By Katie Lee
Recently, the New York Times Green Blog described how two major Southern California fisheries (kelp and barred sand bass) had collapsed ?right under the noses of management agencies.? The management and oversight of these fish stocks had not changed since 1959. This news is perhaps not surprising as there are more examples of marine species collapses off our coastline than possible to list in this blog post.
Though the media tends to focus on the effects of pollution, climate change, or overfishing, outdated systems of management are actually the main cause of the collapse in many cases.
Palos Verdes Peninsula, home to crucial abalone stocks. Source: Tegner
The ups and downs of abalone stocks off of the coast of Southern California provide an example of how poor fishery management resulted in the collapse of a population. Only a few years after the Palos Verdes Peninsula abalone stocks re-opened for commercial fishing in 1943, the stocks began to decline again, as more than 9.3 million pink abalone were collected during the peak decade of the fishery (Taniguchi 2013).
These waters are home to one of the largest kelp forests in the Pacific, and this giant kelp (Macrocystis Pyrifera) is the main food source for abalone, sea urchins, and many other fish and marine mammals. Because of a spike in population growth after World War II, a greater amount of sewage was discharged into the water, leading to the deterioration of kelp forests. This pollution, combined with a warmer water temperature because of the 1957 El Ni?o event, rendered the kelp forests practically extinct, which meant to loss of abalones? main food source.
Therefore, because of a lack of food, the abalone either did not reproduce or had badly weakened shells and stunted growth. Even after the kelp gradually grew back and abalone populations increased because of stricter regulations, poaching became a huge problem. Because abalones are found in predictable, accessible locations, and because they have a high unit value, the value of individual animals outweighed any risks or penalties for poaching. Enforcement of the laws was minimal because of California?s small environmental budget?there were only five wardens responsible for monitoring ?hunting, fishing, exotic animals, [and] pollution events? for the entire inland Los Angeles County (Tegner 1993).
Example of an Abalone shell. Source: Mynzah.com
Since 1977, this fishery has been closed to sport and commercial take of abalones along parts of the California coastline. Yet this closure has not led to abalone population recovery because the off-limit areas were not located in areas with existing abalone stocks, so recolonization was not possible. Neither was poaching was not heavily monitored (Tegner 1993). Recent research has also found that opening up abalone reserves to fishing can result in immediate and drastic declines in abalone density, size, and reproductive capacity (Rogers-Bennett 2013). Perhaps only with time and new management strategies will abalone populations have a chance to recover.
The history of the California sardine fishery is another example of failed regulations and drastic overfishing. The fishery began in the late 1800s, developed in response to a demand for food because of World War I. People canned and reduced the fish for food and oil, with small amounts used for live and dead bait. As the fishery grew and expanded, environmentalists and scientists recommended there be a catch limit of 200,000 tons, but since there seemed to be an endless supply of fish, no one listened.
School of sardines. Source: opb.org
From the 1930s to 1940s, the pacific sardine fishery was the largest in North America, but after just a few years, it totally collapsed. From a catch of over 790,000 tons in 1936 to less than 100 tons in the 1970s (Wolf 1992), the sardine fisheries clearly needed better regulations.
In 1967, decades after the fishery had collapsed (Wolf 1992), California passed an emergency bill declaring a two-year moratorium on the harvest of sardines. It was a much-needed acknowledgement that the fishery was no longer viable (Wolf 1992), and gradually the sardine populations began to increase again. The quota limit increased as the fish populations increased, and then would decrease as the populations declined again.
This system of waiting until the fish populations collapse to put in fishery regulations, and then allowing a free-for-all once they recover slightly, will not last in the long term. It is a ?too little too late? policy that eventually will result in either extinction or endangerment of animal species.
Though these two fisheries are now managed with the future of the fish populations in mind, and the government and fishermen appear to have learned from the past, there are still countless fisheries off of Southern California that have collapsed, even within the past few years. Many people blame this surprising decline on something called ?hyperstability.? It?s a phenomenon where a high catch rate masks a decline in actual population of fish because the fish tend to spawn and congregate in large masses, giving an ?illusion of plenty? (UC San Diego 2011). Though the fisheries are now required to tightly monitor the stock of fishes, because the fish congregate in large masses in certain places, their data is always too high a number.
The persistent over-fishing and consistently high catch rates are what lead to the collapse, in addition to the gradual warming of the water since 1980. If we want to preserve the ocean?s beauty and continue to eat sushi, fisheries need to not rely purely on catch rates to determine fish population level, both in Southern California and the rest of the world.
