Marine Reserves as A Fishery Management Tool
~Table of Contents~
- What are marine reserves?
- What are the benefits?
- Debate surrounding marine reserves
- Philippine case study
What are marine reserves?
Marine reserves that have been studied around the world.
Human activities have had serious impacts on the worlds oceans. Areas have become destroyed due to poor fishing practices and or pollution. Due to overfishing many fishiereies have also collapsed. One way people are starting to reduce these negative impacts and improve ocean heath is designing marine reserves. Marine reserves commonly known as "no take areas" are a versatile management tool to help protect and or conserve marine and cultural resources by taking a ecosystem approach (Habitat and Communities: Marine Reserves and Marine Protected Areas, 2011). Marine reserves are a type of Marine protected area that has extensive restrictions on human use. Marine protected areas (MPAs) are defined by the NOAA MPA Center as, "any area of the marine environment that has been reserved by federal, state, tribal, or local laws or regulations to provide lasting protection for part or all of the natural and cultural resources there in." Marine reserves are a subset of this definition, and include restrictions on some or all extractive activities (Habitat and Communities: Marine Reserves and Marine Protected Areas, 2011). Examples of prohibited actives are fishing, aquaculture, dredging, trawling, and mining (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
Marine Reserves are located all over the world. While called "marine", these reserves can also be located in both marine and estuarine environments, and in freshwater estuaries along shores of the great lakes. The map to the right shows the location of 124 marine reserves around the world that have been studied by scientists with the results published in scientific journals. The white boxs tell how many studies have been conducted at each reserve (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
There are many other types of marine protected areas that only exclude some human activities like offshore drilling, mining, or various types of fishing. However, well they provide some benefits they do not provide the same level of benefits as marine reserves . (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
It is important to remember however, that these reserves can be a very effective tools for a variety of objectives such as conservation and fishery management the reserves alone protect against problems such as pollution, climate change, or overfishing. To protect our oceans other marine management strategies are needed in combination with the creation of marine reserves (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
Marine Reserves are located all over the world. While called "marine", these reserves can also be located in both marine and estuarine environments, and in freshwater estuaries along shores of the great lakes. The map to the right shows the location of 124 marine reserves around the world that have been studied by scientists with the results published in scientific journals. The white boxs tell how many studies have been conducted at each reserve (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
There are many other types of marine protected areas that only exclude some human activities like offshore drilling, mining, or various types of fishing. However, well they provide some benefits they do not provide the same level of benefits as marine reserves . (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
It is important to remember however, that these reserves can be a very effective tools for a variety of objectives such as conservation and fishery management the reserves alone protect against problems such as pollution, climate change, or overfishing. To protect our oceans other marine management strategies are needed in combination with the creation of marine reserves (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
What are the benefits?
Marine reserves have been shown to be very beneficial. One of the most common objectives for marine reserves is to increase abundance and diversity of marine life along with inducing spillover of target species into the surrounding area. Many studies have shown that marine reserves commonly accomplish these objective, as well as increasing organisms biomass, size, and density within the reserve. This can be seen in the graph to the right showing the average change of organisms within a series of different marine reserves surveyed (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
The main focus for fisheries is the idea of "spill over" from marine reserves into the surrounding area. Many organisms are mobile and can move in and out of the reserve. So the hope is if these reserves are made and managed correctly that they will either seed the surrounding areas with eggs and larvae, or replenish stocks of fish in the surrounding area, improving commercial and recreational fishing (Babcock, Russ {a}, 2007).
The main focus for fisheries is the idea of "spill over" from marine reserves into the surrounding area. Many organisms are mobile and can move in and out of the reserve. So the hope is if these reserves are made and managed correctly that they will either seed the surrounding areas with eggs and larvae, or replenish stocks of fish in the surrounding area, improving commercial and recreational fishing (Babcock, Russ {a}, 2007).
Marine reserves are the only successful way to protect large fish and invertebrates. This due to the fact that within marine reserves fish and invertebrates grow bigger than in unprotected areas. These large organisms are very important for populations, because they contribute typically more offspring than smaller organisms. For example a as seen in the figure to the left a 23 inch vermilion rockfish produce 17 times more young than when it is 14 inches long. Thus showing that bigger and more abundant organisms living in marine reserves have the potential to produce more young then their younger and smaller counterparts in unprotected water (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007). Unfortunately, it is these older larger fatter fish that are sought after. Thus, marine reserves are very impotent for protecting these larger organisms and the contributions to the population.
Debate surrounding marine reserves:
_ There is a large debate surrounding marine reserves on whether or not they should be implemented and where. The parties involved are stockholders,
resource managers, and government. The biggest concern that people that
are against the implementation of these reserves (mostly fisherman) have
is that the reserves will only "lock up" resources and spill over will
not occur. Thus, preventing fisherman from fishing in prime fishing
areas. However, the other side of the argument (primarily scientist) is
that these reserves will protect fishing populations, and increase
abundance of organisms in the surrounding area. A compressive look at
this debate is summarized in the table below (Babcock, Russ {a}, 2007).
Philippines Case Study:
'Modified from Alcala, 1988'
Coral reefs are very diverse ecosystems and provide many resources and natural services. In the Philippines reef fishing accounts for 10-15% of the fishing industry. However, sense the 1970's most of coral reefs have been damaged or destroyed due to a variety of resounds including poor fishing practices such as overfishing, blasting, cyanide poisoning, muro-ami, bottom trawling, and natural causes. About 70% of the 742 reef areas surveyed in the 1980's had 50% or less life coral (Gomez et at. 1994). Sense the late 1970's Philippine fisheries on a whole have declined, Due to this many marine reserves have been implemented (Alcala, 1998).
