mobile they swim in and out resulting in an increase in the productivity of fishing the surrounding unprotected areas. There are costs associated with maintaining MPAs but the benefits to California’s coastal ecosystems far outweighs the costs associated with maintenance and enforcement since they ensure that fish stocks will be preserved and not completely exploited (3). If current efforts are maintained as well as implementing several additional policies to ensure that every effort is made to protect these important ecosystems.

Improvements

Figure 8. Before & After Restoration Project
Source: 21

Overall the outlook for Southern California’s kelp forests is relatively good because they are able to colonize and grow quite quickly in comparison to terrestrial forests, so recovery is very possible if pollution is reduced and water temperatures remain cool and nutrient rich. There are also numerous non-profit organizations such as The Bay Foundation, Coastkeepers, and LA Waterkeepers which are all helping by participating in kelp forest restoration projects throughout California’s coastal areas helping accelerate the regrowth of many forests (12). These groups grow kelp themselves and cull sea urchin barrens to ensure the recovery of these forests is as quick as possible, and the incredibly high urchin populations results in a lack of available resources leading to a reduction in their size as well (1). The future looks bright for kelp forests if these efforts are continued, for MPA’s are very beneficial, but pollution and runoff continues today throughout Southern California leaving many areas unaddressed (4). One city that provides an example that could be replicated along the coast where funding is available is Huntington Beach, for they depend on tourism during the summer so to combat polluted runoff they began treating the runoff during the summer months. This program was initiated out of economic reasons to protect the tourism industry but incidentally it ended up benefiting the local coastal ecosystems such as kelp forests too, so hopefully in the future programs similar to this one can be developed that most importantly protect coastal ecosystems and biome but can also benefit the local economy as well (9). Despite all of these efforts and legislation to protect these important biomes there is still a much larger issue that needs to be addressed and that is climate change, for climate change is the most important issue facing kelp forests over the long-term because it can result in altered currents, temperatures, and sea levels resulting in a decrease in the overall range and area of kelp forests.

Work Cited

1. Bell Devereaux. 2014. Why divers are restoring California’s kelp forests. Mother Nature Network. http://www.mnn.com/earth-matters/wilderness-resources/stories/why-divers-are-restoring-californias-kelp-forests. Web. 16/11/2015.

2. Bushing, W. W., 1994. Biogeographic and ecological implications of kelp rafting as a dispersal vector for marine invertebrates. In Halvorson, W. and G. Maender (eds.), Proceedings of the Fourth California Islands Symposium: Update on the Status of Resources, March 22-25, 1994. Santa Barbara Museum of Natural History (Santa Barbara, CA). pp. 103-110. 12/11/2015.

3. Guidetti P, Baiata P, Ballesteros E, Di Franco A, Hereu B, Macpherson E, et al. (2014) Large-Scale Assessment of Mediterranean Marine Protected Areas Effects on Fish Assemblages. PLoS ONE 9(4): e91841. doi:10.1371/journal.pone.0091841. Web. 16/11/2015.

4.California Department of Fish and Wildlife. 2015. Southern California Marine Protected Areas. https://www.wildlife.ca.gov/Conservation/Marine/MPAs/Network/Southern-California. Web. 21/11/2015.

5. Carey, Bjorn. 2006. Ancient People Followed ‘Kelp Highway’ to America, Researcher Says. Live Science. http://www.livescience.com/7042-ancient-people-kelp-highway-america-researcher.html. Web. 18/11/2015.

6. Grove, R. S., Zabloudil, K., Norall, T., and Deysher, L. 2002. Effects of El Nin ̃o events on natural kelp beds and artificial reefs in southern California. – ICES Journal of Marine Science, 59: S330–S337. 08/11/2015.

7. Landis, ben Young. 2014. Slowly Swimming Towards Recovery, California’s Sea Otter Numbers Holding Steady. USGS. http://www.usgs.gov/blogs/features/usgs_top_story/slowly-swimming-towards-recovery-californias-sea-otter-numbers-holding-steady/. Web. 20/11/2015

8. Limbaugh, Conrad. (1955). Fish life in the kelp beds and the effects of kelp harvesting. Scripps Institution of Oceanography. UC San Diego: Scripps Institution of Oceanography. Retrieved from: http://escholarship.org/uc/item/4w36x6mb. Web. 18/11/2015

9. Mehta, Steema. 2000. O.C. Pulls Out Stops to Keep Beaches Clean. Los Angeles Times. http://articles.latimes.com/2000/may/19/news/mn-31791. Web. 20/11/2015.

10. Meurant, Gerard. 1987. Advances in Ecological Research. Volume 17. Chapter 5 El Niňo Effects on Southern California Kelp Forest Communities. Academic Press, pp 243-280. 16/11/2015

11. National Oceanic and Atmospheric Administration. 2014. What is a kelp forest. N.O.A.A. http://oceanservice.noaa.gov/facts/kelp.html. Web. 15/11/2015.

12. Steneck Robert S., Graham Michael H., Bourque Bruce J., Corbett Debbie, Erlandson Jon M., Estes James A., and Tegner Mia J. 2002. Kelp forest ecosystems: biodiversity, stability, resilience and future. Environmental Conservation, pp 436-459. doi:10.1017/S0376892902000322. 12/11/2015.

13. The Bay Foundation. 2014. Kelp Forest Restoration. Santa Monica Bay Foundation. http://www.santamonicabay.org/learn/our-work/in-the-ocean/kelp-forest-restoration/. Web. 15/11/2015

14  Figure 1. Kelp Forest Image. http://www.roughguides.com/wp-content/uploads/2014/10/Final-Giant-Kelp-Forests-Monterey-Bay00000-977115-1680x1050.jpg Figure 4. Image of Graph. https://www.lternet.edu/research/keyfindings/wave-impact

15. Figure 2. http://i2.wp.com/goforth-explorer.com/wp-content/uploads/2014/11/Monterey-Bay-Kelp-Forest.jpg?fit=1200%2C1200 

16. Figure 3. http://www.esa.org/esa/wp-content/uploads/2014/08/sea-otter-with-urchins.jpg

17. Figure 4. Image of Graph. https://www.lternet.edu/research/keyfindings/wave-impact

18. Figure 5. http://onlinelibrary.wiley.com/store/10.1111/jbi.12550/asset/image_n/jbi12550-fig-0004.png?v=1&t=ihcm6kg0&s=9fbacd55ab70185aeb9842933f7eaedc21d03f3f

19. Figure 6. Map of California's Kelp Forests. https://noottersnokelp.files.wordpress.com/2015/03/cali-map.jpg

20. Figure 7. MPA vs No MPA Image. http://www.oceanconservancy.org/places/pacific-coast/californias-mpas.html

21. Figure 8. http://www.santamonicabay.org/learn/our-work/in-the-ocean/kelp-forest-restoration/