A combination of scientific research and constant monitoring must be incorporated into fisheries management before the fish population collapses. Even with fish populations displaying extraordinary declines and recoveries, human interferences should never cause such drastic changes in marine life, and people need to immediately take a lesson from the past and implement stricter catch quotas worldwide.
The future of seafood and entire marine ecosystems is not at all certain, and based on past mistakes, stricter regulations and more consistent, updated research are the keys to ensuring that these species that we rely on for food, science, and natural beauty never go extinct.
Author Bio: Katie Lee is a freshman at the University of Southern California?s Dornsife College of Letters, Arts, and Sciences. She lives in Kauai, Hawaii but would reside in the waves if she could. She is currently pursuing a B.S. in Environmental Science and Health with a minor in Business, and hopes to save the oceans in the near future.
References:
Laura Rogers-Bennett, Kristin E. Hubbard, Christina I. Juhasz, Dramatic declines in red abalone populations after opening a ?de facto? marine reserve to fishing: Testing temporal reserves, Biological Conservation, Volume 157, January 2013, Pages 423-431.
Taniguchi, Ian K., et al. ?Testing translocation as a recovery tool for pink (Haliotis corrugata) and green (Haliotis fulgens) abalone in Southern California.? Journal of Shellfish Research 32.1 (2013): 209+. Academic OneFile. Web. 24 May 2013.
Tegner, M.J.1993. Southern California Abalones: Can Stocks Be Rebuilt Using Marine Harvest Refugial Can. 1. Fish. Aquat. Sci. 50: 2010-201 8.
Wolf, Patricia. ?Sardine Recovery and the California Sardine Fishery.??California Department of Fish and Game, Rep., Vol. 33, 1992.
Editor?s note: Scientific Research Diving at USC Dornsife is offered as part of an experiential summer program offered to undergraduate students of the USC Dana and David Dornsife College of Letters, Arts and Sciences through the Environmental Studies Program.? ?This course takes place on location at the USC Wrigley Marine Science Center on Catalina Island and throughout Micronesia. Students investigate important environmental issues such as ecologically sustainable development, fisheries management, protected-area planning and assessment, and human health issues. During the course of the program, the student team will dive and collect data to support conservation and management strategies to protect the fragile coral reefs of Guam and Palau in Micronesia.
Instructors for the course include Jim Haw, Director of the Environmental Studies Program in USC Dornsife, Assistant Professor of Environmental Studies David Ginsburg, Lecturer Kristen Weiss, SCUBA instructor and volunteer in the USC Scientific Diving Program Tom Carr and USC Dive Safety Officer Gerry Smith of the USC Wrigley Institute for Environmental Studies.
Previously in this series:
The 2013 Guam and Palau Expedition Begins
A New Faculty Member on the Team
An Analysis of Sargassum Horneri Ecosystem Impact
Marine Protected Areas and Catalina Island: Conserve, Maintain and Enrich
Northern Elephant Seals: Increasing Population, Decreasing Biodiversity
The Relationship Between the Economy and Tourism on Catalina Island
Guam and Palau 2013: New Recruits and New Experiences
Bringing War to the ?Island of Peace? ? The Fight for the Preservation of Jeju-do
Dreading the Dredging: Military Buildup on Guam and Implications for Marine Biodiversity in Apra Harbor
Is the Commonwealth of the Northern Mariana Islands Doing Enough?
The Status of Fisheries in China: How deep will we have to dive to find the truth?
The Philippines and Spratly Islands: A Losing Battle
The Effects of Climate Change on Coral Reef Health
The Senkaku/Diaoyu Island Dispute in the East China Sea
The UNESCO World Heritage Site Selection Process
Before and After the Storm: The Impacts of Typhoon Bopha on Palauan Reefs
An interconnected environment and economy- Shark tourism in Palau
A Persistent Case of Diabetes Mellitus in Guam
Homo Denisova and Homo Floresiensis in Asia and the South Pacific
Investigating the Effectiveness of Marine Protected Areas in Mexico Using Actam Chuleb as a Primary Example
Okinawa and the U.S. military, post 1945
Offshore Energy Acquisition in the Western Pacific: The Decline of the World?s Most Abundant Fisheries
Military Buildup?s Environmental Takedown
- Molly Sullivan ? Challenges Facing Japan?s Marine Fisheries
Hyperbaric Oxygen: A Spectrum of Emerging Treatments
Source: http://rss.sciam.com/~r/sciam/basic-science/~3/OqKSWlI6U-0/post.cfm
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