'Modified from A.C. Alcala 1988'
The Sumilon and Apo reserves were established by the Siliman University Marine Laboratory in 1974 and 1982. The Sumilon reserve was established by local government ordinance, but has had a complex history of management due to changes in local governance. Sense 1974 the full protection of the Sumilon reserve has been temporarily suspended twice for political reasons (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
The Apo reserve on the other hand was established due to scientific education programs sparked residents interest in protecting and managing marine reserves. The reserve has been fully protected sense 1982 thanks to the joint efforts of the fishing community, local government, and university (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
A.C. Alcala a research professor and director at the Silliman University conducted a survey of these two marine reserves from there creation till 2000 a 26 year period. Results from this study showed that both reserves exported adult fish biomass to the adjacent areas after varying periods of protection(Alcala, 1998). Garry R. Russ et. al also proved this in his study of the Apo reserve (see figure below). He showed that the biomass of the surgeon fish Naso vlamingii tripled over a 18 year period (1983-2001). Also, that the biomass of N. vlamingii increased by a factor of 40 outside but close to the reserve boundaries (200 to 250 m) but not at greater distances (250-500 m). In a hook and line survay in 2000/2001 catch per unit effort (CPUE) was 45 times higher within 200 m of the marine reserve boundary than any other fishing ground combined. This comprises some of the best evidence that reserves can benefit fisheries by spillover (Russ, Alcala 1996).
The Apo reserve on the other hand was established due to scientific education programs sparked residents interest in protecting and managing marine reserves. The reserve has been fully protected sense 1982 thanks to the joint efforts of the fishing community, local government, and university (Partnership for Interdisciplinary Studies of Coastal Oceans, 2007).
A.C. Alcala a research professor and director at the Silliman University conducted a survey of these two marine reserves from there creation till 2000 a 26 year period. Results from this study showed that both reserves exported adult fish biomass to the adjacent areas after varying periods of protection(Alcala, 1998). Garry R. Russ et. al also proved this in his study of the Apo reserve (see figure below). He showed that the biomass of the surgeon fish Naso vlamingii tripled over a 18 year period (1983-2001). Also, that the biomass of N. vlamingii increased by a factor of 40 outside but close to the reserve boundaries (200 to 250 m) but not at greater distances (250-500 m). In a hook and line survay in 2000/2001 catch per unit effort (CPUE) was 45 times higher within 200 m of the marine reserve boundary than any other fishing ground combined. This comprises some of the best evidence that reserves can benefit fisheries by spillover (Russ, Alcala 1996).
'Modified from Russ et. al, 1996'
A.C Alcala study went on to confirm that both Sumilion and Apo marine reserves had a increase of abundance, biomass, and species richness of fish when fully protected, but decreased when protection was lifted as in the case of the Sumilion reserve (figure 3). Also, biomass of predatory target fish was still rising exponentially after 9-18 years of protection. This implies that the carrying capacity of the resrves takes decades to level off and implies that further that protection must be long term in order fo the full benefits of each reserve to be fulfilled. Results showed that fish families respond differently to intense fishing. Large carnivores denisty and biomass was strongly affected by fishing and tended to recover. Well on the other hand, plankton feeding species did decline with fishing but tended to bounce back faster when protected than carnivores fish (Alcala, 1998).
'Modified from Alcala, 1988'
Overall this case study shows that marine reserves are a good tool for aiding in fishery management. It shows that marine reserves have the potential to increase biomass, size, density, and diversity of organisms within a m reserve. Also that spillover does occur and can increase fish stocks around the boundary of the reserve. However, for a reserve to be successful the objectives must be clear, managed correctly, and be established for years before full benefits can be achieved.
References:
- Alcala, A C. "Effects of Marine Reserves on Coral Fish Abundances and Yields of Philippine Coral Reefs." Ambio. Stockholm, 17.3 (1998): 194-199
- Babcock, Russ {a}. "The New Zealand Marine Reserve Experience: The Science Behind the Politics." Hutchings, Pat; Lunney, Daniel [Eds]. Conserving Marine Environments: Out of Sight, out of Mind. Royal Zoological Society of New South Wales, Mosman. 2003: I-viii, 1-140. Chapter Pagination: 108-119, (2003): 1-140. --
- "Habitat and Communities: Marine Reserves and Marine Protected Areas." Pacific Fisheries Management Council. Web. 27 Nov. 2011. <http://www.pcouncil.org/habitat-and-communities/marine-protected-areas/>.
- "Marine Protected Areas." Monterey Bay Aquarium . 2011. Web. 30 Nov. 2011. <http://www.montereybayaquarium.org/cr/oceanissues/marine_protected_areas/default.aspx>.
- "Marine Reserves." National Marine Protected Areas Center. National Oceanic and Atmospheric Administration, Web. 27 Nov. 2011. <http://www.mpa.gov/aboutmpas/definition/marinereserves/-and-communities/marine-protected-areas/>.
- Palumbi, Stephen R. "Marine Reserves." A Tool for Ecosystem Management and Conservation: PEW Oceans Commission, 2003.
- Partnership for Interdisciplinary Studies of Coastal Oceans. 2007. The Science of Marine Reserves (2nd Edition, United States Version). 22 pages. < www.piscoweb.org>.
- Russ, Garry, and Angel Alcala. "Do Marine Reserves Export Adult Fish Biomass? Evidence from Apo Island, Central Philippines." Marine Ecology Progress Series, 132.1-3 (1996): 1-9.